基于变形分级的挤压性围岩铁路隧道断面形状优化设计  

Cross-Section Shape Optimization Design of Railway Tunnel in Squeezing Rock Based on Deformation Classification

作　　者：杨斌 刘天赐 刘志春 李宁 朵生君[5] YANG Bin;LIU Tianci;LIU Zhichun;LI Ning;DUO Shengjun(Gansu Tian Long Railway Co.,Ltd.,Lanzhou 730030,Gansu,China;Hengshui Railway Electrification School,Hengshui 053000,Hebei,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,Hebei,China;Engineering Research Center of Railway Industry of Construction Technology for Long Tunnel in Special and Complex Environment,Xi′an 710043,Shaanxi,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi′an 710043,Shaanxi,China)

机构地区：[1]甘肃天陇铁路有限公司,甘肃兰州730030 [2]衡水铁路电气化学校,河北衡水053000 [3]石家庄铁道大学土木工程学院,河北石家庄050043 [4]特殊复杂环境下长大隧道建造技术铁路行业工程研究中心,陕西西安710043 [5]中铁第一勘察设计院集团有限公司,陕西西安710043

出　　处：《隧道建设（中英文）》2023年第S01期344-355,共12页Tunnel Construction

基　　金：中国铁建股份有限公司科技重大专项(2019-A04);河北省自然科学基金项目(E2021210091);河北省教育厅青年拔尖人才项目(BJ2019009)。

摘　　要：针对较大形变压力作用下挤压性围岩隧道断面形状优化的问题,在时速200 km客货共线铁路隧道建筑限界的基础上拟定单线和双线铁路隧道断面形状,通过结构安全性评价,提出不同变形等级条件下单线和双线铁路隧道较经济、安全的断面形式。研究结果表明:1)随着变形等级的增加,围岩压力显著增大,结构安全系数明显降低,从建筑限界出发拟定的最经济的隧道断面不能满足结构安全性要求。2)拱脚及墙脚是隧道结构受力薄弱部位,通过优化断面曲率实现拱部与边墙、边墙与仰拱的圆顺衔接,可有效改善结构受力状态,提高结构安全性。3)对于单线铁路隧道,Ⅰ级变形条件下推荐采用单线断面A(与常规单线铁路隧道断面相衔接),Ⅱ级变形条件下推荐采用单线断面B(在单线断面A的基础上对断面曲率进行优化),Ⅲ、Ⅳ级变形条件下推荐采用单线断面E(圆形)。4)对于双线铁路隧道,Ⅰ、Ⅱ级变形条件下推荐采用双线断面C(在常规双线铁路隧道的基础上优化断面曲率),Ⅲ、Ⅳ级变形条件下推荐采用双线断面E(圆形)。5)工程实践中,隧道断面优化应综合考虑结构安全、区段衔接和施工便利性,综合确定各区段隧道断面形状;在Ⅳ级变形条件下,应加强注浆加固,并采用多层支护及应力释放等技术措施保证隧道结构安全。To optimize the cross-section shape of squeezed surrounding rock tunnels under large deformation pressure,the cross-section shapes of single-and double-track railway tunnels are determined based on the construction clearance of passenger and freight railway tunnel with a speed of 200 km/h.Economic and safe cross-section types of single-and double-track railway tunnels under various deformation levels are proposed through structural safety evaluation.The conclusions are drawn as follows:(1)With an increase in deformation level,the structural load increases and the structural safety coefficient decreases evidently.The most economical tunnel cross-section proposed based on the construction clearance cannot meet the structural safety requirements.(2)The arch and wall feet are the weak parts of the tunnel structure.By optimizing the curvature of tunnel cross-section,the smooth connection between arch and sidewall and that between sidewall and inverted arch can be realized,thus effectively improving the stress state of the structure and the structural safety.(3)For single track tunnel:single-track A cross-section type(connected with the normal single-track tunnel section)is recommended for grade I deformation,single-track B cross-section type(optimized cross-section curvature based on single-track A cross-section)is recommended for grade II deformation,and single-track E cross-section(circular)is recommended for grades III and IV deformation.(4)For double-track tunnel:double-track C cross-section type(cross-section curvature optimized on the basis of conventional double-track tunnel)is recommended for grades I and II deformation,and double-track E cross-section(circular)is recommended for grades III and IV deformation.(5)In engineering practice,the cross-section type should be comprehensively optimized considering structural safety,zone connection,and construction convenience.Under grade IV deformation condition,strengthened grouting reinforcement,multi-layer support,and stress release should be conducted to ensure the

关 键 词：挤压性围岩 铁路隧道 断面形状 变形分级 安全系数 优化设计 

分 类 号：U45[建筑科学—桥梁与隧道工程]