【摘要】 复合加载情况下,精确求解非均质地基上矩形基础的极限承载力以及评价影响极限承载力的相关因素,具有很强的工程实用与理论参考价值.基于极限平衡原理,在Mohr-Coulomb破坏准则的基础上,将非均质地基上矩形基础极限承载力问题等价为边界待定的泛函极值问题.利用变分方法得到与平衡方程等价的积分约束条件,和相应的欧拉方程与横截条件.在引入问题的边界条件后,求得复合加载情况下非均质地基破坏时的滑裂面函数与破坏包络面.同时研究了土体内摩擦角φ_i、土体黏聚力c_i、矩形基础长宽比L/B、土层强度比c_i/c_i+1与地下水位变化等因素对地基极限承载力与地基破坏包络面的影响.更多还原

【Abstract】 To accurately evaluate the ultimate bearing capacity of rectangular footings on inhomogeneous soil under combined loading is very important in engineering.Based on limit-equilibrium theory and yielding criteria of Mohr-Coulomb,the equilibrium equations can be equivalently transformed to a functional extremization,which boundary values are undetermined,by using the variational method.After introducing the boundary conditions to the functional extremization,the function of the 3-D sliding surface and the failure envelope of rectangular footings on inhomogeneous soil under combined loading are achieved.The effects of the friction angle of soilφ_i,the cohesive force c_i,the ration of L/B,the shear strength ration c_i/c_i+1 and the fluctuation of groundwater level on the ultimate bearing capacity of rectangular footings on inhomogeneous soil foundation and the failure envelop are studied.更多还原