SEISMIC STABILITY OF GABION RETAINING WALL

Abstract

An experimental study has been conducted to investigate the stability of Gabion type retaining walls, R.R. Dry stone walls and Gabion wall with reinforced backfill. All models have same trapezoridal cross section of size 100 cm (height) x 51 cm (Bottom inclined width) x 20 cm (top width) were constructed in the tilt table and backfilled on one side with dry cohesionless Solani sand. Total sixteen models studied have different courses of gabion layers with varying wire meshes. In the first type of models walls were made having horizontal beds. In this, one dry stone wall and six gabion walls were constructed and tested. In the second set of models the beds of gabion layers were kept inclined towards the back fill at 3H:1V. In this case also one dry stone wall and six gabion walls were tested. In the third set, two models having reinforced backfill one reinforced with wire mesh extending 60 cm into backfill and other reinforced with polythene sheets extending into the backfill were constructed and tested. The table was tilted at very slow rate till the failure of wall. Various computations using tilt angle data have been done and the seismic performance of all the walls have been evaluated and tabulated. Earthpressure behind the wall is calculated using IS: 1893-1984 and the analysis of wall is done under pseudostatic condition. In all cases of gabion walls, considerable amount of bulging was observed before failure. Therefore gabion type walls provide sufficient warning before they are actually failed. Strength and weaving of wire mesh also affect the performance of the gabion type retaining walls.