Study On Surface Subsidence Characteristics With Super High Water Material Bag-Type Filling Mining

In recent years,as coal resources become more strained,various localities have gradually expanded the exploitation scale of “under three” resources.The methods of backfill mining is more and more widely used.Superhigh-water material has the characteristics of high water content,solidification speed and high strength,which has good application prospect.In this paper,the Jizhong Energy Handan Mining Group's superhigh-water material bag filling and mining is used as the engineering background.The surface subsidence characteristics of bag filling and mining are mainly used in field investigation,theoretical analysis,similar simulation,numerical simulation and field measurement.The main results are as follows:(1)Based on the geological conditions and filling technology of superhigh-water material backfill mining in Handan mining area,the law of overlying strata activity in filling mining with super-high water content is expounded.The surface control mechanism of filling and mining is analyzed systematically.The influence of filling ratio,structure and performance of hydraulic support and strength of filling body on bag filling mining is studied,and the filling rate is the key factor affecting surface subsidence.(2)Using similar and numerical simulation experiments to analyze the movement of overlying strata in bag filling and mining,the effect of filling rate on surface subsidence characteristics of bag filling and mining was studied,and the results of simulation analysis were carried out.Through the simulation analysis,the filling rate of the bag filling mining face is optimized,and the guarantee measures to improve the filling effect and the related control technology are put forward.(3)Through the field measurement,the control effect of the surface subsidence characteristics of the superhigh-water material bag filling and mining in Handan mining area is verified.The surface subsidence curve of bag filling mining is fitted,and the parameters of equivalent mining height and subsidence coefficient are obtained.Field measurement results show that under the special engineering geological conditions of bag filling mining of extra high water materials in Handan mining area,the filling rate increases,and the surface subsidence characteristics decrease when the equivalent mining height decreases.Bag filling mining working face of the filling rate is greater than 82%,which basically guarantees the protection of ground buildings.