Risk Mechanism and Assessment of Large Deformation in Soft Rock Tunnel
YANG Jianhui1, SHEN Kai1, SHU Lushan2, XUE Yadong2, WANG Jianjiang3
1. Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China; 2. Tongji University, Shanghai 200092, China; 3. The 2nd Engineering Co. Ltd of China Railway 16th Bureau Group, Tianjin 300162, China
Abstract:Research purposes: In high geostress tunnels, the occurrence of large deformation of soft rock has great uncertainty, which is a major difficulty in risk assessment. In order to accurately and effectively assess the large deformation risk of soft rock tunnels, a hierarchical evaluation method for large deformation is proposed based on Bayesian network (BN). Relied on the Yuntunbao tunnel, soft rock large deformation risk database is established and the six major risk sources are identified and reasoned. Research conclusions: (1) The large deformation of soft rock in tunnel is the result of multi factor coupling. By establishing the risk database, the mechanism is divided into two aspects: surrounding rock stability and support stability, and the Bayesian network model and a priori probability are established; (2) Through Bayesian sensitivity analysis, the key factors about the large deformation in soft rock tunnel are integrity of surrounding rock, support strength, ground stress, rock strength, construction method and tunnel shape; (3) Through the update of the risk database during the construction, the Bayesian network can well predict the probability of large deformation of the soft rock during the construction period.
杨建辉, 沈恺, 舒禄山, 薛亚东, 王建江. 基于BN的软岩隧道大变形风险机理与评估[J]. 铁道工程学报, 2022, 39(3): 81-86.
YANG Jianhui, SHEN Kai, SHU Lushan, XUE Yadong, WANG Jianjiang. Risk Mechanism and Assessment of Large Deformation in Soft Rock Tunnel. Journal of Railway Engineering Society, 2022, 39(3): 81-86.
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