Numerical simulation of biaxial tests on structured loess by distinct element method

A relationship between the bond strength and the initial water content is established and used to incorporate water content to a bond contact model. Then using this model, various numerical biaxial tests on remolded and structured loess samples with different water contents are carried out by means of the distinct element method. The following conclusions can be drawn from these simulations. The macro-mechanical behaviors of biaxial tests on numerical and natural loess samples are similar. That is, as the confining pressure and initial water content decrease, the samples exihibit much strain softening and shear dilatancy. As the confining pressure and initial water content increase, however, the samples perform much strain hardening and shear contraction. The macro-mechanical behaviors are associated with the inter-particle bond breakage. Because fewer bonds of samples with lower confining pressure and initial water content are broken in the consolidation, the bonds affect biaxial compression more and the samples exhibit strain softening and shear dilatancy relatively.