Method On Strength Degradation Of Rock Structure And Analysis Of Slope Failure Under Engineering Disturbance

With the development of the country,a large number of exploitation and construction have been developed.And the shortage of land resources has forced large-scale engineering activities to be carried out on mountain or hilly slopes,which destroy the original natural balance of rock mass.As a result,a large number of collapse,landslides and other rock slope instability disaster have been induced.At the same time,the growing impact of these disasters is more and more serious,which directly affect the development of socio-economic and people's lives in all aspects.That is to say the stability analysis of rock slope under the influence of human engineering activities has a long way to go.Domestic and foreign experts and scholars have carried out a lot of researches with regard to the stability analysis of rock slope under engineering disturbance.Many of the existing studies analyze the catastrophe process of rock slopes by engineering monitoring.That is to say many studies are focused on qualitative research and lack of quantitative calibration of rock slope disaster instability and deep mechanism research.In this paper,considering the effects of weak structural plane,the catastrophe induced mechanism and quantitative forecasting of unstable process of rock slope under engineering disturbance would be researched.The research works have carried out from the following several aspects:(1)With the analysis of the factors that affect the stability of rock slope,the multi-level and multi-index evaluation system for analyzing the rock slope stability is established from the geological and environmental conditions of rock slope.The quantitative analysis of the influence level of the evaluation index on the degree of rock slope stability is carried out by the establishment of matter element and the calculation of correlation function which are based on the extension theory.And the most significant factors affecting the rock slope stability and the corresponding evaluation index are obtained.(2)The disturbance process of the rock mass is quantified in the form of stress,and the transmission process of the stress wave in the weak structure plane is analyzed,and the attenuation process is quantified.The stress wave of the engineering disturbance is applied to the structural plane element in the form of horizontal stress and vertical stress,and the original self-weight stress of the weak structure plane is superimposed at the same time.As a result,the stress state analysis and the derivation of the stress formula of the weak structural plane under engineering disturbance are realized.(3)Based on the established stress analysis model and the Coulomb-Navier criterion,the criterion of strength analysis of weak structural plane under engineering disturbance is deduced.Further more,the mathematical expressions between stress and shear strength parameters of structural plane is given.Based on this,the effect of the engineering disturbance on the rock slope strength is realized.Also,the damage effect of the engineering disturbance on the weak structural plane strength of the rock slope is realized and the reduction coefficient is used to describe it quantitatively.(4)Based on the calculation formula of the safety factor of the block,the stability judgment formula of the block under the disturbance of engineering is given by using the reduction coefficient of the damage effect under the action of the engineering disturbance.At the same time,the judgment method of block stability is implanted into GeoSMA-3D software which developed by our own team.Combined with the original block search module in the system,the search and visual analysis of key blocks under engineering disturbance are realized.(5)When the key block is determined,the instability characterization coefficient of key block is proposed.This coefficient takes the safety factor and volume of the key block into account,which achieve a more accurate determination of the key block.At the same time,the weight of each key block on the slope stability is determined by combining this factor with AHP.And the safety factor of the slope can be defined by the product of each key block' s safety factor and its weight.That is to say the information of key blocks was applied to characterize the stability of the slope.And a convenient and feasible evaluation method about rock slope stability is given.