The Stability Analysis Of Cutting Slope In Cataclastic Rockmass In North-South Corridor Of Baohua Town

In recent years,with the increasing number of construction projects,their scales are growing,and the transformation and utilization of the mountain slopes by human are also increasing.While the characteristics of mountain slopes,especially cutting slopes,are different from soil slopes,together with the limited recognition on the cutting slopes,slope failure may occur during construction or after construction.Therefore,aiming at the fractured rock slope with different strata,lithology and weathering degrees,we need a comprehensive understanding of the cataclastic rock slope,determine its failure mode,and evaluate its stability.Then,the corresponding governance plans should be put forward.This paper studied the fractured rock cutting slope along the Baohua Road from north and south,and divided the entire study area into subareas based on the special terrain,topography and hydrogeological conditions.The different types of fractured rock slopes in the subareas were analyzed,respectively..The sliding surface in the extremely soft rock slope was determined and the strength parameters of the structural plane were obtained by the back analysis method based on the reliability theory.The main contents and achievements of the study in this paper are as follows:(1)According to the field geological investigation,The qualitative analysis of the overall stability of the fractured rock slope in the Baohua Road from north and south has been made.The lithology and differences of the strata are deterimined,and then the study areas are divided into several subareas..(2)According to the different failure parts of fractured rock slopes,the failure modes are divided into superficial collapse and deep sliding.The specific failure mode in each subareas are determined by joint statistics,software analysis and other methods to put forward feasible governance programs.(3)Theslope in Longtan and Gufeng Formations are generalize as soil slope,the failure mode of which is assumed as arc sliding.Thus,the stability is analyzed by the limit equilibrium theory.The results show that the safety factors of several slopes are near critical state,and the slopes may slide as a whole along the sliding surface.But the slopes in two terraces did not slip and their stability coefficients are more than 1.However,in simulation,the slopes are still in the unloading stage when the permeability coefficient of the rock mass is relatively small and the rainfall has not yet reached the internal slope so the rainfall is not taken into account in the calculation.As a result,stable state is only temporary and this is a very dangerous situation.In general,the rock slopes made up of Longtan and Gufeng formations are in unstable state.(4)By the back analysis for wedge slope failure in Gaojiabian Formation using the reliability theory and the failure probability,the mechanical strength parameters of rock slopes in critical state are obtained.Results show that,the mechanical parameters obtained by failure probability method are more fit for the actual situation of the project,and can be used for the engineering design.