Bearing Capacity Failure of Supported Cuts in the Presence of Seepage Flow by Coupled Finite Elements and Stress Characteristics Method

摘要

The deep-seated failure caused by inadequate shear resistance against the weight of the surrounding soils is often the more probable mode of failure prior to other types of failure. In this research, stability of flexible supported vertical cuts in granular soils against the deep-seated failure, in the presence of the seepage flow, is investigated. First of all, the flow field is computed by the traditional finite elements method. It is then assumed that the soil in the proximity of the bottom of the cut is at the verge of the limiting equilibrium. Once the flow field solution is known as a steady-state solution, i.e., the background solution, the stress field at the limiting equilibrium subjected to this flow field has been calculated. The method of stress characteristics was used to solve the stress field. It is, therefore, possible to estimate the factor of safety against the deep-seated failure and to assess the overall stability of the system. Results reveal that in spite of quite good margin of safety in the absence of the seepage flow, the deep-seated failure becomes most likely to initiate when the seepage flow exists.