Study On The Laws Of Overlying Strata Movement And Surface Subsidence In Wang He Coal Mine Paste Filling

Paste filling which fills the filling body to the region through pipeline by filing pump, controls the deformation of strata movement and surface subsidence, compared with caving mining, it settles damage caused by coal mining to land resources, water resources, building resources, it has some advantages, such as high security, high recovery ratio and environment friendly, is an effective green mining technology. With the background of 10903 backfill mining working face in Wanghe Mine, this paper researched on the laws between the strata movement and surface subsidence in WangHe coal mine paste filling.This paper, studied the damage laws between caving mining and paste filling of overlying strata character, the growth height of water flowing fractured zone of paste filling was calculated,by using numerical simulation and theoretical analyses.This paper analysis the influence factors of deformation of overlying strata movement and surface subsidence,and the approximate calculation formula of displacement of the rock strata is derived through the establishment of rock beam mechanical model.The results show that overlying strata do not form the traditional “three zone”,but only the fractured and bended zones in paste filling mining. the growth height of water flowing fractured zone is calculated of 8.3m,less than the height of aquifuge layer,compared with the traditional mining, backfill mining can effectively prevent mine water disaster. The roof to floor convergence before backfilling, the gap between the backfilling body and roof, and the compression amount of the backfilling body are the key factors affecting surface subsidence. The roof convergence amount is 30 mm calculated by formula.This paper used the WangHe mine 10903 working face as the model prototype,the numerical simulation software UDEC is used to analyze the different influence of trata movement and surface subsidence deformation in different paste filling conditions such as working face advancing distance, strength of filling body and filling rate.Combined with 10903 working face surface field measurement, WangHe coal mine surface subsidence laws were further analysed,the deformation of the extreme surface subsidence was obtained. it proves that backfill mining can effectively control surface subsidence and satisfy the design requirements of the protection of surface construction when strength of filling body is 1Gpa and filling rate is 80%. results of this paper have certain guiding significance for the subsequent filling to Wanghe coal mining, and provide scientific basis and engineering reference for other similar mine areas.