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| Inversion of in-situ stress and analysis of surrounding rock failure characteristics in rockburst sections of deep-buried tunnels |
| LI Weiping1, LIN Bo2, DUAN Rujian1, LI Xiya1, BAI Xingjin1, HE Benguo2*, LI Yaodong1
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1. China Water Resources and Hydropower Fourteenth Engineering Bureau Co., Ltd., Kunming 650041, Yunnan, China;
2. State Key Laboratory of Intelligent Deep Metal Mining and Equipment, Northeastern University, Shenyang 110819, Liaoning, China |
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Abstract Frequent rockbursts and stress-induced collapses during the construction of deep-buried TBM tunnels under high in-situ stress were investigated through failure characterization, initial stress-field inversion, and graded rockburst control. Based on field investigations, 139 cases of high-stress damage were collected. The results showed that rockburst craters and collapse cavities were jointly controlled by high in-situ stress, structural planes, and surrounding rock properties, whereas their boundary morphology was mainly determined by the number, scale, and spatial combination of structural planes. A three-dimensional geological model considering surface topography and fault-bedding structures was established. Constrained by in-situ stress data from eight hydraulic-fracturing measurement points, five boundary conditions, including self-weight, horizontal extrusion, and shear, were applied, and the regional three-dimensional initial stress field was inverted using multiple linear regression. Good agreement was obtained between the inverted and measured results, with a multiple correlation coefficient of 0.91. Stress distribution along the tunnel axis was extracted, and zones of abrupt stress increase near faults were identified for risk classification. For a typical section with a maximum burial depth of about 1 687 m, significant stress concentration was observed near the tunnel face, while post-excavation stress release and time-dependent redistribution were identified. Timely support after the surrounding rock exited the shield was shown to effectively reduce stress release and rockburst risk. Finally, a construction strategy involving advance prediction, graded control, dynamic monitoring, and safety protection was proposed, together with corresponding measures for slight, moderate, and intense rockbursts.
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Published: 23 March 2026
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