基于非均质边坡强度折减法的三维桥基边坡稳定性分析

基于场变量的强度折减法，以三维一般边坡和陡边坡作为算例模型，对非均质边坡的折减范围进行研究。研究中借鉴某学者研究成果，在ABAQUS中对岩体材料的抗剪强度参数( )和抗拉强度参数T同时进行强度折减，并结合目前边坡失稳判据存在的不足，提出采用坡体内关键部位特征点位移增量 与强度折减系数增量 之比值 和强度折减系数 关系曲线的突变点来确定边坡的临界失稳状态。结果表明，对于一般边坡，只有当黏聚力相差不大的情况下，对黏聚力较小土层实施局部折减才能得到合理的安全系数，对于坡体内存在岩质相差较大的边坡建议采用整体强度折减，相反对于高陡三维边坡而言对相对较软的岩体进行局部折减可以得出较为可信的结果。通过与传统特征点位移法判据相比较，验证了 法的实用性和合理性，同时基于该判据计算出桥基边坡运营期间的安全系数，可为岸坡治理提供理论依据。。

Stability analysis of three-dimensional bridge abutment slope based on strength reduction method for inhomogeneous slope

The three-dimensional general slope and steep slope as numerical models are used to research the inhomogeneous slope reduction scope by the field variables based on finite element strength reduction method. In the study, from some scholars research results, both rock material’s shear strength parameters and tensile strength parameter T are reduced in ABAQUS. In light of the current shortage in existing slope stability criterion, the point mutant which sites on the relationship curves between the ratio of the feature point displacement’s increment to the strength reduction coefficient’s increment and the strength reduction factors is applied to determine the critical state of slope. The results show that the reasonable safety factor can be obtained only when the local reduction in the cohesion of similar circumstances is implemented and suggests that the overall strength reduction can be used for the rock mass difference slope, whereas the more reliable results can be obtained for the relatively soft local reduction in the high and steep three-dimensional slope. Compared with the traditional feature point displacement criterion, the (the relationship between feature point displacement increment and the strength reduction coefficient increment ratio and strength reduction factor) method is proved to be practical and reasonable. Meanwhile, the safety coefficient of bridge foundation is calculated based on the criterion, so as to provide a theoretical basis for the control of the bank slope.