Study On The Relationship Between Support And Surrounding Rock For Paste Filling In Gaohe Coal Mine

Paste filling mining technology as an environment-friendly green mining technology,taking low-quality soil,industrial slag,gangue or tailings as aggregate,processed into required small-size materials,and then mixed with cementitious materials,mine water,fly ash,etc.According to a reasonable mix ratio to make paste filling materials,and then transported to the waiting filling area by self weight and pumping.After the filling material congeals,the roof subsidence is gradually controlled to form a “paste filling support—filling body” surrounding rock support control system,so as to control the roof deformation and surface subsidence.This technology can safely and efficiently recover the “three under” pressure coal resources and protect the ecological environment of the mining area.As a key part of the surrounding rock support system,the setting of the support strength of paste filling support directly affects the roof movement and the strata behavior,and also indirectly affects the resource recovery rate and the effect of ecological environment protection.In this paper,Gaohe coal mine paste filling mining as the research background,according to the overlying rock support system composed of paste filling support,filling body and coal body,based on the elastic foundation beam theory,the paper establishes the mechanical model of the relationship between paste filling support and surrounding rock,deduces the deflection differential equation of the roof rock beam of the filling face,the movement and deformation of the rock beam under the joint action of the support,the filling body and the coal wall are analyzed.The paper also discusses the influence of different factors on the roof.The results show that the elastic foundation coefficient of the support,the elastic foundation coefficient of the filling body and the roof subsidence before the filling body connected to the roof are the main influencing factors of the roof subsidence,and the functional relationship between the elastic foundation coefficient of the support and the support strength is given.According to the mining geological conditions of Gaohe mine,FLAC3 D numerical simulation software is used to establish the paste filling and slicing mining model.The deformation and strata behavior regularity of stope roof and filling false roof under different support strength are studied by simulating.The displacement field and stress field of the roof in the upper working face are analyzed synthetically.When the filling rate is 97%,the support strength is more than 0.6MPa,the effect of support controlling the roof is obviously weakened.According to the stress conditions of thestope obtained from FLAC simulation,a three-dimensional simulation model of paste filling support is established,and the mechanical response characteristics of the top beam,column and isolation combination of filling support under different support strength are studied by using the SW simulation finite element static analysis module.The research shows that when the support strength is greater than 0.6MPa,the column at all levels enters into the stress relief area,and its stress state no longer changes with the support strength,which confirms the FLAC simulation results from the perspective of the support mechanical characteristics.There are 94 figures,12 tables and 89 references in this paper.