水平矩形浅锚极限抗拔力分析

在对锚板极限抗拔力进行分析时,既有研究手段和方法基本上都建立在相关联流动法则和岩土体材料的线性破坏准则基础上,然而大量实验成果证实岩土体材料一般并不遵循相关联流动法则且破坏准则具有非线性,因而现有极限抗拔力计算结果往往偏大。在上限定理的基础上,根据非相关联流动法则和非线性破坏准则,分别通过修正岩土材料的抗剪强度参数c*,φ*引入非关联流动法则和通过"切线法"引进非线性抗剪强度指标ct,φt的方法,研究了水平矩形浅埋的极限抗拔承载力问题。研究结果表明:岩土体材料的剪胀特性和岩土材料破坏准则的非线性对锚板基础的承载能力和稳定性有着重要的影响,因而客观评价岩土体材料的真实力学特性将更加符合工程实际。

Ultimate pullout capacity of horizontal rectangular plate anchors

The linear Mohr-Coulomb failure criterion and the associated flow rules have been widely used in geotechnical engineering.However,the experimental results show that the strength envelopes of almost all geomaterials have the nature of nonlinearity and the associated flow rules are unsuitable to geomaterials too.Therefore,larger results would be yielded.Based on the upper bound limit analysis theorem,the nonlinear M-C failure criterion and non-associated flow rules,and the ultimate pull-out capacity(UPC) of horizontal rectangular anchors are studied by means of the kinematical approach of limit analysis theory.The non-associated flow rules are introduced by means of the modification shear strength parameters(φ and c) and the nonlinear shear strength parameters(internal friction angle φt and cohesive force ct) are treated as variable parameters too for the calculation schemes.From the numerical results,it can be seen that the shear dilatancy of geomaterials and the nonlinearity of failure criteria have significant effects on the pullout stability.Therefore,a proper assessment for mechanical characters of geomaterials benefits engineering practice.