The Mechanical Criterion of Activation and Instability of Normal Fault Induced by the Movement of Key Stratum and Its Disaster‐Causing Mechanism of Rockburst in the Hanging Wall Mining

Abstract

Coal mine rockburst is closely related to the complex geological structure. Understanding the criterion of the fault activation instability and the disaster-causing mechanism of rockburst under the influence of mining is the theoretical premise and important guarantee of safe and efficient coal mining. In this paper, based on the theory of key stratum, the mechanical model of fault slip instability in the normal fault during the hanging wall mining was established, and the instability criterion was derived. It is concluded that the fault slip instability of the hanging wall is mainly controlled by two factors: (1) the distance between coal seams and key stratum and (2) the distance between working face and fault. Moreover, these two factors have an inverse relation to the occurrence of rockburst. Subsequently, three conceptual models of rockburst induced by the fault stress transfer, stress concentration of coal pillars, and fault structural instability were proposed. Based on the rock mechanics theory, the rockburst carrier system model of “roof-coal seam-floor” near the fault was established. The mechanical essence of fault rockburst was obtained as follows: under the action of fault, the static load of fault coal pillar was increased and superimposed with the fault activation dynamic load, leading to high-strength rockburst disaster. Based on the occurrence mechanism of fault rockburst, the monitoring and prevention concept and technical measures were proposed in three aspects, including the monitoring and control of fault activation dynamic loads, the monitoring of high static load in fault coal pillar and stress release, and the strengthening roadway support. These prevention and control measures were verified in the panel 103down02 of the Baodian Coal Mine in engineering, and the effectiveness of these measures was proved.

Mining Stress Distribution in Stope and Overlying Rock Fracture Characteristics and Its Disaster-Pregnant Mechanism of Coal Mine Earthquake

“…Te complex and changeable engineering efect was caused by mining in stope. Te mechanical balance system consisting of the coal seam, roof, and foor are always changing when the working face is advancing [14,15]. Such as the advance support pressure, lateral pressure, and height of overlying rock of three zones were changed when the working face mining.…”

Unified Mechanism of Rock Burst Induced by Coal Mine Earthquake and Its Activity and Response Characteristics

“…It mainly studied about the hard roof type coal mine earthquake in references [22][23][24][25][26][27][28][29]. Te large overburden area easily produced a strong dynamic load and induced rock burst after breaking hard roof in references [22,23].…”

“…Te large overburden area easily produced a strong dynamic load and induced rock burst after breaking hard roof in references [22,23]. Te occurrence mechanism of rock burst under the control of thick conglomerate and thrust fault was analyzed in references [24,25]. Te superposition sum of the transmissible stress of thick conglomerate and construction stress of thrust fault was estimated.…”

A New Method to Predict Shock-Type Coal-Gas Outburst Disaster and Its Application

“…Domestic and foreign scholars have carried out a lot of research results on coal-gas outburst predictions, forming a series of commonly used coal-gas outburst danger prediction technology, such as drilling cuttings method [16], drilling gas inrush initial velocity method [17], etc. Meanwhile, geophysical methods have been gradually applied to coal-gas outburst prediction in recent years, such as the acoustic emission method [18], microseismic method [19], and electromagnetic radiation method [20].…”