| In our country,Coal mining has over one hundred,the demand for coal has increased year by year,simple mining conditions of coal seam mining mostly complete,and with the increase of mining depth,coal seam mining phenomenon more and more common,and at the same time our country southwest mountainous area widely distributed in the flat slope of coal-bearing strata slope,high and steep slope topography on the airport and steep slow,structural plane development,has a "hard and soft interbed" slope structure.Underground mining activities exist in the lower slope for a long time,and most of them are multi-layer mining.The superposition of special geological conditions and multi-layer mining activities leads to the complicated overburden movement law,surface deformation law and slope deformation and failure mechanism.Therefore,it is of great significance to analyze and study the multilayer mining effect of mining slope deformation under such special geological conditions.Faer coal mine is located in liupanshui city,guizhou province,belongs to low mountain landscape,due to the strong tectonic erosion,cause ear fold down rolling terrain,low area south west high terrain north east,outcropped strata for the set of sandstone and mudstone longtan feixianguan group sandstone,to master the characteristics of the slope for the hard and soft layer,and by regional structure,terrain conditions,slope body structure and the effect of slope rock mass structure is complex,the rock mass integrity is poor,structural plane development.The area has a long history of mining.Since mining in 2006,6 layers of M1,M3,m5-2,m5-3,M7 and M10 have been mined.Under the action of multi-seam mining,jianshanying deformation body has been deformed for many years,but no overall damage has occurred so far.So this article to send ear in guizhou coal jianshan camp deformation as the research object,by collecting the mine data,field survey and geophysical exploration methods,find out the deformation of the slope body structure,jianshan camp mined-out area distribution characteristics and characteristics of deformation and failure,which is based on physical simulation and theoretical analysis method,analysis of the multilayer mining under the slope stress field change rule and displacement field change rule,overburden migration rule and rule of the surface dynamic mobile deformation.On this basis,the deformation and failure mechanism of the slope is analyzed,and the relationship between the thickness of the coal seam and the deformation of the slope surface is obtained.The main research achievements are as follows:(1)According to the detailed geological survey in the field,the basic characteristics of the deformation body in jianshan camp and the mining situation and goaf distribution characteristics of fayer coal mine in different periods were identified by means of uav,Insar and mine data collection.(2)According to the indoor rock mechanics test,the deformation jianshan camp each rock mechanical parameters,based on the results of field investigation and set up camp of jianshan geological concept model of deformation,the conceptual model we consider the interbed of hard and soft,the structure of the slope surface,and the coal bed mining,and so on and so forth,physical model similar than for the latter,by means of orthogonal experimental method to carry on the similar material proportion,select the optimal ratio of similar materials of various kinds of lithology.(3)Generalizing the geological model of jianshan camp deformation,using similar model test to analyze the stress change characteristics of the multi-layer mining slope,the deformation change of the slope body and the fracture expansion process.This paper analyzes and summarizes the laws of overlying rock movement and surface movement,and obtains the curve fitting formula of relation between mining thickness and surface displacement,and has a preliminary understanding of the deformation and failure rules of multi-layer mining slope.(4)By physical simulation test results as well as the predecessors have done research,can be summed up the overburden movement deformation mainly include:the dynamic process of deformation,crack development and fracture,the rock caving four stages,in the process of the strata movement,the four kinds of rock mass failure stage is a continuous cyclical dynamic evolution process.(5)Based on the actual field investigation,indoor physical simulation test and previous research results,the deformation and failure mechanism of jianshan yingying deformation body is systematically and comprehensively analyzed,and its evolution process can be divided into the following four stages: "Mining disturbance-bending crack → multi-layer mining-top crack → deformation intensification stage →slope surface collapse".(6)Multi-layer mining and goaf crossing slope foot are the main factors for the dramatic deformation of jianshan yingying deformation in faer coal mine.Slope deformation will continue to evolve and develop on the basis of the existing deformation.For other similar mines,when the mining scheme is designed,the goaf should be avoided from approaching or directly crossing the slope foot,and when the vertical distance between adjacent coal seams is very close,the multiple layers of coal should not be completely mined at the same position. |
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