Application Research Of Gob-side Entry Retaining In Jin Feng Large Mine Height Coalface

The 011802 fully mechanized coalface is the first coalface of JinFeng mine. The average thickness of the coal seam is about 4.2m, the inclination angle is 6°, the coal seam angle is 5 ° ~ 14 °, and the average depth is 180 m. It is very hard to ensure the normal driving speed because of the long lengh of connection working and difficulties in Geological fault and geological tectonic belt. To ensure the normal continuation and production of coal mining, as well as to achieve the goal of production as soon as possible,they decide to implement the gob-side entry retaining on the first coalface after analysis of the geological and mining conditions. However, it is lack of the experiences, even there is only a few instances on engineering gob-side entry retaining under date mining 8m and the wide of the tunnel 5m puts into practice. So it is very necessary to conduct the application research of gob-side entry retaining in JinFeng large mine height coalface.This paper mainly focus on reorganize the method of theoretical analysis, numerical simulation and industrial experiment to study the geological condition of coal mine, the mining conditions of the gob-side entry retaining working face, to analysis the movement and deformation law of surrounding rock, to get the characteristics of the gob-side entry support.Using the separation of rock block method to design the supporting system of the gob-side entry tunnel and conduct industrial experiments.The 011802 fully mechanized coalface of JinFeng mine uses the flexible formwork and concrete gob-side entry retaining technology, because of the high speed and large volume of concrete every day, so the Preparation of transport units using the flexible formwork concrete equipment carried gob-side entry construction. Sucessfully complete 610 m,the tunnel will be used as the transportation tunnel of 011801 fully mechanized coalface.The maximumsubsidence of the roof is 240 mm,the maximum nearer quantity of tunnel sides is 95 mm,the tunnel area is more than 13m2.The construction achieves the desired results and satisfied the production need.The implementation, gob-side entry on 011802 fully mechanized coalface, gains the economic benefits of 732,000 RMB on driving tunnel and 11,480,000 RMB on coal column.The technology has been developed in next three coalface of JinFeng mine. And it provides methods and experiences of gob-side entry retaining in the coal mine of the similar geological and mining conditions.