深埋硬岩隧洞复杂岩性挤压破碎带塌方过程及机制分析——以锦屏地下实验室为例
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摘要
深埋大断面隧洞开挖同时揭露多种不同岩性的岩体,各岩体之间物理力学性质差异大,其破坏规律也不相同。深入研究复杂岩性挤压破碎带的塌方演化过程及机制,对于防塌和治塌具有重要作用。针对锦屏地下实验室二期中3#实验室的复杂岩性挤压破碎带区塌方,通过现场地质调查及矿物分析,发现该处破碎带本身岩性复杂、地应力高是影响这次塌方的关键因素。同时结合现场录像观察的塌落岩体破坏形态、室内电镜扫描结果和不同岩性岩体的空间分布特点,认为此次塌方具有明显的渐进性破坏特征;不同岩性岩体具有不同的破坏机制:南侧边墙和掌子面分布的花斑角砾状大理岩、溶蚀状大理岩为剪切滑移型破坏,北侧边墙方解石化大理岩为节理张开倾倒破坏,顶拱镶嵌组合胶结状大理岩、花斑角砾状大理岩和溶蚀状大理岩为重力型塌落破坏。基于现场录像观察到塌方发生时间的先后顺序和电镜扫描不同岩性岩体的破坏机制,归纳其演化过程为:开挖卸荷→隧洞周边薄层岩体松散垮落→南侧边墙岩体剪切滑移破坏→北侧边墙岩体节理张开倾倒破坏→在两侧边墙卸荷作用下顶拱岩体发生卸荷回弹→重力坍塌破坏。根据岩体破坏机制和塌方演化过程,建议采用围岩表面和内部综合治理的支护措施(初喷不少于10 cm厚的混凝土+带锚垫板的注浆锚杆+挂网+复喷混凝土)。该研究成果可为深埋隧洞穿越复杂岩性挤压破碎带的类似设计、施工、支护提供参考。
The excavation of deep buried tunnel with the large cross section reveals many kinds of rocks with different physical and mechanical properties. It is very important to study the process and mechanism of the collapse for the complex lithological compressive rupture zone. The complicated lithological compressive rupture is located in No.3 laboratory of Jinping underground laboratory. The collapse happened there once. It was found through the field geological investigation and mineral analysis that the complex lithology of rock mass and high in-situ stress were the key factor of collapse. The failure mode of rock collapse recorded by video,the failure mechanism obtained by scanning electron microscope and the different lithological rock mass located in spatial distribution indicated that there was an obvious progressive failure characteristics in this collapse and the different lithological rock masses exhibited the different failure mechanisms. The variegation breccia and the corrosion marbles in the southern side wall and tunnel face exhibited the shearing slip failure,and the calcite marble in the northern side wall exhibited the toppling failure due to joint opening,and the mosaic cementation marble,variegation breccia marble and corrosion marble in top arch exhibited the gravitational collapse. The process of collapse recorded by video and the failure mechanism of different lithological rock mass obtained by SEM show:the excavation unloading→the collapsing of the thin layer rock mass around the tunnel→the shearing slip of the rock in the southern wall→the toppling failure of rock in the northern wall due to joint opening→the rebounding of the top arch rock under the unloading of both sidewalls→the gravitational collapsing. The comprehensive treatment measures inside and outside of surrounding rock(initial shotcrete not less than 10 cm thick + grouting bolt with anchor plate + suspended net + shotcrete again) were recommended.
The excavation of deep buried tunnel with the large cross section reveals many kinds of rocks with different physical and mechanical properties. It is very important to study the process and mechanism of the collapse for the complex lithological compressive rupture zone. The complicated lithological compressive rupture is located in No.3 laboratory of Jinping underground laboratory. The collapse happened there once. It was found through the field geological investigation and mineral analysis that the complex lithology of rock mass and high in-situ stress were the key factor of collapse. The failure mode of rock collapse recorded by video,the failure mechanism obtained by scanning electron microscope and the different lithological rock mass located in spatial distribution indicated that there was an obvious progressive failure characteristics in this collapse and the different lithological rock masses exhibited the different failure mechanisms. The variegation breccia and the corrosion marbles in the southern side wall and tunnel face exhibited the shearing slip failure,and the calcite marble in the northern side wall exhibited the toppling failure due to joint opening,and the mosaic cementation marble,variegation breccia marble and corrosion marble in top arch exhibited the gravitational collapse. The process of collapse recorded by video and the failure mechanism of different lithological rock mass obtained by SEM show:the excavation unloading→the collapsing of the thin layer rock mass around the tunnel→the shearing slip of the rock in the southern wall→the toppling failure of rock in the northern wall due to joint opening→the rebounding of the top arch rock under the unloading of both sidewalls→the gravitational collapsing. The comprehensive treatment measures inside and outside of surrounding rock(initial shotcrete not less than 10 cm thick + grouting bolt with anchor plate + suspended net + shotcrete again) were recommended.
引文
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[7]FRALDI M,GUARRACINO F.Analytical solutions for collapse mechanisms in tunnels with arbitrary cross sections[J].International Journal of Solids and Structures,2010,47(2):216–223.
[8]FRALDI M,GUARRACINO F.Evaluation of impending collapse in circular tunnels by analytical and numerical approaches[J].Tunnelling and Underground Space Technology,2011,26(4):507–516.
[9]FRALDI M,GUARRACINO F.Limit analysis of collapse mechanisms in cavities and tunnels according to the Hoek–Brown failure criterion[J].International Journal of Rock Mechanics and Mining Sciences,2009,46(4):665–673.
[10]YANG X L,HUANG F.Collapse mechanism of shallow tunnel based on nonlinear Hoek-Brown failure criterion[J].Tunnelling and Underground Space Technology,2011,26(6):686–691.
[11]YANG X L,YANG Z H,PAN Q J,et al.Kinematical analysis of highway tunnel collapse using nonlinear failure criterion[J].Journal of Central South University,2014,21(1):381–386.
[12]METE K,TURGAY O.Influence of the fault zone in shallow tunneling:a case study of Izmir metro tunnel[J].Tunnelling and Underground Space Technology,2013,33(1):34–45.
[13]ZAREI H R,UROMEIHY A,SHARIFZADEH M.Evaluation of high local groundwater inflow to a rock tunnel by characterization of geological features[J].Tunnelling and Underground Space Technology,2011,26(2):364–373.
[14]刘乃飞,李宁,李国锋,等.库尉输水隧洞塌方机制分析及加固效果评价[J].岩石力学与工程学报,2014,33(12):2 433–2 442.(LIU Naifei,LI Ning,LI Guofeng,et al.Collapse mechanism of Kuyu water conveyance tunnel and the appraisement of the consolidate effect[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2 433–2 442.(in Chinese))
[15]曹树刚,洛锋,程崇胜,等.富水断层破碎带井筒围岩控制[J].岩石力学与工程学报,2014,33(8):1 536–1 545.(CAO Shugang,LUO Feng,CHENG Chongsheng,et al.Surrounding rock control of shaft in water enriched fault fracture zone[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(8):1 536–1 545.(in Chinese))
[16]李生杰,谢永利,朱小明,等.高速公路乌鞘岭隧道穿越F4断层破碎带涌水塌方工程对策研究[J].岩石力学与工程学报,2013,32(增2):3 602–3 609.(LI Shengjie,XIE Yongli,ZHU Xiaoming,et al.Research on countermeasure of water gushing with collapse in process of Wushaoling highway tunnel crossing F4 fault fracture zone[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(Supp.2):3 602–3 609.(in Chinese))
[17]左清军,吴立,林存友,等.富水软岩隧道跨越断层段塌方机制分析及处治措施[J].岩石力学与工程学报,2016,35(2):369–377.(ZUO Qingjun,WU Li,LIN Cunyou,et al.Collapse mechanism and treatment measures for tunnel in water-rich soft rock crossing fault[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(2):369–377.(in Chinese))
[18]马涛.浅埋隧道塌方处治方法研究[J].岩石力学与工程学报,2006,25(增2):3 976–3 981.(MA Tao.Treatment method for collapse treatment of shallow-buried tunnel[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(Supp.2):3 976–3 981.(in Chinese))
[19]冯夏庭,张传庆,李邵军,等.深埋硬岩隧洞动态设计方法[M].北京:科学出版社,2013:332–349.(FENG Xiating,ZHANG Chuanqing,LI Shaojun,et al.Dynamic design method of deep buried hard rock tunnel[M].Beijing:Science Press,2013:332–349.(in Chinese))
[20]吴强,刘新荣,杜小平,等.马垭口隧道塌方事故发生机制的研究[J].地下空间与工程学报,2009,5(6):1 241–1 247.(WU Qiang,LIU Xinrong,DU Xiaoping,et al.Study on collapsed mechanism in the Mayakou tunnel[J].Chinese Journal of Underground Space and Engineering,2009,5(6):1 241–1 247.(in Chinese))
[21]朱合华,黄锋,徐前卫.变埋深下软弱破碎隧道围岩渐进性破坏试验与数值模拟[J].岩石力学与工程学报,2010,29(6):1 113–1 122.(ZHU Hehua,HUANG Feng,XU Qianwei.Model test and numerical simulation for progressive failure of weak and fractured tunnel surrounding rock under different overburden depths[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(6):1 113–1 122.(in Chinese))
[22]张成平,韩凯航,张顶立,等.城市软弱围岩隧道塌方特征及演化规律试验研究[J].岩石力学与工程学报,2014,33(12):2 433–2 442.(ZHANG Chengping,HAN Kaihang,ZHANG Dingli,et al.Test study of collapse characteristics of tunnels in soft ground in urban areas[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2 433–2 442.(in Chinese))
[23]徐前卫,程盼盼,朱合华,等.跨断层隧道围岩渐进性破坏模型试验及数值模拟[J].岩石力学与工程学报,2016,35(3):433–446.(XU Qianwei,CHENG Panpan,ZHU Hehua,et al.Experimental study and numerical simulation on progressive failure characteristics of the fault-crossing tunnel surrounding rock[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(3):433–446.(in Chinese))
[24]冯夏庭,吴世勇,李邵军,等.中国锦屏地下实验室二期工程安全原位综合监测与分析[J].岩石力学与工程学报,2016,35(4):649–657.(FENG Xiating,WU Shiyong,LI Shaojun,et al.Comprehensive field monitoring of deep tunnels at Jinping underground laboratory(CJPL–II)in China[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(4):649–657.(in Chinese))
[25]凉山州气象局.凉山彝族自治州2015年气候公报[R].凉山:凉山州气象局,2015.(Liangshan State Bureau of Meteorology.Liangshan Yi Autonomous Prefecture 2015 climate bulletin[R].Liangshan:Liangshan State Bureau of Meteorology,2015.(in Chinese))
[26]王明年,李玉文.公路隧道围岩亚级分级方法[M].成都:西南交通出版社,2008:161–167.(WANG Mingnian,LI Yuwen.Subclassification method of surrounding rock in highway tunnel[M].Chengdou:Southwest Transportation Press,2008:161–167.(in Chinese))
[27]屈鹏程.层状碎裂结构隧道围岩稳定性分析及防灾对策研究[硕士学位论文][D].成都:成都理工大学,2015.(QU Pengcheng.Layered fracture structure of tunnel rock mass stability analysis and disaster prevention countermeasures research[M.S.Thesis][D].Chengdu:Chengdu University of Technology,2015.(in Chinese))
[2]魏志云,徐光黎,申艳军,等.大岗山水电站地下厂房区辉绿岩脉群发育特征及稳定性状况评价[J].工程地质学报,2013,21(2):206–215.(WEI Zhiyun,XU Guangli,SHEN Yanjun,et al.Characteristics and stability evaluations of diabase dikes group surrounding underground caverns of Dagangshan hydropower station[J].Journal of Engineering Geology,2013,21(2):206–215.(in Chinese))
[3]王国欣.高速公路隧道施工灾病害与监控反馈研究[R].上海:同济大学,2005.(WANG Guoxin.Studise on the hazards,diseases and monitoring feedback in the construction of expressway tunnel[R].Shanghai:Tongji University,2005.(in Chinese))
[4]汪成兵.软弱破碎隧道围岩渐进性破坏机制研究[博士学位论文][D].上海:同济大学,2007.(WANG Chengbing.Study on the progressive failure mechanism of the surrounding rock of tunnel constructed in soft rock[Ph.D.Thesis][D].Shanghai:Tongji University,2007.(in Chinese))
[5]陈洁金,周峰,阳军生,等.山岭隧道塌方风险模糊层次分析[J].岩土力学,2009,30(8):2 365–2 370.(CHEN Jiejin,ZHOU Feng,YANG Junsheng,et al.Fuzzy analytic hierarchy process for risk evaluation of collapse during construction of mountain tunnel[J].Rock and Soil Mechanics,2009,30(8):2 365–2 370.(in Chinese))
[6]汪成兵,朱合华.隧道塌方机制及其影响因素离散元模拟[J].岩土工程学报,2008,30(3):450–456.(WANG Chengbing,ZHU Hehua.Tunnel collapse mechanism and numerical analysis of its influencing factors[J].Chinese Journal of Geotechnical Engineering,2008,30(3):450–456.(in Chinese))
[7]FRALDI M,GUARRACINO F.Analytical solutions for collapse mechanisms in tunnels with arbitrary cross sections[J].International Journal of Solids and Structures,2010,47(2):216–223.
[8]FRALDI M,GUARRACINO F.Evaluation of impending collapse in circular tunnels by analytical and numerical approaches[J].Tunnelling and Underground Space Technology,2011,26(4):507–516.
[9]FRALDI M,GUARRACINO F.Limit analysis of collapse mechanisms in cavities and tunnels according to the Hoek–Brown failure criterion[J].International Journal of Rock Mechanics and Mining Sciences,2009,46(4):665–673.
[10]YANG X L,HUANG F.Collapse mechanism of shallow tunnel based on nonlinear Hoek-Brown failure criterion[J].Tunnelling and Underground Space Technology,2011,26(6):686–691.
[11]YANG X L,YANG Z H,PAN Q J,et al.Kinematical analysis of highway tunnel collapse using nonlinear failure criterion[J].Journal of Central South University,2014,21(1):381–386.
[12]METE K,TURGAY O.Influence of the fault zone in shallow tunneling:a case study of Izmir metro tunnel[J].Tunnelling and Underground Space Technology,2013,33(1):34–45.
[13]ZAREI H R,UROMEIHY A,SHARIFZADEH M.Evaluation of high local groundwater inflow to a rock tunnel by characterization of geological features[J].Tunnelling and Underground Space Technology,2011,26(2):364–373.
[14]刘乃飞,李宁,李国锋,等.库尉输水隧洞塌方机制分析及加固效果评价[J].岩石力学与工程学报,2014,33(12):2 433–2 442.(LIU Naifei,LI Ning,LI Guofeng,et al.Collapse mechanism of Kuyu water conveyance tunnel and the appraisement of the consolidate effect[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2 433–2 442.(in Chinese))
[15]曹树刚,洛锋,程崇胜,等.富水断层破碎带井筒围岩控制[J].岩石力学与工程学报,2014,33(8):1 536–1 545.(CAO Shugang,LUO Feng,CHENG Chongsheng,et al.Surrounding rock control of shaft in water enriched fault fracture zone[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(8):1 536–1 545.(in Chinese))
[16]李生杰,谢永利,朱小明,等.高速公路乌鞘岭隧道穿越F4断层破碎带涌水塌方工程对策研究[J].岩石力学与工程学报,2013,32(增2):3 602–3 609.(LI Shengjie,XIE Yongli,ZHU Xiaoming,et al.Research on countermeasure of water gushing with collapse in process of Wushaoling highway tunnel crossing F4 fault fracture zone[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(Supp.2):3 602–3 609.(in Chinese))
[17]左清军,吴立,林存友,等.富水软岩隧道跨越断层段塌方机制分析及处治措施[J].岩石力学与工程学报,2016,35(2):369–377.(ZUO Qingjun,WU Li,LIN Cunyou,et al.Collapse mechanism and treatment measures for tunnel in water-rich soft rock crossing fault[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(2):369–377.(in Chinese))
[18]马涛.浅埋隧道塌方处治方法研究[J].岩石力学与工程学报,2006,25(增2):3 976–3 981.(MA Tao.Treatment method for collapse treatment of shallow-buried tunnel[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(Supp.2):3 976–3 981.(in Chinese))
[19]冯夏庭,张传庆,李邵军,等.深埋硬岩隧洞动态设计方法[M].北京:科学出版社,2013:332–349.(FENG Xiating,ZHANG Chuanqing,LI Shaojun,et al.Dynamic design method of deep buried hard rock tunnel[M].Beijing:Science Press,2013:332–349.(in Chinese))
[20]吴强,刘新荣,杜小平,等.马垭口隧道塌方事故发生机制的研究[J].地下空间与工程学报,2009,5(6):1 241–1 247.(WU Qiang,LIU Xinrong,DU Xiaoping,et al.Study on collapsed mechanism in the Mayakou tunnel[J].Chinese Journal of Underground Space and Engineering,2009,5(6):1 241–1 247.(in Chinese))
[21]朱合华,黄锋,徐前卫.变埋深下软弱破碎隧道围岩渐进性破坏试验与数值模拟[J].岩石力学与工程学报,2010,29(6):1 113–1 122.(ZHU Hehua,HUANG Feng,XU Qianwei.Model test and numerical simulation for progressive failure of weak and fractured tunnel surrounding rock under different overburden depths[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(6):1 113–1 122.(in Chinese))
[22]张成平,韩凯航,张顶立,等.城市软弱围岩隧道塌方特征及演化规律试验研究[J].岩石力学与工程学报,2014,33(12):2 433–2 442.(ZHANG Chengping,HAN Kaihang,ZHANG Dingli,et al.Test study of collapse characteristics of tunnels in soft ground in urban areas[J].Chinese Journal of Rock Mechanics and Engineering,2014,33(12):2 433–2 442.(in Chinese))
[23]徐前卫,程盼盼,朱合华,等.跨断层隧道围岩渐进性破坏模型试验及数值模拟[J].岩石力学与工程学报,2016,35(3):433–446.(XU Qianwei,CHENG Panpan,ZHU Hehua,et al.Experimental study and numerical simulation on progressive failure characteristics of the fault-crossing tunnel surrounding rock[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(3):433–446.(in Chinese))
[24]冯夏庭,吴世勇,李邵军,等.中国锦屏地下实验室二期工程安全原位综合监测与分析[J].岩石力学与工程学报,2016,35(4):649–657.(FENG Xiating,WU Shiyong,LI Shaojun,et al.Comprehensive field monitoring of deep tunnels at Jinping underground laboratory(CJPL–II)in China[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(4):649–657.(in Chinese))
[25]凉山州气象局.凉山彝族自治州2015年气候公报[R].凉山:凉山州气象局,2015.(Liangshan State Bureau of Meteorology.Liangshan Yi Autonomous Prefecture 2015 climate bulletin[R].Liangshan:Liangshan State Bureau of Meteorology,2015.(in Chinese))
[26]王明年,李玉文.公路隧道围岩亚级分级方法[M].成都:西南交通出版社,2008:161–167.(WANG Mingnian,LI Yuwen.Subclassification method of surrounding rock in highway tunnel[M].Chengdou:Southwest Transportation Press,2008:161–167.(in Chinese))
[27]屈鹏程.层状碎裂结构隧道围岩稳定性分析及防灾对策研究[硕士学位论文][D].成都:成都理工大学,2015.(QU Pengcheng.Layered fracture structure of tunnel rock mass stability analysis and disaster prevention countermeasures research[M.S.Thesis][D].Chengdu:Chengdu University of Technology,2015.(in Chinese))