Research on Fault Activation Law in Deep Mining Face and Mechanism of Rockburst Induced by Fault Activation

Abstract

To effectively monitor and control the severe mining-induced rockburst in deep fault area, the fault activation law and the mechanical essence of rockburst induced by crossing fault mining were studied through theoretical analysis, microseismic monitoring, field investigation, and other methods; numerical simulation was employed to verify the obtained fault activation law and the mechanical nature. First, the distribution of microseismic sources at different mining locations and the fault activation degree were analyzed. According to the microseismic frequency and the characteristics of the energy stage, the fault activation degree was divided into three stages: fault stress transfer, fault pillar stress behavior, and fault structure activation. It was determined that the impact disaster risk was the strongest in the stage of the fault pillar stress behavior. Based on the periodic appearance law of microseisms in fault area, three types of conceptual models of fault-type rockburst were proposed, and the rockburst carrier system model of “roof-coal seam-floor” in the fault area was established. The mechanical essence of fault-type rockburst was obtained as follows: under the action of fault structure, the static load of the fault coal pillar was increased and superimposed with the active dynamic load of the fault, leading to high-strength impact disaster. Finally, the prevention and treatment concepts of fault-type rockburst were proposed. The monitoring and prevention measures of fault-type rockburst were taken from two aspects: the monitoring and characterization of fault rockburst and weakening control of the high static load of the fault coal pillar and dynamic load of fault activation. The proposed concepts and technical measures have been verified in the working face 14310 of Dongtan Coal Mine with sound results. The research results have a guiding significance for the prevention and control of rockburst in a similar mining face under crossing fault mining.

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

“…It is mainly distributed in Shandong, Henan, Heilongjiang, Jilin, Inner Mongolia, and other provinces, cities, and autonomous regions [2,3]. Tere are more than 1000 severe dynamic-appearing mines accompanied by the induced strong coal mine earthquakes during coal mining [4,5]. In recent years, with the extension of coal mining to the deep, the number of rock burst mines continued to increase and the degree of rock burst danger continued to strengthen.…”

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

“…The fault activation would easily induce high energy shock disturbance near the working face. According to relevant research results [36] judge the disturbance strength index of the fault to the shock-type stress release coal-gas outburst. When the 4 Geofluids coal wall is 62~39 m away from the fault, the coal-rock disturbance strength index is 2; when the coal wall is 40~18 m away from the fault, the coal-rock disturbance strength index is 3; when the coal wall is 18~0 m away from the fault, the coal-rock disturbance strength index is 4; when the coal wall crosses the fault 0~40 m, the coal-rock disturbance strength index is 2; when the coal wall crosses the fault 40~80 m, the disturbance strength index is 1.…”

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

“…Te earthquake hypocenter plane was transverse O-X distribution. Te quantitative relationship between mining activities and coal mine earthquakes was discussed under the microseismic and mining data in references [10,11]. It was considered that continuous mining has a cumulative efect on strong coal mine earthquake occurrence.…”