DYNAMIC MODEL TESTS ON L-SHAPED GRAVITY RETAINING WALLS

摘要

Seismic design of retaining walls is traditionally based on the Mononobe-Okabe method of analysis. This method is an extension of the classical wedge theory in which both vertical and horizontal inertia forces are introduced in order to take into account the effect of earthquake shaking on the thrust acting on the wall. In recent years a number of theoretical analyses have been presented to predict the seismic behaviour of gravity retaining walls. Although all these studies provided interesting results, there is the need of experimental evidence and documented real cases. In this paper some shaking table tests performed on a L-shaped gravity wall retaining dry sand are described and the experimental results are presented with the aim to provide, though qualitatively, an insight into some important aspects of the dynamic behaviour of retaining structures resting on rigid foundation soil. Two different systems have been taken into consideration, namely, a wall retaining a horizontal backfill and a wall retaining an inclined backfill. During tests, both accelerations and wall displacements were measured. Through the transparent sides of the test box it was possible to observe the development of the failure surface and to measure the angle formed by such surface to the horizontal axis.