4  Slope Stabilization With EPS Geofoam

4.1         Introduction

Geofoam introduced in recent years has provided solutions to a number of engineering problems. One of these problems is the slope stability problem. In a slope stability problem a slip surface develops between two portions of the soil as in figure 4-1. One portion tends to slip over the other making it unsafe for engineering constructions on the top or at the toe of the slope.

A sliding mass can be partitioned unto two main blocks: the driving block and the resisting block as shown in figure 4-1. If the mass of the driving block increases shear stress along the slip surface increases and the equilibrium in the slope is reduced. If the mass of the resisting block increases the equilibrium in the slope increases as the shear strength along the slip surface in the resisting mass block increases. One way to increase the factor of safety of a slope is to reduce the driving mass by replacing an amount of soil by foam.

Two techniques of analyses are used in this study; the limiting equilibrium method and finite difference method. Each method is used in separate numerical simulation softwares. Results by the two methods are compared for cases with and without geofoam. A parametric study was done to provide guidance for practical applications. 

Figure 4‑1 Driving and Resisting Blocks in a Failure Zone

Different values of horizontal seismic coefficients were applied to simulate earthquake effects on slope equilibrium. Important results of this study and a case history are presented in this chapter.