Study on control technology of gob-side entry retaining of flexible concrete wall in large dip angle of thick coal seam
In order to solve the difficult problems that the roof is not easy to collapse and the mine pressure is severe under the condition of hard roof,the surrounding rock control technology of"pre-splitting blasting top relief pressure+anti-scour mesh+flexible concrete wall protection+strengthening support"is proposed based on the engineering background of the goalless retaining roadway of full-mechanized mining face with large tilt angle and thick coal seam.Field industrial experiments show that the short-arm beam structure can be formed effectively and the mining pressure of roadway can be reduced by pre-cracking blasting.The use of flexible mesh and flexible concrete wall can not only effectively alleviate the impact force of gangue,but also provide greater support resistance together with bulged gangue.By strengthening support in roadway and temporary support in lagging area,the damage of surrounding rock is reduced and the stability of roadway is improved.Through the surrounding rock control technology,better surrounding rock control effect is obtained,which provides scientific and technical guidance for retaining roadway along goaf under similar engineering geological conditions.