A new nonlinear method for vertical settlement prediction of a single pile and pile groups in layered soils

2012 ◽  
Vol 45 ◽  
pp. 118-126 ◽  
Author(s):  
Zhongjin Wang ◽  
Xinyu Xie ◽  
Jinchang Wang
Keyword(s):  
Single Pile ◽  
Layered Soils ◽  
Pile Groups ◽  
Nonlinear Method ◽  
Settlement Prediction

Prediction of the horizontal load-displacement curves of pile groups based on the results of single pile tests

2000 ◽  
Vol 37 (5) ◽  
pp. 951-962 ◽  
Author(s):  
António GF de Sousa Coutinho
Keyword(s):  
Pile Group ◽  
Full Scale ◽  
Soil Parameters ◽  
Single Pile ◽  
Horizontal Load ◽  
Pile Groups ◽  
Nonlinear Method ◽  
Pile Test ◽  
Elastic Plastic ◽  
Load Displacement

This paper presents the prediction of horizontal load-displacement curves of pile groups based on the results of single pile tests. Although the same basic model is employed, two different approaches are taken: one assumes soil to be linear elastic-plastic, and the other assumes it to be elastic nonlinear. The model is calibrated on the basis of the results of a full-scale single pile test. Special emphasis is placed on model calibrations, since the success of any prediction method depends on a careful characterization of the soil. Some new approaches for determining the soil parameters are presented. Two methods for predicting load-displacement curves, one from each model approach, are then proposed and discussed. Special emphasis is placed on group efficiency in the elastic-plastic method and on the boundary conditions of the single pile and the pile group in the elastic nonlinear method. Using the soil characteristics from the model calibrations, the load-displacement curves for a given pile group are then predicted. These predictions are compared with the results of a full-scale pile group test carried out at the same site as that of the single pile test. Agreement between the predictions and the test results tends to validate the methods proposed.Key words: displacement predictions, pile groups, model calibration, pile tests.

Dynamic analysis of laterally loaded pile groups in sand and clay

2002 ◽  
Vol 39 (6) ◽  
pp. 1358-1383 ◽  
Author(s):  
Yasser E Mostafa ◽  
M Hesham El Naggar
Keyword(s):  
Dynamic Loading ◽  
Dynamic Load ◽  
Load Transfer ◽  
Pile Group ◽  
Nonlinear Behaviour ◽  
Single Pile ◽  
Offshore Platforms ◽  
Group Effect ◽  
Pile Groups ◽  
Pile Head

Pile foundations supporting bridge piers, offshore platforms, and marine structures are required to resist not only static loading but also lateral dynamic loading. The static p–y curves are widely used to relate pile deflections to nonlinear soil reactions. The p-multiplier concept is used to account for the group effect by relating the load transfer curves of a pile in a group to the load transfer curves of a single pile. Some studies have examined the validity of the p-multiplier concept for the static and cyclic loading cases. However, the concept of the p-multiplier has not yet been considered for the dynamic loading case, and hence it is undertaken in the current study. An analysis of the dynamic lateral response of pile groups is described. The proposed analysis incorporates the static p–y curve approach and the plane strain assumptions to represent the soil reactions within the framework of a Winkler model. The model accounts for the nonlinear behaviour of the soil, the energy dissipation through the soil, and the pile group effect. The model was validated by analyzing the response of pile groups subjected to lateral Statnamic loading and comparing the results with field measured values. An intensive parametric study was performed employing the proposed analysis, and the results were used to establish dynamic soil reactions for single piles and pile groups for different types of sand and clay under harmonic loading with varying frequencies applied at the pile head. "Dynamic" p-multipliers were established to relate the dynamic load transfer curves of a pile in a group to the dynamic load transfer curves for a single pile. The dynamic p-multipliers were found to vary with the spacing between piles, soil type, peak amplitude of loading, and the angle between the line connecting any two piles and the direction of loading. The study indicated the effect of pile material and geometry, pile installation method, and pile head conditions on the p-multipliers. The calculated p-multipliers compared well with p-multipliers back-calculated from full scale field tests.Key words: lateral, transient loading, nonlinear, pile–soil–pile interaction, p–y curves, Statnamic.

scholarly journals Simplified non-linear approaches for response of a single pile and pile groups considering progressive deformation of pile–soil system

2016 ◽  
Vol 56 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Qian-qing Zhang ◽  
Shan-wei Liu ◽  
Shi-min Zhang ◽  
Jian Zhang ◽  
Kang Wang
Keyword(s):  
Single Pile ◽  
Pile Groups ◽  
Progressive Deformation ◽  
Soil System ◽  
Non Linear

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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