Performance-based three-level fortification goal and its application in anti-dislocation countermeasures:A case study of Shantou Submarine tunnel  

作　　者：Tianqiang Wang Ping Geng Guoguo Liu Changjian Chen Wenqi Gu 

机构地区：[1]Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China

出　　处：《Underground Space》2023年第5期251-270,共20页地下空间（英文）

基　　金：supported by the National Natural Science Foundation of China(No.52130808);the National Key Research and Development Program of China(No.2022YFE0104300)。

摘　　要：The dislocation momentum is the design basis for anti-dislocation to tunnel when a tunnel crosses an active fault.The influence of different dislocation levels on tunnel performances is not clear.Thus,based on seismic activity parameters at the site of interest and probability of fault dislocation,probability fault displacement hazard analysis(PFDHA)methodology was introduced in this paper to ascertain the fault dislocation level under different exceeding probabilities(63%,10%,and 2%–3%).Then,based on the definition of different ground motion strength and fortification goals of the tunnel,a three-level fortification goal with different performance requirements of the tunnel was proposed.The first attempt to use the proposed indexes including the maximum dislocation of the tunnel and maximum relative deformation of the tunnel was tried to evaluate deformation and failure states with an experimental approach.Subsequently,the feasibility of the three-level fortification goal was further investigated according to the self-defined qualitative description and quantitative indexes in the segmental design and sectional expansion tunnels comprehensively.The results show that the fault dislocations relying on PFDHA at the site of the Shantou Submarine Tunnel are firstly ascertained as 0.04,1.8,and 2.4 m respectively.Taking the fault dislocation as model input values into account,the dislocation mechanism of the tunnel under the three levels was revealed.More importantly,judging from the dislocation performance requirements of the three-level fortification goal,the tunnel deformation and failure states are mitigated by adopting the countermeasures.The sectional expansion design can well meet the requirements without the restriction of a strong earthquake,while the effectiveness of the segmental tunnel can be proved under frequently occurred and fortification earthquake.The final research results are expected to provide a new fortification goal for anti-dislocation hazard evaluation on expansion design in high-intensity se

关 键 词：Fault-crossing tunnel PFDHA methodology Three-level fortification goal Failure modes Anti-dislocation countermeasures 

分 类 号：U455[建筑科学—桥梁与隧道工程]