沿空留巷围岩结构稳定性力学分析
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摘要
以往对沿空留巷围岩结构特征了解不够,难以准确计算巷旁支护阻力,导致沿空留巷困难甚至失败。因此,根据沿空留巷上覆岩层垮断特征,提出了"大结构"、"小结构"概念,分别构建了围岩"大结构"、"小结构"力学模型,研究分析了"大结构"形成"低形态拱"和"高形态拱"的条件,推导出了拱高计算式,研究认为:在巷旁顶板岩层残留边界二次破断前,若及时加固煤帮,提高巷内和巷旁支护阻力,则上覆岩层易形成"低形态拱";若巷道煤帮松软,或巷道支护阻力不足,则易形成"高形态拱"。通过研究拱脚的水平力对"大结构"形态演化及其稳定性影响,发现拱脚处的水平力是造成拱破坏的主要原因,若拱脚处的水平力大于其抗剪力,拱将失稳破坏,造成"低形态拱"的拱高增加或"高形态拱"的跨度向外扩展,引起"小结构"的岩层载荷增加,"小结构"的岩层载荷不仅与"大结构"的形态、拱高和跨度相关,而且与二次破断区顶板"铰接岩层"的稳定性密切相关,根据关键层理论,确定"大结构"拱高范围内顶板硬岩层位置及其所控制的软岩层组,采用滑落失稳判据和挤压变形失稳判据,自上而下判别出顶板"铰接岩层"的稳定性,进而确定围岩"小结构"的岩层载荷,据此推导出巷旁支护阻力计算式。
Analyzing thoroughly the characteristics of surrounding rock structure,calculating accurately roadside supporting resistance,and controlling serious deformation and failure of rocks surrounding,lead to supporting difficulty in gob-side entry retaining increased,even fail. Therefore,based upon the breaking off characteristics of overlying rock,the mechanical models of big and small structure were built,the formation conditions of low arch and high arch were analyzed,the formulas of their arch rise were derived,and the effect of horizontal force at arch foot on form evolvement and the stability of big and small structure. Research suggested that before the residual boundary of roadside roof the second broke off,if the coal side of roadway was strengthened timely and roadway-inside and roadside supporting resistance were improved,then overlying rock was easy to form low arch; if the coal side of roadway was soft,or the supporting resistance of roadway was insufficient,then overlying rock was easy to form high arch. Horizontal force at archfoot was the main reason of arch instability,if horizontal force at arch foot was larger than shearing resistance at arch foot,then the arch would lose stability,consequently the arch rise of low arch or the arch span of high arch would increase,which caused the overburden load of small structure increase. Overburden load of small structure was not only related to arch form,arch rise and arch span of big structure,but also closely related to the stability of articulated rock of roadway roof in secondary breaking off zone. Based on this,combining with the key strata theory,the locations of hard rock layers and their controlling soft rock group within the scope of arch rise were determined,using slide instability criterion and extrusion deformation instability criterion,the stability of articulated rock of roadway roof was identified from above to below,the overburden load of small structure was determined,and accordingly the reasonable formula of roadside supporting resistance were derived.
Analyzing thoroughly the characteristics of surrounding rock structure,calculating accurately roadside supporting resistance,and controlling serious deformation and failure of rocks surrounding,lead to supporting difficulty in gob-side entry retaining increased,even fail. Therefore,based upon the breaking off characteristics of overlying rock,the mechanical models of big and small structure were built,the formation conditions of low arch and high arch were analyzed,the formulas of their arch rise were derived,and the effect of horizontal force at arch foot on form evolvement and the stability of big and small structure. Research suggested that before the residual boundary of roadside roof the second broke off,if the coal side of roadway was strengthened timely and roadway-inside and roadside supporting resistance were improved,then overlying rock was easy to form low arch; if the coal side of roadway was soft,or the supporting resistance of roadway was insufficient,then overlying rock was easy to form high arch. Horizontal force at archfoot was the main reason of arch instability,if horizontal force at arch foot was larger than shearing resistance at arch foot,then the arch would lose stability,consequently the arch rise of low arch or the arch span of high arch would increase,which caused the overburden load of small structure increase. Overburden load of small structure was not only related to arch form,arch rise and arch span of big structure,but also closely related to the stability of articulated rock of roadway roof in secondary breaking off zone. Based on this,combining with the key strata theory,the locations of hard rock layers and their controlling soft rock group within the scope of arch rise were determined,using slide instability criterion and extrusion deformation instability criterion,the stability of articulated rock of roadway roof was identified from above to below,the overburden load of small structure was determined,and accordingly the reasonable formula of roadside supporting resistance were derived.
引文
[1]阚甲广,张农,李宝玉,等.典型留巷顶板条件下巷旁充填体支护阻力分析[J].岩土力学,2011,32(9):2778-2784.KAN Jiaguang,ZHANG Nong,LI Baoyu,et al.Analysis of supporting resistance of backfilling wall for gob-side entry retaining under typical roof conditions[J].Rock and Soil Mechanics,2011,32(9):2778-2784.
[2]唐建新,邓月华,涂兴东,等.锚网索联合支护沿空留巷顶板离层分析[J].煤炭学报,2010,35(11):1827-1831.TANG Jianxin,DENG Yuehua,TU Xingdong,et al.Analysis of roof separation in gob-side entry retaining combined support with bolting wire mesh[J].Journal of China Coal Society,2010,35(11):1827-1831.
[3]康红普,牛多龙,张镇,等.深部沿空留巷围岩变形特征与支护技术[J].岩石力学与工程学报,2010,29(10):1977-1987.KANG Hongpu,NIU Duolong,ZHANG Zhen,et al.Deformation characteristics of surrounding rock and supporting technology of gob-side entry retaining in deep coal mine[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(10):1977-1987.
[4]张农,张志义,吴海,等.深井沿空留巷扩刷修复技术及应用[J].岩石力学与工程学报,2014,33(3):468-474.ZHANG Nong,ZHANG Zhiyi,WU Hai,et al.Technology and application of reparation in deep gob-side entry retaining[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(3):468-474.
[5]伍永平,王红伟,解盘石.大倾角煤层长壁开采围岩宏观应力拱壳分析[J].煤炭学报,2012,37(4):559-564.WU Yongping,WANG Hongwei,XIE Panshi.Analysis of surrounding rock macro stress arch-shell of longwall face in steeply dipping seam mining[J].Journal of China Coal Society,2012,37(4):559-564.
[6]文志杰.无煤柱沿空留巷控制力学模型及关键技术研究[D].青岛:山东科技大学,2011.
[7]赵彭年.考虑水平方向原始应力时巷道顶板上自然平衡拱的形态[J].中国矿业大学学报,1978,7(1):51-58.ZHAO Pengnian.The forms of natural arch above the roadway roof under the condition of considering horizontal original stress[J].Journal of China University of Mining&Technology,1978,7(1):51-58.
[8]宋振骐,宋扬,刘义学,等.内外应力场理论及其在矿压控制中的应用[A].水电与矿业工程中的岩石力学问题——中国北方岩石力学与工程应用学术会议文集[C].1991.
[9]郑桂荣,杨万斌.煤巷煤体破裂区厚度的一种计算方法[J].煤炭学报,2003,28(1):38-40.ZHENG Guirong,YANG Wanbin.A calculation method of the failure zone width of side coal-wall of roadway in seams[J].Journal of China Coal Society,2003,28(1):38-40.
[10]侯朝炯,马念杰.煤层巷道两帮煤体应力和极限平衡区的探讨[J].煤炭学报,1989(4):21-29.HOU Chaojiong,MA Nianjie.Stress in in-seam roadvay sides and limit equilibrium zone[J].Journal of China Coal Society,1989(4):21-29.
[11]黄庆享,刘玉卫.巷道围岩支护的极限自稳平衡拱理论[J].采矿与安全工程学报,2014,31(3):354-358.HUANG Qingxiang,LIU Yuwei.Ultimate self-stable arch theory in roadway support[J].Journal of Mining&Safety Engineering,2014,31(3):354-358.
[12]钱鸣高,缪协兴,许家林.岩层控制的关键层理论[M].徐州:中国矿业大学出版社,2003.
[13]钱鸣高,石平五,许家林.矿山压力与岩层控制[M].徐州:中国矿业大学出版社,2010.
[14]高明中.锚固体梁的弯曲突变失稳问题分析[J].岩土力学,2008,25(8):1267-1270.GAO Mingzhong.Study on bending catastrophe phenomena of anchor roof beam[J].Rock and Soil Mechanics,2008,25(8):1267-1270.
[15]华心祝,李迎富.沿空留巷底板变形力学分析及底鼓防控[J].煤炭学报,2016,41(7):1624-1631.HUA Xinzhu,LI Yingfu.Mechanics analysis on floor deformation of gob-side entry retaining and the prevention and control of floor heave[J].Journal of China Coal Society,2016,41(7):1624-1631.
[2]唐建新,邓月华,涂兴东,等.锚网索联合支护沿空留巷顶板离层分析[J].煤炭学报,2010,35(11):1827-1831.TANG Jianxin,DENG Yuehua,TU Xingdong,et al.Analysis of roof separation in gob-side entry retaining combined support with bolting wire mesh[J].Journal of China Coal Society,2010,35(11):1827-1831.
[3]康红普,牛多龙,张镇,等.深部沿空留巷围岩变形特征与支护技术[J].岩石力学与工程学报,2010,29(10):1977-1987.KANG Hongpu,NIU Duolong,ZHANG Zhen,et al.Deformation characteristics of surrounding rock and supporting technology of gob-side entry retaining in deep coal mine[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(10):1977-1987.
[4]张农,张志义,吴海,等.深井沿空留巷扩刷修复技术及应用[J].岩石力学与工程学报,2014,33(3):468-474.ZHANG Nong,ZHANG Zhiyi,WU Hai,et al.Technology and application of reparation in deep gob-side entry retaining[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(3):468-474.
[5]伍永平,王红伟,解盘石.大倾角煤层长壁开采围岩宏观应力拱壳分析[J].煤炭学报,2012,37(4):559-564.WU Yongping,WANG Hongwei,XIE Panshi.Analysis of surrounding rock macro stress arch-shell of longwall face in steeply dipping seam mining[J].Journal of China Coal Society,2012,37(4):559-564.
[6]文志杰.无煤柱沿空留巷控制力学模型及关键技术研究[D].青岛:山东科技大学,2011.
[7]赵彭年.考虑水平方向原始应力时巷道顶板上自然平衡拱的形态[J].中国矿业大学学报,1978,7(1):51-58.ZHAO Pengnian.The forms of natural arch above the roadway roof under the condition of considering horizontal original stress[J].Journal of China University of Mining&Technology,1978,7(1):51-58.
[8]宋振骐,宋扬,刘义学,等.内外应力场理论及其在矿压控制中的应用[A].水电与矿业工程中的岩石力学问题——中国北方岩石力学与工程应用学术会议文集[C].1991.
[9]郑桂荣,杨万斌.煤巷煤体破裂区厚度的一种计算方法[J].煤炭学报,2003,28(1):38-40.ZHENG Guirong,YANG Wanbin.A calculation method of the failure zone width of side coal-wall of roadway in seams[J].Journal of China Coal Society,2003,28(1):38-40.
[10]侯朝炯,马念杰.煤层巷道两帮煤体应力和极限平衡区的探讨[J].煤炭学报,1989(4):21-29.HOU Chaojiong,MA Nianjie.Stress in in-seam roadvay sides and limit equilibrium zone[J].Journal of China Coal Society,1989(4):21-29.
[11]黄庆享,刘玉卫.巷道围岩支护的极限自稳平衡拱理论[J].采矿与安全工程学报,2014,31(3):354-358.HUANG Qingxiang,LIU Yuwei.Ultimate self-stable arch theory in roadway support[J].Journal of Mining&Safety Engineering,2014,31(3):354-358.
[12]钱鸣高,缪协兴,许家林.岩层控制的关键层理论[M].徐州:中国矿业大学出版社,2003.
[13]钱鸣高,石平五,许家林.矿山压力与岩层控制[M].徐州:中国矿业大学出版社,2010.
[14]高明中.锚固体梁的弯曲突变失稳问题分析[J].岩土力学,2008,25(8):1267-1270.GAO Mingzhong.Study on bending catastrophe phenomena of anchor roof beam[J].Rock and Soil Mechanics,2008,25(8):1267-1270.
[15]华心祝,李迎富.沿空留巷底板变形力学分析及底鼓防控[J].煤炭学报,2016,41(7):1624-1631.HUA Xinzhu,LI Yingfu.Mechanics analysis on floor deformation of gob-side entry retaining and the prevention and control of floor heave[J].Journal of China Coal Society,2016,41(7):1624-1631.