Simplified Method for Calculating the Active Earth Pressure on Retaining Walls of Narrow Backfill Width Based on DEM Analysis

Minghui Yang,Bo Deng

doi:10.1155/2019/1507825

Abstract

Spaces for backfills are often constrained and narrowed when retaining walls must be built close to existing stable walls in urban areas or near rock faces in mountainous areas. The discrete element method (DEM), using Particle Flow Code (PFC-2D) software, was employed to simulate the behavior of cohesionless soil with narrow width behind a rigid retaining wall when the wall translation moved away from the soils. The simulations focused on the failure model of the soil when the movement of the wall reaches the value where active earth pressure occurs, and the shape of the sliding surface was captured. Then, based on the limit equilibrium method with the obtained slip surfaces in PFC-2D, a simplified analytical method is presented to obtain a solution of the active earth pressure acting on rigid retaining with narrow backfill width. The point of application of the active earth pressure is also obtained. The calculated values agree well with those from physical tests in the previous literature. Furthermore, the effects of the width of the backfill, internal friction angle of soil, and wall-soil friction angle on the distribution of active earth pressure are discussed.

Highlights

For simplification, traditional methods such as those based on the Rankine theory and Coulomb theory are commonly used to estimate the active lateral earth pressure
The discrepancy of the active earth pressure of narrow cohesionless backfill against rigid retaining walls is calculated by traditional theories, and the field data have been verified by centrifuge model tests
It is observed that the coefficient of active lateral earth pressure decreases with the depth and is smaller than the value calculated with the Rankine theory

Summary

Introduction

For simplification, traditional methods such as those based on the Rankine theory and Coulomb theory are commonly used to estimate the active lateral earth pressure Both of the theories assume the backfills can extend to a sufficient distance in which the failure plane can fully develop, so that these approaches cannot take account of the influence of the backfill width behind the wall [1, 2]. The distribution, as well as the location of the resultant of active earth pressures, was discussed in the paper

Numerical Modeling by Using DEM and Verification

Parameter Analysis

Findings

Methods b