Prediction on Water Flow in Goaf at Initial Mining Period of Fully-Mechanized Top Coal Caving Face

In order to effectively predict water flow in goaf at the initial mining period of fully-mechanized top coal caving face,an empirical formula was applied to calculate the height of the roof falling zone and the height of the water flow zone in fully-mechanized top caving face. According to the borehole information,No. 9 aquifer was located in a water flow zone as determined. Based on the circumstances,a FLAC3Dsoftware was applied to simulate the mining process of fully-mechanized coal caving face,the distribution law of the roof falling zone and water flow fracture zone occurred by the vertical displacement of the overburden strata was obtained and the interconnection between the water flow fracture zone and No. 9 aquifer would be the water sources of the water flow in the goaf of the coal mining face. The results showed that before a full mining reached,the water flow fracture zone was arch shape and the water flow in goaf,numerical simulation on the coal mining at 108—112 m of the coal mining face and the site mining at 106 m of the coal mining face was fitted. Thus the results verified the numerical simulation could accurately predict the water flow in goaf.