基于势能驻值原理的隧道底鼓变形计算理论  

Deformation Calculation Theory of Tunnel Floor Heave Deformation Based on Potential Energy Stationary Value Theory

作　　者：张向民[1] 张勇 ZHANG Xiangmin;ZHANG Yong(School of Civil Engineering,Central South University,Changsha 410075,China;Guangdong Meilong Railway Co.,Ltd.,Guangzhou 510101,China)

机构地区：[1]中南大学土木工程学院,长沙410075 [2]广东梅龙铁路有限公司,广州510101

出　　处：《铁道标准设计》2024年第12期130-138,175,共10页Railway Standard Design

基　　金：中国国家铁路集团有限公司科技研究计划重大课题(K2021G026)。

摘　　要：针对铁路隧道底鼓的病害难题,首先建立隧道仰拱隆起变形的围岩-支护体系统一力学模型,采用势能驻值原理和瑞利里兹法进行解析计算;深入分析仰拱边界条件、矢跨比、衬砌厚度、围岩厚度与级别、地应力以及温度力等参量的影响规律;最后阐释隧道仰拱隆起变形研究对高原铁路隧道工程建设具有的启示意义。研究结果表明:(1)隧道仰拱隆起病害是构造应力、膨胀力或外水压力在抗力不足的软岩中作用的结果;(2)当二衬厚度取30 cm,仰拱隆起1 cm时隧底垂向应力为17.37 kPa,而二衬厚度取60 cm时为30.48 kPa,两者相差43%,因此如果不考虑围岩作用,二衬对仰拱隆起影响显著,在高应力区域突显了铁路隧道设置仰拱作为安全储备的必要性;(3)参与支护作用的围岩厚度取600 cm,仰拱隆起1 cm时垂向应力为569.47 kPa,而不考虑围岩作用时仅为33.94 kPa,因此隧道仰拱支护中围岩起主要承载作用;(4)Ⅲ级围岩仰拱隆起1 cm时垂向应力为1336.22 kPa,Ⅴ级围岩为187.40 kPa,表明围岩类型对隧道仰拱稳定的影响显著;(5)地应力80 MPa仰拱隆起1 cm时垂向应力为436.32 kPa,如果不考虑地应力为566.11 kPa,因此在隧道仰拱稳定性设计中,地应力作用不可忽略;(6)高原非均匀高应力场、强地震活动性、大埋深、复杂地质环境是铁路沿线隧道面临的主要问题,其中穿越活动断裂带和软弱岩层地段成为影响工程建设的关键带,因此沿线地球动力学、地震活动性、地应力场和岩体流变学的研究对于隧道结构安全性至关重要。In response to the issue of tunnel inverted arch heave in railway tunnels,a unified mechanical model of the surrounding rock and support system for tunnel inverted arch heave was established.The principle of potential energy stationary value,combined with the Rayleigh Ritz method,was used for analytical calculations.Then,the effects of various parameters,such as arch boundary conditions,rise-span ratio,tunnel-lining thickness,surrounding rock thickness and grade,geostress,and temperature forces,were analyzed in detail.The study also discussed the implications of tunnel inverted arch heave research for the construction of plateau railway tunnels.The results showed that:(1)Tunnel inverted arch heave was the result of structural stress,expansion forces,or external water pressure acting on soft rocks with insufficient resistance.(2)With a secondary lining thickness of 30 cm and a 1 cm inverted arch heave,the vertical stress at the tunnel bottom was 17.37 kPa.When the secondary lining thickness was increased to 60 cm,the vertical stress increased to 30.48 kPa,a difference of 43%.This demonstrated that,without considering surrounding rock,the secondary lining significantly affected inverted arch heave,emphasizing the necessity of setting up an inverted arch as a safety reserve in high-stress areas of railway tunnels.(3)When the surrounding rock thickness contributing to support was 600 cm,the vertical stress for a 1 cm inverted arch heave reached 569.47 kPa.Without surrounding rock support,the stress was only 33.94 kPa,indicating that the surrounding rock played a major role in supporting the tunnel inverted arch.(4)For Grade III surrounding rock,the vertical stress with a 1 cm inverted arch heave was 1336.22 kPa,while for Grade V surrounding rock,it was 187.40 kPa,indicating the significant impact of surrounding rock type on tunnel inverted arch stability.(5)With a geostress of 80 MPa,the vertical stress with a 1 cm inverted arch heave was 436.32 kPa,but when geostress was neglected,it increased to 566.11 kPa,highligh

关 键 词：铁路隧道 仰拱隆起 势能驻值原理 瑞利里兹法 变形计算理论 

分 类 号：U25[交通运输工程—道路与铁道工程] U451[建筑科学—桥梁与隧道工程]