|
|
|
| Interaction between viscoelastic-plastic surrounding rock and support structure in deep tunnels considering stress path |
| XIA Caichu1，2，XU Chen1，3，DU Shigui1，2 |
| (1. Institute of Rock Mechanics，Ningbo University，Ningbo，Zhejiang 315211，China；2. School of Civil Engineering，Shaoxing University，Shaoxing，Zhejiang 312000，China；3. College of Civil Engineering，Tongji University，Shanghai 200092，China) |
|
|
|
|
Abstract The support reaction force of tunnels increases with time in viscoelastic-plastic rock mass，which makes the stress state of yielding surrounding rock in plastic zones move inward from the yield surface. Therefore，it is necessary to make clear the stress path of the surrounding rock when investigating the long-term mechanical characteristics of the interaction between rock and tunnel support. Considering the effect of the stress path，based on the generalized Kelvin model and Mohr Coulomb strength criterion，a simplified method for analyzing the viscoelastic-plastic stress，strain and displacement of the surrounding rock and the interaction between the support and the surrounding rock is proposed. In this paper，different kinds of“yield-resist combination”support technologies of high geostress soft rock tunnels are summarized into three categories as“yield before resist”， “yield while resist”and “control-yield-resist”. The influences of three kinds of support measures on the stress path of the surrounding rock are analyzed respectively. The deformation of the viscoelastic-plastic surrounding rock and the support reaction under different support measures are further studied. The results show that the calculated surrounding rock displacement is much larger if the stress path is taken into account. Under the condition of the same displacement release and the same stiffness of the lining support，the deformation rate of the surrounding rock at the initial stage is very large by adopting the measure of “yield before resist”，and the increasing support reaction force at the second stage is also the largest after applying the permanent support. It is most appropriate to adopt the “control-yield-resist”support measure under the condition of high geostress and serious deformation(for example，the initial stress exceeds 20 MPa). The prestress long bolt is employed to support the surrounding rock immediately after the tunnel excavation, which can not only control the deformation rate and improve the stability of the surrounding rock in the first stage，but also greatly reduce the additional support force and improve the stability of the lining structure during the second stage. Under the condition of low geostress and slight deformation(for example，the initial stress is less than 10 MPa)，the “yield before resist”measure can effectively control the deformation of the surrounding rock，and the “control-yield-resist” measure is not necessary. The “yield while resist”measure is applicable to the cases between the above two extreme conditions(e.g.，the initial ground stress is between 10 and 20 MPa). In addition，the deformation rate of the surrounding rock with a small viscosity coefficient is very large after excavation，for example，when the viscosity = 2×109 and 1×1010 Pa·d，the initial rock deformation rates are 17.6 and 3.5 cm/d respectively with the “control-yield-resist”measure. Therefore，for the surrounding rock with a small viscosity，large support reaction force must be applied immediately after excavation to control the deformation rate.
|
|
|
|
|
|
[1] MORITZ B. Yielding elements-requirements，overview and comparison[J]. Geomechanics and Tunnelling，2011，4(3)：221–236.
[2] BARLA G，BONINI M，SEMERARO M. Performance monitoring and analysis of a yield-control support system in squeezing rock[C]// Eurock 2010—Rock Mechanics in Civil and Environmental Engineering. [S. l.]：[s. n.]，2010：146–154.
[3] LI C C. Performance of D–bolts under static loading[J]. Rock Mechanics and Rock Engineering，2012，45(2)：183–192.
[4] 刘宇鹏，夏才初，吴福宝，等. 高地应力软岩隧道长、短锚杆联合支护技术研究[J]. 岩石力学与工程学报，2020，39(1)：105–114. (LIU Yupeng，XIA Caichu，WU Fubao，et al. A combined support technology of long and short bolts of soft rock tunnels under high ground stresses[J]. Chinese Journal of Rock Mechanics and Engineering，2020，39(1)：105–114.(in Chinese))
[5] 何满潮，郭志飚. 恒阻大变形锚杆力学特性及其工程应用[J]. 岩石力学与工程学报，2014，33(7)：1 297–1 308.(HE Manchao，GUO Zhibiao. Mechanical property and engineering application of anchor bolt with constant resistance and large deformation[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(7)：1 297–1 308.(in Chinese))
[6] 仇文革，王 刚，龚 伦，等. 一种适应隧道大变形的限阻耗能型支护结构研发与应用[J]. 岩石力学与工程学报，2018，37(8)：1 785–1 795.(QIU Wenge，WANG Gang，GONG Lun，et al. Research and application of resistance-limiting and energy-dissipating support in large deformation tunnel[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(8)：1 785–1 795.(in Chinese))
[7] 韩常领，夏才初，徐 晨. 软岩隧道挤压性大变形控制技术研究进展[J]. 地下空间与工程学报，2020，16(增1)：492–505.(HAN Changling，XIA Caichu，XU Chen. Research progress for the control measures of the tunnel large deformation in squeezing rocks[J]. Chinese Journal of Underground Space and Engineering，2020，16(Supp.1)：492–505.(in Chinese))
[8] 刘国庆. 木寨岭隧道软岩大变形段支护措施研究[J]. 现代隧道技术，2011，48(4)：135–141.(LIU Guoqin. Study of support measures for large deformed section of Muzhailing Tunnel in soft rocks[J]. Modern Tunnelling Technology，2011，48(4)：135–141.(in Chinese))
[9] 夏才初，金天垚，徐 晨，等. 软岩隧道超前导洞应力释放力学机制及适用性[J]. 隧道建设，2020，40(增2)：1–9.(XIA Caichu，JIN Tianyao，XU Chen，et al. Mechanical mechanism and applicability of stress release for advance pilot heading in soft rock tunnel[J]. Tunnel Construction，2020，40(Supp.2)：1–9.(in Chinese))
[10] AYAYDIN N，LEITNER A. Tauern tunnel first and second tubes from the consultant¢s viewpoint[J]. Geomechanics and Tunnelling，2009，2(1)：14–23.
[11] XANTHAKOS P P. Ground anchors and anchored structures[M]. New York：John Wiley and Sons，1991：494–501.
[12] KIMURA F，OKABAYASHI N，KAWAMOTO T. Tunnelling through squeezing rock in two large fault zones of the Enasan Tunnel II[J]. Rock Mechanics and Rock Engineering，1987，20(3)：151–166.
[13] 余东明，姚海林，段建新，等. 考虑中主应力和剪胀的深埋圆形隧道黏弹塑性蠕变解[J]. 岩石力学与工程学报，2012，31(增2)：3 586– 3 592.(YU Dongming，YAO Hailin，DUAN Jianxin，et al. Viscoelastoplastic creep solutions to deep circular tunnels considering intermediate principal stress and shear dilatancy[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(Supp.2)：3 586–3 592.(in Chinese))
[14] LI C. Study on the loading and deformation of tunnel segments in soft clay with consideration for the soil mass rheological characteristics[J]. Geotechnical and Geological Engineering，2019，37：673–682.
[15] KARGAR A R. An analytical solution for circular tunnels excavated in rock masses exhibiting viscous elastic-plastic behavior[J]. International Journal of Rock Mechanics and Mining Sciences，2019，124：104128.
[16] ZHAO J，WANG G. Unloading and reverse yielding of a finite cavity in a bounded cohesive-frictional medium[J]. Computers and Geotechnics，2010，37：239–245.
[17] EL JIRARI S，WONG H，DELERUYELLE F，et al. Analytical modelling of a tunnel accounting for elastoplastic unloading and reloading with reverse yielding and plastic flow[J]. Computers and Geotechnics，2020，121：103441.
[18] 郑颖人，朱合华，方正昌，等. 地下工程围岩稳定分析与设计理论[M]. 北京：人民交通出版社，2012：59–62.(ZHENG Yingren，ZHU Hehua，FANG Zhengchang，et al. The stability analysis and design theory of surrounding rock of underground engineering[M]. Beijing：People¢s Transportation Press，2012：59–62.(in Chinese))
[19] 夏志皋. 塑性力学[M]. 上海：同济大学出版社，1991：147–148.(XIA Zhigao. Plastic mechanics[M]. Shanghai：Tongji University Press，1991：147–148.(in Chinese))
[20] 卞跃威，夏才初，肖维民，等. 考虑围岩软化特性和应力释放的圆形隧道黏弹塑性解[J]. 岩土力学，2013，34(1)：211–220.(BIAN Yuewei，XIA Caichu，XIAO Weimin，et al. Visco-elastoplastic solutions for circular tunnel considering stress release and softening behaviour of rocks[J]. Rock and Soil Mechanics，2013，34(1)：211–220.(in Chinese))
[21] 储昭飞. 流变软岩中隧道支护-围岩相互作用关系研究[博士学位论文][D]. 北京：北京交通大学，2018.(CHU Zhaofei. Study on interaction between tunnel support and surrounding rock in soft rheological rock[Ph. D. Thesis][D]. Beijing：Beijing Jiaotong University，2018.(in Chinese))
|
|
|
|
2021, Vol. 40 
