Pile Foundation

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FOUNDATION ENGINEERING
Pile Foundation

Luthfi Hasan
Geotechnical expert

Reg : 1.2.500.2.31.09.03.02978

Prospek Teknik Sipil
p 

p 

Bidang Pembangunan Infrastruktur
n 

Konsultan

n 

Kontraktor

Bidang Pemerintahan
n 

Departemen/Dinas P.U

n 

Departemen ESDM

n 

Dinas Tata Kota

n 

Bapenas, Bapeda

n 

Dinas Ketenagakerjaan

Reg : 1.2.500.2.31.09.03.02978

Prospek Teknik Sipil
p 

p 

p 

Bidang Industri Enerji & Pertambangan
n 

Manajer & CEO

n 

Quality Auditor

n 

Quality Assurace Manager

n 

Pertamina, PLN, freeport, Pupuk Kaltim

Bidang Pendidikan
n 

Pengajar

n 

Peneliti

Bidang lainnya
n 

Perbankan

n 

Asuransi
Reg : 1.2.500.2.31.09.03.02978

Yang harus disiapkan
p 

Penguasaan materi Teknik Sipil

p 

Kemampuan digital/komputer

p 

Kemampuan bahasa Inggris minimal pasif

p 

Soft skill/organisasi

Reg : 1.2.500.2.31.09.03.02978

Bidang Teknik Sipil
p  Struktur
p  Geoteknik
p  Transportasi
p  Sumber

Daya Air

p  Manajemen

Konstruksi

Reg : 1.2.500.2.31.09.03.02978

Penguasaan materi
Hadir
Kuliah &
aktif

maksimal
SKS

SUCCESS

Reg : 1.2.500.2.31.09.03.02978

Proporsi penilaian
35 % UTS

Penilaian

50 % UAS
15 % kehadiran ≥ 10 kali

Target
pencapaian

p 

Mengetahui dasar fondasi dalam

p 

Mampu mendesain fondasi dalam
(pile foundation)
Reg : 1.2.500.2.31.09.03.02978

FOUNDATION ENGINEERING
(pile foundation)

Contents
Part one :
p 

Pengertian Geotechnical Project

p 

Penentuan fondasi dangkal & dalam

p 

Jenis Pile foundations

p 

Mekanisme transfer beban pada pile foundations

p 

Pengertian kapasitas fondasi (pile capacity)

p 

Pile capacity di tanah non kohesif (sand)
(end bearing & friction)

p 

Pile capacity di tanah kohesif (clay)
(end bearing & friction)
Reg : 1.2.500.2.31.09.03.02978

FOUNDATION ENGINEERING
(pile foundation)

Contents
Part two :
p 

Pile capacity berdasarkan data CPT dan SPT

p 

Pemancangan (pile driving)

p 

Uji beban (pile load test)

p 

Pile groups

p 

Penurunan (settlement of pile groups)

p 

Bored piles

Reg : 1.2.500.2.31.09.03.02978

Main References
p 

Das, B.M. (2002). Principles of
Geotechnical Engineering, 5th edition,
Brooks/Cole Thomson Learning

p 

Das, B.M. (2004). Principles of Foundation
Engineering, 5th edition, Brooks/Cole
Thomson Learning

Reg : 1.2.500.2.31.09.03.02978

Part One

Reg : 1.2.500.2.31.09.03.02978

Typical Geotechnical Project
Geo-Laboratory
~ for testing

soil properties

Design Office
~ for design & analysis

Soil
mechanics

construction site

Reg : 1.2.500.2.31.09.03.02978

Shallow & Deep
Foundations

Reg : 1.2.500.2.31.09.03.02978

FOUNDATION
load
Foundation

Soil
Condition
Reg : 1.2.500.2.31.09.03.02978

Shallow Foundations
~ for transferring building loads to underlying ground
~ mostly for firm soils or light loads

firm
ground
bed rock

Reg : 1.2.500.2.31.09.03.02978

Deep Foundations
~ for transferring building loads to underlying ground
~ mostly for weak soils or heavy loads

P
I
L
E

weak soil

bed rock

Reg : 1.2.500.2.31.09.03.02978

Perbedaan F. Dangkal & F. Dalam
F. Dangkal

F. Dalam

D/B

Kecil

Besar

Keruntuhan

Sampai
permukaan
tanah

Di dalam
tanah

Digali

Dipancang/
dibor

Instalasi

Reg : 1.2.500.2.31.09.03.02978

Analisis jenis fondasi
Besar

Kecil

Dalam

Fondasi
Dalam

F. Dalam
F. Dangkal

Dangkal

Lapis tanah stabil

Beban

F. Dalam
F. Dangkal

Fondasi
Dangkal

Reg : 1.2.500.2.31.09.03.02978

Pile Foundations

Reg : 1.2.500.2.31.09.03.02978

Pile Foundations
p 

Piles are relatively long and slender members used to
transmit foundation loads through soil strata of low
bearing capacity to deeper soil or rock having a higher
bearing capacity.

p 

Pile resistance is comprised of
n  end bearing
n  shaft friction

p 

For many piles only one of these components is
important. This is the basis of a simple classification
Reg : 1.2.500.2.31.09.03.02978

Use of pile foundations
When one or more upper soil layers are highly
compressible and too weak to support the load
transmitted by the superstructure. Piles are used to
transmit the load to underlying bedrock or a
stronger soil layer

When bedrock is not encountered at a reasonable depth
below the ground surface, piles are used to transmit the
structural load to the soil gradually. The resistance to the
applied structural load is derived mainly from the
frictional resistance developed at the soil-pile interface

Reg : 1.2.500.2.31.09.03.02978

Use of pile foundations
When subjected to horizontal forces, pile
foundation resist by bending , while still
supporting the vertical load transmitted by the
superstructure

The foundations of some structures, such as
transmission towers, offshore platforms and basement
mats below the water table, are subjected to uplifting
forces. Piles are sometimes used for these foundations
to resist the uplifting force

Reg : 1.2.500.2.31.09.03.02978

Use of pile foundations

Bridge abutments and piers are usually are
usually constructed over pile foundations to
avoid the loss of bearing capacity that a
shallow foundation might suffer because of
soil erosion at the ground surface

Reg : 1.2.500.2.31.09.03.02978

Deep Foundations

Reg : 1.2.500.2.31.09.03.02978

Pile foundation

Tall buildings need
piles down to the
rock bed to transfer
the loads directly to
the solid part in the
earth to avoid
uneven settlement
Reg : 1.2.500.2.31.09.03.02978

Jembatan Suramadu

Sisi Surabaya

Sisi Madura
Total panjang jembatan 5438m

Causeway

Cable Stayed 818m
Approach
Approach

Causeway

Reg : 1.2.500.2.31.09.03.02978

PONDASI CABLE STAYED BRIDGE

20 m

15 m

100 m

100 m

56 Tiang

Diameter 2.4 m

Reg : 1.2.500.2.31.09.03.02978

Sutong Bridge - China
1088m

60m

Pondasi:
Panjang = 130m
Diameter = 3.2m - 60m pertama
2.8m - sisanya
Jumlah = 131 tiang

Reg : 1.2.500.2.31.09.03.02978

Piled Foundations

Reg : 1.2.500.2.31.09.03.02978

Pile

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Jembatan Cikubang

Reg : 1.2.500.2.31.09.03.02978

Jembatan Suramadu

Reg : 1.2.500.2.31.09.03.02978

Ciujung

Reg : 1.2.500.2.31.09.03.02978

Type of Pile Foundations

Reg : 1.2.500.2.31.09.03.02978

Types of Piles

Concrete

Steel
Pipe

Timber

Steel H

Pre-cast
Concrete

Composite

Reg : 1.2.500.2.31.09.03.02978

Steel piles
p 

Discription
n 
n 

p 

Advantages
n 
n 
n 
n 

p 

Usual length 15-60 m
Usual load 300-1200 kN
Easy to handle with respect to cut off and extension to the
desired length
Can stand high driving stress
Can penetrate hard layers
High load-carrying capacity

Disadvantages
n 
n 
n 
n 

Relatively costly
High level of noise during driving
Subject to corrosion
H-piles may be damaged or deflected during driving through
hard layers
Reg : 1.2.500.2.31.09.03.02978

Concrete piles
p  Precast

piles

n 

Using ordinary reinforcement

n 

Prestressed : using high-strength steel
prestressing cable

p  Cast-in-situ

piles

Reg : 1.2.500.2.31.09.03.02978

Concrete piles
p 

Discription
n 
n 

p 

Advantages
n 
n 
n 
n 

p 

Usual length 10-15m (press : 10-45m)
Usual load 300-3000 kN (press : 7500-8500 kN)
Can be subjected to hard driving
Corrosion resistant
Can be easily combined with a concrete superstructure
High load-carrying capacity

Disadvantages
n 
n 

Difficult to achieve proper cutoff
Difficult to transport

Reg : 1.2.500.2.31.09.03.02978

Steps in Rational Pile Selection
p 

Adequate Subsurface Investigation

p 

Soil Profile Development

p 

Appropriate Lab/Field Testing

p 

Selection of Soil Design Parameters

p 

Static Analysis

p 

Applied Experience

Reg : 1.2.500.2.31.09.03.02978

Load Magnitude
Deep foundation
type

Typical range of
nominal (ultimate)
resistance (kips)

Typical length
(feet)

Timber pile

75 – 200

20 – 40

Concrete pile

200 – 2,000

20 – 150

Steel H-pile

200 – 1,000

20 – 160

Pipe pile

175 – 2,500

20 – 100

Drilled shaft

750 – 10,000

20 – 160
Reg : 1.2.500.2.31.09.03.02978

What is a Driven Pile?
A Driven Pile is a deep
foundation that is constructed
by driving a concrete, steel or
timber pile to support the
anticipated loads in competent
subsurface material.

Reg : 1.2.500.2.31.09.03.02978

Driven Low Displacement Piles

Reg : 1.2.500.2.31.09.03.02978

Driven High Displacement Piles

Reg : 1.2.500.2.31.09.03.02978

Drilled Shafts (bored piles)

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Driven & Bored Pile
Jenis

Keunggulan

Kekurangan

Driven pile
(Precast pile)

Kualitas terjamin
Dynamic pile capacity
Pelaksanaan singkat
Displacement pile
Human error kecil

Vibrasi saat driving

Tanpa vibrasi
Non displacement pile

Kualitas perlu ketelitian
Non dynamic pile capacity
Pelaksanaan cukup lama
Human error relatif besar

Bored pile
(cast insitu)

Reg : 1.2.500.2.31.09.03.02978

Type of piles based on installation
p  Non

displacement pile (bored pile)

p  Displacement
p  Extra

pile ( driven pile)

displacement pile ( franki ple)

Reg : 1.2.500.2.31.09.03.02978

Pile capacity

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Reg : 1.2.500.2.31.09.03.02978

Ultimate Bearing Capacity Static Formula Method (Qu = Qp + Qs)
Qu = Ultimate Bearing Capacity

Qs = fAs

Embedded
Length

=D

f = Unit Frictional
Resistance
AS = Shaft Area
qP = Unit Bearing
Capacity
AP = Area of Point

QP = qPAP

Reg : 1.2.500.2.31.09.03.02978

Qu
ΔL1

QS1

ΔL2

QS2

Layer 2

ΔL3

QS3

Layer 3

QS4

Layer 4

ΔL4

Layer 1

Qu = ΣQs+Qp

Qp
Reg : 1.2.500.2.31.09.03.02978

End Bearing or Friction?
END BEARING

FRICTION

LOAD

LOAD

L
O
A
D

SANDS

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SOFT
CLAYS

L
L
O
O
A
A
D
D

SANDS
SANDS

CLAYS
CLAYS

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ROCK

SAND
Reg : 1.2.500.2.31.09.03.02978

Method of Support
End Bearing

Side Friction

Combined

Reg : 1.2.500.2.31.09.03.02978

Mekanisme trasfer beban
p 

Tahanan friksi (gesekan permukaan) termobilisasi penuh
jika telah terjadi displacement sebesar :
● 5-10 mm (0,2-0,3 inch)……………..B.M. Das
● 0,30 – 1% lebar/diameter tiang …..Tomlinson

p 

Tahanan ujung termobilisasi penuh jika telah terjadi
displacement sebesar
● 10-25% lebar/diameter tiang ……….B.M. Das
● 10-20% lebar/diameter tiang ……….Tomlinson

Reg : 1.2.500.2.31.09.03.02978

Ultimate Bearing Capacity Static Formula Method
Qu = Ultimate Bearing Capacity

Qu = Qp + Qs

Embedded
Length

=D

Qs = fAs
f = Unit Frictional
Resistance
AS = Shaft Area
qP = Unit Bearing
Capacity
AP = Area of Point

QP = qPAP

Reg : 1.2.500.2.31.09.03.02978

End Bearing Piles

PILES

SOFT SOIL

ROCK

Reg : 1.2.500.2.31.09.03.02978

Friction Piles

PILES

SOFT SOIL

Strength
increases
with depth

Reg : 1.2.500.2.31.09.03.02978

Mekanisme keruntuhan

Terzaghi

Meyerhof

Vesic

Skempton

Reg : 1.2.500.2.31.09.03.02978

Luthfi Hasan (1998)

Reg : 1.2.500.2.31.09.03.02978

Arching at Pile Tip

Ground Surface

B
Arching Action D
f
Zone of
Shear &
Volume
Decrease

PO = αγDf

γDf

Reg : 1.2.500.2.31.09.03.02978

Loads applied to Piles
V
p 

Combinations of vertical, horizontal and moment
loading may be applied at the soil surface from
the overlying structure

p 

For the majority of foundations the loads applied
to the piles are primarily vertical

p 

For piles in jetties, foundations for bridge piers,
tall chimneys, and offshore piled foundations the
lateral resistance is an important consideration

p 

The analysis of piles subjected to lateral and
moment loading is more complex than simple
vertical loading because of the soil-structure
interaction.

M
H

Reg : 1.2.500.2.31.09.03.02978

Estimation of Pile Capacity

Reg : 1.2.500.2.31.09.03.02978

Tahapan desain
p 

Mengusahakan data tanah melalui soil investigation,
berupa :
- Cone Penetration Test (CPT = Sondir)
- Standard Penetration Test (SPT)
- Boring (pengambilan sampel tanah)

p 

Melakukan survei tentang kedalaman fondasi tiang pada
bangunan sekitarnya

Reg : 1.2.500.2.31.09.03.02978

Tahapan desain (lanjutan)
p 

Melakukan estimasi kapasitas fondasi tiang tunggal
menggunakan static formula, berdasarkan data:
- Cone Penetration Test (CPT)
- Standard Penetration Test (SPT)
- Hasil uji laboratorium
- Korelasi dari berbagai data diatas

p 

Melakukan estimasi kelompok tiang berdasarkan hasil
estimasi tiang tunggal dan beban kolom yang harus
ditahan

Reg : 1.2.500.2.31.09.03.02978

Tahapan desain (lanjutan)
p 

Melaksanakan pile driving dengan menggunakan
dynamic formula berdasarkan estimasi nilai static
formula. Menentukan kapasitas tiang yang digunakan

p 

Melaksanakan pile load test bagi fondasi tiang yang
meragukan.

Reg : 1.2.500.2.31.09.03.02978

Estimasi kapasitas tiang
Q u = Q p + Qs − ( W )

Q u = A p .q p + A s .q s
Qall =

A p .q p
SF1

As .q s
+
SF2

Qp

Tahanan ujung end bearing)

Qs

Tahanan friksi (friction resistance)

qp

Unit daya dukung

qs

Unit tahanan friksi

SF1 Angka keamanan untuk tahananujung
SF2 Angka keamanan untuk tahanan friksi
Reg : 1.2.500.2.31.09.03.02978

Menghitung tahanan ujung (end bearing)
Q p = A p .q p
Terzaghi

_

q u = 1,3.c.N c + q N q + 0,4.B.γ.N γ
_

q u = 1,3.c.N c + q N q + 0,3.B.γ.N γ

Square footing
Circular footing

Meyerhof

_

q u = c.N c .Fcs .Fcd + q N q .Fqs .Fqd + 0,5.B.γ.N γ .Fγs .Fγd

Reg : 1.2.500.2.31.09.03.02978

Menghitung tahanan ujung (end bearing)
Deep foundation
General equation

q p = c.N*c

_

+ q .N*q + γ.B.N*γ

N*c , N*q , N*γ Bearing capacity factors
Nilai B atau D kecil

γ.B.N*γ ≈ 0

*
q
=
c
.
N
Sehingga : p
c

_

+ q .N*q

*
Q p = A p (c.N c

_

*

+ q .N q )
Reg : 1.2.500.2.31.09.03.02978

DAYA DUKUNG AKSIAL

Qs =Σ2πr Δl (α C)
+ Σ2πr Δl (k σv tanδ)
Δl
κ σv

Qu = Qp + Qs

Qall =

Qu
F.S.

σv

Qp =Ap(c Nc +q Nq)
Reg : 1.2.500.2.31.09.03.02978

Bearing Capacity Factors for Deep Foundations (Meyerhof, 1976)
1000
800
600
400
200

and

100
80
60
40
20
10
8
6
4
2
1

0

10

20

30

40

45

S oil
 friction
  a ngle,
 
  Ø
 
  (deg)
Reg : 1.2.500.2.31.09.03.02978

Tahanan ujung tiang pada tanah pasir
Tanah pasir c = 0 , sehingga :

Q p = A p .q p
_

Q p = A p . q .N*q

_

q = ∑ γh

Meyerhof’s
Method :

Loose

L=LB

L
LB

Dense

Reg : 1.2.500.2.31.09.03.02978

Tahanan ujung tiang pada tanah pasir
qp akan naik sejalan dengan naiknya LB dan akan maksimum pada :

L B ⎛ L B ⎞
= ⎜
⎟
D ⎝ D ⎠critic
Dibawah (Lb/D)cr digunakan qp
Diatas (Lb/D)cr
digunakan qp = qL (limit/batas)
_

Sehingga :

Q p = A p . q .N*q ≤ A p .q L

q L = 50.N*q . tan φ

kN/m2

q L = 5.N*q . tan φ

T/m2

q L = 1000.N*q . tan φ lb/ft2
Reg : 1.2.500.2.31.09.03.02978

Cases
Case-1
Kedalaman tiang 305x305 mm adalah 12 m. Tanah pasir homogen dengan
γb=16,8 kN/m3, φ = 35o. Hitung nilai tahanan ujung tiang (Qp) dengan cara
Meyerhof

Case-2
5m

loose



13 m

4m

γb=15,7 kN/m3
φ = 30o
c=0
kN/m3

loose

γsat=18,1
φ = 30o
c=0

dense

γsat=19,4 kN/m3
φ = 40o
c=0

Dimensi fondasi : 309 X 309 mm2
Hitunglah : Qp

Reg : 1.2.500.2.31.09.03.02978

Menghitung tahanan friksi (friction)
General :

Qs = ∑ p.ΔL.f

p

= perimeter (keliling tiang)

ΔL

= unit panjang tiang

∑p. ΔL = luas selimut tiang
f =qs

= unit tahanan friksi

f = K.σ'v . tan δ
K = Koefisien tekanan tanah
σ’v = Tegangan efektif vertikal pada kedalaman yang
ditinjau, dianggap konstan setelah kedalaman 15D
(Meyerhof) atau 10D (Schmertmann)
δ
= Sudut gesek permukaan (tanδ = µ)
Reg : 1.2.500.2.31.09.03.02978

DAYA DUKUNG AKSIAL

Qs = Σ2πr Δl (k σ tanδ)
v
Δl
κ σv

Qu = Qp + Qs

Qall =

Qu
F.S.

σv

Qp =Ap(c Nc +q Nq)
Reg : 1.2.500.2.31.09.03.02978

Nilai K dan δ
Nilai K :

Metoda instalasi

K

Tiang pancang, displacement besar

(1-2)Ko

Tiang pancang, displacement kecil

(0,75-1,75)Ko

Bored pile

(0,75-1)Ko

Ko = 1-sinφ
Nilai δ :
Interface

δ

Baja halus

(0,5-0,7) φ

Baja kasar

(0,7-0,9) φ

Precast concrete

(0,8-1) φ

Cast in place

φ

Reg : 1.2.500.2.31.09.03.02978

Menghitung tegangan effektif (σv’)

σ’v akan naik sejalan dengan kedalaman tiang
hingga mencapai kedalaman L’ = 15D (asumsi,
tergantung dari nilai φ, Cc dan Dr), selanjutnya
konstan.

Reg : 1.2.500.2.31.09.03.02978

Case-3
5m

γb=15,7 kN/m3
φ = 30o
c=0

Dimensi fondasi = 400X400 mm ,

loose

γsat=18,1 kN/m3
φ = 30o
c=0

Hitung tahanan friksi tiang (Qs).

dense

γsat=19,4 kN/m3
φ = 40o
c=0

loose



13 m

4m

K = 1-sin φ , δ = 0,6 φ

Reg : 1.2.500.2.31.09.03.02978

Tahanan ujung tiang pada clay (lempung)
Q p = A p (c.N*c

_

+ q .N*q )

_

Tanah lempung : φ = 0

;

q N q ≈ kecil

Nc = 9

Q p = A p .9.c u
cu = undrained cohesion

Reg : 1.2.500.2.31.09.03.02978

Menghitung tahanan friksi (friction)
Banyak metoda diperkenalkan untuk mencari tahanan
friksi pada lempung : Metoda

Metoda
f

α

α, metoda λ dan metoda β

f = α.cu = α.Su

= unit friksi ; α = adhesion factor ;

cu = undrained cohesion ; Su= undrained strength

α dicari dengan beberapa cara, yang banyak digunakan
adalah API (American Petroleum Institute, 1981) dan
Randolph & Murphy (1985)
Reg : 1.2.500.2.31.09.03.02978

DAYA DUKUNG AKSIAL

Qs =Σ2πr Δl (α c)
Δl

Qu = Qp + Qs

Qall =

Qu
F.S.

Qp =Ap.c Nc
Reg : 1.2.500.2.31.09.03.02978

Faktor penentu nilai α
p 

Konsolidasi tanah selama pelaksanaan

p 

Dragdown lapisan diatasnya saat pemancangan

p 

Cara mendapatkan Su atau cu

p 

Tipe instalasi fondasi tiang

Reg : 1.2.500.2.31.09.03.02978

Menentukan α

Reg : 1.2.500.2.31.09.03.02978

Menentukan α

Reg : 1.2.500.2.31.09.03.02978

Nilai undrained shear strength (Su) :
Clay

Su (kPa)

Su (kg/cm2)

Very soft

0-12

0-0,12

Soft

12-24

0,12-0,24

Medium

24-48

0,24-0,48

Stiff

48-96

0,48-0.96

Very stiff

96-192

0,96-1,92

Hard

> 192

> 1,92
Reg : 1.2.500.2.31.09.03.02978

Case-4
5m



5m

20m

cu =30 kN/m2
γ = 18kN/m3
cu =30 kN/m2
γsat = 19,2 kN/m3

cu =100 kN/m2
γsat = 19,8 kN/m3

Hitung :
Kapasitas tiang ijin (Qall)
Jika diamater tiang 315 mm
dan FS = 4

5m

Reg : 1.2.500.2.31.09.03.02978

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