DISPLACEMENT ANALYSIS OF RETAINING WALLS UNDER STATIC AND DYNAMIC CONDITION

Abstract

A retaining wall is a structure constructed to retain vertical or nearly vertical slope of earth and other material such as grain, ore, liquid etc. Retaining walls are susceptible to failure if their displacements under static and dynamic conditions are not properly predicted. Thus displacement criteria becomes Important in the design of retaining walls. A displacement analysis under static condition is proposed by modelling the backfill as closely spaced independent elastic springs. The spring constants are evaluated using the concept of soil modulus. Initially the springs are assumed to be precompressed so as to create at rest condition. Now, for any displacement the spring forces are found out and these are substracted from (or added to) initial forces for displacement' away from the backfill (or towards the backfill). The resulting. sum of spring forces gives the pressure for any given displacement. The displacement of rigid retaining walls under dynamic.. condition, is estimated incorporating combined rotational and translational movements. The backfill soil is replaced by closely spaced independent elastic springs, with dashpot attached in series of each spring. The backfill is treated as elasto-plastic material when the wall moves away from the backfill and elastic when wall moves towards the backfill. Besides displacements, the method of analysis also compute earth force and pressure distribution for any earthquake induced displacement of wall