基于能量法的锚杆失效模糊判别方法研究

Fuzzy identification method for failure of anchors based on energy principle

从能量角度出发,在理想弹塑性土体模型下建立了拉力型锚杆的势能方程,在最小势能约束条件下推导出了锚杆拉拔荷载与锚固体长度的关系解析解,证明了锚杆极限锚固长度的存在,获得了不同土质环境下锚固长度的取值规律及其影响因素。引入模糊理论原理构建了锚杆失效的能量法模糊判别模型,并对模型中的失效隶属函数和临界模糊区间作了具体分析。通过算例,将本文方法与工程实际进行对比,结果表明:本文的计算模型可行有效,能量法模糊判别不仅能对锚杆可靠度做较合理分析,并能对大多数锚杆破坏失效的案例作出解释。

According to the principle of energy,a potential energy equation for tensile type anchors is established based on the ideal elastoplastic soil model.Under the constraints of the minimum potential energy,the analytical solution about the relationship between drawing load and anchoring body length is derived,the ultimate anchorage length is proved,and the values of the anchorage length under different soil environments and their impact factors are found.By introducing the fuzzy theory,a fuzzy identification model is proposed to judge failure state of anchors using the energy method.The failure membership function and the critical fuzzy interval in the model are analysed.By comparing the proposed method with the actual project,the results show that the proposed model is feasible and effective.The energy method-based fuzzy identification can be used to analyze the reliability of anchor reasonably.Most of the damage cases of anchors can be explained.