Limit Analysis & Soil Plasticity
Devoted to the theory and applications of limit analysis as applied to soil mechanics, this text also contains information on soil plasticity and rock-like material such as concrete.
TABLE OF CONTENTS Limit Analysis & Soil Plasticity
Chapter 8: Active and Passive Earth Pressures
8.1 INTRODUCTION
The determination of the lateral earth pressure of a fill on a retaining wall when frictional forces act on the back of the wall is one of the classical stability problems in soil mechanics. In the same way as before, this problem can quite conveniently be solved by limit analysis. In the following sections, limit analysis is first applied to obtain upper and lower bounds for the lateral earth pressure against a vertical standing smooth retaining wall. It is shown by the coincidence of upper and lower bounds that the well-known Coulomb solution (assuming plane sliding wedge) for frictionless walls are exact. Upper-bound technique of limit analysis is then applied to obtain the solutions for the general lateral earth pressure problems including the effect of wall friction.
8.1.1 Active and Passive Pressures (Fig. 8.1)
Before we attempt to find the pressure in the rear face of a retaining wall, we note that lateral earth pressure can be divided into active earth pressure and passive earth pressure as illustrated in Fig. 8.1(a), which shows a particular apparatus consisting of a large bin with a movable end section. By filling the bin with sand, a lateral pressure is developed against the end section which simulates the wall. This wail is constructed so that it can be held in a fixed position or moved inward or outward. A horizontal force P n normal to the wall must be applied to this wall in order to keep the apparatus in equilibrium...
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