Study On Deformation And Stability Of Jointed Rock Slope Based On Probabilistic Statistics

According to the planning scheme of Qinhuai East River Project,it is necessary to excavate the mountain mass in Menjia Mountain of Nanjing City.After excavation,the bedding jointed rock slope will be formed,and deformation and stability of slope are controlled by structural plane.In this article,the distribution characteristics of rock mass structure planes in the study area were analyzed based on the probability and statistics theory through the field geological survey.The influence of structural plane and its distribution characteristics on slope deformation,stability and reliability was discussed based on rock mechanics and engineering geology theory.Under the condition of fully considering the influence of structural plane,the deformation and stability characteristics of slope were simulated and calculated,and the corresponding reinforcement measures and risk assessment conclusions also were given.The main works and achievements of this article are as follows(1)The failure mode of slope was determined to be plane sliding type by the site geological investigation and polar stereographic projection analysis.But under the influence of the combination of structural planes,the failure pattern of the slope will show diversity and even appear the step-like sliding surface.The development characteristics of structural plane were analyzed by means of probability and statistics theory;then,the probability distribution characteristics of structural plane parameters were determined(2)Based on the strength calculation model of the structural plane(JRC-JCS),the parameters of the M-C strength model for the structural plane in the rockmass were obtained by regressive fitting by the least square method.The normal and shear stiffness of the structural plane was determined by using the roughness coefficients of the structural plane and the measured rebound values.The discreteness of the structural plane stiffness was statistically analyzed and the probability distribution model was determined.(3)Fully considering the influence of structural plane,the excavation process of jointed rock slope was simulated by joint finite element method,and the deformation and stability characteristics of jointed rock slope were revealed,and the stability state of rock slope excavated for new river was determined,and the sliding risk of the upper shallow layer of the slope was analyzed.The relationship between stress and deformation of structural plane was given,the failure mechanism of rock mass along structural plane was analyzed,and the effect of key blocks on deformation and stability of slope was also studied in detail(4)Based on the results of theoretical analysis and simulation calculation,some measures for slope reinforcement were put forward.At the same time,the risk assessment of the reinforced slope was carried out,and reinforcement scheme and the early warning in the excavation process were suggested.