考虑碳化的地铁盾构隧道纵缝接头抗弯力学模型研究  

Study on bending mechanical model of longitudinal joint in metro shield tunnel considering concrete carbonization

作　　者：郑勇波 白廷辉[1] 李晓军[1] Zheng Yongbo;Bai Tinghui;Li Xiaojun(Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学,上海200092

出　　处：《土木工程学报》2021年第12期94-103,共10页China Civil Engineering Journal

摘　　要：长期服役的地铁盾构隧道内表面混凝土会产生碳化现象,从而改变纵缝接头的受力性能。针对地铁盾构隧道服役期混凝土碳化典型工况,考虑接缝面细部构造、正常及碳化混凝土不同非线性受力特性、接缝面接触特性以及螺栓预紧等因素,构建可以表征接缝面混凝土压碎、螺栓屈服以及接头极限状态的纵缝接头抗弯力学模型,并结合纵缝接头抗弯足尺试验对碳化后地铁盾构隧道纵缝接头的力学性能进行对比分析,验证工程设计适用性。研究结果表明:采用全积分形式进行纵缝接头混凝土本构关系运算,适用研究混凝土碳化的影响;负弯矩作用下,内表面边缘混凝土接触之前,混凝土碳化无明显的影响;接触之后,随着碳化厚度增加,螺栓应变、接缝张开量及压缩量等最大值均增大,极限弯矩也相应增大,但增幅不断减小;轴力不会对碳化后的纵缝接头力学性能产生明显耦合影响。Concrete carbonization may occur on the inner surface of metro shield tunnel change the mechanical performance of longitudinal joint in long service.Considering details of joint surface,different non-linear mechanical property of general and carbonated concrete,the contact characteristics of joint surface and pre-tightened bolt,the bending mechanical model of longitudinal joint are established,by which the crush of concrete,the yield of bolt and the limit state of longitudinal joint are characterized.Then the flexural behavior of longitudinal joint in metro shield tunnel with carbonization is analyzed using full-scale bending test of longitudinal joint to verify the engineering design suitability.The results show that it is applicable to study the influence of carbonization when the constitutive calculation of longitudinal joint is carried out in full integral form.Meanwhile,concrete carbonization under sagging moment has no significant effect before the concrete contact of inner surface edges.After concrete contact,with the increase of carbonization thickness,the maximum values of bolt strain,seam opening and compression grow while ultimate bending moment all increase,but the growing rate decreases.In addition,the axial force produces no obvious coupling effect on mechanical properties of longitudinal joint after carbonization.

关 键 词：盾构隧道 纵缝接头 抗弯性能 力学模型 碳化 

分 类 号：U455.43[建筑科学—桥梁与隧道工程] U231.3[交通运输工程—道路与铁道工程]