重庆云阳旧县坪滑坡成因特征与变形机制分析

发布时间：2018-04-24 17:57

本文选题：三峡库区 + 旧县坪滑坡　；参考：《水利水电技术》2017年03期

【摘要】：三峡水库蓄水后大量涉水老滑坡产生复活变形,其中旧县坪滑坡是三峡库区典型滑坡之一,自水库蓄水以来一直持续变形,变形位移呈现出典型的阶跃型特征。根据地质调查及专业监测资料,深入分析了滑坡变形特征,得到了滑坡变形的影响因素及其变形机制。结果表明:砂泥岩互层的靠椅形软弱地层为滑坡的形成提供了地质条件,滑坡复活变形的最主要影响因素则是库水位波动,受库水位下降时的饱水加载效应和动水压力效应影响,增加了滑坡下滑力,因此导致坡体稳定性急剧下降,从而产生显著变形。运用SEEP/W程序的计算结果表明,旧县坪滑坡在库水位快速消落期水位下降速率增大或叠加50年一遇的暴雨条件下,稳定性系数位于1.055~1.069范围内,在最危险工况下仍处于基本稳定状态。滑坡整体处于等速蠕滑变形阶段,在持续暴雨情况下有发生局部变形破坏的可能,在汛期须对变形破坏严重处采取局部防护治理措施。研究结果为滑坡监测预警与防治以及实际库水位调度提供了参考和依据。
[Abstract]:After the water storage of the three Gorges Reservoir, a large number of old landslides wading in the water produced resurrection deformation, among which the Jiu Xian Ping landslide is one of the typical landslides in the three Gorges Reservoir area, which has been continuously deformed since the reservoir water storage, and the deformation displacement shows a typical step type characteristic. According to geological investigation and professional monitoring data, the deformation characteristics of landslide are analyzed in depth, and the influencing factors and deformation mechanism of landslide deformation are obtained. The results show that the rock-shaped soft strata of sand and mudstone interbedded provide geological conditions for the formation of landslide, and the fluctuation of reservoir water level is the main influencing factor of landslide resurrection deformation. Under the influence of saturated loading effect and dynamic water pressure effect when the reservoir water level drops, the sliding force of the landslide is increased, and the stability of the slope body decreases sharply, resulting in significant deformation. The calculation results of SEEP/W program show that the stability coefficient of Jiu Xianping landslide is in the range of 1.055 ~ 1.069 under the condition of increasing or superimposing the decreasing rate of water level during the period of rapid fall of reservoir water level. In the most dangerous conditions are still in a basic stable state. The landslide is in the stage of constant speed creep deformation, and local deformation and failure may occur under the condition of continuous rainstorm. Local protective measures should be taken to deal with the serious deformation and failure in flood season. The results provide reference and basis for landslide monitoring, early warning, prevention and control and actual reservoir water level regulation.
【作者单位】：成都理工大学环境与土木工程学院;
【分类号】：P642.22

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