关键词: 厚表土层, 坚硬顶板, 相似材料, 悬臂梁结构, 切顶留巷, 非对称支护

Abstract: Based on the actual situation of thick topsoil thick hard roof slab cutting and retaining roadway in 4307 working face of Guotun coal mine, this paper first simulates the evolution law of lateral overburden structure of thick topsoil thick hard roof slab with similar materials. With the different length of working face, it presents cantilever beam structures such as "L", "triangle" and similar "triangle". Because the thick topsoil is located in the bending subsidence zone above the fracture zone of overburden under 3 coal, the thick topsoil, as a given load, basically has little influence on the movement of overburden. The cantilever beam of thick hard roof slab has large thickness and long cantilever, which has a great impact on Retaining Roadway along the goaf. For the retaining roadway in this case, four key technologies of "full filling", "cut down", "asymmetric" support and "retaining" are proposed. These four key technologies are designed according to the actual situation of 4307 working face, and the determined design parameters are given. The field practice shows that the roadway reserved along the goaf behind the working face can be divided into three zones, the deformation gentle zone within 30m behind the working face, the deformation rapid zone of 30m-100m and the gradually stable zone of 100-240m. The deformation of solid side and bottom heave is large, and the deformation of roof and gangue side is small. After the 4307 track trench retaining roadway is stable, the section is reduced by about 22.1% compared with the original section. The reduced section of the retaining roadway can basically meet the requirements of mining reuse, and has achieved good application results.