Research on Overburdened Rock Structures and Support Resistance of Shallow Buried Large Mining Heights Based on Sheet Gangs

In the mining of shallow coal seams, the increase in mining height will lead to a sharp increase in the probability and degree of coal wall spalling. Rib spalling will affect the normal production of coal mines and may also threaten the safety of miners. Under the state of coal wall ganging in large mining height working faces, determining the working face’s support resistance is a key engineering problem that involves many factors, such as bracket design, the mechanical behavior of the roof rock layer, coal wall stability, and so on. In this paper, (1) the relationship between coal wall pressure and working face support resistance is analyzed by constructing a mechanical model of roof control in the large height mining field, (2) and four roof structure models are established based on the single and double key layer structures of step rock beams in shallow buried coal beds. (3) The calculation methods of working face support resistance after coal wall sheet ganging under the four structural models are deduced. Determining the working face’s support resistance is the key to solving the problem of coal wall ganging in large height working faces, which has a significant impact on the design of bracing, the mechanical behavior of the roof rock layer, and coal wall stability.