A physical model for the interaction between unsaturated soils and retaining structures

Gianluca Speranza,Alessio Ferrari,Lyesse Laloui,R Cardoso,E Romero,C Jommi

doi:10.1051/e3sconf/202019503013

Gianluca Speranza, Alessio Ferrari + Show 4 more

Open Access

https://doi.org/10.1051/e3sconf/202019503013

Copy DOI

Abstract

Temporary and permanent retaining structures interact with soils that are usually in unsaturated conditions. In this work, a 1g-scale physical model is presented to investigate the interactions between retaining walls and unsaturated soils. The physical model is equipped with a water-filled hydraulic cylinder connected to a pressure-volume controller to measure the horizontal component of the later earth thrust and high capacity tensiometers to measure soil matric suction. A system of low-friction linear guideways has been installed at the base of the wall-model. The failure surface is observed through a 3 cm thick glass wall on one side of the container. A series of images are acquired during the tests, and Particle Image Velocimetry (PIV) technique has been used to identify the displacement field. Selected test results on a fine sandy soil are presented, emphasizing the differences in the lateral thrust between dry and partially saturated conditions. The presented results show the impact of the partially saturated condition on both the magnitude of the horizontal component of the lateral earth thrust and the failure mechanism at active state.

Highlights

The lateral earth thrust acting on retaining structures depends on the soil-structure interaction, type of wall movement, soil, and wall’s properties
Interpreting the results provided by the Particle Image Velocimetry (PIV) analysis, it was possible to observe the formation of the failure surface
A new physical model aimed to investigate the interaction between unsaturated soils and retaining structures has been presented

Summary

Introduction

The lateral earth thrust acting on retaining structures depends on the soil-structure interaction, type of wall movement, soil, and wall’s properties. The interaction between dry or saturated soils with retaining structures has been deeply investigated. The effects of the partially saturated condition on the lateral earth thrust have to be well established. Some examples can be found in Pufhal et al, (1983), Lu & Likos, (2004) and Vahedifard et al, (2015) [3,4,5] These studies provided helpful analytical methods for the computation of the lateral earth thrust. An attempt can be found in Vo et al, (2016) [6], in which the authors studied the passive state of a rotating rigid retaining wall interacting with an unsaturated silty soil

Methods

Results

Conclusion