弯曲荷载及锈胀压力作用下盾构隧道管片开裂形态研究  

Study on the Crack Form of Shield Tunnel Segment Under Bending Load and Corrosion⁃Induced Pressure

作　　者：王震 余朔 何益龙 严佳佳 WANG Zhen;YU Shuo;HE Yilong;YAN Jiajia(Key Laboratory of Safe Construction and Intelligent Maintenance for Urban Shield Tunnels of Zhejiang Province,Hangzhou 310015,Zhejiang,China;Power China Huadong Engineering Corporation Limited,Hangzhou 311122,Zhejiang,China)

机构地区：[1]浙江省城市盾构隧道安全建造与智能养护重点实验室,浙江杭州310015 [2]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122

出　　处：《力学季刊》2024年第4期1055-1067,共13页Chinese Quarterly of Mechanics

基　　金：浙江省城市盾构隧道安全建造与智能养护重点实验室开放基金(ZUCC-UST-22-05)。

摘　　要：管片是地铁盾构隧道外部的衬砌结构,受外部荷载及锈胀压力影响会出现不同程度的裂缝,而管片的开裂会严重降低结构的刚度及承载性能.为了明确弯曲荷载及锈胀压力作用下盾构隧道拱腰管片内部的开裂形态分布规律,采用CDM-XFEM(Continuum Damage Mechanics-Extended Finite Element Methods)方法计算了拱腰管片受弯曲荷载作用下的表面开裂形态,并通过足尺试验进行了验证;通过均匀离散化钢筋锈层,基于厚壁圆筒模型推导了管片的不规则锈层-锈胀压力转化方程,在此基础上计算了不同弯曲荷载作用下锈蚀管片内部的开裂形态.研究表明:在弯曲荷载作用下,管片的外弧面呈三条贯通曲线裂缝,而锈胀裂缝在管片钢筋两侧呈波浪状分布形态.当管片弯矩从220 kN·m增大到320 kN·m时,不同区域裂缝处截面的锈胀裂缝横跨度分别增大了27%、51%、37%,说明弯矩的增加对管片中间裂缝处截面的锈胀开裂影响最大.在相同弯矩下各个钢筋的锈裂角曲线形态基本相同,说明弯曲荷载对管片锈裂角影响较小.Segments are the lining structures outside the subway shield tunnel,and are vulnerable to various degrees of cracks due to external loads and rust expansion pressure.Segments cracking can seriously reduce the stiffness and load-bearing performance of the structure.In order to determine the distribution pattern of crack morphology inside the arch waist segment of shield tunnel under the bending load and the rust expansion pressure,the CDM-XFEM(Continuum Damage Mechanics-Extended Finite Element Methods)method was used to calculate the surface crack morphology of the arch waist segment under the bending load,and the results were verified through full-scale tests.By uniformly discretizing the steel rust layer,the irregular rust layer rust expansion pressure transformation equation of the segment was derived based on the thick-walled cylinder model.Based on this,the crack morphology inside the corroded segment under different bending loads was calculated.Research has shown that under the bending loads,the outer curved surface of the segment exhibits three curved through cracks,while the internal cracks exhibit a distribution pattern of three connected ellipses.When the bending moment of the segment increases from 220 kN·m to 320 kN·m,the transverse span of the rust expansion crack at the crack section in different areas increases by 27%,51%,and 37%,respectively,indicating that the increase in bending moment has the greatest impact on the rust expansion cracking at the middle crack section of the segment.Under the same bending moment,the shape of the rust cracking angle curve of each steel bar is basically the same,indicating that the bending load has a relatively small impact on the rust cracking angle of the segment.

关 键 词：盾构隧道 拱腰管片 开裂形态 弯曲荷载 锈胀压力 

分 类 号：TU43[建筑科学—岩土工程]