|
|
|
| Mechanism of control hole on coal crack initiation and propagation under deep-hole cumulative blasting in coal seam |
| GUO Deyong1,ZHAO Jiechao1,ZHANG Chao1,ZHU Tonggong2 |
(1. School of Resource and Safety Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;
2. No. 10 Mine,Pingdingshan Tianan Coal Co.,Ltd.,Pingdingshan,Henan 467000,China) |
|
|
|
|
Abstract This paper is concerned with the effect of control hole on the crack initiation and propagation under the cumulative blasting in coal seam. The propagation characteristics of explosive stress wave,the expansion characteristics of the main coal seam cracks caused by explosion,and the stress state and displacement characteristics of coal seam in the area around the control hole were investigated theoretically and numerically. The results demonstrated that the superposition of the incident compressive stress wave and the reflected tensile stress wave changed the stress field around the control hole and the main crack tip significantly and caused the directional expansion of main cracks and the formation of annular cracks around the control hole. In addition,the displacement compensation space provided by the control hole and the surface properties of the hole wall enhanced the tangential tensile stress between the coal particles on and around the control hole wall,which promoted the development and expansion of the radial cracks around the control hole. Furthermore,during the process of cumulative blasting and breaking,the combination of main cracks created by the explosion,the radial cracks and circumferential cracks around the control hole constitutes a large-scale fracture network under the effect of control hole. Besides,the deep-hole cumulative blasting tests were carried out to study the influence of presence and absence of control hole in coal seam on the degree of permeability increasing. The test results showed that the presence of control hole in coal seam under cumulative blasting improved significantly the permeability of coal seams. The increasing of the mean concentration of extracted gas in the area influenced by the control hole after blasting in the tests carried out in two different time periods are 1.78 and 2.48 times respectively that in the area without influenced by control hole.
|
|
|
|
|
|
[1] SINGH P K,ROY M P,PASWAN R K. Controlled blasting for long term stability of pit-walls[J]. International Journal of Rock Mechanics and Mining Sciences,2014,70:388–399.
[2] 李启月,李夕兵,范作鹏,等. 深孔爆破一次成井技术与应用实例分析[J]. 岩石力学与工程学报,2013,32(4):664–670.(LI Qiyue,LI Xibing,FAN Zuopeng,et al. One time deep hole raise blasting technology and case study[J]. Chinese Journal of Rock Mechanics and Engineering,2013,32(4):664–670.(in Chinese))
[3] 戴 俊. 深埋岩石隧洞的周边控制爆破方法与参数确定[J]. 爆炸与冲击,2004,24(6):493–498.(DAI Jun. The controlled contour blasting technique and its parameter determination for rock tunnel at depth[J]. Explosion and Shock Waves,2004,24(6):493–498.(in Chinese))
[4] 张 欣,李术才. 爆破荷载作用下青岛胶州湾海底隧道覆盖岩层稳定性分析[J]. 岩石力学与工程学报,2007,26(11):2 348–2 355. (ZHANG Xin,LI Shucai. Stability analysis of rock cover of qingdao kiaochow bay subsea tunnel under explosive loads[J]. Chinese Journal of Rock Mechanics and Engineering,2007,26(11):2 348–2 355.(in Chinese))
[5] 李 宁,张承客,周 钟. 边坡爆破开挖对邻近已有洞室影响研究[J]. 岩石力学与工程学报,2012,31(增2):3 471–3 477.(LI Ning,ZHANG Chengke,ZHOU Zhong. Influence research of slope blasting excavation on adjacent existed tunnel[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(Supp.2):3 471–3 477.(in Chinese))
[6] 卢文波,李海波,陈 明,等. 水电工程爆破振动安全判据及应用中的几个关键问题[J]. 岩石力学与工程学报,2009,28(8):1 513– 1 520.(LU Wenbo,LI Haibo,CHEN Ming,et al. Safety criteria of blasting vibration in hydropower engineering and several key problems in their application[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(8):1 513–1 520.(in Chinese))
[7] 杨小林,侯爱军,梁为民,等. 隧道掘进爆破的损伤机制与振动危害[J]. 煤炭学报,2008,33(4):400–404.(YANG Xiaolin,HOU Aijun,LIANG Weimin,et al. Damage mechanism and vibration effects in tunnel blasting[J]. Journal of China Coal Society,2008,33(4):400–404.(in Chinese))
[8] 穆朝民,王海露,黄文尧,等. 高瓦斯低透气性煤体定向聚能爆破增透机制[J]. 岩土力学,2013,34(9):2 496–2 500.(MU Chaomin, WANG Hailu,HUANG Wenyao,et al. Increasing permeability mechanism using directional cumulative blasting in coal seams with high concentration of gas and low permeability[J]. Rock and Soil Mechanics,2013,34(9):2 496–2 500.(in Chinese))
[9] 郭德勇,裴海波,宋建成,等. 煤层深孔聚能爆破致裂增透机制研究[J]. 煤炭学报,2008,33(12):1 381–1 385.(GUO Deyong,PEI Haibo,SONG Jiancheng,et al. Study on spliting mechanism of coal bed deep-hole cumulative blasting to improve permeability[J]. Journal of China Coal Society,2008,33(12):1 381–1 385.(in Chinese))
[10] CHO S H,NAKAMURA Y,KANEKO K. Dynamic fracture process analysis of rock subjected to stress wave and gas pressurization[J]. International Journal of Rock Mechanics and Mining Sciences,2004,41(3):433–440.
[11] ALIABADIAN Z,SHARAFISAFA M. Numerical modeling of presplitting controlled method in continuum rock masses[J]. Arabian Journal of Geosciences,2014,7(12):5 005–5 020.
[12] 何满潮,高玉兵,杨 军,等. 无煤柱自成巷聚能切缝技术及其对围岩应力演化的影响研究[J]. 岩石力学与工程学报,2017,36(6):1 314–1 325.(HE Manchao,GAO Yubing,YANG Jun,et al. An energy-gathered roof cutting technique in no-pillar mining and its impact on stress variation in surrounding rocks[J]. Chinese Journal of Rock Mechanics and Engineering,2017,36(6):1 314–1 325.(in Chinese))
[13] 郭德勇,商登莹,吕鹏飞,等. 深孔聚能爆破坚硬顶板弱化试验研究[J]. 煤炭学报,2013,38(7):1 149–1 153.(GUO Deyong,SHANG Dengying,LV Pengfei,et al. Experimental research of deep-hole cumulative blasting in hard roof weakening[J]. Journal of China Coal Society,2013,38(7):1 149–1 153.(in Chinese))
[14] 郭德勇,赵杰超,吕鹏飞,等. 煤层深孔聚能爆破动力效应分析与应用[J]. 工程科学学报,2016,38(12):1 681–1 687.(GUO Deyong,ZHAO Jiechao,LV Pengfei,et al. Dynamic effects of deep-hole cumulative blasting in coal seam and its application[J]. Chinese Journal of Engineering,2016,38(12):1 681–1 687.(in Chinese))
[15] 刘 健,刘泽功,高 魁,等. 深孔定向聚能爆破增透机制模拟试验研究及现场应用[J]. 岩石力学与工程学报,2014,33(12):2 490– 2 496.(LIU Jian,LIU Zegong,GAO Kui,et al. Experimental study and application of directional focused energy blasting in deep boreholes[J]. Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2 490–2 496.(in Chinese))
[16] MOHANTY B. Explosion generated fractures in rock and rock-like materials[J]. Engineering Fracture Mechanics,1990,35(4):889–898.
[17] NAKAMURA Y,HO C S,YONEOKA M,et al. Model experiments on crack propagation between two charge holes in blasting[J]. Science and Technology of Energetic Materials,2004,65(2):34–39.
[18] NAKAMURA Y. Model experiments on effectiveness of fracture plane control methods in blasting[J]. International Journal for Blasting and Fragmentation,1999,3(1):59–78.
[19] CHO S H,NAKAMURA Y,MOHANTY B. Numerical study of fracture plane control in laboratory-scale blasting[J]. Engineering Fracture Mechanics,2008,75(13):3 966–3 984.
[20] 魏 炯,朱万成,魏晨慧,等. 导向孔对两爆破孔间成缝过程影响的数值模拟[J]. 工程力学,2013,30(5):335–339.(WEI Jiong,ZHU Wancheng,WEI Chenhui,et al. Numerical simulation on contribution of guide-hole to crack coalesence of two boreholes[J]. Engineering Mechanics,2013,30(5):335–339.(in Chinese))
[21] 龚 敏,王德胜,黄毅华,等. 突出煤层深孔控制爆破时控制孔的作用[J]. 爆炸与冲击,2008,28(4):310–315.(GONG Min,WANG Desheng,HUANG Yihua,et al. Action of control holes on deep-hole blasting in outburst coal seams[J]. Explosion and Shock Waves,2008,28(4):310–315.(in Chinese))
[22] 岳中文,杨仁树,郭东明,等. 爆炸作用下空孔周围应力场变化的模型实验[J]. 煤炭学报,2009,34(5):624–628.(YUE Zhongwen,YANG Renshu,GUO Dongming,et al. Model experimental of stress field around empty hole under blasting loading[J]. Journal of China Coal Society,2009,34(5):624–628.(in Chinese))
[23] 汪海波,宗 琦,赵要才. 立井大直径中空孔直眼掏槽爆炸应力场数值模拟分析与应用[J]. 岩石力学与工程学报,2015,34(增1): 3 223–3 229.(WANG Haibo,ZONG Qi,ZHAO Yaocai. Numerical analysis and application of large diameter cavity parallel cut blasting stress field in vertical shaft[J]. Chinese Journal of Rock Mechanics and Engineering,2015,34(Supp.1):3 223–3 229.(in Chinese))
[24] 罗 勇,沈兆武. 深孔控制卸压爆破机制和防突试验研究[J]. 力学季刊,2006,27(3):469–475.(LUO Yong,SHEN Zhaowu. Study on mechanism and test of controlled stress relaxation blasting in deep hole[J]. Chinese Quarterly of Mechanics,2006,27(3):469–475.(in Chinese))
[25] 王文龙. 钻眼爆破[M]. 北京:煤炭工业出版社,1984:165–172.(WANG Wenlong. Drilling and blasting[M]. Beijing:China Coal Industry Publishing House,1984:165–172.(in Chinese))
[26] HALLQUIST J O. LS-DYNA keyword user?s manual[M]. [S. l.]:Livermore Software Technology Corporation,2007:509–520. |
| [1] |
BAI Gang1, 2, 3*, HE Huixin1, XIN Tianyu1, 2, ZHANG Xiaowen1, 2, ZHOU Zhongjie4. Deformation damage variation law of liquid CO2 cyclic freeze-thaw coal[J]. , 2026, 45(6): 1657-1669. |
|
|
|
|