There are shallow buried bias and broken surrounding rock in the tunnel portal section. In order to explore the dynamic response law of the tunnel portal section under the action of earthquake and give the quantitative evaluation index of safety, a numerical model is established based on the No.6 tunnel of Yawan high-speed railway. Four seismic waves of artificial synthetic wave, EI wave, KB wave and WL wave are input respectively. Based on the extension theory, an extension matter-element model is established. The results of four safety evaluation indexes of bending moment, axial force, relative displacement and acceleration of the tunnel portal section under the most unfavorable seismic wave are obtained by numerical simulation method, and the safety evaluation of the No.6 tunnel portal section of Yawan high-speed railway is carried out with quantitative indexes. The seismic fortification length is proposed. At the same time, the dynamic response law of No.6 tunnel portal section of Yawan high-speed railway under different seismic waves is also analyzed. The results show that; (1)Under the action of Yawan artificial wave, the dynamic response degree of each evaluation point of the tunnel is about 1.2 times that of the other three natural waves; (2)The four evaluation indexes calculated by each seismic wave have basically the same variation law along the longitudinal direction. The peak values of axial force and bending moment appear at the arch foot of the spandrel arch, and the peak values of relative displacement occur from the inverted arch to the vault line at the entrance of the cave. The peak time of the evaluation index is slightly lagging behind the corresponding time of the peak acceleration of the seismic wave. (3)Under the action of YW wave, the seismic fortification length of No.6 tunnel portal section of Yawan high-speed railway is 45~55 m, which is 3.5~4 times of the tunnel diameter. The research results can provide reference for determining the seismic fortification length of tunnel portal section by quantitative index.
[1]高波,王峥峥,袁松,等.汶川地震公路隧道震害启示[J].西南交通大学学报,2009,44(3):336-341, 374. (Gao Bo, Wang Zhengzheng, Yuan Song,et al. Wenchuan Earthquake highway tunnel damage enlightenment [J].Journal of Southwest Jiaotong University, 2009,44 (3) : 336-341, 374.(in Chinese))
[2]李天斌.汶川特大地震中山岭隧道变形破坏特征及影响因素分析[J].工程地质学报,2008,16(6):742-750. (Li Tianbin. Analysis of deformation and failure characteristics and influencing factors of mountain tunnel in Wenchuan earthquake [J]. Journal of Engineering Geology, 2008,16 (6) : 742-750.(in Chinese))
[3]孙铁成. 双洞错距山岭隧道洞口段地震动力响应及减震措施研究[D]. 成都:西南交通大学, 2009. (Sun Tiecheng. Study on seismic dynamic response and damping measures of double-hole staggered mountain tunnel portal section [D]. Chengdu: Southwest Jiaotong University,2009.(in Chinese))
[4]代勇,李冰天,邓旨珩,等.基于强度折减法裂损衬砌隧道地震稳定性分析[J].地下空间与工程学报,2021,17(增2):940-948. (Dai Yong, Li Bingtian, Deng Zhiheng, et al. Seismic stability analysis of cracked lining tunnel based on strength reduction method [J]. Chinese Journal of Underground Space and Engineering, 2021,17 (Supp.2) : 940-948.(in Chinese))
[5]梁波,赵冯兵,任兆丹,等.特大断面公路隧道地震动力响应分析[J].地下空间与工程学报,2020,16(1):243-248, 294. (Liang Bo, Zhao Fengbing, Ren Zhaodan, et al. Seismic dynamic response analysis of super-large section highway tunnel [ J ]. Chinese Journal of Underground Space and Engineering, 2020,16 (1) : 243-248, 294.(in Chinese))
[6]高峰,石玉成,严松宏,等.隧道洞口段的抗震设防长度[J].中国公路学报,2006, 19(3):65-69. (Gao Feng, Shi Yucheng, Yan Songhong, et al. The seismic fortification length of tunnel portal section [J]. China Journal of Highway, 2006, 19(3) : 65-69.(in Chinese))
[7]唐锞. 山岭隧道洞口段地震动力响应影响因素规律研究[D].成都:西南交通大学,2009. (Tang Ke. Study on influencing factors of seismic dynamic response of mountain tunnel portal section[D]. Chengdu: Southwest Jiaotong University, 2009.(in Chinese))
[8]耿萍,曹东杰,唐金良,等.铁路隧道洞口合理抗震设防长度[J].西南交通大学学报, 2012,47(6):942-948. (Geng Ping, Cao Dongjie, Tang Jinliang, et al. The reasonable seismic fortification length of railway tunnel entrance [J]. Journal of Southwest Jiaotong University, 2012,47 (6) : 942-948.(in Chinese))
[9]王新民,康虔,秦健春,等.层次分析法-可拓学模型在岩质边坡稳定性安全评价中的应用[J].中南大学学报(自然科学版),2013,44(6):2455-2462. (Wang Xinmin, Kang Qian, Qin Jianchun, et al. The application of analytic hierarchy process-extenics model in the safety evaluation of rock slope stability[J]. Journal of Central South University(Natural Science Edition), 2013,44 (6):2455-2462.(in Chinese))
[10]王天瑜,徐德宇,张孝广,等.盾构隧道开挖面塌方的可拓评价预警[J].安全与环境学报,2020,20(6):2052-2059. (Wang Tianyu, Xu Deyu, Zhang Xiaoguang, et al. Extension evaluation and early warning of collapse in excavation face of shield tunnel[J].Journal of Safety and Environment,2020,20(6):2052-2059.(in Chinese))
[11]梁桂兰,徐卫亚,谈小龙.基于熵权的可拓理论在岩体质量评价中的应用[J].岩土力学,2010,31(2):535-540. (Liang Guilan, Xu Weiya, Tan Xiaolong. Application of extension theory based on entropy weight in rock mass quality evaluation[J]. Rock and Soil Mechanics, 2010,31(2):535-540.(in Chinese))
[12]蔡文.可拓论及其应用[J].科学通报,1999, 44(7):673-682. (Cai Wen. Extension theory and its application[J].Scientific Notification,1999, 44(7):673-682.(in Chinese))
[13]中华人民共和国建设部.铁路隧道设计规范(TB 10003-2016)[S].北京:中国铁道出版社,2016. (Ministry of Construction of the People's Republic of China.Railway tunnel design code (TB10003-2016)[S].Beijing: China Railway Press,2016.(in Chinese))
[14]Huang N E, Shen Z, Long S R, et al. The empirical mode decomposition and Hilbert spectrum for non-linear and non-stationary time series analysis [J]. Proceedings of the Royal Society of London Series A-Mathematical physical and Engineering Sciences, 1998, 454: 903 - 995.
[15]邓雪,李家铭,曾浩健,等.层次分析法权重计算方法分析及其应用研究[J].数学的实践与认识,2012,42(7):93-100.(Deng Xue, Li Jiaming, Zeng Haojian, et al. Analytic hierarchy process weight calculation method analysis and application research[J]. Mathematics Practice and Understanding,2012,42(7):93-100.(in Chinese))
[16]Xu J S, Xu H, Sun R F,et al.Seismic risk evaluation for a planning mountain tunnel using improved analytical hierarchy process based on extension theory[J].Journal of Mountain Science,2020,17(1):244-260.
[17]Wang W, Wang H P, Zhang B, et al. Coal and gas outburst prediction model based on extension theory and its application[J]. Process Safety and Environmental Protection,2021,154: 329-337.
[18]中华人民共和国铁道部.铁路工程抗震设计规范(GB50111—2006)[S].北京: 中国计划出版社,2006. (Ministry of Railways of the People's Republic of China.Code for seismic design of railway engineering (GB50111-2006)[S].Beijing:China Planning Press,2006.(in Chinese))
[19]Chen Q, Yu W, Li C H, et al. Application of extension theory based on improved entropy weight method to rock slope analysis in cold regions[J]. Geotechnical and Geological Engineering,2021, 39(6): 4315-4327).
