Study On The Slope Stability Of Miaofeng Mountain Highway Under Heavy Rain

A large number of artificial slope projects have been formed in the construction of new projects such as highway,railway,water transportation and mine,which are characterized by high height,large area,large scale,wide influence range and complex and changeable engineering geological conditions.The mountainous terrain is widely distributed in Yunnan Province,frequent extreme weather such as heavy rain,landslide,debris flow,collapse and other slope failure accidents are common.Take the typical Chu-Da highway slope in Yunnan Province,the highway slope of Mount Miaofeng as background,the literature study,field survey and data collection,on the basis of combination of theoretical analysis,experimental research and numerical simulation method,the Mount Miaofeng high-steep rock slope engineering stability are analysis,the suggestion that ensure the slope stability is put forward.Its main research contents include:(1)Combined with the existing studies,the infiltration theory of rock slope under rainfall is summarized,the influence of rainfall process on rock mass mechanics is analyzed,and the steps of solving the saturated-unsaturated seepage problem with Galerkin finite element method are discussed based on the governing equation of saturated-unsaturated seepage.(2)The Mount Miaofeng rock slope engineering geologic condition,hydrogeological condition and the design scheme are discussed.Then BQ classification method of engineering rock mass classification in the Mount Miaofeng,mechanics of rock mass in the position of the representative sampling test.By uniaxial compression test and hygroscopicity test the strength of the change rule and the hydraulic characteristics of rock mass slope,the different soaking time of rock under scanning electron microscope(SEM)test,rock mass under the effect of different flooding is analyzed.(3)The typical slope section model of Mount Miaofeng is established by midas Soilworks software,the limit equilibrium method and finite element strength subtraction calculation of slope stability are calculated respectively.Then the inputparameters,the slip plane assumption,the differences between two methods are compared.The rainfall condition analysis model is established based on the finite element strength reduction method to study the rainfall infiltration law of unsaturated rock mass.(4)A 3D slope model of Mount Miaofeng rock slope is established by midas GTS NX software.The variation law of pore water pressure and saturation of rock mass at different rainfall times is analyzed,and the calculated safety coefficient and potential sliding surface position of slope at different rainfall times are obtained.Based on the established 3D slope model,the influence degree of anchor cable design parameters on slope stability is discussed by changing anchor cable length,anchor cable dip angle and anchor cable row spacing.