反倾层状岩体边坡稳定性的数值分析

 反倾层状岩体边坡的破坏和普通的滑坡不同，其破坏过程和破坏机制尚未十分清晰。弯曲倾倒是其中的一种特殊破坏形式，这种形式的边坡破坏和地质构造有很大的关系，用通常的连续介质理论不能很好地模拟和解析。根据不连续体理论，利用离散元软件UDEC，模拟弯曲倾倒破坏行为，讨论影响边坡稳定性的各种因素，为实际的边坡施工提供参考数据。通过模拟现场的边坡滑移过程，确定合适的分析参数。在此基础上，改变不同的边坡高度、倾角以及岩层的倾角和厚度，总结影响边坡稳定性的几个重要因素的相互关系。模拟结果表明，除了岩层间的力学参数以外，岩体边坡的稳定性还受岩层的厚度、倾角/走向以及人工边坡倾角的影响。这几个因素相互影响，相互制约边坡的稳定性。人工边坡的设计及施工应该对这几个因素综合考虑。

NUMERICAL ANALYSIS OF STABILITY FOR AN ANTIDIP STRATIFIED ROCK SLOPE

As a specific instability of rock slope，an antidip stratified rock slope is different from the sliding one，and the failure mechanism has not been clarified yet. It is clear that the flexural toppling behavior is influenced by the geological structure significantly，and the numerical method based on continuum theory does not seem to work well. It is aimed to discuss the flexural toppling mechanism by using a universal distinct element code(UDEC)，and to find out the critical parameters for the future large slope cutting. Firstly，a numerical analysis has been conducted to simulate the flexural toppling failure phenomenon，which happened in a construction site. Then，a series of numerical analyses have been carried out further in order to find out the critical geometrical parameters of the slope for flexural toppling prediction. A significant slip behavior is found between the blocks in the UDEC model；and typical flexural failure phenomenon is reproduced in the simulation. According to the numerical results，a thinner spacing of joints leads to a trend of flexural toppling in case of the same geometrical parameters of the dip angle and the gradient of the cutting slope. The toppling failure is related with an alternate relationship between the joint dip angle and the gradient of the cutting slope.