深部地下泵站厂房锚固岩体时效变形特征与加固效应
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摘要
预应力锚索支护系统能够有效抑制地下洞室围岩塑性区的扩展。基于原位监测和数值计算分析,对高边墙、大跨度地下洞室开挖过程中顶拱和边墙的变形演化过程以及锚索拉力的时效特征进行分析研究,得出地下洞室顶拱、拱腰、边墙位置预应力锚索拉力分别呈单向增长型、先减后增波动型、单向衰减型的3种变化模式;进一步采用有限差分软件FLAC~(3D),对锚索支护岩体开挖全过程的变形特性进行分析,并对锚索拉力变化模式及其支护效应进行探讨。结果表明,锚索拉力具有明显的时效特征,拉力演化模式与空间位置密切相关;进水池和主厂房洞室间隔墙内对穿锚索有效减小了岩墙塑性区分布范围。该研究成果具有重要理论价值,并对同类工程的设计和施工具有一定指导意义。
The support system of prestressed anchor cables can effectively reduce the expansion of the plastic zone of the surrounding rock in underground cavers. Based on in-situ monitoring and numerical analysis for the high-wall and long-span underground caverns,the deformation evolution process of the surrounding rock and the time-dependent characteristics of the anchor cable tension are analyzed. Three types of change modes of the anchor cable tension, including monotonically increasing, decreasing firstly and then increasing, and monotonically decreasing respectively at the top arch,arch waist and side wall of the underground cavern,are proposed. The deformation characteristics of the anchored rock during the excavation process are analyzed by using the finite difference software FLAC~(3D),and the variation mode of the anchor cable tension and the supporting effect are discussed. The results show that the anchor cable tension presents remarkable timedependent characteristics and is closely related to its spatial position;The thru-anchor cable in the middle partition wall effectively reduces the distribution range of the plastic zone of the rock wall. The research conclusion has important theoretical value and guiding significance for the design and construction of similar projects.
The support system of prestressed anchor cables can effectively reduce the expansion of the plastic zone of the surrounding rock in underground cavers. Based on in-situ monitoring and numerical analysis for the high-wall and long-span underground caverns,the deformation evolution process of the surrounding rock and the time-dependent characteristics of the anchor cable tension are analyzed. Three types of change modes of the anchor cable tension, including monotonically increasing, decreasing firstly and then increasing, and monotonically decreasing respectively at the top arch,arch waist and side wall of the underground cavern,are proposed. The deformation characteristics of the anchored rock during the excavation process are analyzed by using the finite difference software FLAC~(3D),and the variation mode of the anchor cable tension and the supporting effect are discussed. The results show that the anchor cable tension presents remarkable timedependent characteristics and is closely related to its spatial position;The thru-anchor cable in the middle partition wall effectively reduces the distribution range of the plastic zone of the rock wall. The research conclusion has important theoretical value and guiding significance for the design and construction of similar projects.
引文
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[2]朱泽奇,盛谦,张勇慧,等.大岗山水电站地下厂房洞室群围岩开挖损伤区研究[J].岩石力学与工程学报,2013,32(4):734-739.(ZHU Zeji,SHENG Qian,ZHANG Yonghui,et al.Research on excavation damage zone of underground powerhouse of Dagangshan hydropower station[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(4):734-739.(in Chinese))
[3]罗忆,卢文波,周创兵,等.高地应力条件下地下厂房开挖动态卸荷引起的变形突变机制研究[J].岩土力学,2011,32(5):1 553-1 560.(LUO Yi,LU Wenbo,ZHOU Chuangbing,et al.Mechanism study of abrupt deformation of underground powerhouse induced by excavation unloading under high in-situ stress[J].Rock and Soil Mechanics,2011,32(5):1 553-1 560.(in Chinese))
[4]李建林,邓华锋,黄建文,等.卸荷岩体锚固预应力损失的影响因素分析[J].岩土力学,2005,26(增1):292-295.(LI Jianlin,DENGHuafeng,HUANG Jianwen,et al.Analysis of factors affected on prestress losses of unloading rock mass[J].Rock and Soil Mechanics,2005,26(Supp.1):292-295.(in Chinese))
[5]LIU X M,WANG J Q,HUANG J,et al.Full-scale pullout tests and analyses of ground anchors in rocks under ultimate load conditions[J].Engineering Geology,2017,228:1-10.
[6]JIANG S H,LI D Q,ZHANG L M,et al.Time-dependent system reliability of anchored rock slopes considering rock bolt corrosion effect[J].Engineering Geology,2014,175:1-8.
[7]SUN H Y,WONG L N Y,SHANG Y Q,et al.Systematic monitoring of the performance of anchor systems in fractured rock masses[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(6):1 038-1 045.
[8]ZHU W S,SUI B,LI X J,et al.A methodology for studying the high wall displacement of large scale underground cavern complexes and it's applications[J].Tunnelling and Underground Space Technology,2008,23(6):651-664.
[9]ZHU W S,LI X J,ZHANG Q B,et al.A study on sidewall displacement prediction and stability evaluations for large underground power station caverns[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(7):1 055-1 062.
[10]REZAEI M,RAJABI M.Vertical displacement estimation in roof and floor of an underground powerhouse cavern[J].Engineering Failure Analysis,2018,90:290-309.
[11]LI Y,ZHU W S,FU J W,et al.A damage rheology model applied to analysis of splitting failure in underground caverns of Jinping Ihydropower station[J].International Journal of Rock Mechanics and Mining Sciences,2014,71:224-234.
[12]段淑倩,冯夏庭,江权,等.高地应力下白鹤滩地下洞室群含错动带岩体破坏模式及机制研究[J].岩石力学与工程学报,2017,36(4):852-864.(DUAN Shuqian,FENG Xiating,JIANG Quan,et al.Failure modes and mechanisms for rock masses with staggered zones of Baihetan underground caverns under high geostress[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(4):852-864.(in Chinese))
[13]WU A Q,WANG J M,ZHONG Z,et al.Engineering rock mechanics practices in the underground powerhouse at Jinping I hydropower station[J].Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):640-650.
[14]ZHOU X P,XIA E M,YANG H Q,et al.Different crack sizes analyzed for surrounding rock mass around underground caverns in Jinping I hydropower station[J].Theoretical and Applied Fracture Mechanics,2012,57(1):19-30.
[15]SONG S W,FENG X M,LIAO C G,et al.Measures for controlling large deformations of underground caverns under high in-situ stress condition-a case study of Jinping I hydropower station[J].Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):605-618.
[16]王克忠,吴慧,赵宇飞.深部地下厂房锚索预应力损失与岩体蠕变耦合分析[J].岩石力学与工程学报,2018,37(6):1 481-1 488.(WANG Kezhong,WU Hui,ZHAO Yufei.Coupling between reduction of force in prestressed anchor cable and rock creep in deep-buried underground powerhouse[J].Chinese Journal of Rock Mechanics and Engineering,2018,37(6):1 481-1 488.(in Chinese))
[17]CHEN G Q,CHEN T,CHEN Y,et al.A new method of predicting the prestress variations in anchored cables with excavation unloading destruction[J].Engineering Geology,2018,241:109-120.
[18]刘国锋,冯夏庭,江权,等.白鹤滩大型地下厂房开挖围岩片帮破坏特征、规律及机制研究[J].岩石力学与工程学报,2016,35(5):865-878.(LIU Guofeng,FENG Xiating,JIANG Quan,et al.Failure characteristics,laws and mechanisms of rock spalling in excavation of large-scale underground powerhouse caverns in Baihetan[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(5):865-878.(in Chinese))
[19]刘泉声,雷广峰,彭星新.深部裂隙岩体锚固机制研究进展与思考[J].岩石力学与工程学报,2016,35(2):312-332.(LIU Quansheng,LEI Guangfeng,PENG Xingxin.Advance and review on the anchoring mechanism in deep fractured rock mass[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(2):312-332.(in Chinese))
[20]李仲奎,戴荣,姜逸明.FLAC3D分析中的初始应力场生成及在大型地下洞室群计算中的应用[J].岩石力学与工程学报,2002,21(增2):2 378-2 392.(LI Zhongkui,DAI Rong,JIANG Yiming.Improvement of the generation of the initial stress field by using FLAC3D and application in a huge underground cavern group[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(Supp.2):2 378-2 392.(in Chinese))
[21]冯夏庭,张传庆,李邵军.深埋硬岩隧洞动态设计方法[M].北京：科学出版社,2013:140-141.(FENG Xiating,ZHANG Chuanqing,LI Shaojun.Dynamic design method for deep tunnels in hard rock[M].Beijing:Science Press,2013:140-141.(in Chinese))
[22]徐干成,郑颖人,乔春生.地下工程支护结构与设计[M].北京：中国水利水电出版社,2013:55-56.(XU Gancheng,ZHENGYingren,QIAO Chunsheng.Supporting structure and design in underground engineering[M].Beijing:China Water Power Press,2013:55-56.(in Chinese))
[23]李帅军,冯夏庭,徐鼎平,等.白鹤滩水电站主厂房第I层开挖期围岩变形规律与机制研究[J].岩石力学与工程学报,2016,35(增2):3 947-3 959.(LI Shuaijun,FENG Xiating,XU Dingping,et al.Study of the characteristics and mechanism of surrounding rock deformation during the first layer excavation in Baihetan hydorpower station underground main powerhouses[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(Supp.2):3 947-3 959.(in Chinese))
[24]LI H B,YANG X G,ZHANG X B,et al.Deformation and failure analyses of large underground caverns during construction of the Houziyan hydropower station,southwest China[J].Engineering Failure Analysis,2017,80:164-185.
[25]江权,冯夏庭,陈国庆,等.高地应力条件下大型地下洞室群稳定性综合研究[J].岩石力学与工程学报,2008,27(增2):3 768-3 777.(JIANG Quan,FENG Xiating,CHEN Guoqing,et al.Stability study of large underground caverns under high geostress[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(Supp.2):3 768-3 777.(in Chinese))
[2]朱泽奇,盛谦,张勇慧,等.大岗山水电站地下厂房洞室群围岩开挖损伤区研究[J].岩石力学与工程学报,2013,32(4):734-739.(ZHU Zeji,SHENG Qian,ZHANG Yonghui,et al.Research on excavation damage zone of underground powerhouse of Dagangshan hydropower station[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(4):734-739.(in Chinese))
[3]罗忆,卢文波,周创兵,等.高地应力条件下地下厂房开挖动态卸荷引起的变形突变机制研究[J].岩土力学,2011,32(5):1 553-1 560.(LUO Yi,LU Wenbo,ZHOU Chuangbing,et al.Mechanism study of abrupt deformation of underground powerhouse induced by excavation unloading under high in-situ stress[J].Rock and Soil Mechanics,2011,32(5):1 553-1 560.(in Chinese))
[4]李建林,邓华锋,黄建文,等.卸荷岩体锚固预应力损失的影响因素分析[J].岩土力学,2005,26(增1):292-295.(LI Jianlin,DENGHuafeng,HUANG Jianwen,et al.Analysis of factors affected on prestress losses of unloading rock mass[J].Rock and Soil Mechanics,2005,26(Supp.1):292-295.(in Chinese))
[5]LIU X M,WANG J Q,HUANG J,et al.Full-scale pullout tests and analyses of ground anchors in rocks under ultimate load conditions[J].Engineering Geology,2017,228:1-10.
[6]JIANG S H,LI D Q,ZHANG L M,et al.Time-dependent system reliability of anchored rock slopes considering rock bolt corrosion effect[J].Engineering Geology,2014,175:1-8.
[7]SUN H Y,WONG L N Y,SHANG Y Q,et al.Systematic monitoring of the performance of anchor systems in fractured rock masses[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(6):1 038-1 045.
[8]ZHU W S,SUI B,LI X J,et al.A methodology for studying the high wall displacement of large scale underground cavern complexes and it's applications[J].Tunnelling and Underground Space Technology,2008,23(6):651-664.
[9]ZHU W S,LI X J,ZHANG Q B,et al.A study on sidewall displacement prediction and stability evaluations for large underground power station caverns[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(7):1 055-1 062.
[10]REZAEI M,RAJABI M.Vertical displacement estimation in roof and floor of an underground powerhouse cavern[J].Engineering Failure Analysis,2018,90:290-309.
[11]LI Y,ZHU W S,FU J W,et al.A damage rheology model applied to analysis of splitting failure in underground caverns of Jinping Ihydropower station[J].International Journal of Rock Mechanics and Mining Sciences,2014,71:224-234.
[12]段淑倩,冯夏庭,江权,等.高地应力下白鹤滩地下洞室群含错动带岩体破坏模式及机制研究[J].岩石力学与工程学报,2017,36(4):852-864.(DUAN Shuqian,FENG Xiating,JIANG Quan,et al.Failure modes and mechanisms for rock masses with staggered zones of Baihetan underground caverns under high geostress[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(4):852-864.(in Chinese))
[13]WU A Q,WANG J M,ZHONG Z,et al.Engineering rock mechanics practices in the underground powerhouse at Jinping I hydropower station[J].Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):640-650.
[14]ZHOU X P,XIA E M,YANG H Q,et al.Different crack sizes analyzed for surrounding rock mass around underground caverns in Jinping I hydropower station[J].Theoretical and Applied Fracture Mechanics,2012,57(1):19-30.
[15]SONG S W,FENG X M,LIAO C G,et al.Measures for controlling large deformations of underground caverns under high in-situ stress condition-a case study of Jinping I hydropower station[J].Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):605-618.
[16]王克忠,吴慧,赵宇飞.深部地下厂房锚索预应力损失与岩体蠕变耦合分析[J].岩石力学与工程学报,2018,37(6):1 481-1 488.(WANG Kezhong,WU Hui,ZHAO Yufei.Coupling between reduction of force in prestressed anchor cable and rock creep in deep-buried underground powerhouse[J].Chinese Journal of Rock Mechanics and Engineering,2018,37(6):1 481-1 488.(in Chinese))
[17]CHEN G Q,CHEN T,CHEN Y,et al.A new method of predicting the prestress variations in anchored cables with excavation unloading destruction[J].Engineering Geology,2018,241:109-120.
[18]刘国锋,冯夏庭,江权,等.白鹤滩大型地下厂房开挖围岩片帮破坏特征、规律及机制研究[J].岩石力学与工程学报,2016,35(5):865-878.(LIU Guofeng,FENG Xiating,JIANG Quan,et al.Failure characteristics,laws and mechanisms of rock spalling in excavation of large-scale underground powerhouse caverns in Baihetan[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(5):865-878.(in Chinese))
[19]刘泉声,雷广峰,彭星新.深部裂隙岩体锚固机制研究进展与思考[J].岩石力学与工程学报,2016,35(2):312-332.(LIU Quansheng,LEI Guangfeng,PENG Xingxin.Advance and review on the anchoring mechanism in deep fractured rock mass[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(2):312-332.(in Chinese))
[20]李仲奎,戴荣,姜逸明.FLAC3D分析中的初始应力场生成及在大型地下洞室群计算中的应用[J].岩石力学与工程学报,2002,21(增2):2 378-2 392.(LI Zhongkui,DAI Rong,JIANG Yiming.Improvement of the generation of the initial stress field by using FLAC3D and application in a huge underground cavern group[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(Supp.2):2 378-2 392.(in Chinese))
[21]冯夏庭,张传庆,李邵军.深埋硬岩隧洞动态设计方法[M].北京：科学出版社,2013:140-141.(FENG Xiating,ZHANG Chuanqing,LI Shaojun.Dynamic design method for deep tunnels in hard rock[M].Beijing:Science Press,2013:140-141.(in Chinese))
[22]徐干成,郑颖人,乔春生.地下工程支护结构与设计[M].北京：中国水利水电出版社,2013:55-56.(XU Gancheng,ZHENGYingren,QIAO Chunsheng.Supporting structure and design in underground engineering[M].Beijing:China Water Power Press,2013:55-56.(in Chinese))
[23]李帅军,冯夏庭,徐鼎平,等.白鹤滩水电站主厂房第I层开挖期围岩变形规律与机制研究[J].岩石力学与工程学报,2016,35(增2):3 947-3 959.(LI Shuaijun,FENG Xiating,XU Dingping,et al.Study of the characteristics and mechanism of surrounding rock deformation during the first layer excavation in Baihetan hydorpower station underground main powerhouses[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(Supp.2):3 947-3 959.(in Chinese))
[24]LI H B,YANG X G,ZHANG X B,et al.Deformation and failure analyses of large underground caverns during construction of the Houziyan hydropower station,southwest China[J].Engineering Failure Analysis,2017,80:164-185.
[25]江权,冯夏庭,陈国庆,等.高地应力条件下大型地下洞室群稳定性综合研究[J].岩石力学与工程学报,2008,27(增2):3 768-3 777.(JIANG Quan,FENG Xiating,CHEN Guoqing,et al.Stability study of large underground caverns under high geostress[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(Supp.2):3 768-3 777.(in Chinese))