Factors to Be Considered for the Design of Face Supports in Longwall Mining Method

Abstract

The main purpose of mine workings is the exploitation of ores and minerals that are used in different aspects of life. The most common underground method all over the world is the longwall mining method. The increasing demand for minerals and ores and the difficult mining conditions at greater depths make the longwall mining system a good candidate in mining. The equilibrium condition is disrupted when the longwall face advances, and as a result, the surrounding rocks eventually fracture and cave. Moreover, the induced pressure due to caving or fractures of the immediate roof rocks and the tilting of the main roof exerts an excessive load on the hydraulic supports in the longwall faces. Induced disturbances of the overburden rocks must be thoroughly investigated since this will enhance our understanding of rock pressure and ground control. The main objectives of this paper are to review the importance of the longwall mining system as an exploitation method and its applications around the world. as well as the main factors affecting the stability of supports in longwall faces, especially hydraulic supports. From this study, it can be seen that the most important technical factor that affects face stability is the rate of face advance. In addition, the significant natural factors affecting the stability of workings are roof conditions and the geometry of the panel.

Current Theories and Concepts for the Determination of Roof Loading over the Hydraulic Supports in Longwall Faces

“…Determining the accurate roof loading in longwall faces is a very important matter in the selection of the optimum hydraulic supports and guarantees stability during mining workings [1,2]. For the successful employment of longwall systems in the underground exploitation of ores, a correct and deep understanding of the interaction between the hydraulic supports and the neighbouring rocks is vitally important.…”