大直径地铁盾构隧道牛腿开裂机理研究  

Cracking Mechanism of Corbel in Large Diameter Metro Shield Tunnel

作　　者：李伟 LI Wei(Nanjing Metro,Nanjing 211135,China)

机构地区：[1]南京地铁运营有限责任公司,南京211135

出　　处：《现代交通技术》2025年第1期67-70,共4页Modern Transportation Technology

基　　金：江苏省科技项目(BE2020082-2);江苏省建设系统科技项目(2019ZD116)。

摘　　要：为探究大直径地铁盾构隧道内部牛腿开裂机理,基于现场调研,分析了牛腿裂缝的分布特征;并利用有限元分析,获得了牛腿裂缝的扩展过程和扩展曲线。统计结果表明:仅有12.6%的管片环对应的牛腿未出现开裂,隧道轨行区上行线与下行线内牛腿裂缝数量基本相等;共计有43.9%的牛腿裂缝位于管片环缝或预制烟道板接缝附近。分析表明:环缝错台是牛腿开裂的主要原因,在竖向位移和水平位移的作用下,裂缝自牛腿前端斜面向根部扩展;裂缝扩展长度变化曲线经历3个阶段,其中第二阶段为裂缝长度增长的主要阶段。In order to explore the cracking mechanism of corbel in large diameter metro shield tunnel,the distribution charac-teristics of corbel cracks were analyzed based on field investigation results.By means of extended finite element analysis,the crack propagation process and expansion curve of corbel crack were obtained.The statistical results showed that only 12.6%of the corbel corresponding to the segment ring did not crack,and the number of corbel cracks in uplink and downlink of the tunnel track area was basically the same.A total of 43.9%of the corbel cracks were located near the circumferential joint of the segment or the joint of the prefabricated flue plate.The analysis shows that the primary cause of corbel cracking was the dislocation of the circumferential seam.Under vertical displacement and horizontal displacement,the crack extended from the front slope of the corbel to the back.The variation curve of crack propagation length went through three stages,of which the second stage was the main stage of crack length growth and propagation.

关 键 词：大直径盾构隧道 牛腿开裂 裂缝分布 扩展曲线 

分 类 号：U457[建筑科学—桥梁与隧道工程]