Negative Poisson's ratio anchor cable support for fault tunnels with different inclination angles under earthquake  

作　　者：YANG Xiaojie ZHANG Xiaoyu FENG Yuxiang ZHAO Yi TAO Zhigang WEN Lifan TIE Jingjing 

机构地区：[1]State Key Laboratory for Tunnel Engineering,Beijing 100083,China [2]School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China

出　　处：《Journal of Mountain Science》2024年第11期3814-3831,共18页山地科学学报（英文）

基　　金：funded by the National Natural Science Foundation of China(Grant No.42377154).

摘　　要：It is inevitable to encounter fault zones in tunnel construction.These faults can lead to significant deformations and potential collapses of the surrounding rock in the tunnel.Therefore,it is crucial to study the influence of different fault angles on tunnel deformation.The Tabaiyi Tunnel,located in Yunnan Province of China passes through a multi-stage fault zone.The dynamic response characteristics of the surrounding rock in the Tabaiyi Tunnel were studied under various fault dip angles and the most unfavorable angle was identified.Physical model tests were conducted using two types of anchor cables with specific parameters.Additionally,a relationship between the engineering rock mass and energy absorption by the anchor cables was established,demonstrating the advantages of negative Poisson's ratio(NPR)anchor cables.Experimental results indicate that stress concentration tends to occur at the junctions between faults and the surrounding rock mass.Tunnels supported by NPR anchor cables effectively mitigate amplification effects,achieving energy absorption increases of up to 87%compared to positive Poisson's ratio(PR)anchor cables.Furthermore,the highest acceleration amplification was observed at a fault dip angle of 45°,with peak acceleration reaching twice that of the original input wave,indicating that this angle should be avoided in tunnel design.These findings provide valuable insights for the safe management of tunnels traversing fault zones.

关 键 词：Different dip angles Fault areas NPR anchor cable Physical model test 

分 类 号：U455.7[建筑科学—桥梁与隧道工程]