Research On Distributed Fiber Monitoring And Damage Characteristics Of Overlying Strata In Multi-Coal Mining

As an important energy source for our country,coal plays an important role in the development of the national economy.As coal mining depth and mining intensity continue to increase,mining conditions are more complex.And more coal seam mining conditions increase,resulting in increased safety issues.Therefore,the characteristics of overlying strata deformation and surface subsidence caused by structural changes in multi-seam mining have important practical significance and great social and economic benefits for the safe mining of coal resources and the effective use of land resources in goaf areas.This dissertation takes the geological structure of overburden mining in the coal seam of Daliuta mining area as research background,adopts distributed optical fiber sensing technology,designs a similar material model test for overlying strata,analyzes the evolution characteristics of cracks in roof overburden,and discusses the variation of surface subsidence parameters.The research results of the relevant papers are as follows:(1)Through the distributed monitoring of overburden deformation under single coal seam and multi-coal mining conditions,the evolution of stress evolution in goaf and coal pillar area is analyzed,and the vertical settlement and horizontal movement characteristics of overlying strata during coal seam mining are discussed.(2)Distributed optical fiber strain data is used to classify the overburden and surface impact areas,and combined with the characteristics of surface subsidence caused by coal mining,the acquisition method of mining subsidence parameters is proposed.(3)To study the correlation between the subsidence angle of coal mining,the advancing distance of the working face and the development height of the fissure zone,and to explore the influence of the spatial distribution between the upper and lower coal seams on the evolution of the overburden fracture and the subsidence angle of the coal seam in the multi-seam mining structure.