岩质高陡边坡地震动力响应共性和差异性

Research on the Generality and Otherness of Seismic Responses of the Steep Rock Slope

以国道G213左侧两处典型的单面、双面岩质高陡边坡为原型,采用新型离散元计算方法 CDEM,对高烈度地震作用下单面、双面高陡边坡上的滑体由变形累计到破坏滑动的全过程进行了模拟,并结合振动台试验结果,对单面、双面高陡岩质边坡的地震滑坡响应进行了研究。研究结果表明:单面、双面高陡边坡地震动力响应存在一定的共性和差异性。两者发生滑塌破坏的过程基本一致,即在地震力和重力作用下,滑体顶部先出现拉应力集中,造成滑体沿滑体结构面后缘产生变形,进而造成该处出现拉伸、剪切破坏点,之后随着地震动的持续,滑体结构面上的剪切破坏点逐渐向滑体中前部的锁固段扩展,同时伴随着滑体表面拉伸破坏点的增加,最终造成锁固段发生渐进性破坏,滑体从剪出口滑出形成滑坡。而两者在坡面、坡体加速度的高程放大效应、坡面加速度的傅里叶谱、反应谱等动力响应方面存在差异,说明了坡体形态、坡面角度对上述动力响应具有显著的影响。

A high steep hill with two-side slopes and a high steep hill with one-side slope near National Road 213 were used as a prototype. A full process from initial deformation to sliding of the slope during ground shaking was simulated by a new discrete element method （CDEM）. The results showed that there are some commonalities and differences about the dynamic responses between the slopes with two-side and one-side. The stress concentration phenomenon appears at the top of the sliding mass firstly, and then some tension failure points and some shear failure points appear there, which expands toward the toe of the sliding mass from the top of that along the struc- tural plane. The number of tension failure points gradually increases. At last, the toe of the sliding mass breaks, and then the sliding mass shears out from the toe, which results in the landslide. There are some differences in the accelerations on the slope and in the slope, as well as the Fourier spectrums of accelerations and the responses of the accelerations on the slope,which fully verifies that there are some remarkable effects of the slope angle and the slope structural kinds on those dynamic responses.