Effects of dead loads on the lateral response of battered pile groups

2002 ◽  
Vol 39 (3) ◽  
pp. 561-575 ◽  
Author(s):  
L M Zhang ◽  
M C McVay ◽  
S J Han ◽  
P W Lai ◽  
R Gardner
Keyword(s):  
Pile Group ◽  
Lateral Load ◽  
Load Test ◽  
Vertical Load ◽  
Pile Groups ◽  
Dead Load ◽  
Vertical Loading ◽  
Lateral Resistance ◽  
Tension And Compression ◽  
Load Tests

The effects of vertical load on the lateral resistance of single piles were initially reviewed to facilitate the interpretation of the test results of pile groups. Then, 18 different lateral load tests were carried out in the centrifuge on the 3 × 3 and the 4 × 4 fixed-head battered pile groups to investigate the effects of vertical load on the group lateral resistance. Vertical dead loads ranging from approximately 20 to 80% of the vertical ultimate group capacity Puv were applied. Based on these tests, the effects of vertical dead load on the lateral resistance of the battered pile groups are found to depend on pile arrangement, pile inclination, and soil density. The lateral resistances of the 3 × 3 pile groups do not appear to vary considerably with the vertical dead loads in the range of the vertical loads studied. For the 4 × 4 pile groups however, the lateral resistances at vertical loads of approximately 50 and 80% Puv may be 26-29% and even 40% higher than that at the 20% Puv dead load. It may be inferred that designs based on standard lateral load tests with small vertical dead loads would be on the safe side. Three mechanisms for vertical load effects are discussed in terms of axial tension and compression failures, influence of pile inclination, and initial subgrade reaction caused by vertical loading. Preliminary numerical analyses are also performed to simulate the responses of some of the battered pile groups.Key words: pile group, battered pile, lateral resistance, load test, pile-soil interaction, centrifuge test.

scholarly journals Comparison of static lateral behavior of three pile group configurations using three-dimensional finite element modeling

2018 ◽  
Vol 55 (1) ◽  
pp. 107-118 ◽  
Author(s):  
Murad Abu-Farsakh ◽  
Ahmad Souri ◽  
George Voyiadjis ◽  
Firouz Rosti
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Three Dimensional ◽  
Pile Group ◽  
Lateral Load ◽  
Material Behavior ◽  
Soil Resistance ◽  
Pile Groups ◽  
Element Modeling ◽  
Lateral Resistance

The lateral resistance of three pile group configurations was investigated using three dimensional (3-D) finite element modeling. The three pile groups considered in the study were a vertical pile group, a battered pile group, and a mix of vertical and battered piles in a group. The study was motivated by the full-scale static load test that was conducted on the M19 pier foundation in the I-10 twin span bridge in Louisiana. The static lateral resistance of the M19 battered pile group was investigated previously using a 3-D finite element simulation and verified with the aid of experimental results. In the present study, the M19 battered pile group model was used as the basis for the vertical and mixed pile groups for developing their 3-D finite element models. The nonlinear material behavior was accounted for using elastoplastic constitutive models such as the concrete damaged plasticity model and the anisotropic modified Cam clay model. The lateral resistance of the pile groups was investigated in terms of load–displacement, axial load, bending moment, pile damage, soil resistance, and p-multipliers. The results show that the battered pile group had the largest lateral resistance, followed by the mixed and vertical pile groups, respectively. The largest lateral load share was carried by the two middle rows in the battered pile group, while it was in the leading row in the vertical and mixed pile groups. The soil resistance profiles show that the vertical pile group mobilized greater soil resistance than the battered and mixed pile groups at the same lateral load. The back-calculated p-multipliers are the highest in the battered pile group case, followed by the mixed and vertical pile groups, respectively.

Field and numerical analysis on effect of axial load on the lateral response of a pile

2019 ◽  
Vol 16 (1) ◽  
pp. 191-200
Author(s):  
Yogendra Tandel ◽  
Gaurang Vesmawala
Keyword(s):  
Numerical Simulation ◽  
Axial Load ◽  
Lateral Load ◽  
Load Test ◽  
Vertical Load ◽  
Content Type ◽  
Remarkable Effect ◽  
A Value ◽  
Lateral Response ◽  
Load Tests

Purpose Piles often carry combination of axial and lateral. Currently, piles are designed separately for axial and lateral load. In the literature, few information is available on the influence of axial load on lateral behaviour of the pile. This paper aims to present the results of load deformation of a pile under pure lateral load and combined axial and lateral load. Design/methodology/approach The field load tests were carried out on four different pile diameters at two different bridge sites. Moreover, the paper addresses the numerical simulation of filed load test carried out on the pile under the combination of axial and horizontal load. Findings After field load tests and numerical simulation, it was found that the vertical load had a remarkable effect on the lateral load response of a pile. The lateral deflection of the pile was decreased about 25% under the effect of vertical load. In addition to this, the results from field and numerical simulation are quite comparable. Originality/value Typical field load tests were simulated numerically. This research adds a value in the areas of pile foundation subjected to vertical and lateral load particularly for structure such as transmission line tower and jetty.

Full-Scale Lateral Load Tests of Pile Groups

1976 ◽  
Vol 102 (1) ◽  
pp. 87-105
Author(s):  
Jai B. Kim ◽  
Robert J. Brungraber
Keyword(s):  
Lateral Load ◽  
Full Scale ◽  
Pile Groups ◽  
Load Tests

Closure to “Full-Scale Lateral Load Tests of Pile Groups”

1977 ◽  
Vol 103 (10) ◽  
pp. 1187-1190
Author(s):  
Jai B. Kim ◽  
Robert J. Brungraber
Keyword(s):  
Lateral Load ◽  
Full Scale ◽  
Pile Groups ◽  
Load Tests

Experimental and Numerical Study of Laterally Loaded Pile Groups with Pile Caps at Variable Elevations

2000 ◽  
Vol 1736 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Michael C. McVay ◽  
Limin Zhang ◽  
Sangjoon Han ◽  
Peter Lai
Keyword(s):  
Numerical Study ◽  
Ground Surface ◽  
Pile Group ◽  
Special Device ◽  
Pile Groups ◽  
Finite Element Program ◽  
Lateral Resistance ◽  
Pile Cap ◽  
Element Program ◽  
Pile Caps

A series of lateral load tests were performed on 3×3 and 4×4 pile groups in loose and medium-dense sands in the centrifuge with their caps located at variable heights to the ground surface. Four cases were considered: Case 1, pile caps located above the ground surface; Case 2, bottom of pile cap in contact with the ground surface; Case 3, top of pile cap at the ground surface elevation; and Case 4, top of pile cap buried one cap thickness below ground surface. All tests with the exception of Case 1 of the 4×4 group had their pile tips located at the same elevation. A special device, which was capable of both driving the piles and raining sand on the group in flight, had to be constructed to perform the tests without stopping the centrifuge (spinning at 45 g). The tests revealed that lowering the pile cap elevation increased the lateral resistance of the pile group anywhere from 50 to 250 percent. The experimental results were subsequently modeled with the bridge foundation-superstructure finite element program FLPIER, which did a good job of predicting all the cases for different load levels without the need for soil–pile cap interaction springs (i.e., p-y springs attached to the cap). The analyses suggest that the increase in lateral resistance with lower cap elevations may be due to the lower center of rotation of the pile group. However, it should be noted that this study was for pile caps embedded in loose sand and not dense sands or at significant depths. The experiments also revealed a slight effect for the case of the pile cap embedded in sand with a footprint wider than the pile row. In that case the size of the passive soil wedge in front of the pile group, and consequently the group’s lateral resistance, increased.

scholarly journals An Experimental Study on Pile Spacing Effects under Lateral Loading in Sand

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mahdy Khari ◽  
Khairul Anuar Kassim ◽  
Azlan Adnan
Keyword(s):  
Pile Group ◽  
Experimental Investigations ◽  
Pile Groups ◽  
Dense Sand ◽  
Spacing Effects ◽  
Pile Diameter ◽  
Lateral Resistance ◽  
Model Pile ◽  
Pile Interaction ◽  
Subgrade Modulus

Grouped and single pile behavior differs owing to the impacts of the pile-to-pile interaction. Ultimate lateral resistance and lateral subgrade modulus within a pile group are known as the key parameters in the soil-pile interaction phenomenon. In this study, a series of experimental investigation was carried out on single and group pile subjected to monotonic lateral loadings. Experimental investigations were conducted on twelve model pile groups of configurations 1 × 2, 1 × 3, 2 × 2, 3 × 3, and 3 × 2 for embedded length-to-diameter ratiol/d= 32 into loose and dense sand, spacing from 3 to 6 pile diameter, in parallel and series arrangement. The tests were performed in dry sand from Johor Bahru, Malaysia. To reconstruct the sand samples, the new designed apparatus, Mobile Pluviator, was adopted. The ultimate lateral load is increased 53% in increasing ofs/dfrom 3 to 6 owing to effects of sand relative density. An increasing of the number of piles in-group decreases the group efficiency owing to the increasing of overlapped stress zones and active wedges. A ratio ofs/dmore than6dis large enough to eliminate the pile-to-pile interaction and the group effects. It may be more in the loose sand.

Load tests on bedrock

1970 ◽  
Vol 7 (4) ◽  
pp. 464-470 ◽  
Author(s):  
J. L. Seychuk
Keyword(s):  
Elastic Material ◽  
Steel Plate ◽  
Applied Pressure ◽  
Load Test ◽  
Vertical Load ◽  
Subgrade Reaction ◽  
Concrete Piles ◽  
Limestone Bedrock ◽  
Load Tests ◽  
Pile Load Test

Load tests involving the use of a steel plate, a concrete socket, and full scale concrete piles were carried out at two separate sites in Ontario to determine the load bearing characteristics of shale and limestone bedrock. It was found that the essentially sound bedrock behaved as an elastic material under the maximum applied pressure of 260 tons/sq. ft (254 × 104 kg/m2). In addition to the vertical load tests on the rock, a lateral pile load test was carried out to evaluate the modulus of horizontal subgrade reaction of the fissured clay overburden at one of the sites.

Experimental study of interaction and coupling effects in pile groups subjected to torsion

2008 ◽  
Vol 45 (7) ◽  
pp. 1006-1017 ◽  
Author(s):  
L. G. Kong ◽  
L. M. Zhang
Keyword(s):  
Coupling Effect ◽  
Pile Group ◽  
Test Results ◽  
Pile Groups ◽  
Coupling Effects ◽  
Lateral Resistance ◽  
Torsional Resistance ◽  
Pile Interaction ◽  
Group Configuration ◽  
Centrifuge Model Tests

Piles in a pile group subjected to torsion simultaneously mobilize lateral and torsional resistances. Hence, complicated pile–soil–pile interaction effects and load deformation coupling effects occur in the pile group. In this study, a series of centrifuge model tests were carried out to investigate these effects in three-diameter spaced 1 × 2, 2 × 2, and 3 × 3 pile groups subjected to torsion in both loose and dense sands. The test results showed that the effect of horizontal movement of a pile on lateral behaviors of its adjacent piles is significant in 3 × 3 pile groups and such effect varies with group configuration and pile position. The p-multiplier concept can be used to quantify the effect and values for the p-multiplier are suggested. The effect of lateral movement of a pile on the torsional resistances of its adjacent piles and the effect of torsional movement of a pile on the lateral resistances of its adjacent piles were found to be minor in these tests. For an individual pile in a pile group subjected to torsion, the mobilized lateral resistance was found to substantially increase the torsional resistance of the pile. Such a coupling effect is quantified by a coupling coefficient, β, which describes the contribution of subgrade reaction to the increase of torsional shear resistance.

Lateral load tests to examine large-strain (seismic) behaviour of piles

1992 ◽  
Vol 29 (2) ◽  
pp. 245-252
Author(s):  
Ernest Naesgaard
Keyword(s):  
Lateral Displacement ◽  
Large Strain ◽  
Field Tests ◽  
Lateral Load ◽  
Soil Liquefaction ◽  
Load Test ◽  
Seismic Behaviour ◽  
Seismic Liquefaction ◽  
Load Tests ◽  
Lateral Displacements

Three different 406 mm diameter piles were tested with lateral, vertical, and moment loadings. The purpose of the full-scale field tests was to assess the ability of the piles to withstand large lateral deformations that may be caused by earthquake-induced soil liquefaction. Two concrete shaft piles were tested to failure with lateral displacements at the pile top of up to 300 and 650 mm and pile curvatures of up to 0.16 and 0.35 rad/m, respectively. The third pile, a concrete-filled steel pipe shaft pile, reached a maximum lateral displacement at the pile top of 550 mm and a curvature of 0.08 rad/m without failure or significant distress. It is concluded that stronger piles that push through the soil may tolerate larger lateral displacements than weaker piles and that reducing the spiral reinforcing pitch from 150to 100 mm on concrete piles greatly increases the pile ductility. Key words : lateral load test, piles, reinforced concrete, concrete-filled pipe, seismic, liquefaction, pile curvature.

Settlement analysis of pile groups in layered soils

2006 ◽  
Vol 43 (8) ◽  
pp. 788-801 ◽  
Author(s):  
Roberto Cairo ◽  
Enrico Conte
Keyword(s):  
Dynamic Stiffness ◽  
Pile Group ◽  
Nonlinear Behaviour ◽  
Layered Soils ◽  
Pile Groups ◽  
Linear Elastic ◽  
Vertical Loading ◽  
Stiffness Matrices ◽  
Interaction Factor ◽  
Settlement Analysis

This paper presents a method to perform a nonlinear analysis of pile groups subject to vertical loading. The method makes use of the dynamic stiffness matrices to simulate the response of layered soils. These matrices are incorporated in a calculation procedure that is computationally very efficient because the response of a pile group can be achieved using essentially the solution for a single pile. The method is first used to perform a linear elastic analysis of pile groups and is then extended to include the nonlinearity effects. In this context, the widely accepted approach is adopted in which nonlinearity is considered to be confined in a narrow zone close to each pile, whereas outside this zone the soil is assumed to behave as a linear elastic medium. Moreover, a global interaction factor is introduced to account for the interaction among the piles in the group. The theoretical predictions from the proposed method are compared with experimental measurements from several published full-scale and model tests on pile groups loaded up to failure. The agreement between predicted and observed behaviour is found to be very satisfactory, even approaching the ultimate load, when the results of loading tests on single piles are available and the group efficiency with respect to the failure load is close to unity.Key words: pile groups, settlement analysis, nonlinear behaviour, layered soils.

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