Study On The Overlying Strata Movement By UCG Mining With Backfill In Tongyi Coal Mine

Underground coal gasification is the coal in situ subsurface direct combustion and gasification, is a self-heating type gasification combustion mode, fuel gasification furnace flame working face and around the temperature can reach 1000 DEG C or so, burning empty region of high temperature air by convection and radiation heat transfer heating of stope surrounding rock, the rock temperature burnt. Queening rock physical and mechanical properties of burning will occur great changes, underground coal gasification on mining field of surrounding rock stability and gasifier operation safety caused certain effect.Underground coal gasification fuel filling of mined out area is on the gasification combustion empty area within the scope of the filling of cemented filling materials, to support the roof, controlling the ground subsidence, reduce the number of overlying rock fissure and range, reduce the gasification furnace is closed to the influence of. The filling material can also be consolidated to the gasification of pollutants, reduce the migration of pollutants, and thus reduce the pollution of the underground environment. According to the actual mining environment, this chapter summarizes the domestic widely used coal mine filling technology, designed to apply to the underground coal gasification process of coal combustion.In a mining problem solving process, the force under the condition of burning empty zone of overlying strata should stress distribution and rock movement analysis. According to the related strata pressure monitoring data, the theory of beam on elastic foundation model can be very good agreement related to the rock pressure phenomenon of small deformation and low stress. Therefore, in order to analyze the movement and deformation of overlying strata under the condition of filling and filling, the elastic foundation beam model with temperature field needs to be studied. This chapter to establish the filling condition with temperature field of elastic foundation beam mechanical model, considering the burning thermal damage to the empty district country rock, established the basis of injury fuel filling of mined out area of elastic foundation beam model, and solving the covering key rock layer deflection equation of the analytical solution.This chapter in accordance with the agreement of the actual situation of the mine geological environment, comparative study of agreed to underground coal gasification combustion variation of overlying strata deflection curve under the condition of non-filling and filling of mined out area, show that under the condition of non-filling and filling law of overlying strata movement is basically the same, but filling conditions under the movement of overlying strata deformation decreased, and is beneficial to control the movement of overlying strata and to ensure the gasification furnace closed.In this paper, the surface and overlying strata movement monitoring system of Tongyi coal mine is designed to monitor the movement of the earth’s surface and overlying strata. Verify the correctness of the theoretical calculation, ensure the reliability of the gasifier operation.