天然和饱水状态下路堑边坡稳定性离散元分析

路堑边坡稳定性分析是公路工程建设中的核心问题,而大多数滑坡都是在雨季或降雨后的短时间内发生,在边坡稳定性分析中合理地考虑降雨作用的影响是十分必要的。以渝黔高速公路某路堑边坡为研究对象,根据工程施工的实际情况,分五个开挖步、六个阶段对处于天然及饱水两种状态下的边坡稳定性进行了离散元动态模拟,并对软弱结构面处的关键块体进行了跟踪分析。分析结果表明,在整个开挖过程当中,天然状态时的边坡整体稳定性较好;如果边坡岩体处于饱水状态,边坡的稳定性程度则会明显降低,尤其是当边坡开挖至第3阶段时,即软弱结构面被切割临空后,边坡的位移值及安全系数大小均出现了大的跳跃式变化。再次证明了该岩质路堑边坡是否可能滑坡,实质上是受软弱夹层的强度控制,而水是导致边坡发生失稳破坏的诱发因素。研究结果能够为边坡的合理防治提供必要的理论依据。

Analysis of discrete element methods on stability of cutting slope at the nature state and saturation state

Stability analysis of cutting slope is the core issue of highway engineering construction.Most of the landslide occur in rainy season or a short time after rainfall.The effect of rainfall by considered reasonably is very necessary in the stability analysis of slope.For the sake of recognizing the deformation and destruction characters of cutting slope engineering,taking the cutting slope of YU-Qian highway for example,five excavation steps and six analysis stages are divided into simulating the slope stability dynamically by discrete element methods at the nature state and saturation state respectively according to the actual situation of the engineering construction,meanwhile,the key element of the weak interlayer is traced to analyzing.The results show that the slope has better stability at the nature state in the middle of excavating,and the slope stability level decreases obviously when the cutting slope is at the saturation state.Especially,when the slope is excavated to step 4,that is to say,when the weak interlayer is cut overhead,the fluctuation of deformation and safety factor is increased.The phenomena reconfirms that the weak interlayer is the important factor of controlling the slope stability,and water that causes slope instability and failure is inducing factor.The research results can offer necessary theory basis for the reasonable control of slope.