Limit Deformation Analysis of Unsaturated Expansive Soils During Wetting and Drying Cycles

Experimental observation on unsaturated expansive soils subjected to wetting and drying cycles presents a stabilized limit equilibrium state at the end of the suction cycles. Models developed previously for this behavior introduce a large number of parameters which lead to a time-consuming procedure to calibrate. This paper develops a limit analysis method with the Zarka concept for the mechanical behavior of expansive soils subjected to wetting and drying cycles. The required parameters of the proposed limit analysis method are calibrated by the experimental results obtained for bentonite/sand mixtures subjected to cyclic suction loadings in an odometric test. The comparison between the test results and the model predictions demonstrates the capacity of the proposed method to calculate the limit deformation during suction cycles and simulate the subsequent mechanical behavior of the expansive soils after suction cycles.