Monitoring and effect evaluation of subsidence reduction by superhigh-water material in old goaf

The monitoring and evaluation of the effect of grouting and sinking are important for the rational utilization of the coal mining subsidence area and the optimization of grouting and sinking scheme in the old goaf.In this study, the old goaf of Julong Mining Group Co., Ltd.is taken as the research object, the point surface monitoring is measured on site in the grouting filling process of the old goaf, and is evaluated effect through sinking after grouting.The results show that the surface subsidence is reduced by 25% compared with without grouting after grouting in the old goaf; the subsidence speed of the monitoring point is obviously slowed down by the grouting, and the surface subsidence is significantly reduced during the monitoring period.Grouting to old goaf could reduced the surface subsidence and ensured the safe operation of the surface construction.