Modern Steel Construction - September 2014

Published on December 2016 | Categories: Documents | Downloads: 69 | Comments: 0 | Views: 669
of 70
Download PDF   Embed   Report

Comments

Content


September 2014
Modern
STEEL CONSTRUCTION
Autodesk
®
Advance Steel is BIM
software for steel detailing
and fabrication that integrates
with Autodesk
®
AutoCAD
®

and Autodesk
®
Revit software
products to help accelerate time
to fabrication and construction.

Be part of
the BIM
revolution.
Download a 30-day free trial today www.autodesk.com/advancesteel
4 SEPTEMBER 2014
MODERN STEEL CONSTRUCTION (Volume 54, Number 9) ISSN (print) 0026-8445: ISSN (online) 1945-0737. Published monthly by the American Institute of Steel
Construction (AISC), One E. Wacker Dr., Suite 700, Chicago, IL 60601. Subscriptions: Within the U.S.—single issues $6.00; 1 year, $44. Outside the U.S. (Canada
and Mexico)—single issues $9.00; 1 year $88. Periodicals postage paid at Chicago, IL and at additional mailing offices. Postmaster: Please send address changes to
MODERN STEEL CONSTRUCTION, One East Wacker Dr., Suite 700, Chicago, IL 60601.
DISCLAIMER: AISC does not approve, disapprove, or guarantee the validity or accuracy of any data, claim, or opinion appearing under a byline or obtained or
quoted from an acknowledged source. Opinions are those of the writers and AISC is not responsible for any statement made or opinions expressed in MODERN
STEEL CONSTRUCTION. All rights reserved. Materials may not be reproduced without written permission, except for noncommercial educational purposes where
fewer than 25 photocopies are being reproduced. The AISC and Modern Steel logos are registered trademarks of AISC.
September 2014
ON THE COVER: Marquez Hall brings a modern motif to the Colorado School of Mines in Golden, Colo., p. 22. (Photo: Nic Lehoux)
business issues
17

I’m Sorry...You Were Saying?
BY ANNE SCARLETT
Thoughts on adjusting your sales
approach toward prospective clients with
short attention spans.
columns
22
Thinning Out
BY CHRISTOPHER O’HARA, P.E.,
AND JULIAN LINEHAM, P.E.
Slender steel elements and expanded
cantilevers define the structural system of
a new building for the Colorado School of
Mines.
28
Staying Afloat
BY MCKAY M. PARRISH, S.E.
A new convenience store keeps its head above
water with an innovative structural steel
framing system.
33
National Treasure
BY LUCA COVI
Structural renovations brace an iconic museum
for the future.
41
Time Tested
BY JENNIFER MCCONNELL, PH.D.,
DENNIS R. MERTZ, PH.D., AND
HARRY W. SHENTON, III, PH.D.
A look at the performance of the national
uncoated weathering steel bridge inventory.
46
Justice is Served
BY JASON STONE
A criminal justice school blends the new with
the old in an urban expansion project.
52
Piece by Piece
BY MICHAEL P. CULMO, P.E.
Span-by-span bridge construction, using
modular steel bridge elements, can serve
as a viable and economical bridge-building
alternative.
56
Crossing the Delaware
BY JIM TALBOT
A steel truss, at the site of one of the first
bridges over the Delaware River, is still
standing after numerous floods and more than
100 years of life.
features
departments
6 EDITOR’S NOTE
9 STEEL INTERCHANGE
12 STEEL QUIZ
60 NEWS & EVENTS
66 STRUCTURALLY SOUND
resources
64 MARKETPLACE
65 EMPLOYMENT
in every issue
22
IES, Inc.
800.707.0816
[email protected]
www.iesweb.com
IES VisualAnalysis
Frame and finite element analysis.
Simple. Productive. Versatile.
Accurate results. Excellent value.
Intuitive Software for
Structural Engineers
·|·a.|a·»| ¹-·.g- .· ||- ..·-
.( ..· |.·.--··. iз »||.«·
.· |. »...¬¸|.·| ||»| .- »
¡...|, ¸·.¹..|..- ¬»---·.


6 SEPTEMBER 2014
Since the section began more than two
decades ago, every reader survey we’ve done
ranks it as number one. Originally, the col-
umn featured questions sent in by our readers,
which were then answered in later editions by
other readers. Staff response was sometimes
to answer questions, but more often to simply
vet the answers provided by readers. With the
creation of the AISC Steel Solutions Center,
however, the column morphed into a section
where almost all of the answers were staff-
generated. And today, most of the questions
aren’t sent directly to the magazine; rather,
the questions are taken from those submitted
to the Solutions Center.
Each week the AISC Steel Solutions Center
responds to nearly 200 questions (that’s more
than 125,000 inquiries since the SSC opened
its doors in 2001). Despite this, hardly a day
goes by where I don’t see a question about
structural steel posed elsewhere. I’m always
amazed when someone asks about the Code
of Standard Practice or has a question about
composite beams and they don’t simply email
[email protected]. You’ll usually get a
response within one business day—and best
of all, it’s free.
The SSC is just one of AISC’s free re-
sources. While it’s often diffcult to navigate,
there’s a boatful of freebies on the AISC web-
site (www.aisc.org), including all of the speci-
fcations and codes published by AISC. The
best place to start is by clicking on “ePubs and
FreePubs.” Everyone can download design
examples, the shapes database, the latest issue
of Engineering Journal and a lot more. We’re
even converting some items that used to be
available for a fee, into free resources. For
example, this fall we’re planning on releasing
the AISC Detailer Education Program as a
free online course.
We’ve also posted videos of almost every
NASCC: The Steel Conference since 2008.
Simply visit www.aisc.org/2008nascconline
or substitute any other year for 2008 in the
URL, and you can access more than 750 hours
of educational video on everything from steel
joists to moment connections.
For those of you who are AISC members
(and really, the cost is so nominal I’m always
surprised when I encounter someone in the
steel industry who isn’t), the freebies are
even larger. Members can download copies
of all of the Steel Design Guides and every
article from every issue of Engineering Journal
(plus they receive substantial discounts you
get on continuing education and printed
publications).
But whether or not you’re a member, the
AISC SSC is free. So if you have a question,
know that AISC has an answer.
Editorial Offices
1 E. Wacker Dr., Suite 700
Chicago, IL 60601
312.670.2400 tel
Editorial Contacts
EDITOR & PUBLISHER
Scott L. Melnick
312.670.8314
[email protected]
SENIOR EDITOR
Geoff Weisenberger
312.670.8316
[email protected]
ASSISTANT EDITOR
Tasha Weiss
312.670.5439
[email protected]
DIRECTOR OF PUBLISHING
Areti Carter
312.670.5427
[email protected]
GRAPHIC DESIGNER
Kristin Egan
312.670.8313
[email protected]
AISC Officers
CHAIR
Jeffrey E. Dave, P.E.
VICE CHAIR
James G. Thompson
SECRETARY & GENERAL
COUNSEL
David B. Ratterman
PRESIDENT
Roger E. Ferch, P.E.
VICE PRESIDENT AND CHIEF
STRUCTURAL ENGINEER
Charles J. Carter, S.E., P.E., Ph.D.
VICE PRESIDENT
Jacques Cattan
VICE PRESIDENT
John P. Cross, P.E.
VICE PRESIDENT
Scott L. Melnick
Advertising Contact
Account Manager
Louis Gurthet
231.228.2274 tel
231.228.7759 fax
[email protected]
For advertising information,
contact Louis Gurthet or visit
www.modernsteel.com
Address Changes and
Subscription Concerns
312.670.5444 tel
312.893.2253 fax
[email protected]
Reprints
Betsy White
The Reprint Outsource, Inc.
717.394.7350
[email protected]
editor’s note
SCOTT MELNICK
EDITOR
WHAT’S YOUR FAVORITE SECTION IN MODERN STEEL CONSTRUCTION? Unless
you’re one of my kids, odds are it’s Steel Interchange.
DESIGN CONNECTIONS
WITH SDS/2
HOW/2
S E RI E S BY S DS / 2
I NT RODUC I NG T HE
FULL JOINT ANALYSIS
TRUE CONNECTION DESIGN,
NOT SIMPLY CONNECTION
VERIFICATION
CLASH PREVENTION
SDS/2 is the only system that provides true connection
design — for individual members, as well as all interacting
members in a structural joint.
SDS/2 checks for interaction with other connections within
a common joint. That means adjusting connections for
shared bolts, checking driving clearances for bolts, sharing,
adjusting and moving gusset and shear plates when re-
quired, and assuring erectablity of all members. All adjusted
connections are automatically verified based on selected
design criteria.
Instead of choosing a connection from a library, SDS/2 designs
the connection for you, based on parameters that you establish
at the beginning of a project.
All connections SDS/2 automatically designs will comply with
the connection design code standards the user chooses.
SDS/2 provides long-hand calculations
of all designed connections, which sim-
plifies the verification process. Scan the
QR code to view an example of SDS/2’s
automatically generated calculation
design reports.
LEARN MORE
Want to see how simple it really is to design
connections in SDS/2? Scan the QR code to
watch SDS/2’s connection design in action.
800.443.0782
sds2.com | [email protected]
COMPLETE CONNECTION
DESIGN REPORTS
Modern STEEL CONSTRUCTION 9
Weld Designation
What do the “U” and "a" indicate in the prequalified weld
type B-U4a?
The U indicates that the weld can be used with material of
unlimited thickness, as opposed to an L, which would indicate
that the weld is only appropriate within a range of thicknesses.
AWS D1.1 states: “The lower case letters—e.g., a, b, c, etc.—
are used to differentiate between joints that would otherwise
have the same joint designation.” In this case there are two
prequalified butt welds (B) using a single-bevel groove (4) with
no limitation on thickness (U) listed in AWS D1.1. One of the
listed welds uses backing (a) and the other does not (b). The “a”
in your designation, “B-U4a”, indicates that backing is used.
Larry S. Muir, P.E.
Mixed Hole Sizes in Slip-Critical Connections
We have designed slip-critical connections with standard
holes. When the structure was erected, a few of the bolts
could not be installed due to mislocated holes. Can we
make the mislocated holes oversized and leave the others
as standard holes? Does the strength of the connection
need to be reduced due to the oversized holes?
There is nothing in the RCSC or AISC Specifications that
discusses the mixing of standard and oversized holes in a
slip-critical connection, so you will have to rely on your own
judgment. I will provide some comments that might assist you
in this process.
It is not uncommon to see slip-critical connections with
oversized holes that contain a couple of standard holes to
help maintain the intended geometry during erection, so
the mixing of hole types is relatively common. In such cases,
the entire group is designed using oversized holes, while
also incorporating a couple of standard holes; this leads to a
more conservative design strength. Your situation is also not
uncommon, since things do not always fit the way we would
like in the field. Some engineers would tend to design the
entire group using the values for oversized holes, although this
is likely not necessary. Though the strength provided in the
Specification is less for connections with oversized holes, there
is no loss of pretension or slip resistance due to the oversized
holes. The lower nominal load is due to a higher factor of
safety (reliability) to account for the consequences of slip. This
is discussed in the Commentary to Section J3.8.
Since most of the holes in your connection are standard
holes, the amount of slip that could occur prior to the bolts
going into bearing would likely be small, and the higher factor
of safety against slip likely is not warranted.
Carlo Lini, P.E.
DTIs Used For Preinstallation Verification
Can tension indicator washers be used in lieu of a
Skidmore Wilhelm tension calibrator to perform pre-
installation verification?
The answer to your question is yes, unless you are tensioning
the bolts using turn-of-nut installation. This is covered in the
commentary to Section 7.1 in the 2009 RCSC Specification (a
free download at www.boltcouncil.org), which states:
Direct tension indicators (DTIs) may be used as tension
calibrators, except in the case of turn-of-nut installation. This
method is especially useful for, but not restricted to, bolts that
are too short to fit into a hydraulic tension calibrator. The
DTIs to be used for verification testing must first have the
average gap determined for the specific level of pretension
required by Table 7.1, measured to the nearest 0.001 in. This
is termed the “calibrated gap.” Such measurements should be
made for each lot of DTIs being used for verification testing,
termed the “verification lot”…This technique cannot be used
for the turn-of-nut method because the deformation of the
DTI consumes a portion of the turns provided. For turn-of-
nut pre-installation verification of bolts too short to fit into a
hydraulic calibration device, installing the fastener assembly
in a solid plate with the proper size hole and applying the
required turns is adequate. No verification is required for
achieved pretension to meet Table 7.1.
Carlo Lini, P.E.
Square-Cut Sloping Beams
There are large wide-flange beams that slope with the roof
pitch of ¼ in. per foot. In some instances they connect to
girders and in other instances they connect to HSS col-
umns. Can the beams be cut square leaving a varying dis-
tance from the end of the beam to the face of the support?
Especially for heavy shapes, cutting the member square is
easier than making a bevel cut. The decision on whether
to bevel-cut the beam or to bevel the connection material
is usually based on economics. As the bevel increases, the
eccentricity on the connection increases, potentially adding
to the connection cost and overriding any benefit of square-
cutting the beam. In your case, the bevel adds only about ¾ in.
to the usual setback; therefore, standard shear end connections
likely can be used for the strength calculations. In this case,
square-cutting the beam will be preferred by most fabricators,
and this is acceptable from an engineering standpoint.
Bo Dowswell, P.E., Ph.D.
steel
interchange
If you’ve ever asked yourself “Why?” about something
related to structural steel design or construction,
Modern Steel’s monthly Steel Interchange is for you!
Send your questions or comments to [email protected].
10 SEPTEMBER 2014
Special Inspection Waivers for Erectors
We are an erector. Once AISC Certified, do we become
self-inspecting as erectors?
The decision to waive third-party inspection, or Special
Inspection, is the responsibility of the building official
(authority having jurisdiction). As an erector, you are always
responsible for the QC inspections outlined in Chapter N
of the AISC Specification. The waiver of Special Inspection at
the fabrication shop has become commonplace over the years,
while the concept of waiver of Special Inspection at the job
site is quite new (2010).
The bottom line is that Special Inspection will be required
unless the building official decides otherwise. The IBC does
provide the mechanism that the Building Official can use
to waive Special Inspection for an approved contractor in
Chapter 17, Section 1704.2.5.2.
Keith Landwehr
Special Inspections and Small Projects
The 2012 IBC has recently been adopted by our local
government, and inspections in accordance with Chapter
N of the AISC Specification are now required. I am cur-
rently working on a small renovation project that did not
even require the design of a lateral force resisting system.
The inspections required by Chapter N seem excessive
for this small project. Must all of these inspections always
be performed?
IBC generally requires special inspections through reference
to AISC Chapter N. However, there are at least a couple of
provisions that would allow the authority having jurisdiction
to waive the requirements. Waivers are often granted for
approved contractors in accordance with IBC Chapter 17,
Section 1704.2.5.2 (AISC Certified contractors, for example).
There are also provisions in IBC that do not require special
inspections for "work of a minor nature." Chapter N states
that the QA shall be performed “when required by the
authority having jurisdiction (AHJ), applicable building code
(ABC), purchaser, owner, or engineer of record (EOR).” It
does not independently mandate inspections.
Larry S. Muir, P.E.
Comparing AISC 360 Chapter J and
Appendix 3 Requirements
I have four rods, threaded on one end, supporting a stair
platform. The unthreaded end of the rod is welded to the
upper support and the other end passes through an HSS,
and a nut is installed. The AISC Specification seems to
provide conflicting requirements related to the design of
these rods. Table J3.2 provides a nominal tensile strength
of 0.75F
u
. However, Tables A-3.1 of Appendix 3 states
that the threshold stress is limited to 7 ksi. Appendix  3
also bases the stress calculation on net tensile area while
Chapter J neglects the reduction in area due to the
threads. When I design the rods for my 5.3-kip load using
these provisions of Chapter J and Appendix 3, I get very
different results. It seems that Appendix 3 would always
govern, so why must the Chapter J checks be performed?
First, both Chapter J and Appendix 3 account for the
reduction in area due to the threads. However, they take
different approaches. Equation J3-1 refers to Table J3.2 for
the nominal tensile strength. Table J3.2 provides a nominal
strength of 0.75F
u
. The 0.75 coefficient accounts for the
reduction in area due to the threads. This is explained in
the Commentary, which states: “The factor of 0.75 included
in this equation accounts for the approximate ratio of the
effective tension area of the threaded portion of the bolt to the
area of the shank of the bolt for common sizes.”
Table J3.2 also states that the threaded rods shall conform
to Section A3.5, which states: “Threads on anchor rods and
threaded rods shall conform to the Unified Standard Series
of ASME B18.2.6 and shall have Class 2A tolerances.” When
used with the designated threads and the applicable safety
factors, the 0.75 assumption provides an adequate estimate of
the net tensile area, though the actual ratio of net tension area
to nominal area will vary somewhat with diameter. Appendix 3
uses a more precise calculation of the net tension area.
It also has to be recognized that Chapter J and Appendix 3 are
quite different requirements and apply to different conditions.
The strength calculated using Chapter J should be compared
to the total load on the hanger. The strength calculated using
Appendix 3 only applies to the portion of the load causing fatigue.
So, first you must determine if fatigue must be considered for
your condition. If it must, then the net tensile stress area should
be calculated as shown in Equation A-3-9. However, the 7 ksi is
not compared to the total load, but rather only to the stress range.
For example, the dead load of stair platform will contribute to
the total load but will not contribute to the stress range. Only
cyclic loads will contribute to the stress range.
Larry S. Muir, P.E.
steel interchange
Larry Muir is director of technical assistance and Carlo Lini is staff engineer–technical
assistance, both with AISC. Bo Dowswell and Keith Landwehr are consultants to AISC.
Steel Interchange is a forum to exchange useful and practical professional ideas and
information on all phases of steel building and bridge construction. Opinions and
suggestions are welcome on any subject covered in this magazine.
The opinions expressed in Steel Interchange do not necessarily represent an official position of
the American Institute of Steel Construction and have not been reviewed. It is recognized that the
design of structures is within the scope and expertise of a competent licensed structural engineer,
architect or other licensed professional for the application of principles to a particular structure.
If you have a question or problem that your fellow readers might help you solve, please
forward it to us. At the same time, feel free to respond to any of the questions that you
have read here. Contact Steel Interchange via AISC’s Steel Solutions Center:
1 E Wacker Dr., Ste. 700, Chicago, IL 60601
tel: 866.ASK.AISC • fax: 312.803.4709
[email protected]
The complete collection of Steel Interchange questions and answers is available online.
Find questions and answers related to just about any topic by using our full-text search
capability. Visit Steel Interchange online at www.modernsteel.com.
Call us at 800-782-2110 for a free quote.
www.greinerindustries.com
We’re not afraid of the really big or really complex jobs. In fact,
we love them! That’s because we have highly skilled people
operating the very best equipment. Some are one-of-a-kind.
• Advanced Major Steel Bridge Fabrication
Certification with fracture critical & sophisticated
paint endorsements
• The American Railway Engineering & Maintenance-
of-Way Association (AREMA) Certification
• 140-ton lifting capacity with 31-foot hook height
• High-definition plasma cutting with drilling &
contour beveling capabilities
• Structural Steel Fabrication
• Steel Plate & Sheet Metal
Fabrication
• Miscellaneous Metals
• Machining
• Rolling & Forming Services
• Cutting Services
• Industrial Coatings
• Industrial & Electrical Contracting
• Crane Rental & Trucking Services
• Heat-Bending & Cold
Cambering Services
(AISC Certified for Advanced
Major Steel Bridge Fabrication)
Capacity. Precision. Efficiency.
80-foot long railroad girder with
bolt holes drilled zero to 80 feet
within 1/32-inch. Bottom flange of girder.
More than 187,500 holes.
12 SEPTEMBER 2014
1 For the beam shown in Figure 1, calculate the C
b
value.
Lateral bracing is provided at the support points only.
2 Assuming the length L in Figure 2 is long enough that
lateral-torsional buckling controls, which of the following is
true about the flexural strength of beam segments A? It is:
a) Equal to the flexural strength of segment B
b) Greater than the flexural strength of segment B
c) Less than the flexural strength of segment B
3 Given: From AISC Manual Table 3-6, the L
p
value for a
W18×35 beam is equal to 4.31 ft. The beam below has
an unbraced length of 6 ft. True or False: The nominal
flexural strength of the beam will be less than M
p
= F
y
Z
x
.
4 True or False: C
b
values are routinely useful in the design
of HSS used as beams.
This month’s Steel Quiz looks at the use of design tables in the AISC
Steel Construction Manual. steel quiz
TURN TO PAGE 14 FOR ANSWERS
Figure 1
1.5k/ft
L
b
= 30'-0"
P
L/3 L/3 L/3
P
(A) (A) (B)
Braced at
Load Points
Figure 2
P
6'-0"
Braced at
Load Points
6'-0" 6'-0" 6'-0"
P P
W18×35
Figure 3
Specify New Millennium. We are your unparalleled resource
for competitive structural steel solutions. Nationwide engineering,
manufacturing and supply of steel joists and steel decking for roof
and floor applications.
14 SEPTEMBER 2014
ANSWERS steel quiz
1 Use Specification Equation (F1-1) to determine C
b
.
Note that this C
b
value, and many others for common
cases, are provided in AISC Manual Table 3-1.
2 b) Greater than the flexural strength of segment B.
The C
b
value for segments A is greater than that for
segment B. Given that LTB controls the design, this is
true because all other variables in AISC Specification
Equation F2-2 are constant. The C
b
value for each
segment is shown in Figure 4 below and can be
determined via the User Note in Section F1, where C
b
=
1.0 for the case of equal end moments of opposite sign
(uniform moment) and C
b
= 1.67 when one end moment
equals zero. Also, see AISC Manual Table 3-1.
3 False. Per AISC Specification Equation F2-2, the nominal
flexural strength is equal to the plastic bending moment,
M
p
= F
y
Z
x
(because of the effect of C
b
). Per AISC Manual
Table 3-6, L
p
= 4.31ft and L
r
= 12.3ft. Per AISC Manual
Table 3-1, C
b
= 1.11 for the two interior segments (the
outer segments have a higher value of C
b
). Per Table 1-1,
S
x
= 57.6 in.
3
, Z
x
= 66.5 in.
3
M
p
= F
y
Z
x
= 50 ksi × 66.5in.
3
= 3,330 kip – in.


=3,380 kip – in. ≤ 3,330 kip – in.
=3,330 kip – in.
Therefore, the design is controlled by yielding and M
n
=M
p
.
Note that AISC Specification Commentary Figure C-F1.2
clearly illustrates the effect C
b
can have on the nominal
flexural strength, M
n
.
4 False. HSS beams are generally not sensitive to lateral-
torsional buckling—because their torsional strength and
stiffness are so high—and so their strength is governed
by the yield or local buckling strength of the member.
Therefore, C
b
rarely impacts the design of an HSS beam.
Figure 4
M
L
b
L
b
L
b
1.67 1.67 1
w × x
2
M
A
= M
C
= (L–x) = (30ft – 7.5ft) =
1.5kip – ft × 7.5ft
2
12.5M
max
2.5M
max
+3M
A
+4M
B
+3M
C
C
b
= = =1.14
12.5 × 169
6.5 × 169+6 × 127
w × L
2

8
M
max
= M
B
= = = 169 kip – ft
1.5kip – ft × 30ft
2
8
127kip – ft
[ ]
= 1.11 3,330 – (3,330 – 0.7 × 50 × 57.6) ≤
6 – 4.31
12.3 – 4.31
( )
M
n
= C
b
M
p
– (M
p
– 0.7F
y
S
x
) ≤ M
p
L
b
– L
p
L
r
– L
p
( ) [ ]
3,330kip – in.
Show that its done right.
the best way to bolt!
DuraSquirt® DTIs
DuraSquirt® DTIs
USA’s only Quenched and Tempered DTIs
appliedbolting.com
Need to prove its tight? Need to prove its tight?
Learn
More
Tekla software solutions provide a data-rich 3D environment that can be shared by
general contractors, structural engineers, steel detailers and fabricators, and concrete
contractors and rebar detailers. Choose Tekla for the highest level of detail, accuracy,
constructability and integration in project delivery.
> www.tekla.com
Using the Tekla model, Structural Consultants, Inc. (SCI) delivered more information to the estimators
earlier in this challenging project, lowering the fnancial risk to the owner and his contractors. The
steel package gave the fabricator, detailer and erector a better understanding of the engineer’s design
intent and put greater certainty into the cost model for a major subcontract early in the project. At
the same time, the architect and SCI successfully exchanged BIM models to collaborate their designs.
COLLABORATE
TO REDUCE RISK
“Being able to collaborate and coordinate our design
efforts in the Tekla environment was a tremendous
asset to this project, that really paid off during the
construction phase.”
Wayne Muir, P.E., Managing Principal & President,
Structural Consultants, Inc.
Modern STEEL CONSTRUCTION 17
RECENTLY, MY FIRM RECEIVED A QUERY from a “hot
prospect” through our website. Based on a series of initial
conversations, I deduced that the prospect had a notably short
attention span.
According to Archives of General Psychiatry and the WebMD
article “ADHD in the Workplace” (by Laura J. Martin, MD),
4.4% of working adults have been formally diagnosed with
ADHD, which accounts for an estimated 10-12 million profes-
sionals in the American workplace. I’m not a physician and I’m
certainly not diagnosing this prospect with ADHD, but merely
stressing the point that short attention spans of varying degrees
abound.
At any rate, in crafting my sales strategy, it made sense to
adjust my approach in order to best accommodate this prospect.
I decided to research adult ADHD-like symptoms. My goal
was to formulate best practices around selling (and relationship
building) toward professionals ftting this profle.
After conducting my research, I concluded that there was
an opportunity to modify my “typical” selling approach. After
all, savvy sales professionals aim to make their client look good
(and feel good) in their professional role. So, I made some
adjustments, with the intention of both maximizing their posi-
tive skill sets and assisting in areas they might fnd challenging.
The frst step is to leverage the potential strengths often
found in professionals who exhibit ADHD-like behaviors—or
at the very least, short attention spans. Those behaviors include
the following:
Creative: People with ADHD-like behavior often propose
ideas that may or may not seem relevant. To handle that, prepare
a mini “parking lot” during the meeting. At the onset of your
meeting, walk the prospect through your proposed agenda (you
do prepare a meeting agenda, don’t you?) to confrm agreement.
Then, let the prospect know that you’ll set aside a blank piece of
paper for recording any “ideas or topics worthy of exploration
at a different time.” This tactic is very useful in group meetings
and can also help capture spin-off ideas, thoughts and com-
ments. Later, one attendee takes responsibility for determining
(or delegating) next steps for each.
In short: Explain and use the parking lot practice with appli-
cable clients to record extraneous ideas.
Talkative/communicative: A forthright person is a sales per-
son’s dream, right? Indeed, this behavior may enable you to learn
about the prospect’s goals and challenges with minimal probing
efforts. That said, you may need to maintain meeting focus on
the intended topics by succinctly summarizing them (even par-
roting back their words) throughout the entire conversation.
In short: Offer mini oral summaries as you move forward in
the meeting.
Curious: Perhaps one of the most beautiful things about some-
one with ADHD symptoms is their innate sense of curiosity. They
may ask something like “How can this be done better?” If you are
new to the prospect, then the “What’s better?” attitude can work
in your favor, and you will follow your personal approach toward
demonstrating value and differentiating your services.
If you are an incumbent but looking to grow your business
with an existing client who exhibits these behaviors, then you
must realize this question may be top-of-mind for your client.
How might you nip their “feeling” in the bud by either a) brain-
storming together about how to handle a future project or b)
walking them through the post-project outcomes to demon-
strate that it was done well? How might you underscore that
your frm remains the best ft for their needs?
In short: Remain acutely aware of the “What’s the next big
thing?” or “What’s better?” questions. Proactively address it
during conversations with the prospect or client.
On the fip side, be aware of potential challenges that pro-
fessionals with symptoms of ADHD face. Do your best to help
them overcome them during your sales process and beyond.
Some of those challenges include:
Short attention span: As you always do while selling, take
good care to engage with enthusiasm, energy and warmth.
Don’t muddle your message with detail. Keep everything con-
cise and be ready to switch on a dime if their eyes glaze over
or they seem restless. When offering something new, highly
stimulating or intriguing, then you may be able to capture—
I’M SORRY…
YOU WERE SAYING?
BY ANNE SCARLETT
business issues
Thoughts on adjusting your sales
approach toward prospective clients
with short attention spans.
Anne Scarlett is president of
Scarlett Consulting, a Chicago-
based company specializing in
AEC-specific strategic marketing
plans, marketing audits and
coaching. She is also on the
adjunct faculty of Columbia
College of Chicago and DePaul
University. She can be contacted
through her website,
www.annescarlett.com.
18 SEPTEMBER 2014
business
issues
and hold—their attention. Continually ask yourself if there’s a
way you can reshape your message so that it feels exciting and
new to them.
In short: Deliver with energy, omit the details and empha-
size what’s “new.”
Diffculty staying on track and sticking to time commit-
ments: If you want to make sure the meeting starts on time,
make it easy by going to them. Meet in their offces, if pos-
sible. Once you’ve launched the meeting, try visibly checking
off items on the agenda as you go through them. This will give
everyone a sense of progress and accomplishment throughout
the meeting.
In short: Give the overall sense that things are moving along.
Fidgety, often wants to
move around: Business devel-
opers within the AEC industry
love when a prospect wants to
experience our projects frst-
hand through a site visit. This
might be just the type of per-
son who would be willing to
trek to the site for a tour. (Ide-
ally, you will provide trans-
port.) Try offering this early in
your sales cycle.
In short: Arrange a site visit,
suggest a walk-and-talk after your meetings or take a “stretch
our legs” coffee break.
Frustrated with their lack of focus: It can be maddening
for an adult to strive for career success while tackling their
ADHD symptoms. Whenever possible during your sales pro-
cess, try to subtly demonstrate empathy. Examples might be
“Wouldn’t you know it? I completely spaced out at a meeting
I had last week.” Or “Boy, I sure am having trouble getting
through my action items list for this project.” Whatever you
can (honestly) share about yourself that gives them the sense
that they are not alone will be appreciated. After all, many of
us experience these symptoms. (A personal example: It took
me a long time to write this piece; I have acquiesced to many
distractions).
In short: Relate to them by sharing your own relevant
challenges.
Experience challenges when reviewing detailed written
work: Streamline any written documentation, and present con-
tent in bullet format. Tighten the language in your fee propos-
als and, if at all possible, orally walk through them through the
proposal.
In short: Keep. It. Short.
Disorganized: Since these folks are often “organization-
ally challenged,” make sure any experiences they have with
you appear well organized. Ideally, they will associate you with
organization.
To do this in a sales meeting, start off by helping them get
organized by providing a brief list of what they should bring
to the meeting. This can be done in your email confrma-
tion. Perhaps they need to bring a calendar, business cards,
other colleagues, specifc documentation about their poten-
tial project, budget numbers, etc. Also, be very organized
yourself when you are conducting the meeting. Present your
materials in an even more organized manner than you might
otherwise. (One example: Put materials about their project
in a three-ring binder with labeled tabs. This radiates a level
of competency, and a “we can handle this for you” spirit.)
In short: Demonstrate your
own über-organized skills.
Procrastinate: As with any
prospective client, you always
want to agree upon a “next step.”
In these cases, you may want to
reiterate scheduled steps/com-
mitments more than once (i.e.,
orally during the meeting, recap
at the close of the meeting and
in a follow-up email). Also, try
to keep the next steps as close
together as possible. While this
is certainly a goal in every sales process, there might be ways to
shave off a day here or a day there to help the procrastinator to
feel the sense of urgency that he/she might actually thrive within.
In short: Strive to keep the process tight.
Express emotion that may seem intense, short-fused
or irrational for the workplace. Help guide them back to a
rational, calm and professional state of mind (but try not to
squelch any positive passion or personal investment). Suggest
win-win alternatives whenever possible. If the discussion is
going south with no signs of immediate recovery, then pro-
pose a break for 15 minutes before reconvening. This might
be more likely to happen if you are up-selling to an existing
client rather than working through the sales process with a
prospective client.
In short: Aim for win-win; demonstrate a calm, professional
demeanor; suggest a break.
These are the adjustments that I’ve used with the prospec-
tive client I mentioned earlier. So far, I have managed to get to
know her better through a series of fairly successful “touches.” I
feel optimistic about turning her company into a client.
To reiterate, I am a complete novice when it comes to adult
ADHD. If any of you readers have advice and comments from
your experiences in similar situations, I would enthusiastically
welcome your feedback.

Don’t muddle your message with detail.
Keep everything concise
and be ready to switch on a dime if their
eyes glaze over or they seem restless.
S T E E L T H I N K I N G
1he Lndeavor ls Lhe laLesL addluon Lo Lhe llcep compleLe producL range of drllllng and sawlng sysLems for Lhe fabrlcauon of sLrucLural sLeel. 1he englneerlng deparLmenL
aL llcep has Laken Lhelr decades of drlll llne experlence Lo creaLe Lhe cleanesL, mosL Lrouble-free sysLem on Lhe markeL Loday. ln addluon Lo Lhe slmpllclLy of deslgn, Lhe
Lndeavor feaLures such unlque capablllues as a sub axls on each of Lhe Lhree splndles Lo permlL slmulLaneous scrlblng and drllllng even when Lhe holes, for example, do
noL share Lhe same llneal dlmenslon. As parL of Lhe slmpllclLy Lheme LhaL ls evldenL LhroughouL Lhe Lndeavour, all Lhe splndles are ºulrecL urlve" so Lhey dellver up Lo
37 PÞ aL Lhe Lool as Lhere ls no Lransmlsslon power loss. 1he producL range lncludes muluple models wlLh slze capablllues ranglng from 24" Lo 100".
ENDEAVOUR
The latest in beam processing
llcep ls Lhe Lrue markeL share and Lechnology leader ln Lhe producuon of sysLems for Lhe
fabrlcauon of sLrucLural sLeel and plaLe. CurrenLly, llcep has sysLems lnsLalled ln nearly 90
counLrles globally LhaL are servlced by 13 llcep worldwlde companles.

llcep oñers compleLely lnLegraLed sysLems wlLh full auLomauon
of Lhe equlpmenL and Lhe maLerlal handllng. no longer are
operaLors ued Lo each machlne ln a sysLem as Lhe auendanL
monlLors Lhe mulu-Lasklng sysLem operauons. !obs or
sequences are even slmulaLed prlor Lo fabrlcauon Lo achleve
Lhe opumum producuvlLy. uurlng Lhe hands-oñ operauon of
Lhe compleLe sysLem, Lhe acuvlLy can be graphlcally vlewed
remoLely and uploaded Lo Lhe model for Lrue 4u capablllLy.
Automatic Systems
GEMINI
Automanc CNC Þ|ate Iabr|canon Center for Dr||||ng,
1app|ng, M||||ng, Mark|ng and 1herma| Cumng
1he Cemlnl ls a compleLe range of plaLe fabrlcauon cells for Lhe drllllng,
Lapplng, mllllng, marklng and Lhermal cumng of ñnlshed parLs lncludlng
bevellng for weld prep. 1he Cemlnl's unlque sub axls wlLh dual splndle
capablllLy doubles Lhe producuvlLy over slngle splndle sysLems wlLhouL a
sub axls.
I|cep Corporanon
2301 Industry Court
-
Iorest n|||, Mary|and 210S0
Þhone (410) S88-S800
-
Iax (410) S88-S900
www.hcepcorp.com
At least it was to the construction team on the Missouri River Bridge
project when their initial concrete design priced over budget at almost
$45 million. They then had to scramble for other options.
Turned out the solution was steel. After coming up with a new design,
they turned to Nucor. And we were able to help them build a
beautiful, easy to maintain and environmentally friendly bridge at less
than half the cost of concrete. Who would’ve thought.
www.nucoryamato.com
It’s Our Nature.
®
22 SEPTEMBER 2014
Slender steel elements and expanded cantilevers
defne the structural system of a new building for the Colorado School of Mines.
BUILDINGS CAN EXHIBIT not only progress and expansion,
but also a shift in focus.
Marquez Hall, a new 87,000-sq.-ft facility for the Petroleum Engi-
neering Department at the Colorado School of Mines in Golden, Colo.,
was designed to refect the country’s energy shift from petroleum to
renewables. The building, designed by the Seattle offce of Bohlin
Cywinski Jackson in partnership with Denver-based Anderson Mason
Dale Architects, reinforces the school’s vision for the future by looking
to the user, the campus and community to achieve an aesthetic refec-
tive of the school’s nationally recognized engineering programs and in-
novative applied science research. The structural steel framing system,
featuring long cantilevers and architecturally exposed steel, was chosen
to help achieve a dynamic vision for the building and address the basic
structural need of supporting gravity and lateral loads (total steel used,
including miscellaneous, was 773 tons). Vibration requirements for the
laboratories contained within also required a high degree of sensitivity.
Thinning
OUT
BY CHRISTOPHER O’HARA, P.E., AND JULIAN LINEHAM, P.E.
Christopher O’Hara ([email protected]) is a cofounder,
principal and façade director, and Julian Lineham (jlineham@
studionyl.com) is a cofounder and principal, both with Studio
NYL Structural Engineers in Boulder, Colo.
Modern STEEL CONSTRUCTION 23



Steel fins in the lobby.
The west elevation of Marquez Hall.
Box girder-to-column construction.
Two overriding themes can be found throughout the design
of the building’s structure: the varied use of cantilevers (for vi-
sual effect in some areas and to develop effciencies of mate-
rial and cost savings in others) and the use of slender elements
throughout the primary structure and cladding systems.
In terms of layout, two parallel, linear programmatic bars, as
well as a wing to the southeast, allow users to easily understand
and navigate the facility’s varied program of public, semi-public
and private spaces. Functionally, the building forms one edge
of the pedestrian walkway that connects the campus’ two main
quadrangles, thus opening its interior spaces to the area’s ex-
traordinary Front Range mountain views. Its L-shaped plan di-
vides the building into two bars while defning a new courtyard
featuring custom seating to encourage interaction. The north-
ern bar houses a combination of graduate and undergraduate
laboratories, a 4D visualization classroom and a drilling simula-
tor room. The southern bar holds offces and laboratory sup-
port spaces, and the southeastern wing includes a lecture hall
as well as four levels of smart classrooms and seminar rooms.
Cantilevers
On the southeastern wing, full-story cantilevered trusses
take their cues from staggered truss concepts and are recon-
fgured to create a cost-effective 20-ft cantilever for the third
and fourth levels. Diagonal ties applied in the cavity inside
the solid walls—similar to a cable-stayed bridge—suspend the
building’s extension over the campus quad below. While this
feature provides refuge for people entering and exiting the
building and a sense of closure to the end of the quad, the driv-
ing force for this design move was cost savings, as providing ad-
ditional foundations and traditional columns would have been
more expensive than the diagonal framing. Additionally, the
Nic Lehoux
Nic Lehoux
Kari Rogne
building is supported on deep-drilled pier
foundations because of the area’s poor soils,
and the structure of the surrounding foor
plates is arranged to bear on the backspan
of the story-high trusses, thus eliminating
the possibility of a net uplift on columns
and foundations.
The laboratories of the northern wing,
separated from campus offces by a primary
circulation corridor, have been designed to
strict laboratory vibration criteria through
the use of steel composite beams and gird-
ers. The structural framing is oriented to
minimize footfall-induced and corridor
vibrations from being transmitted into
the laboratories. Beams within the labo-
ratory run north-south, while the remain-
ing beams span east-west, parallel to and
independent of the laboratories’ girders.
The girders feature a double-cantilevered
design to help maintain defection criteria
in the presence of shallower beams that
permit signifcant mechanical duct runs to
cross the girder line.
Slenderness
Along the south façade of the northern
bar is the building’s primary entry point
from the quad. Because the design team
was not satisfed with the cost and fnish
quality of intumescent paint for application
on the heavily loaded south-side columns,
a solution beyond a freproofed, wrapped
column was pursued. This lead the team to
investigate and discover fre-rated compos-
ite columns (as per Appendix 4 of ANSI/
AISC 360-05), allowing the architects to
use a high-quality Tnemec paint, eliminate
column covers and avoid a costly solution
known for its inferior fnish.
The use of slender steel elements
was most notable in areas outside of the
primary structure. While plate stringer
stairs are quite common and are used
throughout Marquez Hall, the feature
stair joining the west lobby with the
laboratory and offce bars of the building
took it a step further. Here the balustrade
and stringer are all one element with
½-in.-thick by 48-in.-deep plates spanning
more than 40 ft. Fabricator Zimkor used
software to locate the center of gravity
so it could design and locate lifting lugs
that could be rigged to lift the stair at
its installed pitch. Shipping bracing
incorporated in the lifting lugs braced the

Tekla models of the structure.
24 SEPTEMBER 2014
LVTA
Modern STEEL CONSTRUCTION 25
stair sides to avoid bending them during
hoisting. The balustrades around the stair
opening are constructed using ½-in.-
thick plates cantilevered from the foor
structure. The steel was left natural with
a simple oiled fnish (and sealed) to make
it clear that all of the slender elements are
indeed raw steel.
Slender Cantilevers
The main feature of the building, the
west lobby, is at the end of the northern
wing. It serves as a focal point and assem-
bly space for entertaining potential donors.
This transparent exhibition and lobby
space marks a potent position on the cam-
pus’s main thoroughfare and serves as the
building’s main entrance. Since the lobby
is primarily glass, a long roof extension was
required to shade it from the region’s plen-
tiful sunlight. To solve this from a struc-
tural standpoint, glazed glass walls hang
from a 60-ft cantilevered roof via a pair of
tapered box girders that extend out from
the east side of the lobby.
Because the at-grade perspectives do
not permit an angle suffcient to see the
roof’s slope, the tapered girders main-
tain a fat bottom fange with a sloped
top fange to create the illusion of a thin
structure. To help maintain the cantilever,
the building’s mass is oriented to bear on
a story-high truss at the end of the canti-
lever’s backspan. This signifcant mass acts
as ballast for Colorado’s snow loads, and
the harsh 116-mph wind speeds prevalent
along Colorado’s Rocky Mountain Front
Range. The girders and their supporting
columns vary in depth from 24-in. at the
tip to 84 in. deep at the column girder
intersection, and 12-in.-deep steel beams
spring from them to extend the cantilever
a bit further. Finally, the perimeter gutter
system truncates down to just 6 in. using
angle ribs with gage thickness plate to
form the gutter.
To achieve the architect’s goal of a trans-
parent façade while maintaining a respon-
sible budget, a structural steel fn system
was used to support the façade. The fns
replace the traditional aluminum mullion
and steel wind girt system that would typi-
cally be required for this 30-ft span under
the building’s wind loads. By hanging the
system and directly mounting the double-
insulated glass panels to the structure, the

The west façade of the lobby.
Nic Lehoux
SEISMIC PROTECTION
FROM TAYLOR DEVICES
Stand firm. Don’t settle for less than the seismic protection
of Taylor Fluid Viscous Dampers. As a world leader in
the science of shock isolation, we are the team you
want between your structure and the undeniable forces
of nature. Others agree. Taylor Fluid Viscous Dampers
are currently providing earthquake, wind, and motion
protection on more than 550 buildings and bridges.
From the historic Los Angeles City Hall to Mexico’s
Torre Mayor and the new Shin-Yokohama High-speed
Train Station in Japan, owners, architects, engineers,
and contractors trust the proven
technology of Taylor Devices’
Fluid Viscous Dampers.
YOU BUILD IT.
WE’LL PROTECT IT.
Taylor Devices’ Fluid Viscous Dampers give you the seismic protection
you need and the architectural freedom you want.
North Tonawanda, NY 14120- 0748
Phone: 716.694.0800 • Fax: 716.695.6015
www.taylordevices.com
26 SEPTEMBER 2014
fns are essentially prestressed to feel as though they are in ten-
sion. The system does not have any horizontal steel members.
The localized load due to seismic loading on the weak axis of
the fn is resisted using the glass panels as “shear walls.” The
fns vary in depth but are only ½ in. thick. Structural steel bear-
ing plates extend from the fns to eliminate the need for costly
point-fxed glazing solutions, and the glass adheres to the fns
laterally with structural silicone.

Steel sunshades on the
south end of the building.

Looking in at the steel fins.

The facility uses 773 tons of steel in all.
Nic Lehoux Zimkor
ReIax!
CompIere Pro]eer Supporr
St. Louis Screw & Bolt
2000 Access Blvd Madison, IL 62060
Phone: 800-237-7059 Fax: 314-389-7510
Email: [email protected]
Web: www.stlouisscrewbolt.com
You dId order
your boIra trom
Sr. LouIa Serew O
BoIr... DIdn'r You ?
Nic Lehoux
Modern STEEL CONSTRUCTION 27
Getting it Done
The Marquez Hall project required an extremely aggressive
schedule, which would not have been possible without close inte-
gration of the design and construction teams. Revit models were
confgured with tight tolerances for cuts on exposed elements,
and 3D connection elements, where critical to the design intent,
were exported to the fabricator and lead detailer through an .ifc
format for inclusion in the Tekla model. With an accurate Revit
model, direct import into Tekla was possible, which saved critical
time and decreased the possibility of misinterpretation, allowing
the detailing team to meet the tight schedule.
The construction team proactively conducted meetings on-
site with the design team to prereview shop drawings, discuss
erection strategies for the intricate elements of the west lobby
and perform coordination reviews with other trades, such as
HVAC, through general contractor Adolphson and Peterson
Construction’s Navisworks model. Due to the size and weight
of the box girders, feld splices and erection were a challenge,
thus two shoring towers were erected and all splices were ar-
ranged with temporary bolt splices to facilitate feld welds. As
the system was primarily governed by defection, all welds
were confgured to use only fllet and partial penetration
welds, and precise splice locations were determined by truck-
ing limitations. The street layout in this area of the campus is
quite tight, so the team needed to verify that the chosen box
girder feld splice locations would yield shipping lengths that
wouldn’t cause turning problems (and Zimkor also needed to
verify that it had the hoisting capacity to lift each shipping
piece in the shop).
Whether it was an exposed feature such as sunshades, fa-
çade fns, stairs or fre-rated columns, or hidden elements
such as the story-high trusses of the southeastern wing/bar
or tapered box girders of the west lobby, the agile capabilities
of structural steel—along with the design and construction
team’s ingenuity—created a beautiful building that not only
expands the school’s capabilities, but also signals progress in
terms of energy use.

General Contractor
Adolphson and Peterson, Aurora, Colo.
Design Architect
Bohlin Cywinski Jackson, Seattle
Architect of Record
Anderson Mason Dale, Denver
Structural Engineer
Studio NYL Structural Engineers, Boulder, Colo.
Steel Team
Fabricator
Zimkor, Littleton, Colo. (AISC Member/AISC Certified
Fabricator)
Detailer
Lehigh Valley Technical Associates, Northampton, Pa.
(AISC Member)
“Sir, can I interest you in
one of our hard to
find domestics?”
Ask About
Our Services...
FLAME CUTTING
SAWING
CAMBERING
888.538.9022

Fax: 908.754.8728
At AZCO, specialties of
the house always include
unusual shapes,
sizes and grades
from a 30,000
ton domestic
inventory. Mill
certification is available
on all material as well as
24-36 hour delivery…
even to Canada and Mexico.
A-588, A-992,
A-572, A-36
Jumbo Beams
MC Channels
Thick Plates
1-Beams
Bars, Angles
A Division Of Bushwick Metals, LLC.
Phone: 281-2ô0-9749 Fax: 281-2ô0-9771
8PE6|AL|Z|NC |N 6U8T0H
8TEEL 60NNE6T|0N 0E8|CN
stee|connect|ondes|gn.com
Y0UR
ENC|NEER|NC
C0hhEC7/0h
Exper|enced
Professionel Engineers
Reg|stered Nat|onw|de !
• 3lruclura| 3lee| Correcl|or 0es|çr
• 3la|r ard Ra|||rç 0es|çr
• 3|op 0raW|rç Rev|eW ard 3uperv|s|or
• 0es|çr 8u||d 3erv|ces
• Corslrucl|or 0|spule Reso|ul|or
Consulting Services, Inc.
28 SEPTEMBER 2014
A new convenience store
keeps its head above water with an innovative structural steel framing system.
HEADING DOWN to the corner store for a gallon of milk is
a bit of a different experience at Lake Powell’s Wahweap Marina.
That’s because the store foats. Situated between the marina’s
docks and houseboats, the 6,655-sq.-ft building—which houses
the Wahweap Marina Store, a restaurant and offce space—is
supported by a 10,144-sq.-ft foating platform. The structure is
topped with a 1,425-sq.-ft covered deck on the second foor that
allows visitors to relax and drink in their surroundings.
The facility has been designed to accommodate the constant-
ly changing water level of the lake (Wahweap Marina is located
toward the south end of the lake, just south of the Arizona-Utah
border near the beginning of the Grand Canyon). The foata-
tion portion of the structure consists of wide-fange and HSS
McKay Parrish (mckayp@
arwengineers.com) is a project
structural engineer with ARW
Engineers.
Staying
AFLOAT
BY MCKAY M. PARRISH, S.E.
beams that are designed as a truss system to evenly distribute
loads throughout the platform. This “T” shaped foatation
system is approximately 8 ft deep in the middle section and
5 ft deep in the side sections. The side walls and bottom of
the foatation’s structural hull are covered with ¼-in. and
5
∕16-in.
steel plates and angles, and the top of the fotation structure
consists of a sloping 7½-in. suspended concrete slab on metal
deck. The lower section of the hull houses all of the mechani-
cal equipment and also doubles as a storage room. The upper
structure consists of exposed HSS beams and battered columns
that project away from the building and provide the lower deck
with shade. The upper patio area is constructed with a 4½-in.
suspended concrete slab on metal deck with a covered steel roof
system above, and wood-sheathed steel stud shear walls provide
lateral resistance for wind and wave loads.
The battered columns consist of HSS8×8×
3
∕16 sections that
extend from the lower deck to the upper canopy roof. The
architectural design pushed for an exposed structure, so the
HSS8×8 columns around the perimeter of the building are off-
set from the exterior shear walls to show off these beams and
columns. The four columns supporting the upper deck and roof
canopy are designed as cantilevered columns that are braced at
the low roof; they cantilever to the high roof to avoid the use of
bracing that could have obstructed views from the upper deck.
All roof framing members consists of exposed HSS beams that
range in size from HSS12×4 members to HSS16×8 members.

Modern STEEL CONSTRUCTION 29


The 6,655-sq.-ft building
houses the Wahweap
Marina Store, a restaurant
and office space.
The floatation portion of
the structure consists of
wide-flange beams and
HSS that are designed as
a truss system to evenly
distribute loads through-
out the platform.

Aramark
Aramark
Aramark
Aramark
Most of the lower hull foat framing consists of continuous
W8×18 or W8×24 beams that are full-pen welded at the joints.
The traditional and Vierendeel truss confgurations used in the
hull consist of W8 beams that form the top and bottom chords,
with HSS4×4 and HSS5×5 posts at approximately 8 ft on center
and matching diagonal HSS members where needed. The truss
systems occur at approximately 6 ft on center and are designed
to align directly beneath the column locations so that the truss
system can be used to evenly distribute the structures loads.
Launching a Building
As the structural engineer, ARW Engineers’ role went be-
yond the typical goal of providing practical and economic
structural solutions to satisfy the owner’s and architect’s overall
vision for the project. They were also tasked with providing so-
lutions for including fuctuating water levels, determining con-
struction sequencing of the foat system with launching and bal-
lasting restrictions, designing deeper hull sections in the lower
foat structure for better accessibility to storage and mechanical
units and integrating exposed beams with cantilevered decks.
Typical building projects begin with geotechnical reports
and foundations designed to mitigate any potential settlement
in the structure. But the Wahweap Marina Store is anything but
typical. Instead of ordering geotechnical reports and determin-
ing seismic loads, the project team and owner focused on work-
ing together to determine how they could best move the build-
ing during construction so it could be launched into the water.
One unique aspect of this building system is the trusses in
the hull section. Unlike structures built on soil with indepen-
dent footings supporting individual columns, the truss mem-
bers were designed to carry multiple columns and act together
with adjacent trusses to distribute loads evenly over the built-
up plates below; this allowed the localized “settlement” beneath
each individual column to be minimized. The structure is de-
signed to accommodate a fuctuation in the storage dead loads
and live loads each day; as buoyancy pressure beneath the truss
system increases as water depth increases, the pressure used to
analyze the truss system changes as well. The upper level build-
ings loads are not equally distributed over the structural foat,
and this requires a ballasting system to keep the building from
tipping toward the entrance where the structure is heaviest due
to the second-level framing.
The decision of how the foatation platform and upper
structure would be built and launched played a vital role in this
process. The marina is located in a remote part of Lake Powell
that is surrounded by cliffs. The boat launch ramps are the only
access to the waterfront, and clogging up the boat ramps during
the summer months was not an option. Consequently, differ-
ent methods of constructing the foatation system off-site were
discussed and after reviewing the additional time and material
required to construct the foat in sections, it was decided that
a portion of the parking lot and one of the ramps would be
dedicated to the accelerated construction of the facility during
the winter.
30 SEPTEMBER 2014

The store floats on Lake Powell’s Wahweap Marina in northern Arizona, near the eastern end of the
Grand Canyon.

This “T” shaped floatation system is approximately 8 ft deep in the middle section and 5 ft deep in
the side sections. The side walls and bottom of the floatation’s structural hull is covered with ¼-in.
and
5
∕16-in. steel plates and angles.
ARW Engineers
Modern STEEL CONSTRUCTION 31
Once the steel-encased foatation system was built and
launched, the middle 8-ft-deep storage section was so buoy-
ant without the steel and concrete structure above that it liter-
ally supported the side sections and suspended them above the
water. The contractor was directed to fll the deeper foat sec-
tion with water so that the suspended W-2 deck and concrete
topping could be poured without causing damage to the truss
members. The suspended concrete foor was poured in such
a way that the structure did not lean or cause torsion in the
structural members.
The new store is located at the same site as the original fa-
cility, which was constructed in the early 1960s and had expe-
rienced a number of additions and renovations over its 50-year
life (it contained little or no storage space, had defcient me-
chanical systems and only had a small convenience store, hence
the replacement). The construction process undertaken with
the new structure allowed the majority of the new facility to
be constructed away from the site and then moved into place
after the existing building was disconnected from the docks and
removed. This allowed for the ongoing service to the marina
visitors with minimal disruption.
Previous, similar projects with this client had incorporated
the use of long cylindrical tanks that can be flled with water (as
needed) to buoy up and/or ballast the foatation system—simi-
lar to what is used on a pontoon boat. Any piping beneath these
structures is exposed to severe weather conditions and erosion.
For this project, the owner requested that a mechanical
room and storage room be placed beneath the structure and
that all of the ducts and piping be placed within this space. They
also required approximately 28 in. of freeboard between the
water and the top of the deck to allow for neighboring docks
to be attached at similar levels and to allow boats to pull up to
the walkway. Creating too deep of a storage area would pro-
duce too much buoyancy, making it diffcult to tie the platform
into surrounding structures. Innovative approaches were used
in the design of the deeper storage section so that the forces
were transferred throughout the structure to increase its stiff-
ness and meet the required buoyancy objectives. The T-shaped
section was designed to mitigate any warping or twisting of the
platform with the changing loads.
The project, which uses approximately 300 tons of (foat-
ing) structural steel, opened for business in time for the 2013
high season.

Owner
Aramark, Wahweap Marina
General Contractor
Lake Powell Construction, Page, Ariz.
Architect
VCBO Architects, Salt Lake City
Structural Engineer
ARW Engineers, Ogden, Utah


The facility has been designed to accommodate the constantly changing water
level of Lake Powell; it is supported by a 10,144-sq.-ft floating platform.
VCBO Architects
Aramark
Aramark
Vulcraft Group joists were used to assemble an inventive design for the Golden Gate Pavilion in honor of the
Bridge’s 75th Anniversary. “The Golden Gate Bridge has been hailed as one of the modern wonders of the world.
Its visitor center deserves the latest technology and innovation.” said Louis Lozano, Vulcraft’s Northern California
District Sales Manager.
Working with design team, Project Frog, it was determined that Vulcraft’s LH series joists with their open web
aspect were the right choice. These special profle joists are designed to reach longer spans while supporting
large loads.
As an engineered products group of Nucor Corporation, Vulcraft is the leading producer of steel joists and decking
in the United States. Our team members are dedicated to creating solutions for a range of customers. And
landmarks.
All photots by Mariko Reed
www.vulcraft.com
Vulcraft’s joists play a vital aesthetic role in the
design and architecture of the Golden Gate Pavilion.
Modern STEEL CONSTRUCTION 33
Structural renovations brace an iconic
museum for the future.
THE SMITHSONIAN INSTITUTION’S Arts and Indus-
tries Building is widely known as the frst U.S. National Museum.
The dream of the Smithsonian’s frst curator, Spencer Ful-
lerton Baird, it was designed by architecture frm Adolf Cluss
and Paul Schulze and frst opened its doors in 1881. In recent
years, renovations became necessary thanks to roofng, HVAC
and plumbing leaks, which led to structural renovation as
well. Exterior enclosure and structural improvements to the
102,200-sq.-ft structure were completed early this year at a to-
tal construction cost of roughly $44 million.
As with any National Historic Landmark, there is a delicate
balance in preserving a structure’s historical elements while
also revitalizing the building to meet the needs of the present
day. Using prior knowledge of the original construction time
frame, the architects were able to successfully depict an over-
whelming majority of elements, despite the fact that many were
hidden in three to fve wythes of masonry.
The design team performed an extensive amount of existing
condition surveys, which was an integral frst step in completing the
roof replacement and in kind, the repair/replacement of the struc-
tural framing. The existing lead-coated copper and slate roofng was
replaced with 20-gauge stainless steel and new slate to match the
existing patterns, and the new roofng system weighed considerably
more than the existing one. The new structure needed to not only
support the additional weight of the new roofng system, but also
improve seismic, wind, blast and snow load performance.
National
TREASURE
BY LUCA COVI
P
e
t
e
r

C
r
a
n
e
Luca Covi ([email protected])
is business development manager
with Grunley and served as senior
project manager for the Arts and
Industries Building renovation.

The building first opened in 1881.
34 SEPTEMBER 2014
The building is laid out as four quads around a central rotunda.
Each quad consists of six individual structures (hall, court, transition,
range, entrance/tower and pavilion) that were systematically demol-
ished and rebuilt using modern steel components while matching
the fabric of the original design. Each quad was unique in terms of
dimension and geometrical confguration, a condition that required
each area to be feld checked for correct dimensions and elevations;
in some cases, 3D sketches were drawn by hand in the feld. Our
team took this information and loaded it into SDS/2 to develop fab-
rication and erection drawings, and the feld checking and modeling
exercise totaled in excess of 3,000 labor hours.
The four quads were integral to one another and required sig-
nifcant in-house engineering to ensure proper ft-out of new and
existing structural members between quads. Each quad consisted of
approximately 2,200 pieces of steel weighing approximately 125 tons
per quad, 15,000 pieces of hardware (A325 and A490 TC structural
bolts with nuts and washers of various diameters and lengths, as well
as 2,400 Hilti epoxy anchors of various sizes) and 26,000 sq. ft of
decking. A portion of the existing iron structure was reused, requir-
ing signifcant remediation to meet the new structural requirements.
Installation of the new structural framing began on the rotunda
roof, then the team moved into the southwest quad hall structure
and continued in a clockwise fashion around the building, fnish-
ing with the topping out of the roof structure replacement. The
➤ ➤
Installation of the new structural framing began on the rotunda
roof, then moved into the southwest quad hall and continued
in a clockwise fashion around the building.
Exterior enclosure and structural improvements to
the 102,200-sq.-ft Smithsonian Institution’s Arts and
Industries Building were completed early this year.
The four quads were integral to one another
and required significant in-house engineering to
ensure proper fit-out of new and existing structural
members between quads. Each quad consisted
of approximately 2,200 pieces of steel weighing
approximately 125 tons per quad.
P
h
o
t
o
s

t
h
i
s

s
p
r
e
a
d
:

C
h
r
i
s
t
o
p
h
e
r

F
e
e
h
e
l
y


Modern STEEL CONSTRUCTION 35
fnal enhancements were made to existing trusses
in the southeast range portion. Each truss was at
a different elevation and the required improve-
ments had to be made on a per-truss basis to al-
low the roof system to be installed properly.
One key strategy to the success of this project,
and a great example of innovation, was the use of
temporary scaffold decks. The scaffold decks pro-
vided the necessary work platform, acted as tem-
porary roofng and provided lateral bracing of the
exterior walls. In lieu of trying to fnd a way to keep
water from entering the building, our team devel-
oped a plan to purposefully route the water inside.
To accomplish this, we built scaffolding platforms
just below the existing roof levels with knee walls
and waterproofed them to the existing walls. To
maintain consistent temperature and humidity
levels between the inside and outside of the walls,
Installation of the new structural framing began on
the rotunda roof, then moved into the southwest
quad hall and continued in a clockwise fashion
around the building.

36 SEPTEMBER 2014
The building is laid out as four quads
around a central rotunda. Each
quad consists of six individual struc-
tures (hall, court, transition, range,
entrance/tower and pavilion) that
were systematically demolished and
rebuilt using new steel components.


Christopher Feehely
Peter Crane
we installed vents in the knee walls. On the
scaffold decks, we installed an ethylene pro-
pylene diene monomer (EPDM) layer and
foor drains. To protect the EPDM roofng
(since the scaffold decks were the main work
platform) we covered the entire surface with
horse mats. Although rubber horse mats are
normally used for lining stables, we found
them to be perfect for our application as well,
and we have been able to reuse almost every
single mat on other projects. This system al-
lowed the ironworkers to perform elevated
work at what felt like ground level.
Modern STEEL CONSTRUCTION 37




Each truss was at a different elevation
and the required improvements had to
be made on a per-truss basis to allow
the roof system to be installed properly.
The new structure needed to not only
support the additional weight of the roof-
ing system, but also improve seismic,
wind, blast and snow load performance.
Christopher Feehely
Christopher Feehely
Christopher Feehely
Christopher Feehely
38 SEPTEMBER 2014
To enhance productivity, Grunley established a
work sequence that fowed from the highest roof
elevation to the lowest elevation, while simulta-
neously progressing clockwise around the build-
ing. The installation of each level of roofng was
followed by window installation. This productive
sequence reduced the risk of damage to the new
windows, limiting the need to work off of the new-
ly installed roof and ensuring safety for workers by
reducing overhead activities. A tower crane was
erected in the southeast quadrant and was able to
reach 90% of the roof structure. Since staging was
limited and all material deliveries had to be stra-
tegically scheduled, the tower crane provided eff-
cient material handling capabilities with the ability
to reach all three staging and unloading areas.

General Contractor
Grunley Construction Company, Inc.,
Rockville, Md.
Architects
Ennead Architects, LLP, New York, and
SmithGroupJJR, Washington, D.C.
Structural Engineer
McMullan and Associates, Reston, Va.
Steel Fabricator, Erector and Detailer
Superior Iron Works, Inc., Sterling, Va. (AISC
Member/AISC Certified Fabricator/Advanced
Certified Steel Erector)
The building is widely known as the first U.S. National Museum.
Peter Crane


Phone 205-791-2011
Fax 205-791-0500
E-mail: [email protected]
Web: www.whitefab.com
BENT ON SATISFACTION
11 Bending Machines
Easyway and Hardway: Beams, Tubes, Angles, Tees, Channels, Flats,
Pipe & Rail
Sheet/Plate
Shearing (to ½” x 20’), Forming, Rolling (to 1¼”), and Coning
6 Press Brakes
1000 Ton x 30’ 750 Ton x 24’
400 Ton x 23’ 3-225 Ton x (10’, 12’, 14’)
CNC Machining
Quality
WhiteFab’s patented structural bending process minimizes
deformation and provides smoother curvatures. Each bent
section is verified for accuracy along its arc.
Facilities
170,000 sq. ft. of production area, under roof
“IF QUALITY IS WHAT YOU NEED,
LET WHITEFAB TAKE THE LEAD”
DESIGNED FOR PERFORMANCE.
OPTIMIZED FOR SEISMIC.
TAKE EFFICIENCY, ECONOMY AND
INTEGRITY TO NEW HEIGHTS
Approved for ANSI/AISC 358-10, Supplement 2, including
bi-axial connections (2 directions) and HSS beams,
SidePlate makes it easier and more economical to
design your seismic projects with confidence.
Toll Free: (800) 475-2077
Telephone: (949) 238-8900
www.sideplate.com/seismic
FuII Member
Modern STEEL CONSTRUCTION 41
A look at the performance of the
national uncoated weathering steel bridge inventory.
ALL RESEARCH TAKES PLACE in a lab—of sorts.
For uncoated weathering steel (UWS) bridges, that lab is
out in the open, exposed to the elements, in various types of
environments across the country.
UWS bridges have now seen domestic use for nearly a half-
century, an appropriate time frame for assessing their long-
term performance. Such an assessment has been the focus of
recent research, “Evaluation of Unpainted Weathering-Steel
Highway-Bridge Performance,” conducted at the University of
Delaware’s Center for Innovative Bridge Engineering in part-
nership with the Federal Highway Administration’s (FHWA)
Long Term Bridge Performance Program (LTBPP) and Rut-
gers University. Specifcally, UWS performance has been as-
sessed through surveying the varied experiences of 52 US
transportation agencies as well as through compiling a national
database of UWS bridges and performing a data analysis on the
condition of these bridges. In total, the performance of nearly
10,000 structures has been quantifed as a result of these efforts.
Qualitative Performance
Through a survey facilitated by the organizational structure
of FHWA’s LTBPP—which has “state coordinators” in each
state, Puerto Rico and the District of Columbia—data has been
compiled regarding owners’ perceptions on the performance of
UWS. Respondents were asked to “briefy describe your gen-
eral perception of the overall performance of unpainted weath-
ering steel in highway bridges within your agency.”
“Overall performance” was defned as performance away
from problematic details such as leaking joints, details that
trap moisture and debris, etc., because the reasons for inferior
performance at the locations of problematic details is relatively
well understood and theoretically easy to remedy with suff-
cient maintenance resources. Rather, a major goal of this survey
was to reveal general information on the frequency and charac-
teristics of structures suffering from accelerated corrosion over
more widespread areas.
The responses to this question were categorized into the
three distinct categories listed below, which emerged as the re-
sults were reviewed:
➤ Entirely Positive (EP): No overall performance problems
with UWS indicated.
➤ Mostly Positive (MP): A generally positive perception of
UWS performance was indicated, but some drawbacks
were also mentioned.
➤ Negative: A response indicating a negative perception of
UWS performance.
Based on these defnitions, Figure 1 (on fthe following page)
shows the geographic distribution of the 50 responses to this ques-
tion (agencies not reporting data for this question are flled with a
dashed pattern). The map indicates that 96% of the respondents
have a positive perception of the performance of UWS, including
29 of the 50 respondents (58%) being in the EP category. The
38% of respondents in the MP category reported issues typically
associated with various specifc environments or situations. These
TIME Tested
BY JENNIFER MCCONNELL, PH.D., DENNIS R. MERTZ, PH.D., AND HARRY W. SHENTON, III, PH.D.
Jennifer Righman McConnell
([email protected]) is an associate
professor, Dennis Mertz (mertz@
udel.edu) is a professor and Harry
W. Shenton, III ([email protected])
is a professor and department chair,
all with the Department of Civil and
Environmental Engineering at the
University of Delaware.
42 SEPTEMBER 2014

problematic environments were most often related to the use of
deicing agents on underpass roadways. The only two states with
a negative perception of UWS were Michigan and Alaska—nei-
ther of which has constructed any UWS bridges since guidance
on proper UWS maintenance (“Uncoated Weathering Steel in
Structures Technical Advisory”) was published by FHWA in 1989.
(Michigan’s newest UWS bridge was constructed in 1983 and all
of four of Alaska’s UWS bridges were built in 1974 or 1975.)
Quantitative Performance
A national UWS bridge database was created through co-
operation with 46 state coordinators and representatives from
eight federal agencies who identifed the UWS bridges within
their inventory. As a relatively simple means to assess the per-
formance of this extensive inventory of UWS bridges, the Na-
tional Bridge Inventory (NBI) superstructure condition rating
(SCR) of each structure was compiled. The SCR is an integer
value from 0 to 9 that is meant to describe the overall condition
of girders, cross-frames, bearings, etc., with 0 being the worst
condition (failed) and 9 being the best condition (excellent).
The rating takes several factors into consideration, including
fatigue cracks and other visual signs of over-stressed members,
damage resulting from vehicular impacts, missing bolts in struc-
tural connections and corrosion. From the review of numerous
inspection reports of specifc structures, it has been observed
that the last of these (corrosion) is one of the more common
causes of decreasing SCR. Thus, when reviewing these ratings
for an extensive sample size of UWS bridges, the authors have
shown that these ratings give a general quantitative indication
of UWS performance.
The data summary shown in Figure 2 shows that on average
UWS bridges perform quite well, with the most populated SCR
being 8, which represents “very good” condition, and 50% of
the total inventory of UWS bridges having either a SCR of 8 or
9. Furthermore, 95% of the UWS population has a rating of 6
or better, indicating “satisfactory” performance or better. Note
that only 1% of the UWS population received a rating of 4 or
less. Furthermore, the SCR values of 0 to 3 were not found to
be a direct result of UWS or corrosion-related issues; instead,
they were most commonly related to un-arrested fatigue cracks
in the sample of bridges for which detailed information has
been obtained. Figure 3 shows, perhaps unsurprisingly, that a
clear factor affecting SCR is the age of the structures. Specif-
cally, a relatively linear decreasing trend in SCR with increasing
age is observed, where the average SCR for bridges 10 years old
and younger is 8.0 and is 6.5 for bridges 41 years old and older.
Comparative Performance
The signifcance of the above data increases when viewed
in context relative to other material types. Figure 4 shows the
SCR versus age for UWS bridges in two representative agen-
cies (one from an agency in the “entirely positive” category and
the other from the “mostly positive” category based on the sur-
vey results discussed above) plotted relative to the other steel
(OS) bridges in these same agencies. As a simple means to aid in
interpretation of and comparison between data sets, trend lines
based on linear regression analysis of each data set are added to
each of these data series.
In comparing the performance of the UWS and OS data
sets, it is observed that in the entirely positive category, the
performance trend of the UWS data set is similar to the per-
formance trend of the OS data set, with UWS tracking slightly
above. This difference is more pronounced for younger bridg-
es, although even UWS bridges designed prior to the publica-
tion of the FHWA UWS technical advisory outperform their
OS counterparts. For the mostly positive performance category,
it is also observed that the UWS bridges display similar per-
formance relative to their OS counterparts. For these two data
sets, the trend lines are very similar, with the UWS trend line
being slightly superior to the OS trend line for ages between 1
and 25 years and the OS data set being slightly superior oth-
erwise. However, this fnding should be viewed in light of two
facts. The frst is that even though data is plotted here for ages
1 through 49, there are relatively few (only nine) bridges older
than 35 years old, so data for these structures is not statistically
Favorable performance of a UWS overpass.
Entirely Positive
Mostly Positive
Negative
Figure 1. Owners’ perception of the performance of UWS
bridges in their state.

Modern STEEL CONSTRUCTION 43
signifcant in light of the total number of bridges
considered in this fgure (12,000). The second is that
it has been 25 years since the FHWA UWS techni-
cal advisory was published. Thus, it is possible that
design or maintenance practices implemented since
that time would change these trend lines as the new-
er bridges in this population age in the future.
Further Work
As a result of the data presented herein, we
have concluded that UWS generally provides
reliable performance in highway bridge applica-
tions throughout the U.S. Specifcally, as a result
of the survey of bridge owners, it was found that
96% of the respondents have a positive perception
of UWS performance within their inventory and
that the remaining two agencies had not built any
UWS bridges since 1983—which was, again, prior
to the FHWA guidance on this topic being pub-
lished in 1989. When reviewing the NBI ratings of
the structures in the newly created national UWS
bridge inventory, it was found that the superstruc-
ture condition ratings of the majority of UWS
bridges are classifed as excellent or very good.
While these tend to be newer UWS bridges, UWS

Figure 2. Distribution of UWS population by SCR.
Figure 3. Distribution of UWS population by
age with corresponding SCR.
Figure 4. Superstructure condition rating vs.
age, UWS vs. other steel bridges.
N
u
m
b
e
r

o
f

U
W
S

B
r
i
d
g
e
s
A
v
e
r
a
g
e

S
C
R
EP UWS
EP OS
MP UWS
MP OS
Linear (EP UWS)
Linear (EP OS)
Linear (MP UWS)
Linear (MP OS)
S
u
p
e
r
s
t
r
u
c
t
u
r
e

C
o
n
d
i
t
i
o
n

R
a
t
i
n
g
Age (years)
N
u
m
b
e
r

o
f

U
W
S

B
r
i
d
g
e
s
SCR


44 SEPTEMBER 2014
bridges that have been in service for over
40 years were shown to be also generally
performing well.
Furthermore, based on the fact that
Figure 4 shows the average performance
of UWS is on par with or better than
the average performance of painted steel
superstructures for the representative
agencies evaluated here, we can con-
clude that when choosing between these
two corrosion-control strategies and
considering the economic and environ-
mental benefits of UWS bridges, UWS
is a sound choice in many different en-
vironments. That said, complementary
research is recommended to more care-
fully evaluate potential exceptions to
this general statement.
One such research topic has been to
analyze UWS performance as a function
of climate (see “National Review on Use
and Performance of Uncoated Weather-
ing Steel Highway Bridges” in ASCE’s
Journal of Bridge Engineering). This work
revealed that UWS bridges generally
performed well across all climate cat-
egories and suggested that maintenance
practices may be a more influential in-
dicator of UWS performance than cli-
mate; this latter hypothesis is of interest
for future evaluation. Furthermore, the
climate analysis to date has consisted
of broadly categorizing bridges into re-
gional climate categories. However, re-
cent creation of a geographic informa-
tion system (GIS) database combining
the UWS inventory, climate data and
atmospheric chemical concentrations
now allows the specific climate condi-
tions (e.g., monthly humidity values, an-
nual snowfall and atmospheric chloride
levels) of each UWS bridge to be known,
which could reveal new insights on the
effects of local climates.
Lastly, feld work to more rigorously
evaluate specifc UWS bridges is also un-
derway, along with a complementary effort
to obtain as much information as possible
from existing inspection reports of ad-
ditional UWS bridges so that additional
metrics beyond SCR, such as element-level
condition state data and visual observations,
can be considered. Through such efforts,
guidance on expected UWS performance
in representative realistic conditions can be
obtained, which can ultimately lead to the
development of UWS best practices and
guidelines.

46 SEPTEMBER 2014
A criminal justice school blends the new with the old
in an urban expansion project.
THE YEAR FOLLOWING the attacks of September 11th ini-
tiated a sudden boom in the popularity of criminal justice careers.
As the trend continued over the years, this led one of the
country’s most highly esteemed criminal justice schools, the
City University of New York’s (CUNY) John Jay College of
Criminal Justice in Manhattan, to eventually expand its campus.
The result is a new 625,000-sq.-ft academic building, com-
prised of a 15-story tower on 11th Avenue and a four-story po-
dium with a garden roof that connects to the college's existing
Haaren Hall, which dates back to the late 19th century, on 10th
Avenue. The building doubles the existing facilities and unifes
of the campus into one city block.
Justice is
SERVEDBY JASON STONE
SOM
Modern STEEL CONSTRUCTION 47
Abadan Mustafa of Skidmore Owings and Merrill, the proj-
ect’s architect, explained the design concept thusly: “Criminal
justice is not something that should be hidden away. Glass
makes the relationship to inside and outside clearer. It relates
to our ideals of transparency and justice, the way justice is ap-
plied to everyone equally and openly."
The new facilities offer traditional college campus amenities in-
cluding classrooms, offces, research laboratories, theaters, lounges
and fexible collaboration spaces. In addition, unique features specif-
ic to educating future investigators and law enforcement offcers in-
clude a ballistics room, areas for chemical storage and analysis, space
for mock trials and an emergency control center simulation lab.
Over the Tunnel
There are many challenges to construction in Manhattan,
not the least of which are the countless train tunnels below the
streets, and a shallow Amtrak tunnel cuts through a corner of
the project site. To effectively isolate the building from the train
vibration and noise, two layers of structure were provided. The
train tunnel was enclosed with a hollow core precast plank ceil-
ing and concrete crash walls, and the main steel-framed build-
ing structure spans over and behind these elements (the columns
were mostly W14, with the largest being W14×665, and the
beams were typically W14×22 that frame to W18 and W36 gird-
ers at the long spans). At points of convergence, creative detailing
was required to maintain the load path and necessary separation.
However, accommodating the almost two-story change in
grade between 10th and 11th Avenues would pose a challenge, as
would a second main entrance to the building that occurs along
59th Street and negotiates this steep slope. To design for these
conditions, the perimeter columns, which are in an area that sup-
ported heavy loads from the rooftop garden, were eliminated and
the entrance was pulled back to allow room for the necessary
steps and ramps. One-story-deep trusses were ft inside the walls
of the fourth-foor classrooms to effciently accomplish the 40-ft
cantilever out to the tip of a V-shaped tapering canopy.
The interior architecture also responded to the sloped grade
with a series of cascading staircases and escalators that compli-
cated the structure but still facilitated circulation to all parts of
the campus.

A partial section view from 11th Avenue at the Amtrak tunnel
(the structural system is highlighted).

Careful detailing at the train tunnel was required to isolate
members supporting the precast tunnel enclosure from the
main building structure.
Jason Stone (jason.stone@
lera.com) is a senior associate
with LERA Consulting Structural
Engineers.
Hung floors
Core columns
Perimeter
hangers
Penthouse trusses
(cantilevered from core)
Column-free
5th floor cafeteria
Traditional framing
Amtrak tunnel
Temporary
erection
column
Support structure
cantilevered
over tunnel
Setbacks in the façade of the main entrance at 11th Avenue
were an important aesthetic feature that also reduced the
impact of the load on the shallow train tunnel below.
“The cascade replicates a miniature Manhattan, with the ‘travelers’
passing through different building functions and academic departments
rather like the squares—Madison, Herald and Times, among others—that
bisect Broadway and function as independent nodes within the city,” said
Mustafa. Additionally, a large skylight supported by narrow architecturally
exposed narrow HSS20×4×½ provides natural light into these main circu-
lation areas and offers views in from the garden roof.
Hanging System
Accommodating the necessary two layers of structure around the train
tunnel mandated a practical limit to the weight that could be supported.
After exploring numerous options, a hanging solution, distinguished by a
grid of rooftop trusses that hang the perimeter of the eight foors below, was
favored by SOM and the Dormitory Authority of the State of New York
(DASNY) and was adopted for numerous reasons. One of these was achiev-
ing the series of distinguishing setbacks that frame the west façade’s main
entrance along 11th Avenue. The hanging system was continued around the
full perimeter to balance the weight, complete the column-free aesthetic
and take advantage of the thin plate hangers that could ft inside a standard
partition wall instead of traditional column enclosures. The hanging sys-
tem was stopped where the structure over the tunnel could accommodate
conventionally framed foor weight to maintain effciency. The ffth foor
was chosen for this transition, allowing the transparent column-free foor
to align with the podium roof garden, and providing views of the Hudson
River for the full 195-ft width of the building.
The primary challenge was to achieve approximately level foors as well as
a 2-in. stack joint in the curtain wall at the transition foor between the con-
ventionally framed original building and the new hung structure. (The steel
that frames between the hanging perimeter—increased for anticipated defec-
tion—and the down-to-the-ground supported core steel sloped upward until
the temporary support columns at the sixth foor were distressed/removed.)
To simplify the steel frame erection, the design accounted for temporary
columns at the ffth foor around the tower perimeter and temporary angles
bolted to the plate hangers above the sixth foor to stiffen these elements dur-
ing erection. This allowed the construction process to proceed similarly to
conventional construction and maintain the project schedule. Once the truss
assembly was fnished, jacks at the temporary columns slowly lowered the
building and engaged the trusses. At this point, the temporary columns and
angles could be removed and concreting of the tower could begin.
Calculating the required amount of vertical cambering of the steelwork
(or how much to super-elevate the perimeter steel at each of the 26 hang-
er/column locations to account for the anticipated defection during con-
struction) proved to be a challenge as well. Design estimates were based on
the assumed construction schedule, estimated construction loads and real-
istic modeling of the structural behavior. During construction, continuous
surveying verifed whether the perimeter was behaving as we anticipated.
Once shop drawings were available for the nonstructural elements, a full
reanalysis was done incorporating what was being learned from the sur-
veying. This reanalysis revealed that it was likely the perimeter would not
come down as much as originally thought (one reason being the curtain
wall was 30% lighter than assumed in design) and feld adjustments were
made to lower the steel frame prior to starting the truss erection. Based on
the last survey data received, this adjustment proved effective as the perim-


With the temporary columns removed, the load path for
the hanging structure is clear.

The rooftop truss hanging system supports the 26
perimeter hangers.
48 SEPTEMBER 2014
Eduard Hueber
Modern STEEL CONSTRUCTION 49
eter settling and fnal stack joint were tracking closely with the predicted
behavior and targeted fnal thickness.
Future Expansion
During the expansion, the college decided that fexibility for future
generations was important. A design was considered that allowed for an
additional ten foors over the podium to raise this section to the height of
the new tower. When the decision was made, the podium structural steel
was already mostly fabricated and the caisson foundations were actively
being drilled in some of the affected areas.
It was then agreed upon to only reinforce the foundations up to the
slab-on-ground and take advantage of a hanging structural system similar
to the one used in the tower; this would reduce the affected area to the in-
terior core and limit the fnancial and schedule impacts as much as possible.
Additional elevator pits with knock-out slabs were provided along with
signifcantly reinforced foundations, based on the anticipated future circu-
lation and structural weight needs. Instead of increasing the column and
vertical bracing member sizes for the expected future loads, the additional
capacity is intended to come from a high-strength composite concrete en-
casement, allowing the already fabricated vertical members to still be used.
Up on Top
The 65,000-sq.-ft roof terrace atop the podium serves as a new, out-
door gathering place for students and faculty. The planted green roof is

Construction over the Amtrak tunnel was done at night and coordinated
around the train schedule. Noise and vibration were controlled by isolat-
ing the tunnel enclosure from the tower structure.

Invest in StruM.I.S technology for your steel fabrication business and enhance core competencies to
gain competitive advantage.
Fabricators from coast to coast use StruM.I.S advanced steel fabrication management software to
èhc|èn||g ron ||è|r cpèra||cns. Cor prccoc|s arè ccnpa||c|è v||| CNC è¢o|pnèn| anc najcr CAD
packages.
With StruM.I.S you can connect your business resources and obtain time, cost and process
savings for greater emciencies, traceabiIitg and productivitg leading to increased proñtabiIitg.
Ccn|ac| os |ccag |c arrançè a FREE software demonstration of StruM.I.S.
Manage Your Steel Fabrication
Business With StruM.I.S
Image courtesy of Canam Group
BIM Integration
Ccn|rac|s lanaçènèn|
Dcconèn| lanaçènèn|
Estimating
lnvèn|crg Ccn|rc|
Production
Planning & Scheduling
Purchasing
Multi-Facility Management
50 SEPTEMBER 2014
landscaped with large grassy zones, full-sized trees and decked outdoor dining areas,
which students have immediately embraced and nicknamed “Jay Walk.”
To preserve the dramatic views, the hanger spacing was increased to nearly 50
ft at the middle of both the east and west faces for the hung tower foors. These
long-span conditions created a problem for the laboratories on the sixth, seventh
and eighth foors, where strict vibration criteria needed to be met; stiffening the
foor resulted in deeper and heavier members than could be tolerated in the ceiling
package. The solution, which saved material and depth in the foor members, was to
remove the problematic excitation by adding an isolation joint in the foor between
the labs and the adjacent main circulation corridor.
The John Jay College Expansion project exceeded the expectations of owner and
client, giving the students and faculty a new state-of-the-art home they feel proud
of, along with the fexibility to adapt to whatever the future holds.

Owner
Dormitory Authority of the State of New
York
Client Team
City University of New York
John Jay College of Criminal Justice
Construction Manager
Turner Construction, New York
Architect
Skidmore Owings and Merrill, New York
Structural Engineer
Leslie E. Robertson Associates (LERA)
Consulting Structural Engineers, New York
Steel Team
Fabricator and Detailer
Owen Steel, Columbia, S.C. (AISC
Member/AISC Certified Fabricator)
Erector
Cornell and Company, Woodbury, N.J.
(AISC Member/AISC Certified Erector)

A cross section of the building. The
15-story, 625,000-sq.-ft facility sits atop
a four-story podium and is connected to
the college’s existing Haaren Hall.
Edith Green-Wendell Wyat Federal Building Portland, OR. Disney’s Aulani Resort & Spa Ko Olina, HI. San Diego Downtown Central Library San Diego, CA.
-Angle -Flat Bar -Square Bar -Wide Flange -Channel -Square Tubing
-Tee -Rectangular Tubing -Round Tube & Pipe -Round Bar -Rail -Plate
ANNIVERSARY!
Servicing the Steel Industry Since 1939
75
Toll-Free: (866) 252-4628 www.albinaco.com
12080 SW Myslony St. Tualatin, OR 97062 [email protected]
YOUR BENDING EXPERTS
th
SOM
There’s always a solution in steel.
American Institute of Steel Construction
One E Wacker Drive, Suite 700
Chicago, IL 60601
www.aisc.org 312.670.2400
Class begins September 22, 2014
AISC
Night School

www.aisc.org/nightschool
Connection Design 2
Bracing Connections
Written and presented by William A. Thornton, P.E., Ph.D.
Monday nights 7:00 p.m. Eastern Time
(90 minutes each)
• Uniform Force Method
• Behavior of bolted joints
including prying action
• Chevron gusset plate design
(wind and seismic)
• Corner bracing connections
and more...
52 SEPTEMBER 2014
Span-by-span bridge construction, using modular steel bridge elements,
can serve as a viable and economical bridge-building alternative.
ACCELERATED BRIDGE CONSTRUCTION (ABC) has
come a long way in the last 10 years.
And prefabricated, modular elements made with steel beams
have been a big factor in making this happen, as they can be
used to reduce the weight of the assemblies, thereby making
crane installations more cost effective and viable.
Modular steel beam/deck elements generally consist of two
or three steel beams with a composite concrete deck cast in the
fabrication plant. They are erected quickly and joined with re-
inforced concrete closure pours made with high-early-strength
concrete; a bridge superstructure can be built in as little as two
days using this technique.
One of the more successful examples of this method was
the 93Fast14 project in Medford, Mass. (a 2012 NSBA Prize
Bridge Awards winner), which involved replacing 41 spans on
14 bridges along Interstate 93. The 14 bridge superstructures
were replaced during ten 55-hour weekend work periods. The
use of structural steel for the beam elements made the project
possible since crane capacities controlled many of the sites.
Span by Span
Let’s take a look at the two common ABC methods to design
and construct a multi-span bridge. The frst is to detail multiple
simple spans between supports, sometimes referred to as “span-
by-span” construction. Conventional simple-span bridges re-
quire expansion joints at each pier—historically a problematic
feature of many bridges—as leaking joints, considered by many
to be the most common cause of premature bridge deteriora-
tion, lead to the corrosion of beam ends and deterioration of
the substructures under the joints.
The second method for designing multi-span bridges is to
use continuous-span beams, which do not require deck expan-
sion joints at the interior supports, and require less structural
steel for a given span arrangement.
Span-by-span beams are simply erected on the substruc-
tures without the need for splicing and shoring towers. The
problem with leaking deck joints has been addressed by de-
signing these bridges to be either joint-less or continuous for
live load by using simple concrete pours at interior supports
to eliminate the need for deck expansion joints. Using span-
by-span techniques for the superstructure can accelerate the
process by eliminating the need for welded or bolted feld
splices in continuous girders. Beam erection can progress
very rapidly as the modular units are inherently stable. Once
set, the crane can release the beam without the need for any
external bracing.
One method that has been developed to eliminate deck
joints on simple-span bridges is “link slab” technology. A
link slab is built by simply casting the slab continuously
across the pier linking the two spans. The link slab is de-
signed to accommodate the live load rotation of the girders
without signifcant cracking. This is accomplished by de-
bonding a portion of the deck near the support to form the
link slab, which acts as a fexible beam. The recommended
Michael P. Culmo (culmo@
cmeengineering.com) is vice
president of transportation and
structures with CME Associates,
Inc., in East Hartford, Conn.
Piece BY Piece
BY MICHAEL P. CULMO, P.E.
caption
caption
length of de-bonding is 5% of the adjacent span on each side
of the pier. Keep in mind that link slabs are not a form of
continuity. The bending moments in the link slab are much
less than typical negative bending moments in continuous
girder bridges; therefore, the design of the girders is based
on simple-span supports.
The bending moment in the link slab can be calculated us-
ing a simple equation. Reinforcing can then be designed to re-
sist the bending and control cracking. The bending stresses in
link slabs are often less than the tension stresses that develop in
continuous-span bridges. The same principals of crack control
reinforcing design are applied to both.
Greater Efficiency
We are taught in engineering courses that continuous steel
girders are more effcient than simple-span girders and that
“least weight equals least cost.” In principle, these lessons are
true. But in order understand the true effciency of steel bridge
construction, the engineer needs to look at the total cost of the
bridge, including the cost of connections, construction meth-
ods and deck reinforcement. In order to study the effciency
of span-by-span construction, we investigated the preliminary
design of a hypothetical two-span bridge. The bridge selected
is a typical expressway overpass with equal spans of 122 ft and
fve girder lines.
Modern STEEL CONSTRUCTION 53
➤The 93Fast14 Project in Medford, Mass., demonstrated the viability of modular steel bridge construction by replacing
41 spans in ten 55-hour weekend work periods.
Bridge deck joints can be eliminated at piers through the use of “link slabs.” ➤
M = 2 EI θ / L
θ = Girder end rotation
L = De-bond length
E = Modulus of elasticity of link slab
I = Gross moment of inertia slab
De-bonding material
Slab de-bond zone
0.05 L 0.05 L
CME Associates, Inc.
Two bridge types were studied for this structure: continu-
ous girders and simple-supported girders. The NSBA computer
program Simon was used to complete a preliminary design of
the girders. (Simon is available for free at www.steelbridges.
org and can be used to design effcient steel girders for sim-
ple- and multiple-span bridges based on the AASHTO LRFD
Bridge Design Specifcations.)
The results of the preliminary design showed that the simple-
span bridge required 30 more tons of steel at a cost of $70,000
more than the continuous-span option (based on construction
costs in the Northeast). The remainder of the study was dedicated
to investigating the total cost of the bridge in order to determine if
other factors would offset the increased cost for the structural steel.
On such factor was splicing. The 122-ft-long simple-span
girders can be shipped in one piece (without feld splices), where
the continuous girders would need at least one feld splice. The
study assumed that two feld splices would be required for the
bridge. It may be possible to build this bridge with one splice,
but the length of the pieces would be more than what some
permitting agencies would allow.
Another NSBA computer program, Splice, was used to de-
sign the bolted splice for the continuous girder study bridge.
This program can effciently design a bolted feld splice accord-
ing to the requirements of the AASHTO LRFD Bridge Design
Specifcations. The fnal design of the splice included 116 high-
strength bolts, and the cost for fabrication and installation of
the splice was estimated to be $5,800 per splice (again, based
on typical regional construction costs). By eliminating the need
for bolted feld splices in the span-by-span bridge, an estimated
cost savings of $58,000 could potentially be realized.
The Bridge Design Specifcations require the use of longi-
tudinal reinforcing steel in the negative moment region of
continuous girder bridges in order to control cracking due to
composite dead load and live load moments. In general, the
design of link slabs results in longitudinal reinforcing that is
much less than that used in continuous girder bridges. In ad-
dition, the link slab reinforcing steel need only be applied over
the link slab zone, which is typically smaller than the negative
moment region of a continuous girder. For the study bridges,
the link slab design saved considerable reinforcing steel when
compared to the continuous-span bridge, which equated to an
approximate savings of $22,000.
Another avenue of potential cost savings with simple-span
construction is erection. Many agencies require the use of shor-
ing towers under bolted splices. Even if shoring towers are not
used, the cranes are required to hold the girders until suffcient
bolts are installed in the feld splices, which is a less effcient
process. The potential erection cost savings for the simple-span
bridge was estimated to be approximately $30,000.
54 SEPTEMBER 2014


Typical two-span overpass bridge.
Continuous girder with bolted splices. Simple-span bridge with joint-less deck.

➤Bolted field splice designed using NSBA’s Splice program.
Modern STEEL CONSTRUCTION 55
When it comes to bearings, simple-span
construction requires two lines of bearings
at the center pier, compared to one line of
bearings in the continuous girder bridge.
The simple-span bearings are small but
there are more to fabricate and install, and
the cost of the extra bearings was estimated
to be approximately $1,500.
When the above items are account-
ed for, an estimated net cost savings of
$38,500 could be realized for the span-by-
span bridge.
Item
Net Cost
Savings
Structural Steel -$70,000
Bolted Splices $58,000
Additional Deck Reinforcing $22,000
Steel Erection Cost $30,000
Bearings -$1,500
Net Savings $38,500
Net cost savings for simple-span
construction as compared to
continuous bridge construction.
To recap:
1. Continuous-girder spans require less
structural steel and fewer bearings.
2. The simple-span construction meth-
od may not need bolted feld splices,
uses less additional deck reinforce-
ment and may be less expensive to
erect when compared to a continuous
girder bridge.
3. Least weight of structural steel does
not always equate to least overall
bridge cost.
4. By using link slab technology, sim-
ple-span construction can be accom-
plished with a joint-less deck that is
durable.
5. Simply put, simple-span construc-
tion is a valuable tool for accelerated
bridge construction projects.
This study was limited in that only one
bridge was investigated. Other bridge con-
fgurations will yield different results. In
some cases, a continuous-girder bridge
may have a lower overall bridge cost. The
conclusion of the study is that simple-span
construction should not be ignored due to
concerns over the structural effciency of
the girders alone. When total bridge costs
are applied, this method can be competi-
tive or even less expensive than conven-
tional continuous-girder designs.


56 SEPTEMBER 2014
CROSSING
the Delaware BY JIM TALBOT
THE MOST FAMOUS CROSSING of the Delaware River happened in
1776, when America’s frst president, George Washington, brought troops
across the river in a surprise attack against Hessian Forces during the Amer-
ican Revolutionary War.
Nearly 40 years later, in September 1814, a covered span followed suit
and became the frst bridge to cross the Delaware River that connected New
Hope, Pa., and Lambertville, N.J., replacing Coryell's Ferry.
Designed by Lewis Wernwag, a German immigrant and pioneering
bridge-builder, the wooden covered bridge was 32 ft wide and had two
wagon lanes and two lanes for pedestrians. Flooding carried the bridge away
in January of 1841, and another food destroyed a second, similar bridge at
this site in 1903.
From Wood to Steel
This led to the construction of a steel, pin-connected Pratt truss bridge in
1904, the New Hope-Lambertville Bridge. Lewis F. Shoemaker and Com-
pany of Pottstown, Pa., built the bridge, listing R.G. Devlin as the engineer.
The cost: $63,818.81.
Today, the bridge carries 14,000 vehicles across the Delaware River daily;
roughly the same number of pedestrians cross the bridge on a single sum-
mer weekend day. No other bridge across the Delaware sees this level of
foot traffc. Tourists, residents, antique shoppers, bikers and others use the
crossing to take advantage of the many attractions offered by the two com-
munities on opposite banks.
The six-span bridge contains 962 tons of steel. Each nine-panel span
measures 171 ft, and the bridge has a total length of about 1,050 ft and a
roadway width of 20.3 ft. Vertical truss members measure 27 ft in height,
and abutments date back to the original 1814 bridge. Pedestrians cross on a
Our nation’s rich past was built on immovable
determination and innovation that found a highly
visible expression in the construction of steel
bridges. The Steel Centurions series offers a
testament to notable accomplishments of prior
generations and celebrates the durability and
strength of steel by showcasing bridges more than
100 years old that are still in service today.
STEEL CENTURIONS
SPANNING 100 YEARS
ST
E
E
L
C
E
N
T
U
R
I
O
N
S
A steel truss, at the site of one of the frst bridges over the Delaware River,
is still standing after numerous foods and more than 100 years of life.
Modern STEEL CONSTRUCTION 57
Jim Talbot is a freelance
technical writer living in Ambler,
Pa. You can reach him at
[email protected].
cantilevered walkway along its southern downstream side. Addi-
tionally, the bridge carries a pumped 8-in. sewer line to a treat-
ment plant located in Lambertville.
For its frst 15 years, tolls supported the bridge's operation
and maintenance, but now tolls on other bridges across the Dela-
ware support these activities, along with security. (The Delaware
River Joint Toll Bridge Commission, created in 1934, owns and
operates the bridge; the commission operates 20 Delaware River
bridges in all.) The bridge carried U.S. Route 202 over the Dela-
ware River until 1971, when the route was realigned to cross the
river upstream on a new bridge; it now carries Route 179.
Surviving the Flood
The food of August 1955—the greatest the Delaware River
had ever experienced—destroyed many of the structures cross-
ing it. The New Hope-Lambertville Bridge was one of the rare
survivors, though its No. 2 span was seriously damaged, forcing a
closure for fve weeks. In 2004, the bridge underwent an exten-
sive $7.7 million rehabilitation project, coinciding with its 100th
anniversary. This fgure included preliminary and fnal design,
public involvement, construction and oversight. It also funded
a free shuttle service for pedestrians, which operated when the
project closed the bridge to traffc on weekdays. On weekends,

construction stopped and the bridge reopened to minimize
economic impact to the two connected communities.
The centennial project replaced fooring systems, sidewalk
and handrails. The walkway was widened from 6 ft to 8 ft and
paneled with fberglass. Other improvements included mis-
cellaneous steel repairs, blast-cleaning, sewer line rehabilita-
tion and modifcations to safety and lighting. Painting crews
added three coats of "bridge green" anticorrosive polyure-
thane paint. The general contractor, J.D. Eckman, Inc., faced
H
i
s
t
o
r
i
c
B
r
i
d
g
e
s
.
o
r
g
J
i
m

T
a
l
b
o
t
The New Hope-Lambertville Bridge opened in 1904 and currently carries 14,000 vehicles across the Delaware River daily. Each of the
bridge's six spans measures 171 ft, and the total length is about 1,050 ft.Vertical truss members measure 27 ft in height, and abut-
ments date back to the original 1814 bridge.
58 SEPTEMBER 2014
with a $10,000 per day reward or penalty, completed
the project a week ahead of schedule.
As part of its security system, nine cameras on the
bridge now feed images to the commission's com-
mand center. Threats of food damage in 2005 and
2006 motivated the commission to install a radar-based
level sensor to the side of the bridge that measures the
river's height every 15 minutes and transmits the data
via satellite to the National Weather Service and other
entities. Biannual maintenance activity includes send-
ing divers underwater to inspect for defects, cracks and
scaling on the bridge's supports.
This past D-Day anniversary (June 6), mainte-
nance crews hung banners at both ends to commemo-
rate 200 years of bridge crossings over the Delaware
River. The banners had images of the steel truss bridge
as it appears today and the wooden bridge destroyed
in the great food of 1903. In addition, a flm cover-
ing the bridge's history premiered in April: The New
Hope-Lambertville Bridge, Connecting Two Towns, Span-
ning Two Centuries.
I
®
®
H
i
s
t
o
r
i
c
B
r
i
d
g
e
s
.
o
r
g
The six-span bridge contains 962 tons of steel.
In 2004, the bridge underwent an extensive $7.7
million rehabilitation project, coinciding with its
100th anniversary.
Vi si t us at www.ascsd.com or cal l 800.726.2727
HiForm

Grade 50 Composite Deck
provides longer unshored spans,
allowing for lighter gauge deck selection
Proven performance verifcation in
IAPMO UES ER-0329 code compliance report
f00f 80¢¢ll0f8 8f0 8 f0ß00ll0ß
0l ¶00f 00M¢8߶
P
h
o
t
o

C
o
u
r
t
e
s
y

o
f

S
a
c
r
a
m
e
n
t
o

I
n
t
e
r
n
a
t
i
o
n
a
l


A
i
r
p
o
r
t
At ASC Steel Deck, we add value to your supply chain
You
should
see
what
we
can do.
SteelDay
®
is an annual
event hosted by the
American Institute of
Steel Construction,
its members and
partners. Plan your
SteelDay
®
visits and
see first hand why it
makes sense to build
with structural steel.
@aisc
/AISCdotORG
/AISCsteelTV
American Institute of Steel Construction
One East Wacker Drive, Suite 700
Chicago, IL 60601
312.670.2400 www.aisc.org
There’s always a solution in steel.
SteelDay
It’s coming... 9.19.2014
www.SteelDay.org
60 SEPTEMBER 2014
news
People and Firms
• Vi ctor Technol ogi es wi l l
award more than $30,000 in
equipment and cash prizes
as part of i ts 2014 “A Cut
Above” student contest. The
contest is open to students in
cutting, welding and related
programs at secondary and
pos t - s econdar y s chool s .
Entri es are accepted now
through October 31, wi th
rules and entry forms available
at www.victortechnologies.
com/acutabove.
• Carney Engineering Group,
a multi-discipline structural
engineering firm serving the
Mid-Atlantic region, has hired
Eric Alwine as a structural
project manager. His previous
experiences include projects
ranging from the $110 million
renovati on of a hi stori cal
23-building campus to building
hotels and casinos in San Juan,
Puerto Rico.
• Dexter + Chaney, provider
of Spectrum Construction
Software, has unveiled its
new Proj ect Pl an Room
mobi l e app, whi ch al l ows
users to distribute construction
documents, communicate data
and relay project information
in real time to employees’ and
subcontractors’ mobile devices
on the job site. (Visit www.
dexterchaney.com.)
NSBA
Jeff Carlson Joins NSBA
as Western Regional Director
STEELDAY
SteelDay Gears up with Chicago High-Rise Tour
An 11-story, 157,000-sq.-ft steel residen-
tial high-rise known as Circa 922 is cur-
rently under construction just west of the
Chicago Loop. It’s the frst project in the
city to be built using the Girder-Slab sys-
tem, and AISC recently hosted a tour of
the building, which drew more than 100
construction professionals.
The project site tour and presentation
served as a “pre” SteelDay event, offer-
ing a sneak peak at the dozens of events
scheduled in Chicago and around the
country on SteelDay. Set for Friday, Sep-
tember 19, SteelDay is an annual event,
sponsored by AISC and hosted by its
members and partners, celebrating struc-
tural steel. It offers events all over the
country for AEC professionals, university
faculty and students and the general pub-
lic to get an inside look at how the struc-
tural steel industry works to build Amer-
ica. You can also keep up with SteelDay
updates and discussions via AISC’s social
media channels at www.facebook.com/
AISCdotORG, www.twitter.com/aisc
and www.youtube.com/AISCsteelTV.
The National Steel Bridge Alliance
welcomes Jeff Carlson, P.E., as its Western
Regional Director. Carlson is responsible
for working with state DOTs, bridge
design consultants and construction
professionals in Alaska, Arizona,
California, Colorado, Hawaii, Idaho,
Montana, Nevada, New
Mexico, Oregon, Utah,
Washington and Wyoming,
providing technical and
project assistance and
communicating the
advantages that structural
steel brings to bridge
projects.
“Jeff’s background
adds another dimension
and a fresh perspective
to the NSBA team,” said
Bill McEleney, NSBA’s
managing director. “His experience
dealing directly with owners will surely
be appreciated by our DOT colleagues
as we work to better quantify the life-
cycle advantages of steel bridges.”
Carlson brings more than a decade
of project management and engineering
experience to NSBA. Most recently,
he was a fnancial analyst and project
manager for Omni Development
Corporation in Denver, where he was
responsible for managing real estate
redevelopment projects, overseeing
several construction professionals,
providing fnancial
recommendations and
developing budgets for
presentations to the
owner. Prior to that, he
was a research analyst for
Cornerstone Real Estate
Advisors in Hartford,
Conn. Before entering
the real estate market, he
worked for six years as
a professional engineer
and project manager for
Martin/Martin Consulting
Engineers in Lakewood, Colo.
Carlson lives in Englewood, Colo.,
and can be reached at 720.440.3011 or
[email protected]. To view a
map of NSBA staff’s territories, visit the
NSBA website homepage (www.steel-
bridges.org).
Go to www.aisc.org/seminars
for more information.
$350 for Members,
$600 for Member + Buddy
(Sign up two people
and save $50 per registrant!)
The 2nd Edition
Seismic Design Manual
will be available for purchase
for $100
(a discount from $175 member price/
$350 non-member price)
The Louis F. Geschwindner Seminar
Seismic Design Manual and Application
of the 2010 AISC Seismic Provisions
Written by Thomas A. Sabol, S.E., Ph.D. | 0.8 CEUs/8.0 PDHs
2014
FALL
SEMINARS
There’s always a solution in steel.
American Institute of Steel Construction
One E Wacker Drive, Ste. 700
Chicago, IL 60601
www.aisc.org 312.670.2400
St. Louis, MO
New York, NY
Lexington, KY
Pittsburgh, PA
Batavia, NY
Hosted by ASCE Buffalo Section
Structures Committee
Richmond, VA
Long Beach, CA
9/30
10/7
10/14
10/21
11/4
11/11
12/4
62 SEPTEMBER 2014
news
Engineering Journal has replaced its digi-
tal edition browser with a single down-
loadable PDF fle at www.aisc.org/ej.
The current issue—third quarter 2014—
will be available for download and view-
ing until the next issue is posted.
Articles for the complete collection
of EJ will remain available individually
in the searchable archives. Downloads of
current and past articles in PDF format
are free to AISC members and ePubs
subscribers. Non-AISC members may
subscribe to EJ at the AISC bookstore.
The Q3 2014 of EJ is the second of
two issues with a special focus on the
“simple for dead load–continuous for
live load” (SDCL) design concept. The
premise behind the concept is that gird-
ers erected as simple spans can be made
to function under live load as continu-
ous spans by providing continuity with
a unique feld connection. In addition to
covering research, the issue highlights a
successful SDCL bridge project from the
engineer’s perspective.
Here are the Q3 articles:
➤ 2013-02
HSS Truss Connections with
Three Branches
Jeffrey A. Packer
Hollow structural section (HSS)
three-branch (or KT) connections fre-
quently occur in modifed Warren
trusses, but the design of these planar
welded connections is beyond the scope
of Chapter K of the 2010 AISC Specif-
cation for Structural Steel Buildings. Such
connections are also not covered by oth-
er contemporary HSS design guides and
standards. This paper reviews the many
potential member and loading arrange-
ments, for both gapped and overlapped
KT connections, and offers some design
guidance. A worked example for an over-
lapped square HSS KT connection is
then given, in both LRFD and ASD for-
mats, in accordance with the 2010 AISC
Specifcation for Structural Steel Buildings.
Keywords: Hollow structural sec-
tions, trusses, connections, KT, welded
joints, overlapping branches.
➤ 2012-25R
Field Application Case Studies and
Long-Term Monitoring of Bridges
Utilizing the Simple for Dead–
Continuous for Live Bridge System
Aaron Yakel and Atorod Azizinamini
The performance of three bridges
constructed using the SDCL bridge
system for steel girders was monitored
during and after construction to com-
pare actual performance with predicted
performance. The structure types were
a box-girder bridge, an I-girder bridge
and a box-girder bridge built using ac-
celerated construction details. During
construction, strains and defections
were monitored so that the degree of
continuity over the pier could be deter-
mined. The design concept assumes that
a simply supported condition exists dur-
ing casting of the concrete deck. How-
ever, to provide lateral bracing, the con-
crete diaphragm—or turndown—over
the pier is cast and cured prior to casting
the deck. As expected, encasement of the
girders provides some continuity over
the pier during casting of the deck. The
degree of continuity over the pier can be
reduced by lowering the height of the
construction joint and through the use
of crack-inducing details. Long-term
monitoring of the structures showed
the behavior to be consistent over time
with no signifcant deviations from the
predicted bridge behavior. During the
initial time period of approximately 18
months, a slight overall change in strain
values was observed in concrete ele-
ments. The rate of change slowed dur-
ing this period and eventually ceased.
Subsequently, the response of the struc-
ture has been consistent with only small
seasonal fuctuations observed. These
fuctuations are expected and are gener-
ally attributable to changes in ambient
temperature, relative humidity, incident
solar radiation and ground freeze/thaw
conditions.
Keywords: Steel bridges, steel gird-
ers, SDCL, simple for dead load, con-
tinuous for live load.
➤ 2012-26
Experimental Investigation, Ap-
plication and Monitoring of a
Simple for Dead Load–Continu-
ous for Live Load Connection for
Accelerated Modular Steel Bridge
Construction
Saeed Javidi, Aaron Yakel and Atorod
Azizinamini
The inherently modular nature of
the SDCL system makes it a natu-
ral ft for the accelerated construction
paradigm. A detail capable of connect-
ing pre-topped girders over the middle
supports is developed and described in
this paper. To evaluate the performance
of the proposed connection, a full-scale
specimen was built and subjected to
cyclic and ultimate load testing. The
connection showed very little change
during cyclic loading equivalent for
70 years of traffc. During the ultimate
load test, the connection demonstrated
large displacement ductility, reaching its
ultimate capacity after complete yield-
ing of the longitudinal reinforcement.
After the successful experimental test, a
feld application bridge was constructed
using a modular pre-topped steel box
girder system, which allows much of the
construction process to be performed
prior to placing the girders. The bridge
consisted of three pre-topped steel box
units placed side by side and connect-
ed using longitudinal joints between
pre-topped units. The steel box gird-
ers used 70-ksi high-performance steel
in the bottom fange and 50-ksi steel
in the top fanges and webs. The use of
high-performance steel combined with
the SDCL system allows eliminating
the need for section transitions through
the length of the structure and using
constant cross-section throughout the
length of the girders. Long-term moni-
toring of the structure was performed
and showed that the system worked as
intended.
Keywords: Steel bridges, steel gird-
ers, SDCL, simple for dead load, con-
tinuous for live load.
ENGINEERING JOURNAL
New Format for EJ; Q3 Now Available
Modern STEEL CONSTRUCTION 63
➤ 2013-03
Existing Simple Steel Spans Made
Continuous: A Retroft Scheme for
the I-476 Bridge over the Schuylkill
River
Daniel Griffth and John A. Milius
The rehabilitation of the SR 476
Bridge over the Schuylkill River near
Philadelphia converted existing steel
multi-girder simple spans into three- and
four-span continuous units. Employing a
design method typically used for construc-
tion of new simple-span-made-continuous
(SSMC) steel girder bridges, it is believed
to be the frst bridge rehabilitation project
in Pennsylvania to use such a scheme. The
rehabilitation design upgraded load capac-
ity of the girders to meet current LRFD
code requirements. The SSMC design,
coupled with other deck joint elimination
techniques, was able to reduce the com-
bined number of deck joints on the north-
bound and southbound structures from 25
to 8. With nearly all previous steel dete-
rioration occurring at deck joints, this sub-
stantial reduction in deck joints will aid in
extending the remaining life of the bridge.
This paper will illustrate the construc-
tion methods employed for conversion
of the bridge from multiple simple spans
to continuous spans. It will also provide
detailed insight into the many design re-
quirements for this structural conversion,
from substructure retrofts and sequential
bearing replacements to superstructure
continuity and full-depth concrete dia-
phragm details.
Keywords: Simple-span-made-con-
tinuous (SSMC), bridge rehabilitation,
modifed fxity conditions, steel wedge
plates, bolted steel splice plates, full-
depth concrete diaphragm, staged con-
struction, sequential bearing replace-
ment, steel bolsters.
letter
to the
editor
Evolving Innovation
While reading your July editori-
al, I could not help but think of
something I read in a book about
Steve Jobs. He hated marketing
studies. It was mentioned that if
Henry Ford would have asked a
focus group what they wanted, they
would have said a faster horse. Jobs
and Ford had the same idea. They
invented something that the public
did not even know they could not
live without. Innovation and evolu-
tion will continue. I think Girder-
Slab fits into this category.
We need to look from the out-
side into our operations, visualize
the future and look back to where
we are now.
—Daniel G. Fisher, Sr.
Managing Partner
Girder-Slab Technologies, LLC
marketplace Search employment ads online at www.modernsteel.com.
AISC Continuing Education Seminars
www.aisc.org/seminars.
“Like” AISC on Facebook
facebook.com/AISCdotORG
Follow AISC on Twitter
@AISC
Looking for something from an old issue of Modern Steel?
All of the issues from Modern Steel Construction’s
first 50 years are now available as free PDF downloads
at www.modernsteel.com/backissues.
AISC QUALITY CERTIFICATION
IT WORKS... DON’T WAIT!
For fabrication or erection help
Call Jim Mooney
your Quality Certification Connection
JAMES M. MOONEY & ASSOCIATES
941.223.4332 • [email protected]
Contract Auditor
Quality Management Company, LLC is seeking contractors to
conduct audits for the AISC Certified Fabricator and AISC Certified
Erector Programs. Contractors must have knowledge of quality
management practices as well as knowledge of audit principles,
practices and techniques and knowledge of the steel construction
industry. If you are interested, please submit your statement of
interest [email protected].
64 SEPTEMBER 2014
To advertise, call 231.228.2274 or e-mail [email protected].

Don Kidd or Steve Willems 670-779-1400
STRUCTURAL STEEL FACILITY AVAILABLE
Turn Key Opportunity including Business, Real Estate &
Equipment
* Approx. 150,000 SF under roof on 12 acres
* Rail serviced * AISC certified w/paint endorsement
* Located in SE PA w/close proximity to NY & Baltimore/
Washington metro areas
LATE MODEL STRUCTURAL
STEEL FABRICATING EQUIPMENT
Ficep 2004 DTT CNC Drilling & Thermal Coping Line, 78-3/4” x 24” Max. Beam,
3-Drill, Ficep Arianna CNC Control, 2003 #20382
Controlled Automation ABL-100-B CNC Flat Bar Detail Line, 143 Ton Punch,
400 Ton Single Cut Shear, 40’ Infeed, 1999 #24216
Peddinghaus Ocean Avenger II 1000-1 CNC Beam Drill, Siemens 840D CNC,
(1) Drill Head, 40” x 60’ Beam Capacity, 2004 #20877
Peddinghaus BDL1250 CNC Beam Drill, 50” Max. Beam, (3) 10 HP Spindles,
PC Ctrl (Upgrade 2005), 2000 #21739
Controlled Automation 2AT-175 CNC Plate Punch, 175 Ton, 30” x 60”Travel,
1-1/2” Max. Plate, PC CNC, 1996 #23503
Peddinghaus F1170B CNC Plate Punching Machine, 170 Ton, Fagor CNC, 30” x
60”Trvl., Triple Gag Head, Ext. Tables, 2005 #19659
Controlled Automation BT1-1433 CNC Oxy/Plasma Cutting System, 14’ x 33’,
(1) Oxy, (2) Hy-Def 200 Amp Plasma, 2002 #20654
Controlled Automation BFC-530 (5) Press CNC Beam Line, 36” Max. Beam,
Hem Saw, Conveyor, 1998 #24261
HEM DC-2038RB Double Column Horizontal Band Saw, 20” x 38”, 45-60 Deg.
Miter, 2” Blade, 15 HP, 75-400 SFPM, 2006 #22215
Phone: 631.249.5566 | Fax: 631.249.9494 | [email protected]
Visit www.PrestigeEquipment.com for our inventory & services
Looking for the latest information on
AISC Certification Programs?
Visit www.aisc.org/certification
Email [email protected]
or call 312.670.7520
employment
To advertise, call 231.228.2274 or e-mail [email protected].
Search employment ads online at www.modernsteel.com.
ProCounsel, a member of AISC, can market your skills
and achievements (without identifying you) to any city
or state in the United States. We communicate with
over 3,000 steel fabricators nationwide. The employer
pays the employment fee and the interviewing and
relocation expenses. If you’ve been thinking of making
a change, now is the time to do it. Our target, for you,
is the right job, in the right location, at the right money.
RECRUITER IN STRUCTURAL MISCELLANEOUS
STEEL FABRICATION
Buzz Taylor
PROCOUNSEL
Toll free: 866-289-7833 or 214-741-3014
Fax: 214-741-3019
[email protected]
Modern STEEL CONSTRUCTION 65
Connection Design Engineer
International Design Services is seeking a steel
connection design engineer for our St. Louis office.
Minimum 4 years of experience and the ability to obtain a PE license. Working
knowledge of Mathcad is preferred. Candidate will have experience managing
others and will be responsible for the production of an engineering team.
Candidate must also skillfully interact with the detailing team, fabricator, general
contractor and EOR. IDS offers a benefits package, competitive salary, and
relocation allowance. SE license is strongly preferred.
Please call 314-872-1791 or email your resume to [email protected].
Paxton & Vierling Steel (PVS), a steel fabricator established in 1885
and located in Omaha, Nebraska, is currently recruiting structural steel
estimators and detailers. PVS is an AISC and ISO certified steel fabricator
who’s quality program is compliant with Canadian Weld Bureau and
NQA-1 (nuclear) requirements. PVS’ specialty is industrial and
nuclear projects throughout North America.
For information on our company please visit www.PVSteelFab.com.
Please send your resume to [email protected].
Project Manager
Lenex Steel Company is currently seeking Project Managers to join our
team in the Indianapolis and/or Chicago markets. The Project Manager
has overall responsibility for managing projects from pre-award through
completion and managing project engineers and field project managers.
The ideal candidate has a degree in engineering or building construction
management with structural steel experience. Lenex Steel offers
competitive salaries and a comprehensive benefits package.
Email resume to [email protected].
Lincoln Engineering Group is one of the fastest growing steel detailing
firms in the country located in beautiful Chicago area. We currently have
immediate openings for experienced Project Managers and checkers.
Ideal candidate would have 5 years’ experience in Structural and
Miscellaneous steel detailing and checking, as well as, knowledge
of applicable codes. He/she should be a team leader with excellent
communication skills. Knowledge of CAD & 3D Software such as SDS/2
or Tekla, and Miscellaneous Steel Detailing is a plus but not a must!
We offer a competitive compensation and benefits package.
May consider relocation allowance for the right candidate.
Please submit your Résumé to: [email protected] or
Contact Salah Bassiouny at (630) 445-2111.
Structural Steel Detailing
Project Managers
and Checkers
Estimators • Detailers • Project Managers
West Coast Iron, Inc. has specialized in the detailing, fabrication,
and erection of structural steel, stairs and miscellaneous metals for
some of Southern California’s most prominent and successful general
contractors for over 25 years. We are currently seeking Project
Managers & Estimators with 5 years’ experience in structural steel,
miscellaneous metals, and metal deck and experienced Detailers with
a minimum of 3 years’ experience with TEKLA software to join our
team. West Coast Iron offers competitive salaries and a comprehensive
benefits package.
Please send your resume to
[email protected]
Structural Engineers
Are you looking for a new and exciting opportunity in 2014?
We are a niche recruiter that specializes in matching great structural
engineers with unique opportunities that will help you utilize your talents
and achieve your goals.
• We are structural engineers by background and enjoy helping other
structural engineers find their “Dream Jobs.”
• We have over 30 years of experience working with structural engineers.
• We will save you time in your job search and provide additional
information and help during the process of finding a new job.
• For Current Openings, please visit our website and select Hot Jobs.
• Please call or e-mail Brian Quinn, P.E.
([email protected] or 616.546.9420) so we can
learn more about your goals and interests. All inquiries are kept confidential.
SE Impact by SE Solutions, LLC
www.FindYourEngineer.com
66 SEPTEMBER 2014
A STUNNING MEMORIAL on the State Capitol grounds
in Saint Paul honors the sacrifice of Minnesota firefighters
killed in the line of duty. Designed by Leo A Daly, the memorial
houses the Minnesota Firefighter Memorial Statue, previously
on display at Minneapolis-Saint Paul International Airport.
A large steel monolith hovers above the statue, forming a
pavilion, and a field of light steel columns supports its weight.
The weathering steel of the monolith presents a rich patina,
evolving in a slow process analogous to the rapid oxidation of
fire. The organizing grid of 100 potential columns represents
a century—10 decades by 10 years per decade. There are cur-
rently 86 columns, recording the years in which Minnesota
firefighters have died in the line of duty, and names of the fallen
are inscribed on the columns. Over time, the assemblage will
accumulate additional inscriptions, and new columns will appear
as future firefighter deaths occur in years not yet plotted.
The column-to-monolith connections contain a pipe-
sleeve that joins the upper and lower faces of the monolith;
this sleeve allows the column to support both surfaces and also
joins the two surfaces. The slender columns were made stable
by designing the base and the top connection to be fixed, and
the foundation was designed as a mat slab to accommodate
the nontraditional column layout; this further accommodated
a fixed base plate connection with pretensioned bolts. The
sleeved connection at the top of the column allows fixity in
that it accommodates a spanning knife-plate. The plate’s short
span, in conjunction with the sleeve’s engagement of both
planes, was stiff in both bending and torsion. ■
structurally
sound
IN THE LINE
OF DUTY
Strong Structures Come
From Strong Designs
© 2014 Bentley Systems, Incorporated. Bentley, the “B” Bentley logo, ProjectWise and MicroStation are either registered or unregistered
trademarks or service marks of Bentley Systems, Incorporated or one of its direct or indirect wholly owned subsidiaries. Other brands and product
names are trademarks of their respective owners.
Build it with Bentley! Integrated projects,
teams and software.
Bentley’s Structural Software provides you the tools you need for strong designs and supports
an integrated workflow all the way around. Having all the applications you need for the tasks
at hand, along with the ability to easily synchronize your work with the rest of the project team,
helps you get your job done right, fast and profitably.
Visit www.bentley.com/Structural
to learn more!
With RAM

, STAAD
®
and ProStructures,
Bentley offers proven applications for:
· Metal ßuildings
· Steel/Steel Couposite
· Aluuinuu
· Feinforced Concrete
· Foundation üesign
· Steel Connections
· Structural ürawings and üetails
. all easily coordinated with the
Architect and other teau ueubers
and their design applications -
such as AutoCAü, Fevit, MicroStation
®
and uore.

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close