Scour effects on vertical effective stresses and lateral responses of pile groups in sands

Abstract

For pile-supported structures, scour is a major threat as it removes soils around foundations and causes structural damages. Scour effects on the performance of the pile foundation have been well studied. However, most of these studies are focused on lateral responses of single piles, while very limited research is focused on lateral responses of pile groups. Therefore, prevailing design standards only recommend scour design procedures for single piles. Here, we proposed an improved analytical method (IAM) to analyze laterally loaded pile groups considering various scour-hole dimensions. The IAM was validated against the results of 3D finite element (FE) models calibrated against a full-scale load test. A series of parametric analyses were conducted to investigate the effects of scour-hole depth, scour-hole slope angle, sand relative density, pile spacing, number of piles, and pile group configuration on both post-scour vertical effective stresses and lateral responses of pile groups. Based on the IAM, a simple practical approach called the influence depth method (IDM) was also developed for use in routine design. The feasibility of applying the standard methods for the scoured pile groups was evaluated by comparing them with the 3D FE analyses and the proposed methods (IAM and IDM).