WORKS OF ERECTION ENGINEER tools, machinery, consumables
of work of safety items
progress review meeting erection work have full set of drawings bolts are tightened the structures
Guiding Should Aware
of type of joints
SEQUENCE OF ERECTION
Position Weight Braced Erect
of structures column
steel packing plates of foundation nut with guy rope erection/side runners
Alignment Tightening Tightening Crane
management AND CURING rail alignment erection
GROUTING Crane Crane
Permissible deviations in pitch and gauge of holes for bolts of normal accuracy (high Permissible deviations in each strength bolts Description Hole diam eter Permissible (m ) m Deviations in group of holes included Spacing (m ) m
Carbon Steel 1 a) Deviation in the hole diameter b)Ovality (difference b etween the biggest and the sm allest diameter) c) Curves, exceeding 1mm and cracks on the hole edges d) (i)Non -coincidence of holes in separate details of the assem bled unit, upto 1m m (ii) Above 1 m upto m 1.5 m m e) Slope of axis 2 Upto 17.0 Above 17.0 3 4 +1 +1.5 +1 +1.5 _ No lim its Low Alloyed Steel 5
Upto 17.0; Above 17.0; _
No lim its
Not Perm issible
_ Upto 30%of the thickness of unit
Upto 10% No lim its
Upto 10% No lim its
TOLERANCE OF ASSEMBLED COMPONENTS OF STRUCTURES
Description of Deviation(±) in mm for the Elements of Structures Components of Length in Metres
Structures Up to 1 1 2 I.i) Deviations from the dimensions assembled. Length & width of the Details Cut : a) Manual gas Cutting as 3 per marking b) With shears or with a saw as per marking2 c) With shears or with a saw with a stop 1.5 d) Machine Gas Cutting 2 ii)Length and width of planed ends 1 processed on Edge Pla Machine ning II i) Distance between the Centres of the End holes. a) Drilled according to marking 2 1 to 5 3 5 to 10 4 10 to 15 5 15 to 20 6 20 to 25 7 Over 25 8
3.5 2.5 2 2.5 1.5
4 3 2.5 3 2
4.5 3.5 3 3.5 2.5
5 4 3.5 4 3
b) Drilled according to a gauge with 1 bushing ii)Distance between the centres of adjacent holes a) Drilled according to marking or to a 1.5 gauge b) Drilled according to a gauge with 0.5 bushings III. Deviation in the dimensions of despatch elements after completion of fabrication, Assembled in positio or in ners other Devices with clamps in fixed positioners and also a) According to guide blocks with pins. 2 b) Assembled with bolts 3 c) Size (length & width) between Milled 1 surface (for all cases of assembly) d) The same made in separate details 2 during machining & fixed during the assembling work with clamps e) The same drilled according to 1 positioners in finished structures
3 5 1.5 3 1.5
5 8 2 5 2
7 11 2.5 7 2.5
8 12 3 8 3
9 14 3.5 9 3.5
10 15 4 10 4
P R IS IB E EM S L D sc ip n e r tio A . a ) S u re qa Jo ts: in
D V T NINA S M L O W L E JO T : E IA IO S E B Y F E D D IN S P r issib e m le d v tio e ia n -b tt u ±1m m Se h k tc
G pb tw e a e en th e d o e ns f p te (d la s ) S p in o te p g f o ep teo e n la v r th o e (s) e th r S g Ve in le e g o e Jo ts ro v in (w o t ith u b c in strip ak g ):
a ) b ) c )
Bv la g e e n le (A º) G pb tw e a e en tw P te (d o la s ) S p in o te p g f o ep teo e n la v r th o e (s) e th r R o th k e o t ic n ss (t)
±5 º ±1m m 2m m
C . a )
D u leV ob g o eJo t: ro v in S p in o o e te p g f n p teo e th la v r e o e (s th rs ) D v tio inth e ia n e v lu o R o a e f ot th k e s (t) ic n s D v tio in e ia n B v l a g (A e e n le º) D v tio in e ia n v lu o G p(d a e f a ) L pJo ts a in : O e p(B v rla ) G pb tw e th a e en e s rfa e (e u cs ) 2m m
c ) d ) D . a ) b )
±5 º ±1m m
5m m 1m m
E . a )
T efille J e t o G pb tw e th a e en e e g o th w b de f e e a dth s rfa e n eu c o th fla g (e f e ne )
in : ts 2m m
Sl No. A. 1.
TOLERANCES IN ERECTED STEEL STRUCTURES
Description COLUMNS Deviation of column axes at foundation top level with respect to true axes. i) In Longitudinal direction ±5 ii) In Lateral direction ±5 ±5 Deviation in the level of bearing surface of columns at foundation top with respect to true level Out of plumbness (verticality) of column axis from true vertical axis and measured at column top : a) For columns without any special requirements : i) Upto and including 30m ii) Over 30 m height
±H/1000 25mm height whichever is less ± H/1200 Or ± 35mm maximum
b) For column with special requirements like cranes or such similar requirements : i) Upto and including 30m ii) Over 30 m height 4. Deviation in straightness in longitudinal & transverse planes of columns, at any point along the height Difference in the erected position of adjacent pairs of columns along length or across width of building, prior to connecting trusses / beams, with respect to true distance. Deviation in any bearing or seating level with respect to true lev el. Difference in bearing levels of a member on adjacent pair of columns both across and along the building, from the true difference.
±H/1000 or ± 20mm height whichever is less ± H/1500 or ± 25mm maximum ± H/1000or ± 10mm whichever is less ±5
5. 6. 7.
NOTE :i) Tolerance specified under 3(a) and 3(b) should be read in conjunction with 4 and 5. ii) "H" abo ve is the column height in mm.
3. 4. 5.
TRU SSE S S h ift, at the centre of top chord m em ber of o f h eight sp an in m m or ± 1/250 truss w ith respect to th e centre of span mrm w hich ever is less ± 15 o vertical plan e p assin g th rou gh th e centre of bottom cho rd. L ateral shift of to p ch ord at th e centre o f of truss sp an from th e v ertical ± 1/1500 of span of tru ss in m m or ± plane p assin g throu gh the centre of suppo rtshich ev er is less mm w of the truss. L ateral shift in ation o f truss from its tru e loc vertical p osition. ± 10 L ateral shift in location o f pu rlins from5 true ± position . D eviation in difference of bearin g lev /12 00 o r 20 m m w hich ever is less L els of 18 trusses or b eam from th e true 18 (L = span ) difference.
C 1. 2. 3.
CRANE GIRDERS & RAILS Shift in the centre line of crane rail with respect to centre line of web of crane girder. Shift in plan of alignment of crane rail with respect to true axis of crane rail at any p oint. Deviation in crane track gauge with respect to true gauge : i) For track gauge upto and including 15 m. ii)For track gauge more than 15 m. Deviation in the crane rail level at any point from true level. Difference in levels between crane track rails (across the bay) at i) Supports of crane girders ii)Mid span of crane girders Relat ive shift of crane subject to rail surface at a joint grinding of surface both in plan and elevation for smooth transition Relative shift in the track location of crane stops (end buffers) along the crane tracks, along track ± (web thickness in mm + 2 ) / 2 ±5
±5 ± ( 5+0.25(S -15) ), subject to minimum of +10 mm, where S is the true track gauge ( in metre ) ± 10
15 20 2 mm 1/1000 of gauge S in mm subject to maximum of 20 mm gauge.
D. 1. E. 1. 2. 3.
CHIMNEY & TOWERS Out of plumbness (from the true vertical 1/1000 of the height axis ) of the chimney or tower in mm BUNKERS Deviation in length of length. Deviation in width of width Deviation in height of height bunker from true ± 1/1000 of length in mm bunker from true ± 1/1000 of width in mm bunker from true 1/1000 of height in mm ±
NOTES: 1. The tolerances specified do not apply to st structures where deviations from eel true positions are intimately linked with or directly influence the technological process. In such cases, the tolerances on erected steel structures shall be as per recommendations of process technologists / equi suppliers. pment 2. The observed or calculated values of deviations of steel structures from their true 20 positions shall be rounded off in accordance with IS:2 for comparison with -1960 20 permissible tolerances specified in this table. Tnumber of significant places he retained in the rounded value should be same as that specified in this table. -off