Study On Quantitative Relation Between Load-Unload Response Ratio And Stability Factor & Its Optimized Draining Control Of Huanglashi Landslide

Debris landslide, which includes all of the soil layer landslides, the accumulation landslides in mountainous district, and the loose accumulation landslides caused by constructing, unloading and weathering takes place in the Quaternary System and recent loose accumulation distributed. It has the characteristics of the broad distribution, the big scale, the strong burst and the serious destructiveness. Therefore, it will have a profound theoretical significance and vast economic profit to carry out the scientific prediction and control of this kind of landslides.Supported by the projects of National Natural Science Foundation of China-"Responding Ratio Parameter to loading & unloading and Displacement Dynamic Prediction of the Debris Landslides"(Code No: 40672182) and "Dynamic Parameter to Displacement vector angle and Displacement Integrated forecast in polyphyletic information of the Debris Landslides"(Code No: 40872184), and based on the fieldwork for the Three Gorges region and the system analysis on the basic feature and the displacement dynamic features of Huanglashi landslide, the numerical simulation is carried on the Huanglashi landslide by SEEP/W, SIGMAAV, SLOPE/W of the famous geotechnical engineering analysis software Geo-studio, and also the quantitative relation between the load-unload response ratio and stability factor is researched. Finally, the draining water plan of the Huanglashi landslide is carried on optimized control. The mainly research contents as follows:(1) On the basis of systematical analysis geological investigation and basic geology data on the typical debris landslide-Huanglashi landslide in the Three Gorges reservoir, this paper analyzes its general situation and evolutionary laws.(2) In terms of the numerical simulation and unsaturated seepage theories, the seepage in debris landslide under the conditions of diverse rainfall has been simulated, and the simulated seepage results had been drawn into stress field of slope deadweight, so the variation rules of displacement field can be obtained. Then the variation value of the rainfall can be chosen as the loading/unloading dynamic parameter, and the corresponding acceleration can be used as the loading/unloading response parameter, thus the loading/unloading response ratio model of rainfall can be determined. At the same time, the different stages stabilities including the seepage force have been determined through the numerical simulation, hereby the quantitative relation between the load-unload response ratio and stability factor of the Huanglashi landslide is researched. The result shows that there are the inverse proportion relations between them. Finally, two test points B4 and C3 of the Huanglashi landslide are carried on the confirmation to the obtained quantitative relation, then this relation is applied in the appraisal of this landslide prevention project.(3) This paper also analyzes and summarizes the draining water dredging methods of the landslide. And taking the Dashiban landslide of the Huanglashi landslide group as the optimized control example, this paper simulated eight plans of the landslide underground draining water, thus the preferred plan is that the position of the underground dry well and drainage gallery is arranged in the Front-middle part of the Dashiban landslide for draining water effect and efficient. At the same time, the surface draining water of the Dashiban landslide is researched, and the rainfall condition is carried on the counter-analysis under the different steady states, thus its corresponding rainfall value and the designed volume of the surface drain are gotten.