重力坝深层抗滑稳定多滑面计算方法探讨

Study on Multi-slip Surface Calculation Method for Deep Anti-sliding Stability of Gravity Dam

重力坝坝基深层滑裂面出现多滑面或双滑面形式的滑移节点较大偏移坝址垂线,若直接按照规范以双滑面计算式列出各滑移体的算式求解安全度,存在2个问题:建基面上部水平荷载和铅直荷载在滑移体上的分配方式存在多样;计算公式复杂,不利于迭代。为解决上述问题,将建基面上部荷载分别按应力和重力分配,利用等安全度的思想推导,分别得到了简化的分项系数和单一安全系数多滑面计算式。工程实例证明:采用简化的多滑面计算式验算重力坝深层抗滑稳定安全度是可行的;上部荷载按应力分配的计算结果较重力分配法偏于安全;将多滑面简化为双滑面计算得到的安全度偏大。

Calculation formulas of simplified partial factor and single safety factor were derived by using the equal safety coefficient method.It was proved by practical engineering that the calculation results were more practicable by applying the deduced formulas to calculate the safety factor.The safety factor calculated by the stress distribution method was smaller than that by the gravity distribution method.The result calculated by directly simplifying the multi-slip surfaces model into double-slip surfaces model was greater than that calculated by multi-slip surface model.