锚杆挡土墙可靠度分析与计算方法

提出了锚杆挡墙中肋柱锚杆体系的串-并联模型。将肋柱视为连续梁，锚杆视为弹性支座，引入锚杆与锚固段周围岩土体的复合刚度系数，用位移法导出了各根锚杆所受荷载的统一计算公式。考虑各功能函数之间的相关性，运用系统可靠性理论，提出了单根锚杆3种破坏模式的串联系统与多根锚杆并联系统的体系可靠度计算方法，并编制了计算程序。对一工程实例进行计算，并对计算结果进行了分析，发现单根锚杆的3种失效模式并非相互独立，每种失效模式对锚杆可靠度的影响也不一样，而3根锚杆并联系统的失效概率近似等于在其他锚杆均未破坏的条件下每根锚杆单独失效概率之和。

Analysis and calculation method of reliability of anchored retaining wall

A series-parallel model of rib beam-anchor system in reliability analyses of anchored retaining wall is presented.Regarding the rib beam as a continuous beam and the anchors as an elastic support,introducing a composite stiffness coefficient of anchor and the soil around anchorage section,the application loads acting on each anchor are obtained by displacement method.Considering the correlation of performance functions,based on the system reliability theory,a series system of three failure models for single anchor and a parallel system for multiple anchors are developed,while the calculation method of system reliability for the two systems is derived.The corresponding program of new method herein is used to compute the reliability in an engineering example.The calculation results show that the three failure models for single anchor are related and they have different effects on anchor’s reliability,yet the parallel system failure probability of three anchors is approximately equal to sum of the three single anchor’s failure probability at the condition of other anchors is not failure.