Stability Evaluation And Study On Bedding Rock Slope Of Highway In Mountainous Area

Recently years, in the a lot of bedding rock slope instability accidents happenedin western or southwestern mountainous highway projects in our country, especiallyin period of its construction or continuous heavy rain, and had constituted a majorthreat and damage on people’s life and property security. Therefore, how to accuratelyevaluate stability on bedding rock slope, has become the research focus in study fieldof engineering.This dissertation based on analyzation of the structural features of layered rock,and the stress and strain regularity on it, as well as its hydraulic permeability. Thefurther research on bedding rock slope stability affected by excavation disturbanceand continuous rainfall infiltration was made. The writer had token the bedding rockslope sites from En-lai highway in Hubei province as background project, and havedone slope stability research on the most typical site among them. The writer tried toapply both limit equilibrium theory and numerical simulation method for conductiona more-in-depth analysis and discussion of deformation mechanism and stabilitycalculation in the excavation or infiltration process. The main contents is as follows:(1) Based on the inter structure control theory of layered rock. Through toanalysis for internal structural plane form and deformation and failure mechanism oflayered rock, and statement about several main damage model of bedding rock slope.A more comprehensive understanding about deformation failure mechanism ofbedding rock slope have got.(2) Combined with the basic principle of hydraulic permeability in rock mass,through the infiltration softening mechanism analysis of stratified rock mass, itsstructure bedding plane and internal weak interbed. Writer have made bedding rockslope steady state clear in the gradually stages of infiltration, and have evaluated andanalyzed its stability by limit equilibrium methods and traditional safety factorcalculation method. At the same time, so as to present and analyze the failuremechanism of the two major factors (excavation disturbance and continuous rainfallinfiltration) for bedding rock rock slope.(3) Behind the statistics and defragment of slope structure and geological examination data along En-lai highway have done, then combined it’s engineeringgeological properties and route design, writer constructed a typical site model ofbedding rock slope to make slope structural stability analysis. And according toconsult and survey of geological data and related engineering standards, the slopemodel physical and mechanical parameters would have been selected. After that,using numerical simulation software Flac3D, contrastive analysis about the internalstress fields and deformation characteristics of bedding rock slope by the cut-slopeexcavation steps. Thus, the bedding rock slope stability effect by excavationdisturbance has been described with a more accurate explanation. Meanwhile,through the shear strength parameters amendment of bedding rock slope alongrainfall infiltration stages, At the same time, through to the bedding rock slope inrainfall infiltration in different stages of the strength parameters, contrastive analysisfor limit equilibrium states in different stages would have been done by the shearstrength reduction, Furtherly, the effect of bedding rock slope stability by rainfallinfiltration have been illustrated regard both strength degradation mechanism andtime stage effect.