考虑时效特性的锚固岩质边坡变形可靠度分析

摘要

A non-intrusive stochastic finite element method for time-variant serviceability reliability analysis of anchored rock slopes with consideration of rock bolt corrosion is proposed.A rock bolt corrosion model reflecting the variation of the anchored force of each rock bolt with service time is established.Consequently,the computational procedure for time-variant serviceability reliability analysis of the slope deformation using the non-intrusive stochastic finite element method is proposed.The relationship between the probability of failure for slope deformation and the maximum allowable deformation is investigated; and a method for determining the maximum allowable deformation of the slope is proposed based on parametric sensitivity analysis.An example of reliability analysis of anchored rock slope deformation subjected to surcharge loading is illustrated to demonstrate the validity and capability of the proposed method.The results indicate that the proposed non-intrusive stochastic finite element method can effectively evaluate time-variant serviceability reliability of rock slopes.The rock bolt corrosion has a significant influence on the serviceability reliability of rock slopes as the service time of rock bolts increases.In addition,an approximate linear relationship exists between the logarithm of the time-variant probability of failure for slope deformation,lgpf,and the maximum allowable deformation; and this linear relationship becomes more obvious as the reliability level of the slope increases.%提出基于非侵入式随机有限元法的岩质边坡变形可靠度分析方法.建立考虑腐蚀效应的锚杆锚固力随服役时间变化模型.给出边坡变形可靠度分析非侵入式随机有限元法的计算步骤.研究锚固边坡变形失效概率与最大允许变形值之间的关系,并基于参数敏感性分析提出边坡最大允许变形取值方法.以锚固岩质边坡为例,证明所提方法的有效性.结果表明:非侵入式随机有限元方法为考虑时效特性的边坡变形可靠度分析提供一条有效的途径.随着锚杆服役时间增加,锚杆腐蚀作用对锚固边坡变形可靠度的影响越明显.考虑时效特性的边坡变形失效概率常用对数lgpf与边坡最大允许变形值间存在近似线性关系,而且随着边坡可靠度水平增加,该线性关系表现得越明显.