摘要
Abstract
Based on the in situ investigation data and experimental data from the landslide of the section (109 + 620-109 + 800) of the typical expansive soil channel for the North Hubei Water Transfer Project,the causation of the expansive soil channel landslide is explored from the aspects of fissures,atmospheric precipitation,construction,prevention measures,etc.,and then the mechanism of the landslide failure is studied,while the anti-sliding coefficient for the slope stability before and after the opti mized design and construction is verified through the relevant simulative analysis with the rigid body limit equilibrium method (M -P method).The result shows that the expansive soil channel landslide is mainly dominated by the soil fissure,while the rain fall splitting effect plays the role of connection and breaking-through of fissures.Under the influences of atmosphere or rainfall,steep-dip fissures are developed in the upper weak expansive soil body,which often form the trailing edge of the landslide body with declined deformation.Long and large irregular low-dip fissures are developed in the expansive soil at the slope toe,foundation,etc.,and then provide weak sliding planes or zones for forming the front edge of landslide body.The surface soil is softened by long and strong rainfall,thus its strength is lowered,while the inflow of rainfall plays a fracturing role on the soil body.The non-isotropic fissures broken through by multiple dry-wet circulations create deep weak sliding planes or zones for the slope land slide.Moreover,improper construction and insufficient prevention measures are the human factors to cause the expansive soil landslide of this time.In order to ensure the stability of the expansive soil slope during the late period of the project,the principle of rapid construction,geological prediction,dynamic design,closing in time,backfilling as soon as possible,etc.must be followed for selecting reasonable slope ratio,building up effective drainage system,hardening and continuously covering the primary slope,furthermore,making real-time monitoring and control on slope collapse or sliding.关键词
膨胀土/渠道滑坡/裂隙/大气降雨/滑动面/鄂北地区水资源配置工程Key words
expansive soil/channel landslide/fissure/atmospheric precipitation/sliding plane/North Hubei Water Transfer Project分类
水利科学
