孔隙水压力的变化与滑坡速度的关系  

Relationship Between the Speed of Landslides and the Changes of Pore-Water Pressure

作　　者：曹颖[1] 殷坤龙[1] 徐丽萍[1] 

机构地区：[1]中国地质大学工程学院,武汉430074

出　　处：《地质科技情报》2014年第4期202-206,共5页Geological Science and Technology Information

基　　金：中国地质调查局项目(1212011220173);国家自然科学基金项目(41240023)

摘　　要：为了研究滑坡运动产生的孔隙水压力与运动速度的关系,建立了滑体饱和状态下的无限斜坡模型,结合有效应力原理以及剪切滑带处的土体运动定律,推导出滑坡运动速度v、滑带处的孔隙水压力uw以及滑坡运动时间t三者之间的解析表达式。并以三峡库区三舟溪滑坡为例,运用MATLAB编程计算得到三舟溪滑坡的v(t)-uw(t)之间的关系曲线。分析曲线得出:若滑坡保持某一速度v匀速运动时,由于土体排水固结作用,运动变形产生的孔隙水压力增量及时得到消散;在滑坡加速运动的过程中,孔隙水压力值随着加速度增大而增大,当孔隙水压力的增长速率超过土体的固结排水速率时,孔隙水压力大大削减了土体的抗剪强度,加速了滑坡的破坏。In order to explore the relationship between the speed of landslides and the pore-water pressure generated by landslide movement,in this study,a infinite slope model established under the condition of saturated slope was combined with the principle of effective stress and the soil＇s laws of motion to deduce the formulas on landslide speed v,the pore-water pressure uwat the slip zone,and the movement time.The analysis of the v（t）-uw（t）curves of Sanzhouxi landslide in the Three Gorges Reservoir,calculated by MATLAB programming,is shown as：①When the landslide keeps a constant speed v,the pore-water pressure generated by the motion and deformation is dissipated promptly due to the drainage consolidation of soil;②pore-water pressure increases along with the acceleration motion of landslide;③when the growth rate of the pore-water pressure exceeds the rate of drained,pore-water pressure is generated with greatly reduction of the soil shear strength and accelerate the failure of the landslide.

关 键 词：孔隙水压力 滑坡速度 无限斜坡模型 三舟溪滑坡 

分 类 号：P642.22[天文地球—工程地质学]