摘要
为在大直径盾构隧道中更好发挥接头的抗剪、定位功能,设计安装于管片环缝螺栓孔处、外套于螺栓的空心套筒,为了探究“直螺栓+套筒”新型环间接头的抗剪性能,以成都锦绣隧道为背景,建立环间接头的三维精细化数值模型,并开展足尺试验对数值模型的计算精度进行验证。结果表明:新型环间接头在抗剪过程中主要分为3个受力阶段:摩擦段、构件抗剪段和破坏失效段,其抗剪刚度随着错台的发展呈现出非线性。套筒对接头的抗剪性能有明显的强化作用,将超过其承载能力的剪切荷载平稳过渡给螺栓,避免了管片突然产生滑移错台,并对管片有一定的保护作用。套筒与直螺栓的受力配合机理为:在管片产生微小错台时,套筒发生弹性变形并承担主要剪力,随着错台量增大,套筒逐渐进入塑性状态,螺栓承担主要剪力。套筒的加入能显著改善环间接头对于微小错台的控制能力,并且由于其自身具备的导向定位功能,能在管片拼装阶段就达到降低错台率和错台量的效果。足尺试验表明新型接头的破坏形式为:套筒、螺栓进入塑性状态而失效,管片发生以螺栓孔为对称中心、与水平方向成30°~45°的对称剪切破坏,管片薄弱区域为螺栓孔附近位于管片内弧面一侧的钢筋混凝土。研究成果将为此类接头今后的工程应用提供参考。
In order to optimize the shear capacity and locate function of the joint in large-diameter shield tunnels,a hollow sleeve was designed to be installed at the bolt hole of the ring joint.To investigate the shear performance of the new“straight bolt+sleeve”ring joint,a three-dimensional numerical model of the ring joint was established using Chengdu Jinxiu Tunnel as a reference.Full-scale experiments were conducted to validate the accuracy of this numerical model.The results indicate that during shearing,the new ring joint underwent three stress processes:friction section,shear section,and failure section,with its shear stiffness nonlinearly evolving during each stage.The sleeve significantly enhanced the shear performance of the joint,and smoothly transferred excessive shear loads to the bolt,thereby preventing abrupt segment slippage and providing protection for segments.The force coordination mechanism between sleeve and bolt was as follows:when small misalignment occurs,sleeve deforms elastically and primarily sustains the shear force;as displacement increases,sleeve gradually entered plastic state while the bolt bears main shear force.The addition of the sleeve can significantly enhance the control capability of the ring joint during micro-misalignment stage.Furthermore,due to its inherent orientation and positioning function,it can effectively reduce both the occurrence rate and quantity of the misalignment in segment assembly stage.The full-scale tests demonstrate that the failure modes of the new ring joint are as follows:the sleeve and bolt failed when they entered the plastic state,while symmetrical shear failure took place within the segment with the bolt hole as the center at an angle of 30°~45°from the horizontal direction.Moreover,it is worth noting that the concrete near the bolt hole on the inner arc side of the segment represents a weak area.These research findings could potentially serve as valuable references for future engineering applications involving this type of joint.
作者
刘议文
周子扬
封坤
何川
林刚
LIU Yiwen;ZHOU Ziyang;FENG Kun;HE Chuan;LIN Gang(Key Laboratory for Transportation Tunnel Engineering of the Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2024年第8期3248-3261,共14页
Journal of Railway Science and Engineering
基金
国家重点研发计划资助项目(2021YFB2600900)
国家自然科学基金资助项目(52078430)。
关键词
盾构隧道
环间接头
数值模拟
抗剪性能
接头足尺试验
shield tunnel
ring joint
numerical simulation
shearing resistance
full-scale test of ring joint
作者简介
通信作者:封坤(1983-),男,陕西南郑人,教授,博士,从事盾构隧道教学与研究工作,E-mail:windfeng813@163.com。
