Study On Deformation And Instability Mechanism Of Red Clay Slope Under The Influence Of Goaf

Most open-pit coal mines in western Inner Mongolia,Shanxi,and Yunnan have red clay overburdens.Most of the high and steep slopes formed by the combination of multiple red clay steps during mine mining are in the dynamic development stage of landslides.The stability of red clay slopes in open pit mines is related to the safety of mine production.Therefore,in response to the actual needs of mine enterprises with safety and high efficiency as the first purpose,it is the current time to carry out the study of the stability of red clay slopes under the influence of goafs.Problems that need to be solved urgently.This paper takes the red clay slope of the north side of the East Open Pit Mine of China Coal Pingshuo Company as the engineering practice background.Through the experimental study on the physical and mechanical properties of the rock and soil,the change law of the shear strength of the red clay with the water content is revealed.Based on the method of combining numerical simulation analysis and limit equilibrium analysis theory,the deformation and instability law of red clay slope with mined-out area and the stress distribution law of overlying rock and soil body are studied.Through research,it is found that the supporting arch structure widely exists in In the red clay slope rock and soil layer with mined-out area,the arch effect is one of the reasons for the redistribution of stress in the red clay slope soil layer.It is the premise of ensuring the temporary stability of the slope and is the subsequent arch effect theory.And provide a basis for slope stability calculation and evaluation.Through the numerical simulation study,the existence and characteristics of the supporting arch structure were discovered.The correction coefficient "k" of the thickness of the arch ring was introduced.The mechanical model of the supporting arch structure of the red clay slope under the influence of the goaf was established.Arch effect,and the red clay slope has a "step-like" development and change law from stability to failure,and the "shear-split-slip-collapse" deformation and failure mechanism of the red clay slope is obtained;Under the influence of the goaf,the red clay slope has a step-like development and change law from the initial stable state to the final instability failure.Three stages of deformation and failure are found,namely the initial deformation stage,the uniform deformation stage and the accelerated deformation stage Among them,the accelerated deformation stage is a prerequisite for the failure of the arch effect and the failure of the slope deformation instability;on the basis of the traditional slope stability evaluation,based on the relevant theory of the supporting arch,combined with the unique geological structure of the East Open Mine,a dynamic The slope stability evaluation method,combined with on-site monitoring data,conducted a comprehensive analysis of the stability of the red clay slope under the influence of the goaf and gave The control measures should slope stability.The research in this paper provides a theoretical basis for the study and evaluation of the stability of open-pit mine red clay slopes under the influence of goafs,and provides references and references for the stability control and landslide treatment of similar mine slopes.