Implementation of Laterally Loaded Piles in Multi-Layer Soils

Purdue UniversityPurdue e-Pubs

JTRP Technical Reports Joint Transportation Research Program

2009

Implementation of Laterally Loaded Piles in Multi-Layer SoilsMonica PrezziPurdue University

This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] foradditional information.

Recommended CitationPrezzi, M. Implementation of Laterally Loaded Piles in Multi-Layer Soils. Publication FHWA/IN/JTRP-2009/40. Joint Transportation Research Program, Indiana Department of Transportation andPurdue University, West Lafayette, Indiana, 2009. doi: 10.5703/1288284314332.

http://docs.lib.purdue.edu

http://docs.lib.purdue.edu/jtrp

http://docs.lib.purdue.edu/jtrprogram

Implementation of Laterally Loaded Piles in Multi-Layer Soils

JTRP SPR- 3261Final SAC meeting

SAC membersMir Zaheer and Keith Hoernschemeyer

Purdue University

1

Introduction

Analysis developed for the design of laterally loaded piles in multi-layer soil using energy principles (SPR 2630)

Analysis validation for piles in sandModel pile lateral load tests

(single piles and pile groups)DrivenPreinstalledJacked

2

Objectives

Study the response of piles subjected to lateral load through a series of model pile load tests

Evaluate the effect of pile installation (driven, jacked and preinstalled) on pile response

Compare the model pile experimental results with results from the analysis for preinstalled model piles

3

General scope of work

Task 1

Task 2

Task 3

Task 4

Task 5

Purchase of sensors

Fabrication of piles and pile caps

Fabrication of jacking system

Performance of model pile load tests

Validation of the analysis

4

ContentsModel pile testing planModel pile testing

Sample preparation Soil tank Sand pluviator

Instrumented model pile Driving system Preinstallation method Jacking system

Installation of piles for pile group testing Lateral loading system

Comparison of test and analysis results Single piles Pile groups

Summary and Conclusions

5

Model pile testing plan

Model Pile Test

Laterally Loaded Piles

Single piles

Driven Preinstalled Jacked

Pile groups

Driven (4 piles)

6

Pile Installation Soil Condition Relative Density

Dense sand DR ≈ 90%

Medium dense sand DR ≈ 60%

Loose sand DR ≈ 40%

Multi-layer DR ≈ 60%, 90 %





Loose sand DR ≈ 40%Dense sand DR ≈ 90%Medium dense sand DR ≈ 60%Loose sand DR ≈ 40%Multi-layer DR ≈ 60%, 90 %

Driven

Driven

Preinstalled

Jacked

Single pile

Group piles

Model pile testing plan

7







8

Guide rod

Model pile

Hammer

Soil tank Soil tank (D=2m, H=1.6m)

Reaction beamsupport

Guide arm for pile driving (rotatable and extensible)

9

Soil tank

Holes for draining sand

Reaction beam(detachable)

Guide arm for pile driving

Open

Close

10

Diffuser sieves

Gantry

Soil tank

Sand pluviator Large-scale sand pluviation system (D=2m)

Hoist for adjusting height

Shutter plate

11

Holes for sand pluviation

Top of pluviator

Two sieve layers

Sand pluviator

12

Sand pluviator Schematic view and photo of sand pluviator

Depositedsand

Rainingsand

Falling sand jets

Sandsupply

Chains

Diffusersieves

Shutter plate

Hoist

13

Sample preparation

Top view of pluviator

Sand pluviation

14

Draining sand Draining sand after the test

15







16

Instrumented model pile Smooth steel pipe (D=3cm, L=120cm, t=0.2cm)

Collected wires at pile head Closed-ended pile base

17

Instrumented model pile

22 strain gauges

Closer near the base (higher load transfer rate)

Load cell-shaped pile base

18

Driving System Installation of driven pile

Filled soil tank

Pile Cap

Hammer

Guide Rod

Preinstallation of model pile

Preinstalled pile

20

Pile jacking system

21

Pile jacking system Max. rate = 5 cm/min

Model Pile

Motor

Screw Rod

22

Installation of Group piles Setup

1

23

44 Piles

Pile driving order

Pile driving guide (Wooden Box Frame)

& Steel Cap

23

Lateral loading system

Single pile

Pile groups

24







25

Test results: Single pile

Sand typeQlat, 5%

(kN)Qlat, 10%

(kN)Qlat, 20%

(kN)

Dense 0.42 0.65 0.92

Medium dense 0.24 0.36 0.54

Loose 0.19 0.29 0.44

0

2

4

6

8

10

12

14

16

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Lateral Load (kN)

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Dense sandMedium dense sandLoose sand

Lateral load - deflection curves (driven pile)

Ultimate lateral loadsQlat,5%,

Qlat,10%

Qlat,20%

corresponding to lateral pile head deflections of 5, 10 and 20 % of the pile diameter

1.0 kN = 225 lb

26


h: horizontal distance between gauges

Tε : tensile straincε : compressive strain

Bending moment

( )T cEIMhε ε⋅ −

=

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4

Bending Moment (kN-m)

Dep

th (m

)

0.1 kN 0.2 kN0.3 kN 0.4 kN0.5 kN 0.6 kN0.7 kN 0.8 kN0.9 kN 1.0 kN1.1 kN 1.2 kN

Dense sand (DR=91%) Medium dense sand (DR=59%) Loose sand (DR=38%)

EI: bending stiffness of pile Rollins et al. (1998)

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4


Dep

th (m

)

0.1 kN 0.2 kN0.3 kN 0.4 kN0.5 kN 0.6 kN0.7 kN 0.8 kN0.9 kN

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4


Dep

th (m

)

0.1 kN 0.2 kN0.3 kN 0.4 kN0.5 kN 0.6 kN

Bending moment profiles (driven pile) 1.0 kN-m = 0.738 lb-kips

0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Dense sandMedium dense sandLoose sand

27


Sand typeQlat, 5%

(kN)Qlat, 10%

(kN)Qlat, 20%

(kN)

Dense 0.51 0.71 0.97


Loose 0.21 0.31 0.47

Lateral load - deflection curves (jacked pile)

1.0 kN = 225 lb

28

Test results: Single pile Bending moment profiles (jacked pile)


-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4

Dep

th (m

)


0.2 kN 0.3 kN0.4 kN 0.5 kN0.6 kN 0.7 kN0.8 kN 0.9 kN

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4

Dep

th (m

)



-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4

Dep

th (m

)


0.1 kN 0.2 kN0.3 kN 0.4 kN0.5 kN 0.6 kN

1.0 kN-m = 0.738 lb-kips

29

Test results: Single pile Lateral load - deflection curves (preinstalled pile)

0

2

4

6

8

10

12

14

16

18

20

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6Lateral Load (kN)

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Dense sandMedium dense sand

Sand typeQlat, 5%

(kN)Qlat, 10%

(kN)Qlat, 20%

(kN)

Dense 0.35 0.52 0.73


1.0 kN = 225 lb


30

Dense sand (DR=91%) Medium dense sand (DR=59%)

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4Moment (kN-m)

Dep

th (m

)


-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4Moment (kN-m)

Dep

th (m

)


Bending moment profiles (preinstalled pile)

1.0 kN-m = 0.738 lb-kips

31


Sand typeQlat, 5%

(kN)Qlat, 10%

(kN)Qlat, 20%

(kN)

Multi layer 0.28 0.41 0.61

Load-deflection curves and bending moment profiles (Multi-layer soils)

0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Multi layer

Soil TankMedium dense sand

Dense sand

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 0 0.1 0.2 0.3 0.4

Dep

th (m

)


0.1 kN0.2 kN0.4 kN0.5 kN0.6 kN0.7 kN0.9 kN

32

Effect of pile installation method

Installation Method

Qlat, 10%

(kN)

Jacked 0.71

Driven 0.65

Preinstalled 0.52

Installation Method

Qlat, 10%

(kN)

Jacked 0.42

Driven 0.36

Preinstalled 0.35

Dense sand

Medium dense sandQlat,10% (preinstalled piles) = 84% of Qlat,10% (jacked piles)

Qlat,10% (preinstalled piles) = 73% of Qlat,10% (jacked piles)0

2

4

6

8

10

12

14

16

18

20

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Driven pile (Dense)Jacked pile (Dense)Preinstalled pile (Dense)Driven pile (Medium Dense)Jacked pile (Medium Dense)Preinstalled pile (Medium Dense)

Medium dense

Dense

1.0 kN = 225 lb

33

Comparison of Result with Predictions Comparison of predictions (PYGMY, present analysis) with measurements from model piles driven in dense, medium dense, and loose sand


0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Predicted (PYGMY)

Measured (Driven)

present analysis

0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Predicted (PYGMY)

Measured (Driven)

present analysis

0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Measured

Predicted (PYGMY)present analysis

1.0 kN = 225 lb

34

Comparison of Result with Predictions Comparison of predicted and measured bending moment profiles formodel piles driven in dense sand

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.05 0 0.05 0.1 0.15 0.2

Dep

th (m

)


Pred_0.1 kNPred_0.2 kNPred_0.3 kNPred_0.4 kNMead_0.1 kNMead_0.2 kNMead_0.3 kNMead_0.4 kN

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 0.05 0.1 0.15 0.2

Appl

ied

late

ral l

oad

(kN

)

Max. Moment (kN-m)

Predicted

Measured

1.0 kN-m = 0.738 lb-kips

35

Comparison of Results with PYGMY Comparison of predicted and measured bending moment profiles formodel piles driven in dense sand

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

-0.1 0 0.1 0.2 0.3 0.4

Dep

th (m

)


Mead_0.2kNMead_0.4kNMead_0.6kNMead_0.8kNMead_1.0kNPred_0.2kNPred_0.4kNPred_0.6kNPred_0.8kNPred_1.0kN

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

0.0 0.1 0.2 0.3 0.4 0.5

Appl

ied

Late

ral L

oad

(kN

)

Max. Moment (kN-m)

MeasuredPredicted

1.0 kN-m = 0.738 lb-kips

36

Comparison of Results Comparison of predictions with measurements from model piles driven and preinstalled in dense, medium dense

Dense sand (DR=91%) Medium dense sand (DR=59%)

0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Predicted (PYGMY)Measured (Driven)present analysisMeasured (Preinstalled)

0

2

4

6

8

10

12

14

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Predicted (PYGMY)Measured (Driven)present analysisMeasured (Preinstalled)

37

Input parameters (present analysis)

Suggested f and g (Lee and Salgado, 2000)

Input parameters for the soil

Critical-state friction angle (deg.) 32.8

Max. void ratio (emax) 0.78

Min. void ratio (emin) 0.47

Coefficient of earth pressure 0.4

Model f-g model

DR(%) f g30 0.98 0.1750 0.97 0.270 0.96 0.2390 0.95 0.26

Input parameters for the model pile

Length (m) 1.2

Diameter / width (m) 0.03

Pile modulus (GPa) 210

38

Input parameters (PYGMY)

PYGMY input parameters for the model pile

Pile property Input value

Length (m) 1.2

Diameter / width (m) 0.03

Bending stiffness of pile, EpIp (kN⋅m2) 3.862

Plastic moment (kN⋅m) 0.5

No. of elements 30

PYGMY input parameters for the soil

Soil property Dense sand Medium dense sand Loose sand

Peak friction angle (deg.) 44 39 36

Initial stiffness gradient (kPa/m) 82,000 34,000 12,000

Effective unit weight (kN/m3) 17.34 16.27 15.64

No. of soil layers 1 1 1

39

p-y curve (PYGMY)

Sand: API criterion (1993)

tanh

: lateral pressure: factor to account for static or cyclic loading

0.9 where equilibrium has been reached under cyclic loading (0.3 - 0.8 / )

uu

k x yp A pA p B

pA

AA x B

⋅ ⋅= ⋅ ⋅ ⋅ ⋅

== ≥ 0.9 for static loading

fultimate bearing pressure at the current depth, gradient of initial modulus of subgrade reaction with depth (kPa/m)lateral displacementdepth below surface pile dia

up xkyxB

=

==== meter

40

p-y curves (PYGMY)

predicted p-y curves (dense sand)

41







42

Group piles: Dense sand (DR=90%) Lateral deflection of pile head (4 piles, 3B spacing)

Qlat, 5% = 0.91 kN

Qlat, 10% = 1.59 kN

Qlat, 20% = 2.25 kN

Lateral deflection = 5%, 10%, 20% of the pile diameter

0

2

4

6

8

10

12

14

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Single pile

Pile group

1.0 kN = 225 lb

43

Group piles: Dense sand (DR=90%) Distribution of lateral load

Pile top

4 strain gauges2cm

For lateral load

The difference in the bending momentsdivided by the distance between thestrain gauges is equal to the lateral loadin the pile

0

2

4

6

8

10

12

14

0.0 0.3 0.5 0.8 1.0

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Trailing Pile

Leading Pile

Qh

1.0 kN = 225 lb

44

Group piles: Dense sand (DR=90%) Bending moment of leading and trailing piles

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)


0.5 kN0.9 kN1.3 kN1.6 kN1.9 kN2.2 kN2.5 kN2.9 kN3.2 kN

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)



Group piles

Leading RowTrailing Row

Qh

Distribution of bending moments of trailing piles

Distribution of bending moments of leading piles

1.0 kN-m = 0.738 lb-kips

45

Group piles: Dense sand (DR=90%) Measured p-multipliers and distribution of lateral load

0.0

0.4

0.8

1.2

1.6

0.0 4.0 8.0 12.0

Late

ral L

oad

(kN

)

Lateral Deflection of Pile Head (mm)

Single pile

Leading pile

Trailing pile

Lateral deflection Leading Pile

Trailing Pile

5 % of B 0.76 0.59 10 % of B 0.74 0.58 20 % of B 0.82 0.63

Measured p-multipliers

1.0 kN = 225 lb

46

Group piles: Medium dense sand (DR=60%) Lateral deflection of pile head (4 piles, 3B spacing)

Qlat, 5% = 0.60 kN

Qlat, 10% = 1.20 kN

Qlat, 20% = 1.56 kN


0

2

4

6

8

10

12

14

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Single pilePile group

1.0 kN = 225 lb

47

Group piles: Medium dense sand (DR=60%) Bending moment of leading and trailing piles

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)



-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)





1.0 kN-m = 0.738 lb-kips


Trailing Pile

5 % of B 0.70 0.60

10 % of B 0.68 0.59 20 % of B 0.82 0.71

48

Group piles: Medium dense sand (DR=60%) Measured p-multipliers and distribution of lateral load

0.0

0.4

0.8

1.2

1.6

0.0 4.0 8.0 12.0

Late

ral L

oad

(kN

)


Single pile

Leading pile

Trailing pile


1.0 kN = 225 lb

49

Group piles: Loose sand (DR=40%) Lateral deflection of pile head (4 piles, 3B spacing)

Qlat, 5% = 0.47 kN

Qlat, 10% = 0.80 kN

Qlat, 20% = 1.23 kN


0

2

4

6

8

10

12

14

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Single pile

Pile group

1.0 kN = 225 lb

50

Group piles: Loose sand (DR=40%) Bending Moment of leading and trailing piles

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)



-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)





1.0 kN-m = 0.738 lb-kips


Trailing Pile

5 % of B 0.68 0.59

10 % of B 0.76 0.65

20 % of B 0.80 0.69

0.0

0.4

0.8

1.2

1.6

0.0 4.0 8.0 12.0

Late

ral L

oad

(kN

)


Single pile

Leading pile

Trailing pile

51

Group piles: Loose sand (DR=40%) Measured p-multipliers and distribution of lateral load


52

Group piles: two-layer sand sample Lateral deflection of pile head (4 piles, 3B spacing)

Qlat, 5% = 0.62 kN

Qlat, 10% = 1.21 kN

Qlat, 20% = 1.82 kN


0

2

4

6

8

10

12

14

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Late

ral D

efle

ctio

n of

Pile

Hea

d (m

m)

Lateral Load (kN)

Single

Pile groupSoil Tank

Medium dense sand

Dense sand

1.0 kN = 225 lb

53

Group piles: two-layer sand sample Bending Moment of leading and trailing piles

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)



-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3

Dep

th (m

)





1.0 kN-m = 0.738 lb-kips


Trailing Pile

5 % of B 0.63 0.49

10 % of B 0.71 0.55

20 % of B 0.84 0.65

0.0

0.4

0.8

1.2

1.6

0.0 4.0 8.0 12.0

Late

ral L

oad

(kN

)


Single pile

Leading pile

Trailing pile

54

Group piles: two-layer sand sample Measured p-multipliers and distribution of lateral load


1.0 kN = 225 lb

55

Group piles: p-multipliers

p-multipliers f- p-y relationship for single pile - Reduction in p values for each pile in the group by using f

1

:

1

pn

i ijj

ij

ij

f

i j

β

β

β

== ∏

= = if

Reese et al (2006)

interaction coefficients (pile i and pile j)

56


0.38

0.26

0.34

0.48 1

0.7 1

0.64 1

piLiL

piTiT

piSiT

sB

sB

sB

β

β

β

= ≤

= ≤

= ≤

for a leading pile

for a trailing pile

center-to-center spacing

pile diameter

, , :piL piT piSs s s

for a side-by-side pile

Qh LT

S

S

i

leading offset pile

trailing offset pile

θ

2 2 2 2cos sini iL iSθβ β θ β θ= +

2 2 2 2cos sini iT iSθβ β θ β θ= +

for leading offset pile

for trailing offset pile

:B

57


0.38 0.38

120.090.48 0.48 0.720.03

piLsB

β = = =

4 piles, 3B spacing (=0.09m)

2Qh

4

1

3

1 12 12 13 141

0.623pn

ijj

f β β β β β=

= ∏ = =

for a leading pile

for a side-by-side pile0.34 0.34

130.090.64 0.64 0.920.03

piTsB

β = = =

2 2 2 214 1 1

0.380.38

1

0.340.34

1

2 2 2 214 1 1

cos sin

0.09 20.48 0.48 0.830.03

0.09 20.64 0.64 1.04 10.03

cos sin 0.919

L S

piLL

piLS

L S

sB

sB

β β θ β θ

β

β

β β θ β θ

= +

⋅= = =

⋅= = = →

= + =

for leading offset pile

58


1

2

3

0.64 0.06 1

0.34 0.11 1

0.16 0.14 1

0.04 0.16 1

pL

pT

pT

pT

sf

B

sf

B

sf

B

sf

B

= + ≤

= + ≤

= + ≤

= + ≤

for the leading row

for the 1st trailing row

for the 2nd trailing row

for the 3rd and subsequent trailing row

Mokwa (1999)

59


( )

( )1

0.64 0.06 0.64 0.06 3 0.82

0.34 0.11 0.34 0.11 3 0.67

pL

pT

sf

B

sf

B

= + = + =

= + = + =

for the leading row

for the 1st trailing row

Mokwa (1999)

Leading Pile Trailing Pile

Reese et al (2006) 0.866 0.623

Mokwa (1999) 0.820 0.670

Predicted p-multipliers

60

Group piles: comparison of p-multipliers

0.4

0.6

0.8

1.0

0 5 10 15 20 25 30

p-m

ultip

lier

Lateral Deflection of Pile Head (% of diameter)

Reese et al. (2006)

Mokwa (1999)

Dense

Medium dense

Loose

Leading piles

Comparison of predicted p-multipliers with measurements from pile group tests in dense, medium dense and loose sand

0.4

0.6

0.8

1.0

0 5 10 15 20 25 30

p-m

ultip

lier

Lateral Deflection of Pile Head (% of diameter)

Reese et al. (2006)

Mokwa (1999)

Dense

Medium dense

Loose

61

Group piles: comparison of p-multipliers Comparison of predicted p-multipliers with measurements from pile group tests in dense, medium dense and loose sand

Trailing piles

62


An instrumented model pile, a soil tank, a large-scale pluviator, a driving system, and a jacking system were fabricated

Lateral load tests were performed on preinstalled, driven and jacked model piles installed in sand prepared at different densities

The effects of soil conditions and pile installation method on the model pile capacities were evaluated

63


For single piles, the predictions from the developed analysis were in good agreement with the model pile test results for small pile head deflections (up to 10% of the pile diameter)

For pile groups, the measured p-multipliers are in reasonable agreement with those obtained from Mokwa (1999) and Reese et al. (2006)

the measured p-multipliers for the leading piles were 85%~90% less than the predicted values

for the trailing piles, the measured p-multipliers were in good agreement with the predictions

References Basu, D. (2006). Analysis of laterally loaded piles in layered soil. Ph.D. Thesis, Purdue University.Basu, D., Salgado, R. and Prezzi. M. (2008). “Analysis of laterally loaded piles inmultilayered soil deposits.” Final Report FHWA/IN/JTRP-2007/23, JTRPLee, J. & Salgado, R. (2000). Analysis of calibration chamber plate load tests. Can. Geotech. J., 37, 14-25. Mokwa, R. L. (1999). “Investigation of the resistance of pile caps to lateral loading.” Ph.D. Thesis, Virginia Polytechnic Institute and State University. Mokwa, R. L. & Duncan, J. M. (2001). Experimental evaluation of lateral-load resistance of pile caps. J. Geotech. Geoenv. Engng., Am. Soc. Civ. Engrs. 127, No. 2, 185-192. Poulos, H. G. & Davis, E. H. (1980). Pile foundation analysis and design. John Wiley & Sons,Inc. Randolph, M. F. (1981). The response of flexible piles to lateral loading. Geotechnique 31, No. 2,247-259. Reese, L. C., Isenhower, W. M. & Wang, S.-T. (2006). Analysis and design of shallow and deep foundations. John Wiley & Sons, Inc. Reese, L.C. and Van Impe, W.F. (2001). “Single Piles and Pile Groups Under Lateral Loading”, A. A.Balkema, Rotterdam. Salgado, R. (2008). “The Engineering of Foundations”, McGraw-Hill Science.

Implementation of Laterally Loaded Piles in Multi-Layer Soils

Documents

1st trailing row

diameter width

laterally loaded piles

trailing pilesbending moment

john wiley

dense sandbending moment

leading pilesbending moment

leading offset pile