高铁泥岩隧道围岩蠕变对仰拱底鼓的影响  

Influence of Surrounding Rock Creep on Invert Heave of High-speed Railway Tunnel in Mudstone

作　　者：梁庆国[1] 岳建平[1] 周稳弟 孙纬宇 李景[1] LIANG Qingguo;YUE Jianping;ZHOU Wendi;SUN Weiyu;LI Jing(Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)

机构地区：[1]兰州交通大学,兰州730070

出　　处：《铁道工程学报》2024年第3期80-85,共6页Journal of Railway Engineering Society

基　　金：国家自然科学基金项目(51968041);中国博士后科学基金项目(2021M693843);兰州交通大学“百名青年优秀人才培养计划”;甘肃省教育厅优秀研究生“创新之星”项目(2021CXZX-642,2022CXZX-531)。

摘　　要：研究目的:针对泥岩地区高铁隧道修建过程中出现的仰拱底鼓病害,本文采用参数反演与数值模拟相结合的方法,全面分析围岩蠕变对仰拱底鼓的影响,并采用锚杆支护与仰拱加强的工程措施对仰拱底鼓进行治理。研究结论:(1)Burgers模型能较好地符合泥岩表现出的明显的衰减蠕变和稳定蠕变特征;(2)随着时间的增加,围岩不断向洞内发生变形,且隧道拱顶沉降、水平收敛和拱底隆起一直在增大,并经历了三个阶段:瞬时变形阶段、衰减蠕变阶段与稳定蠕变阶段;(3)仰拱结构内力随着蠕变时间增加同样在增大,并在蠕变一定年限后,仰拱填充中心的拉应力将超过混凝土的抗拉强度,导致仰拱填充沿中心位置开裂;(4)锚杆支护的最优长度为5 m,最佳间距为0.9~1.2 m,在此基础上通过加强仰拱来进一步抑制仰拱底鼓变形,并且建议仰拱支护强度选用C30~C40;(5)本研究结果可为类似工程的建设与施工提供建议与参考。Research purposes:Aiming at the disease of the invert heave during the construction of the high-speed railway tunnels in the mudstone area,the method of parameter inversion and numerical simulation were adopted,the influence of the surrounding rock creep on the invert heave was comprehensively analyzed,and the engineering measures of bolt support and invert reinforcement were used to control the invert heave.Research conclusions:(1)The Burgers model can better describe the obvious decay creep and stable creep characteristics of mudstone.(2)With the increase of time,the surrounding rock was continuously deformed into the tunnel.The tunnel crown settlement,horizontal convergence and invert heave have been increasing,which experienced three stages:instantaneous deformation stage,attenuation creep stage and steady creep stage.(3)The internal force of the invert structure also increases with the passage of creep time.After a certain period of creep,the tensile stress of the invert filling center will exceed the tensile strength of the concrete,causing the invert filling to crack along the center position.(4)The optimal length of the bolt support is 5 m,and the optimal spacing is 0.9~1.2 m.On this basis,the deformation of the invert heave was further suppressed by strengthening the invert.It is suggested that the support strength of the invert should be C30~C40.(5)The research results can provide suggestions and references for the construction and construction of similar projects.

关 键 词：泥岩隧道 仰拱底鼓 参数反演 数值模拟 底鼓控制 

分 类 号：U45[建筑科学—桥梁与隧道工程]