【摘要】 通过对西北某坝肩边坡勘探平硐的现场调查,综合分析边坡的基本特征、岩体结构特征、坡体结构特征、变形破坏特征,认为坡体为形成年代比较久远的变形体,在自重的作用下坡体发生缓慢的变形,地震的作用加速了坡体的变形,从而形成了现今的变形体,但坡体未发生整体的失稳。由于坡体变形年代比较久远,故采用离散元数值模拟对其成因机制进行研究。研究结果表明:自重作用下坡体有沿缓倾坡外层面缓慢滑移变形的趋势,在地震荷载的作用下最终诱发边坡发生比较大的变形。坡体在变形过程中经历了启动、高速变形和自稳3个阶段,在启动阶段坡肩位置首先出现拉张裂缝,然后坡体中部出现变形,最后坡脚位置剪出。通过坡体中监测点加速度、速度的研究发现随着高程的增加坡体的加速度、速度放大系数明显增加。更多还原

【Abstract】 Through the investigation of deformed slope in left dam in northwest china by Exploration adits,the article research the basic characteristics,rock mass structure characteristics,structural characteristics of slope,deformation characteristics of slop. Come to a conclusion that the deformed slop formed for a long time. The deformation occurs slowly in the action of gravity,then,Earthquake accelerated the deformation of slop. Thus the deformed slop was formed,the slop had no overall instability. Due to the deformed slop formed in a long time,the article research formation mechanism of the deformed slope in left dam abutment of a hydroelectric power station in northwest China with discrete element simulation method. The results show that deforming slope inclined gently by the low-angle rock level under the action of gravity and was instability under seismic loads. The simulation of the subsequent movement of the slope shows that the movement mode of deformable body is starting-up →high-speed sliding→selfstabilized. Slop shoulder position fist appear tensile crack in the start-up phase,then the middle of slop deformed,finally cut out in the bottom of slop. Topographic amplification effects are also observed from both acceleration and velocity of the monitoring points of the slope.更多还原