有限元稳定分析法在确定土体结构极限承载力中的应用

本文引入有限元稳定分析法来求解土体结构的极限承载力。在有限元应力应变分析的基础上，通过搜索临界滑动面并增大外荷载使临界滑动面安全系数为1.0来确定极限承载力，并指出由此得到的极限承载力是土体结构沿临界滑动面整体达到极限平衡时的真正承载力。算例表明此法可行，同时将该方法推广到求解边坡极限承载力和地基承载力。文中还研究了边坡极限承载力同自重和坡角的关系。与各传统地基承载力公式比较发现，在土体内摩擦角比较大时，经验公式均低估了地基承载力。最后分析了计算参数变化对地基承载力的影响。

Application of finite element analysis in determining the ultimate bearing capacity of soil mass

The FEM for stability analysis is applied to evaluate the ultimate bearing capacity of soil mass. Based on the finite element stress-strain analysis the ultimate bearing capacity is determine by searching the critical slip surface and increasing the external load until the safety factor of the critical slip surface reaching 1.0. It is indicated that the results obtained from stability assessment by using FEM are the correct bearing capacity of soil mass in the state of limit equilibrium. The effectiveness of this method is verified by some examples and the application of this method is extended to evaluate the ultimate bearing capacity of slope and foundation. The relations of slope ultimate bearing capacity between angle of slope and the unite weight are investigated. The comparison of various classic formulas for bearing capacity with the proposed method shows that the foundation bearing capacity is underestimated by the empirical formulas, under the condition of large internal friction angle. Finally, the effects of parameters variations on foundation bearing capacity are also analyzed.