A structured model for natural soft clay

Natural soft clays in geotechnical engineering always show some structured behaviors, which are characterized by the softening stress-strain relationship. However, the Modified Camclay model, which is built on the basis of remolded soils, cannot capture such kind of structured characteristics. Two parameters of the Modified Camclay model are modified due to the difference between the slopes of the one dimensional compression curve and the failure line of natural structured soft clay and those of remolded soft clay. Changing laws of both the slope of the one-dimensional compression curve and the slope of the failure line is proposed to improve the Modified Camclay model to be able to simulate the softening stress-strain relationship of natural structured soft clay. This improved model is proved to be able to capture the structured behaviors of natural soft clay well by the comparisons between the simulation curves and the experimental curves of the triaxial tests on natural Osaka clay and Bothkennar clay.