This paper studies the fracturing characteristics of hard overlying strata and its control of the strata pressure behavior of the working face based on working face 8015 of coal seam 3-5 of the carboniferous system in Tongxin mine. The critical layer of the working face was determined as well as the initial and cycle fault displacement using critical layer theory. The relationship between critical layer facture and support pressure of the working face was derived based on theory of mechanics of materials to analyze the influence of critical layer facture on the strata pressure behavior of the working face. The results show that the working face of the hard overlying strata had sub-critical layer I, sub-critical layer II, and a main critical layer, the fracture of which led to generation of cycle pressure and complex pressure at the working face, and fracture of the main critical layer led to a relatively large range of pressure. These strata pressure behaviors derived by theoretical analysis are consistent with practical pressure monitoring.

hard overlying strata  /  fracture of critical layer  /  complex strata pressure  /  strata pressure behavior