Numerical Analysis of Pile–Soil–Pile Interaction in Pile Groups with Batter Piles

The p-y curve method and p-multiplier (Pm), which implies a group effect, are widely used to analyze the nonlinear behaviors of laterally loaded pile groups. Factors affecting Pm includes soil properties as well as group pile geometry and configuration. However, research on the change in Pm corresponding to soil properties has not been conducted well. In this study, in order to evaluate the effect of soil properties on the group effect in a laterally-loaded pile group installed in sandy soil, numerical analysis for a single pile and 3×3 pile group installed in loose, medium, and dense sand, was performed using the 3D numerical analysis program, Plaxis 3D. Among the factors considered in this study, the column location of the pile was the most dominant factor for Pm. The effect of the sand property change on Pm was not as significant as that of the column location of the pile. However, as the sand became denser and the friction angle increased, the group effect increased, leading to a decrease in Pm of approximately 0.1. This trend was similar to the result reported in a previous laboratory-scale experimental study.

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Analysis for Axial Vibration and Internal Forces of Totally and Partially Embedded Pile Groups with Flexible Caps

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.3860 ◽

2010 ◽

Vol 163-167 ◽

pp. 3860-3867

Author(s):

Qing Ren ◽

Mao Song Huang

Keyword(s):

Wind Farm ◽

Mass Density ◽

Offshore Wind ◽

Parameter Study ◽

Pile Groups ◽

Inertial Interaction ◽

Soil Deposits ◽

Pile Interaction ◽

Internal Forces ◽

Dynamics Response

In this paper, a simplified analytical method is developed for the axial harmonic response of totally and partially embedded pile groups in homogeneous and layered soil deposits. Based on BDWF model, finite element sub-structure method is used to setup the dynamic model of cap-pile groups which can precisely simulate kinetic interaction and inertial interaction. A comprehensive parameter study focuses on the influence of caps’ elastic modulus and mass density on pile groups’ dynamic response, and then points out the limition of rigid cap in practical design. An approximate solution is finally presented for the internal forces distributed on pile heads due to pile-to-pile interaction. The solution of above approach was compared with that of traditional simplified model (rigid and massless cap solution) in simulating an in-site experiment and dynamics response of partially embedded pile groups for offshore wind farm.

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Numerical modelling of perimeter pile groups in clay

Canadian Geotechnical Journal ◽

10.1139/cgj-2012-0194 ◽

2013 ◽

Vol 50 (3) ◽

pp. 250-258 ◽

Cited By ~ 22

Author(s):

A.V. Rose ◽

R.N. Taylor ◽

M.H. El Naggar

Keyword(s):

Load Distribution ◽

Load Capacity ◽

Relative Effectiveness ◽

Pile Group ◽

Block Type ◽

Pile Groups ◽

Total Load ◽

Group Behaviour ◽

Pile Interaction ◽

Spacing Length

The load distribution among piles in a group varies such that the inner piles often carry a smaller share of the total load compared to the outer piles, which is a result of increased soil–pile interaction. The main objective of this paper is to establish the relative effectiveness of pile groups with no inner piles (perimeter group), when compared to the more common grid configuration. The numerical investigation utilized the finite element programme ABAQUS and considered a range of variables that affect pile group behaviour including number of piles, pile spacing, length/diameter ratio, and soil strength. It was demonstrated that a complete grid group is less efficient than a perimeter group, where efficiency is defined as the load capacity of the whole group expressed as a ratio of the number of piles in the group multiplied by the load capacity of a single isolated pile. Efficiencies close to unity were observed for some perimeter groups. Perimeter groups also showed that a “block” type group failure could occur, where piles were placed at a spacing of less than 2.0 pile diameters,d, centre-to-centre. This often, but not always, led to a reduction in the efficiency of the pile group.

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Numerical analysis of passive pile groups in offshore soft deposits

Computers and Geotechnics ◽

10.1016/j.compgeo.2009.05.003 ◽

2009 ◽

Vol 36 (7) ◽

pp. 1164-1175 ◽

Cited By ~ 7

Author(s):

Sangseom Jeong ◽

Donghee Seo ◽

Youngho Kim

Keyword(s):

Numerical Analysis ◽

Pile Groups ◽

Passive Pile

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

The Scientific World JOURNAL ◽

10.1155/2013/734292 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 11

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.

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A simplified approach for settlement calculation of pile groups considering pile-to-pile interaction in layered soils

Journal of Central South University of Technology ◽

10.1007/s11771-011-0953-6 ◽

2011 ◽

Vol 18 (6) ◽

pp. 2131-2136 ◽

Cited By ~ 7

Author(s):

Ming-hui Yang ◽

Xiao-wei Zhang ◽

Ming-hua Zhao

Keyword(s):

Layered Soils ◽

Pile Groups ◽

Simplified Approach ◽

Settlement Calculation ◽

Pile Interaction

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

Canadian Geotechnical Journal ◽

10.1139/t08-038 ◽

2008 ◽

Vol 45 (7) ◽

pp. 1006-1017 ◽

Cited By ~ 14

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.

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