边坡稳定确定性设计与可靠度设计的安全判据等价性充分条件  

Sufficient conditions for equivalence between safety factor-based deterministic design and reliability-based design of slope stability

作　　者：曹子君[1,2,3] 周强 李典庆[2,3] CAO Zijun;ZHOU Qiang;LI Dianqing(MOE Key Laboratory of High-Speed Railway Engineering,Institute of Smart City and Intelligent Transportation,Southwest Jiaotong University,Chengdu 611756,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Institute of Engineering Risk and Disaster Prevention,Wuhan University,Wuhan 430072,China;Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430010,China)

机构地区：[1]西南交通大学高速铁路线路工程教育部重点实验室智慧城市与交通学院,四川成都611756 [2]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [3]武汉大学工程风险与防灾研究所,湖北武汉430072 [4]长江勘测规划设计研究有限责任公司,湖北武汉430010

出　　处：《岩土工程学报》2023年第8期1703-1712,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金重点项目(U2240211);国家自然科学基金项目(52278368)。

摘　　要：边坡稳定设计中不可避免地存在多种不确定性,确定性设计方法难以合理地考虑各种不确定性。相对而言,可靠度设计方法能够定量考虑岩土工程设计中的不确定性因素。确定性设计与可靠度设计采用了不同的安全判据,具有相同安全系数的设计方案的可靠度水平可能不同,导致两种设计方法的设计可行域不一致(即两种设计方法安全判据不等价),阻碍了可靠度设计方法在工程实践中的应用。相对安全率和广义可靠指标相对安全率建立了两种设计方法安全判据之间的定量联系,将广义可靠指标相对安全率应用于边坡稳定可靠度设计,提出边坡稳定确定设计与可靠度设计的安全判据等价性充分条件。基于随机场模型研究了单层和双层土质边坡确定性设计与可靠度设计的等价关系。结果表明:考虑空间变异性条件下,单层边坡可以满足所提充分条件,确定性设计与可靠度设计可以得到相同的设计可行域;相反,双层边坡不满足所提充分条件,难以建立两种设计安全判据的等价关系。Design of stability of soil slopes inevitably involves many uncertainties,but the deterministic design method is difficult to properly consider various uncertainties.In contrast,the reliability-based design(RBD)can quantitatively consider the uncertainties in geotechnical design.Different safety criteria are adopted in the deterministic design and RBD,and possible designs with the same safety factor may have different levels of reliability and resulting in the inconsistency of feasible design domains of the two design methods(i.e.,the safety criterion is not equivalent),hampering the applications of RBD in practice.The ratio of safety margin and the generalized reliability ratio of safety margin provide a useful tool to bridge the design criterion of the deterministic design method and the RBD.The generalized reliability ratio of safety margin is applied to RBD of slope stability,and the sufficient conditions for the equivalence between the deterministic design and RBD of slope stability are proposed.Based on different random field models,the equivalence between the deterministic design and RBD for two soil slope examples with one layer and two layers is studied,respectively.The results indicate that the one-layer slope satisfies the sufficient conditions when considering spatial variability,and the same feasible design domain can be obtained by the deterministic design and RBD.On the contrary,the sufficient conditions are not satisfied for the two-layer slope.The equivalence between the safety criterion of the two design methods for the two-layer slope example considering the spatial variability cannot be held.

关 键 词：边坡 可靠度设计 安全判据 广义可靠指标相对安全率 充分条件 

分 类 号：TU43[建筑科学—岩土工程]