考虑岩桥断裂的岩质边坡倾倒破坏的流形元模拟

SIMULATION OF TOPPLING FAILURE OF ROCK SLOPE BY NUMERICAL MANIFOLD METHOD CONSIDERING FRACTURE OF ROCK BRIDGES

通过加入多裂隙扩展的跟踪模拟功能,将石根华博士提出的数值流形法进行扩充,使之既可以模拟块体系统的离散特性,又可以模拟完整岩体的拉裂与剪断。在用几个典型的简单算例验证算法及程序的收敛性和精度的基础上,对龙滩水电站左岸高边坡倾倒破坏离心机实验模型进行数值模拟,模拟中考虑1组贯通的陡倾角逆坡向构造和1组缓倾角顺坡向非贯通裂隙,模拟间断裂隙在外荷载作用下的扩展和岩柱的断裂。数值模拟的承载力和破坏模式均与实验结果吻合良好,可再现该类边坡倾倒破坏的机制,表明该方法与程序可以有效地模拟考虑岩桥作用的岩质边坡的倾倒破坏。

By adding the function of tracing the propagation of cracks, the numerical manifold method proposed by Dr. Shi Genhua is developed which can simulate both the discontinuity of block system and the tensile or shear failure of intact rock. Based on the examination of convergence and accuracy through several typical and simple cases, the centrifuge test that is employed to model the toppling failure of high rock slope on the left bank of Longtan Hydropower Station is simulated, which considers one set of connected opposite-slope joints with steep-dips and one set of along-slope cracks which are not disconnected with low-dips. In this numerical simulation, the propagation of disconnected cracks and the fracture of rock block under external loads are simulated; both the beating capacity and failure mode simulated numerically are in well coincidence with results of the test, which presents the mechanism of toppling failure of slopes of this kind again. Also, it shows that the proposed method and the program developed can effectively simulate the toppling failure of rock slope while considering the effects of rock bridges.