Journal of Changjiang River Scientific Research Institute ›› 2025, Vol. 42 ›› Issue (1): 152-161.DOI: 10.11988/ckyyb.20230935

• Rock-Soil Engineering • Previous Articles     Next Articles

Deformation and Failure Characteristics of Deep-buried Water Diversion Tunnel Crossing Active Fault Zone and Corresponding Adaptive Measures

ZHANG Guo-qiang1,2(), CUI Zhen3,4(), YAN Tian-you1,2, ZHANG Mao-chu1,2, LI Jian-he1,2   

  1. 1 Changjiang Survey, Planning,Design and Research Co.,Ltd.,Wuhan 430010,China
    2 Key Laboratory of Water Grid Project and Regulation of Ministry of Water Resources,Wuhan 430010,China
    3 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071, China
    4 University of Chinese Academy of Sciences,Beijing 100049, China
  • Received:2023-08-28 Revised:2023-11-01 Published:2025-01-01 Online:2025-01-01
  • Contact: CUI Zhen

Abstract:

The safety of the tunnel traversing an active fault is a critical issue for the deep-buried long tunnel crossing the Tongcheng River in the Yangtze-to-Hanjiang River Diversion Project. This study addresses this challenge by employing an analysis of the geostress field and numerical simulation methods.Specifically,it examines the lining’s response in scenarios where adaptive structures are not utilized, estimates the design parameters for hinges, and verifies the lining’s behavior under these hinge parameters. Findings reveal that: 1) The angle between the horizontal principal stress and the tunnel axis is approximately 35°. The horizontal stress component along the tunnel axis is about 20 MPa, while the horizontal stress component perpendicular to the axis is around 21 MPa. The vertical stress component is approximately 18 MPa. 2) Without any fault mitigation measures,the tunnel’s relative deformation primarily exhibits convergence between the vault and floor. This convergence is most pronounced within the fault zone. The maximum principal stress values in the vault and floor occur in the fault zone and its affected area, with most of the lining in these regions experiencing damage. 3) Using the proposed method for estimating tunnel hinge design parameters, a reinforcement section length of 6 meters and a hinge section width of 2-4 cm are initially suggested. Following sensitivity analysis of these parameters, it is recommended that the reinforcement section length remains 6 meters, while the hinge section width is set to 5 cm. 4) When the tunnel is reinforced according to the proposed hinge structure parameters, the design effectively reduces the tension experienced by the entire lining in the fault zone. Under hinge design conditions, there is a significant decrease in relative deformation, stress levels, and lining damage. This demonstrates that the hinge structure enhances the tunnel’s resistance to fault-related issues.

Key words: long-distance water diversion project, water diversion tunnel, active fault, rupture response, hinged lining

CLC Number: