带定位榫盾构隧道管片接头剪切力学行为研究  

Study on shear mechanical behavior of shield tunnel segment joint with fixing tenon

作　　者：林刚[1] 易丹[1] 罗世培[1] 晏启祥[2] 张君臣 LIN Gang;YI Dan;LUO Shipei;YAN Qixiang;ZHANG Junchen(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;The Ministry of Education Key Laboratory of Traffic Tunnel Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031 [2]西南交通大学交通隧道工程教育部重点实验室,成都610031

出　　处：《北京交通大学学报》2024年第3期130-139,共10页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家自然科学基金(51878573)。

摘　　要：外套于盾构隧道管片螺栓的空心圆锥筒定位抗剪构件定位榫能有效控制盾构管片错台量和错台值,与管片、螺栓共同形成“管片-定位榫-弯螺栓”接头.为探明盾构隧道管片受压工况、“管片-定位榫-弯螺栓”接头在剪切荷载作用下的结构力学特征和破坏机理,以内径7.5 m、外径8.3 m、弯螺栓连接的盾构隧道衬砌环的纵向接头为例,首先,建立三维有限元模型,对轴力分别为196、392、588和784 kN4种工况的接头剪切破坏全过程进行数值模拟;然后,对接头剪切破坏过程、定位榫和螺栓力学及变形特征、管片接缝面变形破坏特征进行分析;最后,采用原型剪切破坏试验对数值模拟结果进行印证和补充研究.研究结果表明:盾构隧道“管片-定位榫-弯螺栓”接头剪切破坏全过程分为接触面静摩擦、定位榫弹性变形、定位榫塑性错动和螺栓剪切破坏4个阶段;定位榫弹性变形阶段,定位榫表现为“压扁”形态,定位榫塑性错动阶段,定位榫拱顶外侧首先出现塑性屈服区,随着剪切荷载的增加,塑性区将扩展到定位榫端部和横断面内大部分区域,塑性破损过程中定位榫将超过其承载能力的外部剪切荷载转移给螺栓;螺栓杆体受力从定位榫塑性错动阶段开始,最终加载侧杆体将发生“拉直”破坏、固定侧杆体将发生弯剪破坏;管片接缝面混凝土从定位榫塑性错动阶段后期出现塑性区,初始位于榫槽内水平两侧,随着剪力增加,塑性区将向周边扩展,最终与管片内弧面手孔塑性区连通,形成“手孔-螺栓孔-手孔”塑性破坏域.The hollow conical cylindrical fixing tenon,wrapped around the bolt of shield tunnel segments,effectively controls the displacement and value of shield segment misalignment,forming a“segment-fixing tenon-bent bolt”joint configuration with the segment and bolt.This study investigates the compressive conditions of shield tunnel segments,specifically the structural mechanics and failure mechanisms of the“segment-fixing tenon-bent bolt”joint under shear loads,focusing on a longitudinal joint of shield tunnel lining connected by bent bolts with dimensions of 7.5 m inner diameter and 8.3 m outer diameter.Firstly,a three-dimensional finite element model is established to numerically simulate the entire shear failure process under axial forces of 196,392,588,and 784 kN.Subsequently,the shear failure process of the joint,mechanical characteristics of the fixing tenon and bolts,and the deformation and failure characteristics of the segment joint surface are analyzed.Finally,prototype shear failure tests validate and complement the numerical results.The study results reveal that the entire shear failure process of the“segment-fixing tenon-bent bolt”comprises four stages including static friction at the contact surface,elastic deformation and plastic dislocation of fixing tenon,and bolt shear failure.During the elastic deformation stage of the fixing tenon,the tenon exhibits a“flattened”shape.During the plastic dislocation phase of the tenon,the plastic yield zone first appears on the outer arch of the tenon.As shear load increases,plastic zone extends to encompass most of the tenon’s end and cross-sectional areas,with excess shear loads transferred from the tenon to the bolt during plastic failure.Stress on the bolt rod body starts from the plastic dislocation stage of the fixing tenon,leading to“straightening”failure on the loaded side rod body and bending shear failure on the fixed side.The concrete on the joint surface of the shield tunnel segment exhibits a plastic zone in the later stages of the f

关 键 词：盾构隧道 定位榫 管片接头 力学行为 数值模拟 原型试验 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]