Settlement of Surface Strip Foundation Resting on Soft Clay Subjected to Vertical Cyclic Load

Abstract

The nature of dynamic settlement of a shallow foundation is strongly influenced by the response of soil whereas the response of soil largely depends on the cyclic loading. Therefore, it is necessary to study the soil response due to cyclic loading. The present study focuses on investigating the settlement response of a surface strip foundation resting on soft clay subjected to vertical cyclic loading in the form of a rectangular pulse. A strip foundation-soil system is modeled and the settlement response is estimated using numerical programming tool Open System for Earthquake Engineering Simulation (OpenSees). Combinations of an allowable vertical static load and rectangular pulse with a frequency of one cycle per second are applied to the footing. The magnitude of the allowable static load and the amplitude of cyclic load are varied to observe the settlement response of the foundation. The effect of variation in the magnitude of static allowable load and increase in the amplitude of cyclic load on the behavior of the foundation is observed. Based on the results obtained from the numerical study, the critical number of load cycles (ncr) after which the settlement becomes negligible for further cyclic loading, is estimated for each case. Furthermore, the effect of frequency of loading on the settlement response of the foundation-soil system for limited cases has been investigated considering two additional frequency of 0.5 Hz and 2 Hz.