Feasibility Study on Roof Cutting and Pressure Relief Technology of Gob-side Wall Retaining in Large Mining Height Working Face

Abstract

To solve the problem of large deformation of concrete wall caused by large bearing capacity of gob-side wall retaining in large mining height working face, the concrete bearing structure of gob-side brick retaining was determined for the site conditions of Wangzhuang Coal Industry. We calculated the load-bearing capacity of concrete wall and its maximum load-bearing capacity, and proposed roof cutting and pressure relief technology to reduce the load on the wall. Through numerical simulation, it is concluded that the peak stress of lateral support of the working face can be effectively reduced, the load on the concrete wall can be reduced, the stress concentration on the coal side of the mining roadway can be reduced, and the pressure can be relieved. Based on the numerical simulation results, the blasting top cutting technology was determined to be adopted, and the height of the roof cutting was 15 m, and the blasting scheme was designed. The practical results show that the blasting roof cutting scheme has successfully played the role of pressure relief and roadway protection.

Keywords

• gob-side wall retaining
• lateral abutment pressure
• lateral cantilever structure
• wall load
• roof cutting and pressure relief