非关联流动准则条件下条形锚板抗拔特性上限分析

Upper bound limi analysis of uplift behavior of strip anchor platein the case of the non-associated flow rule

岩土材料一般并不服从关联流动准则,考虑关联流动准则会显著提高岩土体材料的抗剪特性。基于极限分析上限定理、非线性Mohr-Coulomb破坏准则和非关联流动准则,构建浅埋水平条形锚板抗拔破坏机制,分别计算速度间断面上的内能耗散功率和外力功率,通过虚功率原理建立抗拔力的泛函表达式。采用变分原理得到土体破裂面方程及其正应力分布,结合边界条件得到锚板的极限抗拔力。通过与数值计算结果的对比分析,验证了本文方法的有效性与准确性。在此基础上,分析了非关联流动准则对锚板抗拔特性的影响规律,结果表明:考虑关联流动准则会提高锚板的抗拔力。

Generally,geomaterials do not obey the associated flow rule,and considering the associated flow rule will significantly improve the shear properties of geomaterials.Based on the upper bound theorem of limit analysis,the nonlinear Mohr-Coulomb failure criterion,and the non-associated flow rule,the uplift failure mechanism of shallow horizontal strip anchor plate was constructed.The internal energy dissipation power on the velocity discontinuity and external force power were calculated respectively,and the functional’s expression of uplift capacity was established by the virtual power principle.The equation of soil fracture surface and its normal stress distribution was obtained through the variational principle.Combined with the boundary conditions,the ultimate pullout capacity of the anchor plate was obtained.Compared with the numerical results,the effectiveness and accuracy of the proposed method were verified.On this basis,the influence of the non-associated flow rule on the uplift behavior of the anchor plate was analyzed.The results show that considering the associated flow rule can improve the pullout resistance of the anchor plate.