Gas outburst affected by original rock stress direction

Abstract In this paper, it was determined that all of the three-dimensional principal stresses increase with depth and that both the maximum and the minimum stresses tend to be aligned in the horizontal orientation. The numerical simulation model was built using the software FLAC3D to simulate two times, as in two different states of original rock stress, respectively; this simulation was used to investigate how the original rock stress affects the gas outburst risk. The results suggest that an outburst is most likely to happen when the maximum original rock stress is perpendicular to the roadway, rather than parallel to the roadway. The results were demonstrated to be correct by a field experiment. The results suggest that most of the roadways in gas outburst risk coal mines should be designed to lie parallel to the maximum stress direction to avoid the high stress concentration in front of the heading face, thereby reducing the gas outburst risk.

[1]  Chengwu Li,et al.  Coal and gas outburst mechanism of the “Three Soft” coal seam in western Henan , 2010 .

[2]  K. Chen,et al.  A new mechanistic model for prediction of instantaneous coal outbursts - Dedicated to the memory of Prof. Daniel D. Joseph , 2011 .

[3]  T. Moriya,et al.  Different stress directions in the aftershock focal mechanisms of the Kushiro-Oki earthquake of Jan. 15, 1993, SE Hokkaido, Japan, and horizontal rupture in the double seismic zone , 1999 .

[4]  Md. Rafiqul Islam,et al.  Numerical simulation of stress distributions and displacements around an entry roadway with igneous intrusion and potential sources of seam gas emission of the Barapukuria coal mine, NW Bangladesh , 2009 .

[5]  C. Özgen Karacan,et al.  Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction , 2011 .

[6]  Jianwei Zhang,et al.  Coal and Gas Outburst Prediction Combining a Neural Network with the Dempster-Shafter Evidence , 2008, ISNN.

[7]  R. Lama,et al.  Management of outburst in underground coal mines , 1998 .

[8]  María B. Díaz Aguado,et al.  Influence of the stress state in a coal bump-prone deep coalbed: A case study , 2009 .

[9]  N. Barton,et al.  FUNDAMENTALS OF ROCK JOINT DEFORMATION , 1983 .

[10]  Wei Yang,et al.  How in situ stresses and the driving cycle footage affect the gas outburst risk of driving coal mine roadway , 2012 .

[11]  Chao Zhang,et al.  A new technology for coal and gas control based on the in situ stress distribution and the roadway layout , 2012 .

[12]  Yu Wu,et al.  In-situ stress measurements and stress distribution characteristics in underground coal mines in China , 2010 .

[13]  Liang Wang,et al.  Characteristics and dominant controlling factors of gas outburst in Huaibei coalfield and its countermeasures , 2013 .

[14]  Zhaohui Huang,et al.  Fracture analysis and determination of in-situ stress direction from resistivity and acoustic image logs and core data in the Wenchuan Earthquake Fault Scientific Drilling Borehole-2 (50–1370 m) , 2013 .

[15]  Syd S. Peng,et al.  Damage mechanics around a tunnel due to incremental ground pressure , 1997 .

[16]  Aitao Zhou,et al.  Propagation law of shock waves and gas flow in cross roadway caused by coal and gas outburst , 2014 .

[17]  Gang Wang,et al.  A coupled approach to simulate initiation of outbursts of coal and gas — Model development , 2011 .

[18]  B. Bohloli,et al.  Subsurface fracture analysis and determination of in-situ stress direction using FMI logs: An example from the Santonian carbonates (Ilam Formation) in the Abadan Plain, Iran , 2010 .

[19]  A. D Alexeev,et al.  True triaxial loading apparatus and its application to coal outburst prediction , 2004 .

[20]  Basil Beamish,et al.  Instantaneous outbursts in underground coal mines: An overview and association with coal type , 1998 .

[21]  Alireza Baghbanan,et al.  Stress effects on permeability in a fractured rock mass with correlated fracture length and aperture , 2008 .

[22]  Tao Xu,et al.  Numerical investigation of coal and gas outbursts in underground collieries , 2006 .