局部失效盾构隧道管片承载特性及破坏机理  

Bearing Characteristics and Failure Mechanism of Partially Failed Segments in Shield Tunnels

作　　者：高晓静[1] 李鹏飞[1] 张明聚[1] 王海峰 贾子琦 冯武 GAO Xiao-jing;LI Peng-fei;ZHANG Ming-ju;WANG Hai-feng;JIA Zi-qi;FENG Wu(Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China;Nantong Railway Construction Component Co.Ltd.,Nantong 226000,Jiangsu,China)

机构地区：[1]北京工业大学城市安全与灾害工程教育部重点实验室,北京100124 [2]南通铁建建设构件有限公司,江苏南通226000

出　　处：《中国公路学报》2023年第11期302-311,共10页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51978019,52278382);北京市自然科学基金项目(8222004)。

摘　　要：局部失效(混凝土或钢筋缺失)会显著影响盾构管片的承载性能,甚至会诱发隧道整体结构的破坏。为明确局部失效对管片承载特性的影响,分别开展了标准管片和跨中及侧部开孔管片承载特性的足尺试验,并对管片的位移、裂缝扩展及混凝土应变进行了监测。试验结果表明:管片破坏过程分为4个典型阶段,并将各个阶段的临界荷载定义为管片的3个特征荷载。根据各特征荷载值对管片的承载特性进行了对比分析,明确了开孔管片的承载能力低于标准管片,且开孔位置对管片的承载特性具有较强影响。为进一步明确局部失效盾构管片试验结果的准确性,采用混凝土弹塑性损伤本构建立了与试验对应的三维精细化数值模型,并通过与模拟的对比验证了试验结果的合理性。随后,依据标准管片各承载特性,定量分析了管片开孔直径及开孔位置等因素对管片抗弯承载特性的影响规律,并初步提出了局部失效盾构管片抗弯承载特性的理论计算模型。研究结果可为极端条件下地铁盾构隧道的安全性评估及加固设计提供理论基础。Local failure(loss of concrete or reinforcement)will significantly affect the bearing capacity of the shield segment,and even lead to the damage of the tunnel structure.To clarify the influence of local failures on the bearing capacity,full-scale tests were carried out on the standard segment,mid-span and side opening segments respectively.Displacements and concrete strains of these segments were monitored during the loading procedure.The loading process of the segment can be divided into four stages,and each stage has a critical load that can be defined as the characteristic load.According to each characteristic load value,the bearing characteristics of the segment were compared and analyzed.The analysis results show that the bearing capacity of the opening segment is lower than that of the standard segment,and the opening position has a strong influence on the bearing characteristics.To further clarify the accuracy of test results,numerical simulations were conducted by using the elastoplastic damage constitutive behavior of concrete,and the reasonableness of the experiment results were verified by comparing with the simulation.According to the bearing characteristics of the standard segment,the influence of the opening diameter and position on the bending bearing characteristics of the partially failed segment was quantitatively analyzed.This paper preliminary proposed a calculation model of the bearing characteristics for the local failed shield segment which can provide a theoretical basis for the safety assessment and reinforcement design of shield tunnels under extreme conditions.

关 键 词：隧道工程 盾构管片 足尺试验 局部失效 承载特性 破坏机理 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]