Mechanisms of Rock Burst in Horizontal Section Mining of a Steeply Inclined Extra-Thick Coal Seam and Prevention Technology

Abstract

Rock bursts have recently become a serious problem in the horizontal section mining of steeply inclined extra-thick coal seams (SIETCSs). However, few studies have been carried out to investigate their mechanisms and prevention. In this study, numerical simulation and field measurements were carried out to investigate the mechanism of rock bursts in the horizontal section mining of an SIETCS. A Universal Distinct Element Code (UDEC) Trigon model was built, based on the Yaojie No.3 Coal Mine, and calibrated through laboratory tests and RQD methods. The results demonstrate that the coal in the elastic zone around the roof is in a high static stress state, due to the asymmetric clamping and squeezing of the roof and floor. Strong dynamic loads are formed by breakage of the roof and the failure of multiple hinged beam structures during the evolution process of the overlying strata. Rock bursts occur on the roof side when the superimposition of the static stress σs and stress increment σd induced by such dynamic loads is greater than the critical stress σmin of the coal and rock. We propose a technical prevention scheme for the considered mine. Field studies suggest that the proposed technology can effectively prevent and control rock bursts in the horizontal section mining of SIETCSs.

Mechanical Properties and Damage Behavior of Rock-Coal-Rock Combined Samples under Coupled Static and Dynamic Loads

“…Rock burst is a dynamic disaster in mining engineering with a sudden and violent release of elastic energy accumulated in coal and rock, which poses a significant risk to mine safety [1][2][3]. The number of coal mines in China with rock burst disasters has been raised from 32 in 1985 to more than 253 in 2019 [4]. For rock bursts in China, some typical features were observed: (1) Accidents are mostly occurred next to gobs or advancing working face [5,6].…”

Study on Failure Characteristics and Rock Burst Mechanism of Roadway Roof under Cyclic Dynamic Load

“…Typical roadway rock burst occurs mostly due to dynamic disturbances such as blasting vibration and roof fracture during the advance of mining face [8][9][10][11]. In the study of rock burst in underground rock mass engineering, many studies have been carried out to understand the deformation characteristics and failure mechanism of roadway surrounding rock, and a series of effective control methods are put forward [12][13][14][15][16][17][18][19][20][21]. However, due to the complexity of site engineering geological conditions and the difference of rock burst types and severity, these current understandings are inadequate.…”

Mechanical Properties of Roof Rocks under Superimposed Static and Dynamic Loads with Medium Strain Rates in Coal Mines

“…A large number of case studies of rock bursts are documented in America [3,4], Australia [5], Poland [6,7], Russia [8], Czech Republic [9,10] and many other countries. In China, nearly 300 coal mines have reported rock burst disasters so far, and the number is increasing [11]. Table 1 lists the major cases of rock burst disasters that occurred in China in the past five years.…”