临坡条形基础极限承载力上限计算  

Bearing Capacity of Strip Footing Adjacent to Slope with Upper Bound Theorem

作　　者：赵炼恒[1] 罗强[1,2] 杨峰[1] 李亮[1] 但汉成[1] 

机构地区：[1]中南大学土木建筑学院,长沙410075 [2]贵州省交通运输厅基建处,贵阳550003

出　　处：《武汉理工大学学报（交通科学与工程版）》2010年第1期84-87,92,共5页Journal of Wuhan University of Technology（Transportation Science & Engineering）

基　　金：西部交通建设科技项目(批准号:2006318802111);铁道部科技研究开发计划重点资助项目(批准号:2008G032-3);国家863计划重点项目(批准号:2007AA021908);湖南省交通厅科技项目(批准号:2007-29);中南大学优秀博士学位论文扶植项目(2008yb004)资助

摘　　要：利用极限分析中的机动法,构建临近边坡条形基础承受极限承载力的二维机动许可破坏模式.根据外力功率与内部耗能相等获得极限承载力的目标表达式,并把其转化成了一个求含有非线性约束的极限承载力上限解最小值问题计算模型.通过编制和调用计算程序,对建立的计算模型采用序列二次规划法(SQP)进行了优化求解.研究结果表明:边坡倾斜程度δ和岩土体内摩擦角φ对临坡条形基础地基承载力影响较大;边坡坡角δ的增加将使地基破坏区域发生显著变化,使各分项系数Nγ,Nc,Nq迅速减小;而内摩擦角φ增加对Nγ、Nc、Nq的影响则相反.The bearing capacity of a near strip footing under action of ultimate bearing capacity problem was studied by means of the kinematical approach of limit analysis theory. And the planar knematically admissible failure mechanism was constructed elaborately for the calculation schemes. The objective functions of bearing capacity were obtained by equating the work rate of external force to internal dissipation along the velocity discontinuities,and then the objective functions were transformed as a up- per-bound mathematic optimization model for bearing capacity as low as possible. The result of upper bound method for planar failure mechanism was obtained by use of the sequential quadratic programming （SQP）. From the numerical results, it can be seen that the dip angle of slope （δ） and internal friction angle （φ） of foundation have significant effects on the bearing capacity factor （Nr,Nc,Nq） of near strip footing.

关 键 词：地基承载力 临坡条形基础 上限定理 序列二次规划法 

分 类 号：U416.14[交通运输工程—道路与铁道工程]