Research on Interaction Relationship between Support and Surrounding Rock in Fault Structural Area and Its Application

Abstract

AbstractIn order to solve the problem of support crushing, rib spalling, and partial roof fall in working face crossing fault structure area, taking II1023 working face of Haizi Mine as the engineering background, the numerical simulation, theoretical analysis, and field measurement were used to simulate the rock activity law in the process of working face crossing fault. Based on this, the mechanical model of the interaction between the support and the surrounding rock in the fault area was established, and the calculation formula of the support strength required by the support under different equilibrium criteria was deduced, which provides a basis for the reasonable selection of hydraulic support. The results show that the rock stress of the working face passing through the fault zone is divided into high-stress section when it is gradually close to the fault and low-stress section after passing through the fault. In the high-stress section, the rock stress increases in front of the working face, and the distribution form is similar to the stress distribution of the narrow coal pillar. The roof easily forms a long hanging roof and slip along the fault surface, which is prone to rib spalling and partial roof fall and support crushing. The support strength is mainly related to fault dip angle, fault cohesion, support beam length, length of the main roof rock beam, and the distance between working face and fault. The reasonable support strength should be determined by the calculation results under different equilibrium criteria. When the working face advances in the high-stress section, the required support strength of the support increases with the increase of the fault dip angle and the length of the main roof rock beam and decreases with the increase of the fault cohesion, the length of support beam, and the distance between working face and fault. With the increase of the fault dip angle, the form of rotary instability changes and the probability increases. The field practice shows that during the fault crossing of the II1023 working face, the working resistance of the support shows the characteristics of high-pressure area and low-pressure area, but it does not exceed the rated working resistance of the selected support. The fully mechanized coal face passed through the fault area safely, and there were no accidents such as support crushing, rib spalling, and partial roof fall.