Proposal for considering the group effect in the prediction of settlements in pile groups through load transfer methods

Francisco Vladson Cardins Gomes Filho,Alfran Sampaio Moura

doi:10.28927/sr.2021.061320

Abstract

When designing a foundation project, it is necessary to ensure that all the elements meet both ultimate and serviceability limit states, which call for predictions of settlement and load capacity. The load transfer methods are a widely used alternative to estimate the load-settlement ratio of piles in the design of foundation projects. However, traditional load transfer methods do not consider the interactive effects between the elements in pile groups. This study proposes changes to the load transfer curves developed by Bohn et al. (2016), aiming to incorporate the group effect in the analysis of load-settlement relationships in pile groups. Comparisons between the predicted settlements obtained using the proposed method and the results of load tests performed by Dai et al. (2012) in Jiangsu, China, showed that the modifications proposed in this study agreed well with the experimental results for most of the analyzed groups.

Highlights

Settlement prediction is an important task that can be performed using different techniques, such as the load transfer methods, which use load transfer functions to determine the load-settlement relationship for a pile
The present study aims to propose changes to the load transfer functions for single piles proposed by Bohn et al (2016) in order to incorporate the group effect in the analysis of load-settlement ratios of pile groups
The method proposed in this study yielded results that agreed quite well with the experimental ones, especially for loads up to 2,500 kN

Summary

Introduction

Settlement prediction is an important task that can be performed using different techniques, such as the load transfer methods, which use load transfer functions (called “t-z” and “q-z” curves) to determine the load-settlement relationship for a pile. These load transfer curves can be developed from theoretical solutions and empirical observations. Load transfer functions were used to describe relationship between unit skin friction and pile settlement and the relationship between the pile tip resistance and the pile tip displacements. Most of the current methods to estimate settlements analyze the piles separately, without considering the influence of the neighboring ones on the field behavior of the pile group

Methods

Results

Conclusion