用DDA 方法验证倾倒边坡变形的制动机制

倾倒边坡通常发育一组反倾坡向的结构面，其破坏形式主要表现为倾倒岩柱旋转弯曲折断破坏。一旦岩柱产生旋转，岩柱倾角随之变化，阻止其进一步翻转的摩擦力也将增加，随着倾角的变化，逐步使岩柱侧面的棱与面接触转换为连续的面接触，倾倒变形会随之停止，由失稳状态重新回到稳态。本文用非连续性变形分析方法DDA对Hoek经典倾倒例题进行验证，模拟了倾倒变形使岩柱产生旋转和张开裂缝，从初始岩柱间面与面接触转化为棱与面接触，再回到面与面接触，最终重归稳定的全过程，初步讨论了倾倒变形的制动机制。

Discussion on the deformation mechanism of topple rock slope using DDA method

The rock slope performing toppling failure usually involves a joint set of counter-tilt, and the failure mode involves rotation, bending and fracture of steeply dipping columns of rock. Once columns of rock rotate, the dip angles will change as well, and at the same time the friction force preventing further overturning will also increase. The edge-to-face contact will switch to continual face-to-face contact gradual- ly as the dip angles change, and then the toppling deformation will stop and the slope will return to the stable state from the unstable state. In this paper, a typical problem designed by Hoek and Bray is veri- fied by using DDA method. The whole process from initially face-to-face contact, through edge-to-face con- tact, then back to face-to-face contact, and finally back into stability is simulated, and the deformation mechanism of toppling failure is primarily discussed.