山区水库高陡边坡稳定性研究

Study on stability of high and steep slope in mountain reservoir

为了研究山区水库边坡的稳定性,以拟建红河特大桥的岸坡为例,采用不同理论计算方法分析了岸坡在自然、暴雨、水库水位变化、地震等不同工况下的边坡稳定性。计算结果表明,自然状态下以及库区排水过程,陡坡的安全系数均大于1,正常情况不出现滑动,处于欠稳定状态。但是地震、暴雨、以及地震和暴雨耦合工况均出现安全系数小于1。而且,暴雨工况比小震工况影响更显著,水位下降也会显著降低边坡安全性。正常工况下边坡潜在滑动体主要出现在边坡中部的上覆土区域,而在小震以上级别地震时边坡潜在滑动体范围扩散显著,甚至延伸到坡底范围。由于拟建桥梁位于边坡中部附近,建议对中部区域上覆土进行挖除或者进行加固,此外建议库区水不宜快速排泄,同时加强对坡体长期稳定性监测,保障桥墩稳定性。

In order to research the stability of the mountainous reservoir slope,taking the slope of the proposed Red River Bridge as an example,the slope stability of the bank slope was analyzed by different theoretical methods under different working conditions such as natural,heavy rain,reservoir water level change and earthquake. The results show that the safety factor of the slope was more than 1 under the natural state and the drainage process in the reservoir area,and it does not appear to slip in the normal situation. But under the seismic conditions,the state of heavy rain,and the coupled state of earthquakes and storms,the safty factor was less than 1. Moreover,the rainstorm state was more significant than the small earthquake state,and the water level decline will significantly reduce the slope safety. Under the normal working conditions,the potential sliding body of the slope mainly appears in the overburden area in the middle of the slope,and the potential slippage of the slope was significantly spread under the high earthquake level,and even extends to the bottom of the slope. As the proposed bridge is located near the middle of the slope,it is suggested that the overburden soil in the central area should be excavated or reinforced. In addition,it is suggested that the reservoir area should not be discharged quickly,and the long-term stability monitoring of the slope should be conducted to ensure the stability of the pier.