新建盾构隧道纵向裂纹病害规律统计与数值分析  

Statistical and Numerical Analysis of Longitudinal Crack Damage in New-built Shield Tunnel

作　　者：卢岱岳[1] 苏昂[1] 何川[1] 王乾屾 LU Dai-yue;SU Ang;HE Chuan;WANG Qian-shen(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]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：《铁道标准设计》2018年第10期135-141,共7页Railway Standard Design

基　　金：国家自然科学基金面上项目(51278424;51578461)

摘　　要：针对某地铁盾构隧道施工阶段管片大范围开裂、脱落等现象,对裂损病害进行现场调研,并深入分析危害最严重的纵向裂纹分布规律、裂损形态特征。在此基础上,建立扩展有限元数值模型,对纵向裂纹产生部位、外观形式、扩展规律、管片破坏形式进行探讨。研究表明:(1)施工阶段盾构隧道裂损可分为为纵向裂纹、拱顶脱落、边角部裂损三类,纵向裂纹是影响管片质量最主要因素;(2)纵向裂纹分为前裂纹和后裂纹,前裂纹比后裂纹数量多、波及范围广、病害程度深,是威胁隧道安全性及耐久性的最主要因素;(3)推力不均和推力过大是影响纵向裂纹产生的主要因素,管片破坏特征分别表现为剪切破坏、区域压溃破坏,推力过大在施工阶段对管片局部影响最大。Aiming at the phenomenon of largescale cracking and falling off of the segments inthe construction stage of the shield tunnel of a certain subway,a field investigation is carried out on the cracking damage. The distribution rule and shape characteristics of the most serious longitudinal cracks are discussed intensively. On this basis,an extended finite element numerical model is established and the location,appearance,propagation rule and failure modes of the segment longitudinal cracks are addressed. The research shows that：（ 1） the form of cracking in the shield tunnel in the construction stage can be classified into three categories： longitudinal cracks,vault fall and corner cracks. The longitudinal cracks are the main factor affecting the quality of segment.（ 2） The longitudinal cracks are divided into front cracks and back cracks. In contrast to back cracks,front cracks have more numbers,spread wider and have a deeper severity,which are the most important factors to threaten the safety and durability of tunnel structures.（ 3） The thrust unevenness and the large thrust are the main factors that affect the generation of the longitudinal cracks. The failure characteristics of the segments are shear failure and regional crushing failure respectively. Excessive thrust has greatest influence on the part of the segments in construction stage.

关 键 词：地铁 盾构隧道 施工阶段 纵向裂纹 病害统计 扩展有限元 

分 类 号：U448.217[建筑科学—桥梁与隧道工程] U311.3[交通运输工程—道路与铁道工程]