重力坝深层抗滑稳定极限状态函数的适用性

建立重力坝坝基深层抗滑稳定极限状态函数是进行可靠度研究的第一步,对已有4种极限状态函数进行比较研究,探讨其合理性.研究结果表明:根据剩余推力法、被动抗力法及等K法表达式建立的极限状态函数计算得到的可靠指标是一致的,3种极限状态函数可统一表达为安全系数极限状态函数,而以上、下游块等可靠指标为约束条件的等β法高估了双滑块模型的失效概率,以此来评价坝基深层抗滑稳定的安全度并不合理.

Applicability of limit state functions of stability against deep sliding of gravity dams

The establishment of limit state function is the first step to analyze the reliability of the stability of gravity dam foundation.The four limit state functions are compared and the reasonability of the four is discussed as well.The results indicate that the same reliability index β could be obtained by the three limit state functions which are established by remaining push force method,passive resisting force method and equal K method.The three functions can be uniformly expressed as limit state function composed of safety factor.The result got by the so called equal β method which aims to make the two blocks have the same β overestimates the failure probability.Therefore,it is unreasonable to evaluate the reliability of gravity dams with deep slide problems by equal β method.