Study on the Formation Mechanism of Rock Burst Caused by Seam Floor Slip under an Ultrathick Conglomerate

Abstract

A rock burst accident occurred on coalface 13230 of the Gengcun Coal Mine in Henan Province. Through a field investigation, theoretical analysis, and microseismic monitoring, we studied how the rock burst, which was caused by overall seam floor slip and instability, occurring under an ultrathick conglomerate. Because the overlying ultrathick conglomerate in the mined-out zone close to coalface 13230 had been inadequately mined, the leading section of the coalface was under a high level of stress. Combined with the tectonic stresses from the F16 faultage and the soft floor structure, these factors caused the floor of this coalface to trigger the overall slip-type rock burst. In this paper, an estimation model of the ultimate bearing capacity of a seam floor under an ultrathick conglomerate and the advancing abutment pressure on the coalface is presented. This model is used to show that the ultimate bearing capacity of the seam floor on coalface 13230 is 26.3 MPa, and the abutment pressure is far more than the floor bearing capacity. We also present pressure relief and reinforced supporting measures, which can effectively prevent floor slip-type rock bursts from occurring. The results of this study provide a reference for the prevention and control of floor slip-type rock bursts in coal mining under an ultrathick conglomerate.

Study on the Impact Failure Rules of Roadway Floor Induced by Dynamic Load Disturbance under Extremely Thick Conglomerate

“…It utilizes the finite difference display algorithm to derive time-step solutions for all motion equations within the model, including internal variables. This approach enables the tracking of progressive material destruction during simulations. , FLAC incorporates specific constitutive equations tailored to the properties of different materials, allowing for an accurate representation of their mechanical behavior. As a result, FLAC finds extensive application in analyzing stress and displacement fields across various domains, including water conservancy, mining, earthquakes, geology, petroleum, and civil engineering. , …”