深部煤层低瓦斯耦合灾变机制
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摘要
为探索深部开采中消突并达到安全开采条件煤层发生瓦斯异常涌出或煤与瓦斯突出的成因,通过文献调研和现场调查,确认含瓦斯煤层低压灾变的存在;通过现场瓦斯监测、微震观测、实证分析,认识消突煤层低瓦斯灾变的过程与成因;通过含低气压大煤样气-固耦合物理试验和理论分析,研究承压煤样低气压应力-应变-渗流场演化路径和气-固耦合物理灾变机制。结果显示,进入深部开采后陆续有消突达到安全开采条件煤层发生低瓦斯灾变现象的报道;现场观测和分析揭示出顶板来压、顶板来压破断冲击和底板来压起臌冲击作用下煤层低瓦斯灾变的模式;模拟采、掘工作面边界条件,0.4 MPa气压条件下的气-固耦合物理试验观察到了低气压灾变过程的3个阶段:弹性压密——气体常速与减速稳态渗流、塑性扩容——气体增速非稳态渗流、破裂失稳——气体非稳态渗流灾变。得到:在防突措施扰动下,稳压区煤层已不再是原生状态裂隙,而有大量新生裂隙产生,为瓦斯解吸游离创造条件,可形成局部富集区,是瓦斯低压灾变的发动区;分析得出采动超前区段瓦斯赋存状态"三带"动态演化规律,根据峰值应力,定量划分出40%极限弹性、极限弹性和极限破坏载荷所对应的"三带"动态演化特征;采动瓦斯赋存"三带"动态演化是导致低压瓦斯灾变的主要原因;提出了瓦斯普通涌出-低值异常涌出-高值异常涌出的灾变过程和条件;顶、底板破断冲击动压叠加作用下,可导致含瓦斯煤层低压灾变提前发动。
In order to explore the causes of unusual gas emission, coal and gas outbursts in coal mines with outburst elimination and traditional safe mining conditions during underground deep-mining process, the existence of low-gas catastrophes in gas-containing coal seams is confirmed by literature review and field investigation. Through field gas monitoring,microseismic observation and empirical analysis,the process and cause of low-gas catastrophes in the outburst elimination of coal seams are recognized. Physical experiment and theoretical analysis on the gas-solid coupling of big coal samples with low-gas, the evolution path of stress-strain-seepage field at low-pressure and the physical catastrophe mechanism of gas-solid coupling for pressure-bearing coal samples are studied. There are many reports that the low-gas catastrophes in the coal seams can happen during mining process in deep coal mines with outburst elimination and traditional safe mining conditions. Field observation and analysis reveal the model of low-gas catastrophes in coal seam under the action of roof weighting,roof weighting breaking impact and floor weighting impact. The boundary conditions of mining and excavation face are simulated, the catastrophic process at low-gas observed in the gas-solid coupling physical experiments at 0.4 MPa pressure involves three steps: elastic compaction-gas constant velocity and deceleration steady seepage, plastic dilatation-gas growth unsteady seepage, and rupture instability-gas unsteady seepage catastrophe. The conclusions are that many secondary fissures are formed in pressure stable area after taking outburst prevention measures, which is beneficial for improving the de-sorption performance of gas. It could be the initial region of low gas pressure catastrophe,along with plenty of gas gathered. A "three-zone" dynamic evolution theory of gas migration in front of mining-induced region of coal seams is given,and its characterization is clarified corresponding to the 40% extreme elasticity,and the ultimate failure load according to the change of stress value. In a word,the "three-zone" dynamic evolution theory of gas migration in front of mining-induced region of coal seams is the main reason of catastrophes with low-pressure gas. The catastrophic process and conditions for ordinary gas emission, unusual gas emission with low-gas,unusual gas emission with high-gas,and catastrophes are given. In addition,low-gas catastrophes in gas-containing coal seams can be initiated in advance under the dynamic pressure impact of the superposition of the roof and floor breakage.
In order to explore the causes of unusual gas emission, coal and gas outbursts in coal mines with outburst elimination and traditional safe mining conditions during underground deep-mining process, the existence of low-gas catastrophes in gas-containing coal seams is confirmed by literature review and field investigation. Through field gas monitoring,microseismic observation and empirical analysis,the process and cause of low-gas catastrophes in the outburst elimination of coal seams are recognized. Physical experiment and theoretical analysis on the gas-solid coupling of big coal samples with low-gas, the evolution path of stress-strain-seepage field at low-pressure and the physical catastrophe mechanism of gas-solid coupling for pressure-bearing coal samples are studied. There are many reports that the low-gas catastrophes in the coal seams can happen during mining process in deep coal mines with outburst elimination and traditional safe mining conditions. Field observation and analysis reveal the model of low-gas catastrophes in coal seam under the action of roof weighting,roof weighting breaking impact and floor weighting impact. The boundary conditions of mining and excavation face are simulated, the catastrophic process at low-gas observed in the gas-solid coupling physical experiments at 0.4 MPa pressure involves three steps: elastic compaction-gas constant velocity and deceleration steady seepage, plastic dilatation-gas growth unsteady seepage, and rupture instability-gas unsteady seepage catastrophe. The conclusions are that many secondary fissures are formed in pressure stable area after taking outburst prevention measures, which is beneficial for improving the de-sorption performance of gas. It could be the initial region of low gas pressure catastrophe,along with plenty of gas gathered. A "three-zone" dynamic evolution theory of gas migration in front of mining-induced region of coal seams is given,and its characterization is clarified corresponding to the 40% extreme elasticity,and the ultimate failure load according to the change of stress value. In a word,the "three-zone" dynamic evolution theory of gas migration in front of mining-induced region of coal seams is the main reason of catastrophes with low-pressure gas. The catastrophic process and conditions for ordinary gas emission, unusual gas emission with low-gas,unusual gas emission with high-gas,and catastrophes are given. In addition,low-gas catastrophes in gas-containing coal seams can be initiated in advance under the dynamic pressure impact of the superposition of the roof and floor breakage.
引文
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[7]文一.孙家湾煤矿“2·14”特大瓦斯爆炸一事故调查专题报道[J].安全与健康,2005(11):4-8.WEN Yi."2·14"especially big gas explosion in Sunjiawan Coal Mine—Special report on accident investigation[J]. Safety&Health,2005(11):4-8.
[8]林士良,马春笑,王广杰.深井煤巷掘进冲击地压与瓦斯突出综合防治技术[J].中州煤炭,2009(7):83-85.LIN Shiliang,MA Chunxiao, WANG Guangjie. Comprehensive prevention technology on rock burst and gas outburst in deep well driving[J]. Zhongzhou Coal,2009(7):83-85.
[9]张福旺,李铁.深部开采复合型煤与瓦斯动力灾害的认识[J].中州煤炭,2009,106(4):73-76.ZHANG Fuwang,LI Tie. Cognizance on compound dynamic disaster of coal and gas in deep mining[J]. Zhongzhou Coal,2009,106(4):73-76.
[10]孟贤正,汪长明,唐兵,等.具有突出和冲击地压双重危险煤层工作面的动力灾害预测理论与实践[J].矿业安全与环保,2007,34(3):1-4.MENG Xianzheng, WANG Changming,TANG Bing,et al. Prediction theory and practice of dynamic disaster occurred in coal face with outburst and rock burst[J]. Mining Safety&Environmental Protection,2007,34(3):1-4.
[11] LU C P,DOU L M,ZHANG N,et al. Microseismic and acoustic emission effect on gas outburst hazard triggered by shock wave:A case study[J]. Natural Hazards,2014,73(3):1715-1731.
[12] SI G,DURUCAN S,JAMNIKAR S,et al. Seismic monitoring and analysis of excessive gas emissions in heterogeneous coal seams[J]. International Journal of Coal Geology,2015,149(49):41-54.
[13]杨程,齐金山,崔杏雨,等.A型沸石/活性炭复合材料的制备及甲烷/氮气吸附分离性能[J].应用化学,2018,35(4):462-468.YANG Cheng,QI Jinshan,CUI Xingyu,et al. Synthesis of zeolite A/activated carbon composite and CH_4/N_2 adsorption separation performance[J]. Chinese Journal of Applied Chemistry, 2018,35(4):462-468.
[14] GENG Y,TANG D,XU H,et al. Experimental study on permeability stress sensitivity of reconstituted granular coal with different lithotypes[J]. Fuel,2017,202:12-22.
[15] YANG J. Experimental study on CH4 permeability and its dependence on interior fracture networks of fractured coal under different excavation stress paths[J]. Fuel,2017,202:483-493.
[16] JIANG C,DUAN M,YIN G,et al. Experimental study on seepage properties, AE characteristics and energy dissipation of coal under tiered cyclic loading[J]. Engineering Geology,2017,221:114-123.
[17] KONG X,WANG E,LIU Q,et al. Dynamic permeability and porosity evolution of coal seam rich in CBM based on the flow-solid coupling theory[J]. Journal of Natural Gas Science&Engineering,2017,40:61-71.
[2]阿维尔申·С·Г.冲击地压[M].朱敏,汪伯煜,韩金祥译.北京:煤炭工业出版社,1959:89-99.
[3]布霍依诺·G.矿山压力和冲击地压[M].李玉生译.北京:煤炭工业出版社,1985:15-16.
[4]张凤鸣,余中元,徐晓艳,等.鹤岗煤矿开采诱发地震研究[J].自然灾害学报,2005,14(1):139-143.ZHANG Fengming,YU Zhongyuan,XU Xiaoyan,et al. Research on induced earthquakes by coal mining in Hegang[J]. Journal of Natural Disasters,2005,14(1):139-143.
[5]李铁,蔡美峰,王金安,等.深部开采冲击地压与瓦斯相关性的探讨[J].煤炭学报,2005,30(5):562-567.LI Tie,CAI Meifeng,WANG Jin'an,et al. Discussion on relativity between rockburst and gas in deep exploitation[J]. Journal of China Coal Society,2005,30(5):562-567.
[6] LI T,CAI M F,CAI M. Earthquake-induced unusual gas emission in coalmines—A km-scale in-situ experimental investigation at Laohutai mine[J]. International Journal of Coal Geology,2007,71(2-3):209-224.
[7]文一.孙家湾煤矿“2·14”特大瓦斯爆炸一事故调查专题报道[J].安全与健康,2005(11):4-8.WEN Yi."2·14"especially big gas explosion in Sunjiawan Coal Mine—Special report on accident investigation[J]. Safety&Health,2005(11):4-8.
[8]林士良,马春笑,王广杰.深井煤巷掘进冲击地压与瓦斯突出综合防治技术[J].中州煤炭,2009(7):83-85.LIN Shiliang,MA Chunxiao, WANG Guangjie. Comprehensive prevention technology on rock burst and gas outburst in deep well driving[J]. Zhongzhou Coal,2009(7):83-85.
[9]张福旺,李铁.深部开采复合型煤与瓦斯动力灾害的认识[J].中州煤炭,2009,106(4):73-76.ZHANG Fuwang,LI Tie. Cognizance on compound dynamic disaster of coal and gas in deep mining[J]. Zhongzhou Coal,2009,106(4):73-76.
[10]孟贤正,汪长明,唐兵,等.具有突出和冲击地压双重危险煤层工作面的动力灾害预测理论与实践[J].矿业安全与环保,2007,34(3):1-4.MENG Xianzheng, WANG Changming,TANG Bing,et al. Prediction theory and practice of dynamic disaster occurred in coal face with outburst and rock burst[J]. Mining Safety&Environmental Protection,2007,34(3):1-4.
[11] LU C P,DOU L M,ZHANG N,et al. Microseismic and acoustic emission effect on gas outburst hazard triggered by shock wave:A case study[J]. Natural Hazards,2014,73(3):1715-1731.
[12] SI G,DURUCAN S,JAMNIKAR S,et al. Seismic monitoring and analysis of excessive gas emissions in heterogeneous coal seams[J]. International Journal of Coal Geology,2015,149(49):41-54.
[13]杨程,齐金山,崔杏雨,等.A型沸石/活性炭复合材料的制备及甲烷/氮气吸附分离性能[J].应用化学,2018,35(4):462-468.YANG Cheng,QI Jinshan,CUI Xingyu,et al. Synthesis of zeolite A/activated carbon composite and CH_4/N_2 adsorption separation performance[J]. Chinese Journal of Applied Chemistry, 2018,35(4):462-468.
[14] GENG Y,TANG D,XU H,et al. Experimental study on permeability stress sensitivity of reconstituted granular coal with different lithotypes[J]. Fuel,2017,202:12-22.
[15] YANG J. Experimental study on CH4 permeability and its dependence on interior fracture networks of fractured coal under different excavation stress paths[J]. Fuel,2017,202:483-493.
[16] JIANG C,DUAN M,YIN G,et al. Experimental study on seepage properties, AE characteristics and energy dissipation of coal under tiered cyclic loading[J]. Engineering Geology,2017,221:114-123.
[17] KONG X,WANG E,LIU Q,et al. Dynamic permeability and porosity evolution of coal seam rich in CBM based on the flow-solid coupling theory[J]. Journal of Natural Gas Science&Engineering,2017,40:61-71.