Abstract
Located on the Qinghai-Tibet Plateau northeast edge, the Muzhailing Tunnel has complex geological conditions: a large buried depth, high in situ stress, developed bedding, and weak-fractured rock mass. Strong deformation and serious damage occur during tunnel construction. Taking the 3# inclined shaft as an engineering example, a large-scale geomechanical model experiment for tunnel excavation and loading under different lateral pressure coefficients is performed to reveal the deformation evolution process and stress‒strain characteristics of layered soft rock tunnel surrounding rock. With increasing lateral pressure coefficient, tunnel cracks develop, the bedding slides and surrounding rocks deform. When the lateral pressure coefficient is greater than 1.5, the tunnel is severely deformed and damaged. A numerical model is established to analyse the surrounding rock deformation and stress during the whole process, and the surrounding rock deformation laws under different bedding inclinations and bedding spacings are studied. With increasing bedding inclination, the maximum displacement occurs in the bedding normal direction and develops from the top and bottom plates to both sides, in which the largest deformation occurs in the tunnel right shoulder for a bedding dip angle of 45 degrees. With increasing bedding spacing, the maximum displacement decreases and progresses from the bottom to top plate, and a sudden change in deformation occurs at the bedding interface. Finally, based on the bedded rock mass failure law, asymmetric coupling support measures with high-prestress constant-resistance anchor cables as the core are proposed and applied in the field. The monitoring results show a good large deformation control effect, which can provide a reference for similar projects.
Similar content being viewed by others
Data availability
Data supporting this research article are available from the corresponding author on request.
References
Behrestaghi MHN, Rao KS, Ramamurthy T (1996) Engineering geological and geotechnical responses of schistose rocks from dam project areas in India. Eng Geol 44(1–4):183–201
Chen F (2018) Experimental study for structure effect of floor heave in deep slowly inclined soft stratum rock mass. China University of Mining & Technology, Beijing
Gao JH, Kang TH, Jin ZM et al (2004) Similar simulation study on crack development law of surrounding rocks of roadway with great-thick thin-bedded top roof. Chin J Rock Mech Eng 23(19):3292–3297
Gao C, Xie LZ, Xie HP et al (2017) Estimation of the equivalent elastic modulus in shale formation: theoretical model and experiment. J Petrol Sci Eng 151:468–479
Gu JC, Gu LY, Chen AM et al (2008) Model experiment study on mechanism of layered fracture within surrounding rock of tunnels in deep stratum. Chin J Rock Mech Eng 27(03):433–438
Guo ZB, Fan JY, Wang FN et al (2021) Geomechanical model experiment study on deformation and failure mechanism of the mountain tunnel in layered jointed rock mass. Adv Civil Eng 2021:1–19
He J, Afolagboye LO (2018) Influence of layer orientation and interlayer bonding force on the mechanical behavior of shale under Brazilian test conditions. Acta Mech Sin 34(2):349–358
He MC, Gong WL, Li DJ et al (2009) Physical modeling of failure process of the excavation in horizontal strata based on IR thermography. Min Sci Technol 19(06):689–698
Hu XY, Yang QH, He C et al (2018) Experimental study on behaviors of segment linings in an anisotropically jointed rock mass. Chinese J Geotech Eng 40(10):1773–1781
Huang F, Zhu HH et al (2013) The effect of weak interlayer on the failure pattern of rock mass around tunnel scaled model experiments and numerical analysis. Tunn Undergr Space Technol 35:207–218
Imani M, Nejati HR, Goshtasbi K et al (2017) Dynamic response and failure mechanism of Brazilian disk specimens at high strain rate. Soil Dyn Earthquake Eng 100:261–269
Li G (2019) Deformation mechanism of deep-buried thin-bedded slate tunnel and control technology of high pre-tightening constant resistance anchor cable. China University of Mining & Technology, Beijing
Lu K, Zhu JC, Yang JC (2012) Study on the failure of tunnel by the geomechanic model experiment. Chinese J Undergr Space Eng 08(03):494–498
Nezhad MM, Fisher QJ, Gironacci E et al (2018) Experimental study and numerical modeling of fracture propagation in shale rocks during Brazilian disk experiment. Rock Mech Rock Eng 51(6):1755–1775
Peng YY, He MC, Gong WL et al (2015) Physical simulation study on failure process of horizontal strata soft rock roadway in Qishan Mine. Coal Science and Technology 43(09):24–29
Pomeroy CD, Hobbs DW, Mahmoud A (1971) The effect of weakness-plane orientation on the fracture of Barnsley Hards by triaxial compression. Int J Rock Mech Mining Scie Geomech Abstr 8(03):227–238
Singh M, Samadhiya NK, Kumar A (2015) A nonlinear criterion for triaxial strength of inherently anisotropic rocks. Rock Mech Rock Eng 48:1387–1405
Sun XM, Chen F, He MC et al (2017a) Physical modeling of floor heave for the deep-buried roadway excavated in 10° inclined strata using infrared thermal imaging technology. Tunn Undergr Space Technol 47:52–63
Sun XM, Xu HC, He MC et al (2017b) Thermography analyses of rock fracture due to excavation and overloading for tunnel in 30° inclined strata. Sci China Technol Sci 60(06):1–13
Sun XM, Zhao CW, Zhang Y et al (2021) Physical model experiment and numerical simulation on the failure mechanism of the roadway in layered soft rocks. Int J Min Sci Technol 31(2):291–302
Tan LH, Ren T, Yang XH, He XQ et al (2018) A numerical simulation study on mechanical behaviour of coal with bedding planes under coupled static and dynamic load. Int J Min Sci Technol 28(5):791–797
Tao ZG, Ren SL, Hao Y et al (2021) Physical model experiment on failure mechanism and NPR anchor cable control effect of layered counter-tilt slope. Rock Soil Mech 42(04):976–990
Wang PT, Cai MF, Ren FH (2018) Anisotropy and directionality of tensile behaviours of a jointed rock mass subjected to numerical Brazilian experiments. Tunn Undergr Space Technol 73:139–153
Wang XY, Huang SL, Ding XL et al (2021) Study on the effect of inhomogeneous bedding plane on the mechanical properties of uniaxial compression of layered rock mass. Rock Soil Mech 42(2):581–592
Xu Y, Zhang ZX (2010) Experiment study on loose characteristics of underground excavation in block-fractured rock mass. Chinese J Geotech Eng 32(02):216–224
Xu JB, Yang CH, Wu W et al (2013) Experimental study of mechanics anisotropy and deformation characteristics of gas shale. Mining Res Dev 04:16–19
Xu GW, He C, Su A et al (2018a) Experimental investigation of the anisotropic mechanical behavior of phyllite under triaxial compression. Int J Rock Mech Minings Sci 104:100–112
Xu GW, He C, Chen ZQ et al (2018b) Effects of the micro-structure and micro-parameters on the mechanical behaviour of transversely isotropic rock in Brazilian experiments. Acta Geotech 13(4):887–910
Yang SQ, Yin PF, Li B et al (2020) Behavior of transversely isotropic shale observed in triaxial tests and Brazilian disc tests. Int J Rock Mech Min Sci 133:1365–1609
Zeng YW, Zhao ZY (2001) Model experimenting studies of underground openings. Chin J Rock Mech Eng 20(S1):1745–1749
Zheng HB, Li PF, Ma GW et al (2022) Experimental investigation of mechanical characteristics for linings of twins tunnels with asymmetric cross-section. Tunn Undergr Space Technol 119:104209
Zhu WS, Li Y, Li SC et al (2011) Quasi-three-dimensional physical model experiments on a cavern complex under high in-situ stresses. Int J Rock Mech Min Sci 48(02):199–209
Acknowledgements
The authors gratefully acknowledge financial support for this work from the National Natural Science Foundation of China (Grant Nos. 51874311 and 51904306) and the Fundamental Research Funds for the Central Universities (Grant No. 2022YJSSB03).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Sun, X., Qi, Z., Miao, C. et al. Research on the large deformation mechanism and control measures of a layered soft rock tunnel. Bull Eng Geol Environ 82, 444 (2023). https://doi.org/10.1007/s10064-023-03467-y
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s10064-023-03467-y