基于非线性Mohr-Coulomb强度准则下锚索极限抗拔力研究

Study on the ultimate pullout force of pre-stressed cable based on nonlinear Mohr-Coulomb failure criterion

根据预应力锚索破裂面的形状参数方程、非线性Mohr-Coulomb强度准则和极限平衡原理,推导出一个能够考虑锚索破裂面形状、岩土体种类、抗拉强度以及围岩压力和灌浆压力等因素的预应力锚索极限抗拔承载力计算公式。理论计算结果和算例分析表明了该理论及其求解方法的有效性和可靠性。

Based on the biparametric equation for shape of rapture surface, according to the limit equilibrium principle and Mohr-Coulomb nonlinear criterion, the ultimate pullout force of prestressed cables could be calculated by the derived equation which considered the shapes of rapture surface, rock types, grouting pressures, grouting materials, unconfined compressive strength of rock and weathering degree. At last, a case of the ultimate pullout force for two type of rapture surface was given by using a nonlinear SQP algorithm and the relation between the nonlinear parameter and the ultimate pullout force was analyzed. The theoretical values agreed with the measured values from the field test.