基于可靠性理论抗滑桩设计体系的研究

Study on designing system of anti-slide piles based on reliability theory

抗滑桩设计的常规方法是建立在定值基础上的,未能考虑计算参数的随机性与变异性,故在抗滑桩设计中存在局限性:一是不能给出抗滑桩设计的边坡安全度;二是设计中过分保守,造成浪费。可靠性分析法考虑了计算参数的随机性。用严格的概率来度量边坡的安全度,弥补了上述传统抗滑桩设计中存在的不足。基于可靠性分析法,以传统边坡稳定性计算公式为基础。建立了抗滑桩设计的边坡稳定性评价模型.并且运用蒙特卡罗法,采用单参数敏感性分析方法,分析抗滑桩设计各参数对边坡安全系数及可靠性指标的影响。结果表明,岩土体抗剪强度参数、岩土体重度、抗滑桩直径等因素对可靠性指标影响较明显,边坡安全系数对岩士体重度、抗滑桩有效长度、抗滑桩直径等随机变量较敏感。

The conventional methods for designing of anti-slide piles are based on constant value;it isn't consider the randomness and variability of the parameters,so the design of anti-slide piles will lead to some limitations:one is the methods can not give the safety of the slope;the second is the relatively conservative designing will lead to waste.But the reliability analysis method that consider the randomness of the parameters can measure.the safety by rigidity probability,so that it also can make up difference that lie in the tradition anti-slides piles.Considering the reliability method,basing on computing formula of traditional slope stability,the evaluation model of slope stability is built.Using the M-C method and the single parameter sensitivity analysis method,the parameters in the design of anti-slide piles on safety factor and the reliability index are presented.It is demonstrated that the reliability index is affected obviously by the shear strength parameters,the gravity of rock and soil,the diameter of anti-slides piles, and the safety factors of slope sensibility is higher in some parameters such as rock and soil gravity,pile effective length,and pile diameter etc.