| With the development of social economy, the transform to natural environment is more and more excesive by scope of human activities expanding quickly, which causes many geological disaster and makes many casualties and property losses.So reinforce the prevention and treatment of geological disaster is very urgent.Phyllite belongs to soft rock or extremely soft rock which is easy to weather,andthere is obvious difference in rock mass strength between rocks which have different degree of rock weathering,higher weather degree,lower mass strength. The phyllite is solid in natuer state,but easy to soften and disintegration under the impact of water, which is easy to triggered off landslide.The study on phyllite landslide is not enough,there is no accepted theory on formation mechanism and influencing factors of sliding surface in phyllite landslide. Landslide stability analysis is a very important procedure in landslide’s governance.In order to get the most close to the actual landslide stability analysis result,we must have strict requirements on accuracy of calculation parameters,expecially the dereference of saturation shear strength.In real project,the saturation shear strength of rock-soil mass comes from consolidation test and in-situ shear test that both have limitation,the former has large deviation,the latter is complex and expensive,so it is important to master accesser methods of the saturation shear strength of rock-soil mass.Phyllite is wide distribution in Yunnan province,like Lvchun in Honghe and Malipo in Wenshan.There are many landslide in Lvchun’s city scale,the government had done many meticulous suivey to proceed massive landslide control to protect people’s life and property form1992.This paper is on the base of gathering many prevention and cure project’s investigation reports,and divide these landslide to three types by sliding surface’s distribution position, completely-strong weathered interface landslide, strong-intermediary weathered interface landslide, wear layer landslide.From analysing the formation mechanism of the three types landslide,there have a certain guiding role to master the formation mechanism and influencing factors of phyllite landslide’ sliding surface.Many rusults of experiments and research have made clear that the saturation shear strength of rock-soil mass will attenuation under warter’s impact.In order to work out the accessor question of saturation shear strength,this paper has arrange many geotechnical investigation’ exploration data, statistical analysis the connection between shear strength and moisture content of completely weathered phyllite and strong weathered phyllite,and draw a conclusion how shear strength changes with the change of moisture content and regression equation.According to physical indexs,like porosity and dry density,we can get rock-soil mass’s percentage of saturated water content, which can bring the saturation shear strength by generation into the regression equation. Earthquake Administration landslide in Malipo occurred in phyllite,the climatic conditions here is exactly similar from Lvchun.This paper takes Earthquake Administration landslide as a example,analysis the formation mechanism and influencing factors of the landslide,and calculates the saturation shear strength of completely weathered phyllite and strong weathered phyllite by that regression equation, and makes the stability analysis.Judging by mastering landslide’s current situation and the result of stability analysis, pre-stressed anchor cable slide-resistant pile is choosed to be the treatment measure,combine the intercepting drain and bioengineering,and there is detailed introduction for the design of pre-stressed anchor cable slide-resistant pile.Earthquake Administration landslide is a double-deck landslide which has Shallow slide block and deep slide block,the impact to the slide-resistant pile by double-deck should be taken into consideration when design the pre-stressed anchor cable slide-resistant pile.First stept is structural calculation under deep slide block’s slide thrust,second is checking computations under shallow slide block.There are not many research on phyllite landslide and double-deck landslide,this paper takes Earthquake Administration landslide as example,analysis its stability analysis and design the governance project of this double-deck landslide,which has useful significance to study phyllite landslide and double-deck landslide. |
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