Numerical back analysis of the behaviour of soft soil improved by rigid piles under cyclic loading

Abstract

The behaviour under cyclic conditions of soft soil improved using rigid piles, and in particular the load transfer mechanisms taking place in the platform, is still an open question and thus appeals to additional research works. A numerical study in a continuum has been performed, with low frequency cyclic surface loading (representing the case of filling and emptying of reservoirs, loading and unloading of storage areas, etc.). This study is developed based on experimental data obtained on a 1g laboratory small scale model, under monotonic and various cyclic loading configurations, simulating the case of a relatively thin granular load transfer platform, placed on top of the improved soil. The soft soil behaviour is simulated with the modified Cam-Clay model and the load transfer platform behaviour with the elastoplastic CY-soil model. The numerical results are compared to the experimental results, in order to conclude on the capacity of the developed numerical model to simulate the observed structure's behaviour.