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| Time-space effects and visco-elastoplastic analysis of deep tunnel excavation |
| CHEN Shihai1,2, XIA Xiao1, PENG Luqiang1, TU Bingxiong1
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1.College of Civil Engineering, Huaqiao University, Xiamen 361021, Fujian, China;
2. Fujian Research Center for Tunneling and Urban Underground Space Engineering(Huaqiao University), Xiamen 361021, Fujian, China |
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Abstract The geometric model of the deep tunnel was established according to the spatial constraint of the excavation face, and the corresponding stress field distribution was obtained. The visco-elasto-plasticity of the rock mass was simulated by the Nishihara model. The excavation disturbance(D)and geological strength index(GSI)were considered to analyze the rock deformation, access to the law of rock deformation. Results showed that the smaller the original rock stress, the better the quality of rock, the smaller excavation disturbance, the smaller creep deformation rate was in the phase II. In addition, the influence of the excavation surface advancing velocity on displacement of surrounding rock was also analyzed. The larger the advancing speed, the greater the changing intensity of the tunnel surrounding rock displacement. Advancing speed did not affect the ultimate displacement of surrounding rock when the original rock stress was relatively small. On the contrary, when the original rock stress was relatively large, the faster the advance speed, the greater the displacement of surrounding rock.
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Received: 27 January 2021
Published: 20 March 2021
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