非线性破坏准则与岩土材料地基承载力研究  

Bearing capacity of a strip footing with nonlinear failure criterion

作　　者：杨小礼[1] 郭乃正[1] 李亮[1] 

机构地区：[1]中南大学土木建筑学院,长沙410075

出　　处：《岩土力学》2005年第8期1177-1183,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.50408020);中国博士后科学基金资助项目(No.2003034468)。

摘　　要：根据线性Mohr-Coulomb破坏准则,前人运用极限平衡法、滑移线理论或极限分析等方法求解地基承载力问题,但实际上岩土在剪切破坏过程中破坏准则具有非线性。因此,为了研究非线性破坏准则对地基承载力的影响,基于上限定理,通过“切线法”引进变量,根据能量耗散情况,将承载力问题转变为非线性规划问题,运用“序列二次规划算法”求出地基承载力的最优解。数值计算结果表明,当非线性破坏准则转变为线性破坏准则时,非线性参数对地基承载力有重要影响。With a linear Mohr-Coulomb failure criterion, an estimate of bearing capacity of a strip footing resting on a homogeneous and isotropic geomaterial foundation had been made using the methods of limit equilibrium, characteristics line and limit analysis in the previous literature. However, experimental data have shown that the strength envelopes of almost all geomaterials have the nature of nonlinearity. In this paper, a nonlinear failure criterion is employed to evaluate the bearing capacity of a strip footing using the upper bound theorem of limit analysis. A generalized tangential technique is presented to formulate the problem of bearing capacity as nonlinear programming problem. The optimum solution is obtained by a nonlinear sequential quadratic programming algorithm. From the numerical results, it can be seen that the nonlinear failure parameter has a significant effect on the bearing capacity; and that the solutions presented in this paper agree well with previous results if the nonlinear failure criterion is reduced to a linear Mohr-Coulomb failure criterion.

关 键 词：地基承载力 上限定理 非线性破坏准则 

分 类 号：TU431[建筑科学—岩土工程] TB115[建筑科学—土工工程]