Abstract:At present, More-Coulomb failure criterion is often used to describe the soil parameters in the excavation calculation of foundation pit. However, the soil mass is a fragmented and three-phase discontinuous material, and it is difficult to reflect its actual mechanical properties with elastic model only, which results in a large deviation between the calculation results and the actual construction conditions. But the non-elastic material model (such as elastoplastic model) can consider the change of soil modulus with stress state, which is more consistent with the real strain characteristics of soil mass. Taking a foundation pit excavation project as the research object, the numerical simulation calculation is carried out based on ABAQUS finite element software. The Moore-Coulomb failure criterion and the Duncan-Zhang model parameters are adopted respectively to compare and analyze the influences of the two models on the horizontal displacement of foundation pit. The results show that the Duncan-Zhang model can describe the nonlinear mechanical behavior of soil more accurately and predict the horizontal displacement of foundation pit more accurately, which provides the theoretical basis and reference for the control of horizontal displacement in the excavation engineering of foundation pit.
