Investigation on fracture models and ground pressure distribution of thick hard rock strata including weak interlayer

Abstract

Dynamic disasters, such as rock burst due to the breaking of large area stiff roof strata, are known to occur in the hard rock strata of coal mines. In this paper, mechanical models of the fracturing processes of thick hard rock strata were established based on the thick plate theory and numerical simulations. The results demonstrated that, based on the fracture characteristics of the thick hard rock strata, four fracture models could be analyzed in detail, and the corresponding theoretical failure criteria were determined in detail. In addition, the influence of weak interlayer position on the fracture models and ground pressure of rock strata is deeply analyzed, and six numerical simulation schemes have been implemented. The results showed that the working face pressure caused by the independent movement of the lower layer is relatively low. The different fracture type of the thick hard rock strata had different demands on the working resistance of the hydraulic powered supports. The working resistance of the hydraulic powered supports required by the stratified movements was lower than that of the non-stratified movements.

Keywords

• Thick hard rock strata
• Thick plate theory
• Stratification movement of rock strata
• Numerical simulations
• Ground pressure distribution