三峡库区巴东李家湾滑坡变形破坏机理研究

以三峡库区李家湾滑坡为例,对库水位变动影响下的滑坡变形机理进行了探讨。通过现场详细调查、原位声波测试和室内岩体单轴抗压和耐崩解试验分析,认为滑坡岩性组合特征、节理裂隙发育状况为其变形破坏提供了运动空间,库水位波动、水流流动为滑坡内部岩体运动提供了动力条件。由于软弱夹层的存在,在自身重力作用下,斜坡内部岩体发生剪切滑移,坡面发生拉裂。在库水位周期性波动影响下,前缘坡脚岩体受到江水侵蚀,泥灰岩软弱夹层向内发生凹陷,岩体发生弯折倾倒破坏;在江水的侧向淘蚀作用下,岩体发生滑移、错动、坍塌破坏。

Research on deformation and failure mechanism of Lijiawan landslide in Three Gorges Reservoir area

Taking Lijiawan landslide of Three Gorges Reservoir area as an example, the landslide deformation mechanism un-der water level fluctuation is discussed. Through the detailed investigation, in-situ acoustic test, uniaxial compressive strength test and resistance to disintegration test, it is believed that the characteristics of lithologic combinations, joint fissure development status have provided space for the deformation and destruction, and the water level fluctuation and the flow motion have provided dynamic conditions for the rock mass movement inside the slope. Due to the weak intercalations, the shear sliding and surface cracking occurred inside the slope under the gravity. The water level fluctuates cyclically, the rocks of the slope toe is eroded by water and the weak interlayer of marlstone collapses inward, the rock mass bend, dump and was destructed;the rock mass slips, ruptures and collapses due to the lateral scouring efforts of the water.