三峡库区水位变化条件下白水河滑坡抗剪强度弱化趋势分析

Study on Weakening of Shear Strength Parameters under Variation of Water Level for Three Gorges Reservoir Region

滑坡演化的本质是滑带土抗剪强度参数在多因素影响下随时间弱化的过程。使用试验法和工程地质类比法得到的滑带土抗剪强度都属于某一时间点,具有时间上的局限性。以滑坡实际监测的位移曲线及其趋势为依据,采用数值模拟手段对滑坡不同时间段的抗剪强度进行连续、继承反演分析,得到滑带土抗剪强度参数随时间有弱化的趋势。并以三峡库区白水河滑坡为例,运用GEO-studio数值模拟软件实现该反演过程,数值模拟结果与监测数据具有较好的一致性,表明通过参数反演得到的不同时间段的抗剪强度比较合理。

The essence of landslide evolution mechanism is a weakening process of shear strength parameters with time under the effect of various factors.But the methods including testing and engineering geologic analogy used to determine shear strength of sliding zone soil always limited to a specific time point.Based on the landslide actual displacement monitoring curve and its trend,numerical simulation method was used to determine the shear strength parameters of different periods with inversion analysis.Then the weakening law of shear strength parameters changing with time was obtained.Furthermore,selecting Baishuihe Landslide in Three Gorges reservoir region as research object,the shear strength parameters of different periods are obtained by using the GEO-studio numerical simulation software.The numerical results agree well with the displacement monitoring.The results show that the shear strength parameters of different periods obtained by inversion analysis are reasonable.