库水升降作用下浮托减重型滑坡稳定性研究

Stability studies of buoyancy weight loss landslides under reservoir water level fluctuation

大坝建成后形成众多涉水滑坡。为研究库水位升降作用对涉水边坡稳定性的影响机制,基于重大涉水滑坡分类,针对浮托减重型滑坡,运用自主研制的滑坡模型试验系统,建立浮托减重型滑坡模型进行库水升降作用试验。试验结果表明,库水位升高,滑坡模型体内有效应力随之减小;库水位降低,有效应力随之增大。对于模型试验过程,运用Geo-studio软件进行渗流及稳定性计算,对照试验结果与数值模拟结果得出土压力及孔隙水压力渗流模拟变化情况与试验实测变化情况基本吻合。库水位上升阶段,滑坡稳定性系数随之减小;库水位下降阶段,滑坡稳定性系数随之降低。由此分析得出库水升降对浮托减重型滑坡稳定性的影响规律是:库水位上升引起滑坡体内阻滑段有效应力随之减小,导致滑坡稳定性降低;库水位下降引起滑坡体内阻滑段有效应力随之增加,使得滑坡稳定性提高。

Numerous wading landslides formed after dams were completed. In order to study the impact of the wading landslide＇s stability induced by water level fluctuation. Based on the classification of significant wading landslide, in light of landslide of buoyancy weight loss, applying the self-made landslide model test system, and establishing the landslide model of buoyancy weight loss, the reservoir water level fluctuation test is carried out. The test results indicate that the effective stresses of the landslide model decrease with the reservoir water level increasing and increase with the water level lowering. For the model test, Geo-studio software is used to model the process of seepage and calculate the stability. By comparing the results of experiment and numerical simulation, it is shown that the changes of seepage simulation of earth and pore water pressure are basically consistent with changes of test results. The stability coefficient decreases with the reservoir water level increasing and rise with the water level lowering. The law of reservoir water level fluctuation on the buoyancy weight loss landslide stability is drawn as follows; that effective stresses of the landslide decrease with the reservoir water level increasing, resulting in lower landslide stability; effective stresses of the landslide increase with the reservoir water level lowering, so as to make the landslide stability increase.