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
(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）
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.
李卫平, 林波, 段汝健, 李西亚, 白兴金, 何本国, 李耀东. 深埋隧道岩爆段地应力反演与围岩破坏特征[J]. 隧道与地下工程灾害防治, .
LI Weiping, LIN Bo, DUAN Rujian, LI Xiya, BAI Xingjin, HE Benguo, LI Yaodong. Inversion of in-situ stress and analysis of surrounding rock failure characteristics in rockburst sections of deep-buried tunnels. Hazard Control in Tunnelling and Underground Engineering, 0, (): 1-18.
