Study On Deformation Mechanism Of Surrounding Rock In Typical Three-soft Coal Seams In Huopu Mine

Due to the particularity of coal storage environment,the problem of soft rock has always been one of the major problems perplexing coal mine safety production and efficient mining.About 60000 meters of roadway are excavated in soft rock every year.With the increase of mining depth,the problem of soft rock is becoming more and more serious,which directly affects the safety production of coal mine and endangers personal safety.The deep mechanical environment is more complex than the shallow one.In order to solve the problems of supporting and maintenance of soft rock roadway,the deformation mechanism and mechanical properties of surrounding rock of soft rock roadway are deeply studied,and then the deformation and failure mechanism of soft rock roadway is revealed,which can provide scientific guidance for similar engineering layout.Taking the inner section of gas control roadway in 260303 working face of Huoshaopu coal mine of Guizhou pan clean coal Co.,Ltd.as the research object,this paper analyzes and studies the surrounding rock deformation mechanism,structural deformation characteristics,stress response mechanism and movement deformation law of soft rock roadway by means of theoretical analysis,similar material simulation and numerical simulation.(1)The empirical formula of material ratio of similar simulation model was obtained by orthogonal test combined with relevant statistical knowledge.Firstly,the orthogonal design of 3factors and 5 levels was designed to make 50 rock samples.Secondly,uniaxial compression test is carried out to analyze its mechanical properties.Finally,according to the ridge regression statistical method,the empirical formula is obtained,and the practicality of the empirical formula is verified.(2)The similar simulation test is used to simulate the different supporting schemes before and after the soft rock roadway,and the deformation structure and stress response characteristics of surrounding rock are obtained.After roadway construction,under the influence of high stress,if no support is carried out,the roadway cross-section will have a large range of convergence deformation;when bolt steel scaffolding is used for roadway support,the roadway cross-section will remain relatively complete,and there is no large damage except the floor.At the same time,the convergence deformation is continuous and has time effect characteristics,and the stress remains stable after 8 hours of excavation.The stress of roof and floor decreases gradually,and the stress of two sides increases gradually.(3)Combined with the simulation test results of similar materials,the numerical simulation model of soft rock roadway engineering is established,and the numerical simulation test research of surrounding rock support based on the process of soft rock roadway is carried out.At the same time,the stress response mechanism and movement deformation law of soft rock roadway are further discussed.In the implementation process of different schemes,the use of anchor cable support and bolt steel scaffolding support are better than other schemes in the distribution of plastic zone,stress and deformation control,especially the bolt steel scaffolding support forms a "double shell" joint bearing mechanism,which combines the active support with bolt surrounding rock as the main body and the passive support with steel scaffolding as the main body The deformation of surrounding rock is limited and the stress of roadway is timely adjusted.