[1]ZHENG Luxin,HU Zhaoxing,ZHANG Jianjun,et al.Research on Seismic Fortification of the Entrance of the Tunnel with Small Interval[J].Journal of Seismological Research,2024,47(02):311-320.[doi:10.20015/j.cnki.ISSN1000-0666.2024.0021
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
47
Number of periods:
2024 02
Page number:
311-320
Column:
Public date:
2023-12-01
- Title:
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Research on Seismic Fortification of the Entrance of the Tunnel with Small Interval
- Author(s):
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ZHENG Luxin1; HU Zhaoxing1; ZHANG Jianjun2; SUN Chuang2; WANG Yang2
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(1.China Railway 9th Bureau Group Co.,Ltd.,Dalian Branch,Dalian 116000,Liaoning,China)(2.Liaoning University of Engineering and Technology,Fuxin 123000,Liaoning,China)
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- Keywords:
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the Luding MS6.8 earthquake; earthquake-caused casualties; geological disaster; aseismic performance
- CLC:
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U45
- DOI:
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10.20015/j.cnki.ISSN1000-0666.2024.0021
- Abstract:
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In order to find out the influence of the clearance distance and the rock mass grade on the seismic fortification length of a tunnel entrance section,based on the project of the small-interval Baoshan Tunnel in the high-and steep-slope section of the Yuxi-Chuxiong super highway,the numerical model of the small-interval tunnel is established by using FLAC3D finite difference software,and the model parameters are determined according to the indoor mechanical test.The corrected Wenchuan wave was inputted as the ground motion loading to analyze the stability of the surrounding rock of the Tunnel entrance section.The dynamic response characteristics of the surrounding rock and supporting structure of the Tunnel under different working conditions are discovered.Further,the Tunnel's reasonable length of seismic fortification is determined.The results show that for the same clearance distance,the higher the surrounding rock grade is,the smaller the response values of lining displacement,internal force,and stress will be,and vice versa.The most unfavorable working conditions for Baoshan Tunnel are Grade V surrounding rock and 0.5B net distance.By the action of the ground-motion loading,the Tunnel's peak displacement is 62.5 cm.The maximum lining axial force is generated at both the left and the right feet; the peak value of the entrance section reaches 1320 kN.At the critical point where the displacement and the peak curve decline,the maximun value is 78 m(6.0B).Finally,the reasonable fortification length of the Baoshan Tunnel's entrance is determined as 78 m.