Performance of caisson in soft clay under cyclic lateral loading

In this paper, the performance of caisson embedded in a soft marine clay has been brought out through the results obtained from tests carried out on model caissons subjected to both static and cyclic loading. The load-ground level deflection curves and the variations in lateral earth pressure with depth are presented and discussed for the cases of static, cyclic and post cyclic static lateral loading for the load eccentricity ratio (e/D) of 2 and caisson embedment ratios (L/D) of 2,3 and 4. Under cyclic loading with cyclic load ratios (CLR) up to 0.6, the lateral capacity of caisson is governed by static loading. With the increase in cyclic load ratio, there is in an increase in the lateral passive earth pressure. However, at higher cyclic load ratios, there is a significant increase in the lateral deflections. Based on the results of the investigation, it is suggested that the seawalls can be formed out of contiguous caissons installed in a line and these walls can be designed for cyclic load ratios up to 0.6 with suitable embedment ratios.