考虑中间主应力影响的条形基础承载力数值解
Numerical solution for bearing capacity of strip footing considering influence of intermediate principal stress
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摘要: 基于双剪统一强度理论使用二维显式有限差分计算程序FLAC,考虑中间主应力的影响计算分析了条形基础地基承载力因子Nc,Nq及Nγ。同时,使用Prandtl及Terzaghi地基承载力公式作为解析解与数值方法计算结果进行了对比。通过计算分析发现,忽略中间主应力影响的条形基础地基承载力数值解与解析解一致;考虑中间主应力应力影响的条形基础地基承载力数值解与解析解之间的差异与岩土材料的剪胀性有关。数值方法计算结果说明中间主应力对条形基础地基承载力的影响与地基土体的内摩擦角相关,而非解析解假定的常数倍关系。Abstract: The bearing capacity factors Nc, Nqand Nγof strip footing are calculated using a two-dimensional explicit finite difference code FLAC with twin shear unified strength theory. The bearing capacity formulae by Prandtl and Terzaghi are used to compare with the numerical solutions. The solutions of analytical and numerical methods are correspondent when the influence of the intermediate principal stress is neglected. The difference between the analytical and numerical methods is related to the dilation, and the influence of the intermediate principal stress on the bearing capacity of strip footing is concerned with the friction angle.