基于离散元地下厂房围岩变形破坏特征分析
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摘要
为了研究结构面对中等地应力区地下厂房开挖过程中应力调整以及围岩变形破坏的影响,以某抽水蓄能电站地下厂房为研究对象,采用离散元软件3DEC对其开挖过程进行仿真计算.研究表明:在开挖断面不大时,掌子面附近的结构面会阻挡围岩应力向深部的调整,加剧拱脚处的应力集中程度,使围岩以应力型破坏为主;当开挖断面增大,围岩卸荷松弛明显,结构面控制型破坏将逐渐占优;用3DEC模拟出的陡倾型结构面的张开是围岩位移产生的主要原因,且其张开位移受前几期的开挖影响较大.研究成果可为类似陡倾角大跨度地下工程开挖的稳定性分析及支护设计提供借鉴.
In order to study the influence of the structure on the stress adjustment and the surrounding rock deformation and failure during the excavation of the underground powerhouse in the middle initial stress, the underground powerhouse of a pumped storage power station was taken as the research object, with discrete element software 3 DEC used to simulate the excavation process. The study shows that when the excavation section is small, the structural surface near the excavation face will block the adjustment of surrounding rock stress and increase stress concentration at the arch foot, mainly leading to stress-dominated failures on the surrounding rock. When the excavation section is enlarged, stress relaxation of surrounding rock is obvious and the controlled failure of the structure plane will gradually dominate. The structural plane opening simulated by 3 DEC is the main cause of surrounding rock displacement, and its opening displacement is greatly affected by the excavation in previous periods. The results could provide an important reference for stability analysis and design support of similar steeply dipped rock strata of large span underground projects.
In order to study the influence of the structure on the stress adjustment and the surrounding rock deformation and failure during the excavation of the underground powerhouse in the middle initial stress, the underground powerhouse of a pumped storage power station was taken as the research object, with discrete element software 3 DEC used to simulate the excavation process. The study shows that when the excavation section is small, the structural surface near the excavation face will block the adjustment of surrounding rock stress and increase stress concentration at the arch foot, mainly leading to stress-dominated failures on the surrounding rock. When the excavation section is enlarged, stress relaxation of surrounding rock is obvious and the controlled failure of the structure plane will gradually dominate. The structural plane opening simulated by 3 DEC is the main cause of surrounding rock displacement, and its opening displacement is greatly affected by the excavation in previous periods. The results could provide an important reference for stability analysis and design support of similar steeply dipped rock strata of large span underground projects.
引文
[1] 杨静熙,黄书岭,刘忠绪.高地应力硬岩大型洞室群围岩变形破坏与岩石强度应力比关系研究[J].长江科学院院报,2019,36(2):63-70.YANG J X,HUANG S L,LIU Z X.Relationship between deformation failure and strength-to-stress ratio of surrounding rock of large-scale underground hard rock caverns under high geo-stress[J].Journal of Yangtze River Scientific Research Institute,2019,36(2):63-70.(Ch).
[2] WANG T,WU H G,SU K,et al.DEM modeling of the stability of the Jurong underground powerhouse cavern[C]// American Rock Mechanics Association,Geomechanics Symposium held in San Francisco,California,USA,25-28 June 2017:448-454.
[3] 杨云浩,王仁坤,邢万波,等.猴子岩水电站洞群硬脆性围岩变形破坏特征的3DEC分析[J].岩石力学与工程学报,2015,34(2):4179-4186.YANG Y H,WANG R K,XING W B,et al.Analysis of deformation and failure of hard rock mass surrounding underground openings in houziyan hydropower station by 3dec numerical simulation[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(2):4179-4186.(Ch).
[4] WANG TAO,WU H EGAOH Y,et al.Numerical investigation of the support system of Qiongzhong underground powerhouse cavern[C]//American Rock Mechanics Association,Geomechanics Symposium held in San Francisco,California,USA,17-20 June 2018:410-417.
[5] 张勇,肖平西,丁秀丽,等.高地应力条件下地下厂房洞室群围岩的变形破坏特征及对策研究[J].岩石力学与工程学报,2012,31(2):228-244.ZHANG Y,XIAO P X,DING X L,et al.Study of deformation and failure characteristics for surrounding rocks of underground powerhouse caverns under high geostress condition and countermeasures[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(2):228-244.(Ch).
[6] 王涛,陈晓玲,于利宏.地下洞室群围岩稳定的离散元计算[J].岩土力学,2005,26(12):1936-1940.WANG T,CHEN X L,YU L H.Discrete element calculation of surrounding rock mass stability of underground cavern group [J].Rock and Soil Mechanics,2005,26(12):1936-1940.(Ch).
[7] 麦锦锋,李端有,黄祥,等.乌东德水电站右岸地下厂房施工期围岩稳定分析[J].长江科学院院报,2016,33(5):43-47.MAI J F,LI R Y,HUANG X,et al.Rock stability of the right bank underground powerhouse of wudongde hydropower station during construction[J].Journal of Yangtze River Scientific Research Institute,2016,33(5):43-47.(Ch).
[8] 李昂,戴峰,徐奴文,等.乌东德水电站右岸地下厂房开挖围岩破坏模式及形成机制研究[J].岩石力学与工程学报,2017,36(4):782-793.LI A,DAI F,XU N W,et al.Failure mechanism and mode of surrounding rock of underground powerhouse at the right bank of Wudongde hydropower station subjected to excavation[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(4):782-793.(Ch).
[9] 中华人民共和国国家标准编写组.GB 50287-2016 水力发电工程地质勘察规范[S].北京:中国计划出版社,2016.The National Standards Compilation Group of People′s Republic of China.GB50287-2016 Code for hydropower engineering geological investigation[S].Beijing:China Planning Press,2016.(Ch).
[10] 钮新强,丁秀丽.地下洞室围岩顶拱承载力学机制及稳定拱设计方法[J].岩石力学与工程学报,2013,32(4):775-786.NIU X Q,DING X L.Bearing mechanism of top arch and stable arch design method for surrounding rock of underground caverns[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(4):775-786.(Ch).
[11] 冯夏庭,肖亚勋,丰光亮,等.岩爆孕育过程研究[J].岩石力学与工程学报,2019,38(1):1-24.FENG X D,XIAO Y X,FENG L G,et al.Study on the development process of rock bursts[J].Chinese Journal of Rock Mechanics and Engineering,2019,38(1):1-24.(Ch).
[2] WANG T,WU H G,SU K,et al.DEM modeling of the stability of the Jurong underground powerhouse cavern[C]// American Rock Mechanics Association,Geomechanics Symposium held in San Francisco,California,USA,25-28 June 2017:448-454.
[3] 杨云浩,王仁坤,邢万波,等.猴子岩水电站洞群硬脆性围岩变形破坏特征的3DEC分析[J].岩石力学与工程学报,2015,34(2):4179-4186.YANG Y H,WANG R K,XING W B,et al.Analysis of deformation and failure of hard rock mass surrounding underground openings in houziyan hydropower station by 3dec numerical simulation[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(2):4179-4186.(Ch).
[4] WANG TAO,WU H EGAOH Y,et al.Numerical investigation of the support system of Qiongzhong underground powerhouse cavern[C]//American Rock Mechanics Association,Geomechanics Symposium held in San Francisco,California,USA,17-20 June 2018:410-417.
[5] 张勇,肖平西,丁秀丽,等.高地应力条件下地下厂房洞室群围岩的变形破坏特征及对策研究[J].岩石力学与工程学报,2012,31(2):228-244.ZHANG Y,XIAO P X,DING X L,et al.Study of deformation and failure characteristics for surrounding rocks of underground powerhouse caverns under high geostress condition and countermeasures[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(2):228-244.(Ch).
[6] 王涛,陈晓玲,于利宏.地下洞室群围岩稳定的离散元计算[J].岩土力学,2005,26(12):1936-1940.WANG T,CHEN X L,YU L H.Discrete element calculation of surrounding rock mass stability of underground cavern group [J].Rock and Soil Mechanics,2005,26(12):1936-1940.(Ch).
[7] 麦锦锋,李端有,黄祥,等.乌东德水电站右岸地下厂房施工期围岩稳定分析[J].长江科学院院报,2016,33(5):43-47.MAI J F,LI R Y,HUANG X,et al.Rock stability of the right bank underground powerhouse of wudongde hydropower station during construction[J].Journal of Yangtze River Scientific Research Institute,2016,33(5):43-47.(Ch).
[8] 李昂,戴峰,徐奴文,等.乌东德水电站右岸地下厂房开挖围岩破坏模式及形成机制研究[J].岩石力学与工程学报,2017,36(4):782-793.LI A,DAI F,XU N W,et al.Failure mechanism and mode of surrounding rock of underground powerhouse at the right bank of Wudongde hydropower station subjected to excavation[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(4):782-793.(Ch).
[9] 中华人民共和国国家标准编写组.GB 50287-2016 水力发电工程地质勘察规范[S].北京:中国计划出版社,2016.The National Standards Compilation Group of People′s Republic of China.GB50287-2016 Code for hydropower engineering geological investigation[S].Beijing:China Planning Press,2016.(Ch).
[10] 钮新强,丁秀丽.地下洞室围岩顶拱承载力学机制及稳定拱设计方法[J].岩石力学与工程学报,2013,32(4):775-786.NIU X Q,DING X L.Bearing mechanism of top arch and stable arch design method for surrounding rock of underground caverns[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(4):775-786.(Ch).
[11] 冯夏庭,肖亚勋,丰光亮,等.岩爆孕育过程研究[J].岩石力学与工程学报,2019,38(1):1-24.FENG X D,XIAO Y X,FENG L G,et al.Study on the development process of rock bursts[J].Chinese Journal of Rock Mechanics and Engineering,2019,38(1):1-24.(Ch).