地表堆载作用下双圆盾构隧道破坏机制试验研究  

Experimental investigations on failure mechanisms of DOT shield tunnel subjected to extreme surface surcharge

作　　者：柳献[1] 刘震 李家平[2] 王如路[2] LIU Xian;LIU Zhen;LI Jiaping;WANG Rulu(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Shanghai Shentong Metro Group Co.,Ltd.,Shanghai 201102,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]上海申通地铁集团有限公司,上海201102

出　　处：《岩土工程学报》2025年第3期487-494,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52078376)。

摘　　要：盾构隧道在服役期间,易受周边工程活动影响导致较大的变形或内力响应。为研究双圆盾构隧道在周边环境扰动下的结构鲁棒性能,为隧道运维提供理论依据,设计并开展了双圆盾构隧道原型结构破坏性试验,采用拟静力试验方法模拟了隧道结构在地表堆载意外作用下的外部荷载状态。基于对试验过程中结构和接头的变形响应演化分析,揭示了双圆盾构隧道结构的破坏机制。研究结果表明,双圆盾构隧道结构在地表堆载意外工况下呈现典型初始线性、塑性损伤快速累积和整体失稳3个阶段。当长轴收敛变形达到25 mm左右时,6号、8号和3号负弯矩接头依次进入弹塑性阶段,结构整体亦进入塑性损伤快速累积阶段(第二阶段)。当左半环底部7号正弯矩接头外弧面混凝土压溃,内弧面铸铁手孔板开裂后,结构基本进入整体失稳阶段(第三阶段)。最终随着左半环上角部B7管片本体受弯破坏,结构彻底丧失承载能力。结构鲁棒性评价表明,双圆盾构隧道相比类矩形盾构隧道更好地利用了圆形隧道的优良受力性能,整体鲁棒性评价指标也更高。研究进一步建立了结构整体收敛变形和接头转角、接头张开量的相互关系,发现受结构、接头构造及材料性能影响,双圆盾构隧道结构在地表堆载意外工况下初期变形主要来源于3号、6号和8号负弯矩接头,在第二阶段后期随着内力重分布,7号正弯矩接头迅速达到线性极限,并进入塑性状态,导致结构左半环收敛变形快速发展。根据结构及接头受力机制,实际隧道运维期间重点监测的关键部位应包含结构长短轴收敛变形、腰部及小海鸥块侧负弯矩接头内弧面压碎及正弯矩接头内弧面张开情况。During the service lifespan of shield tunnels,the surrounding construction activities are easy to cause significant structural responses.To explore the structural robustness of double-o-tube(DOT)shield tunnels in the face of environmental disturbances and to provide a guidance for tunnel operation and maintenance,a failure test is designed and conducted on a prototype DOT shield tunnel structure.In this test,a quasi-static method is utilized to simulate the external loading conditions of the tunnel structures subjected to the extreme surface surcharge.Through an analysis of the evolution of deformation responses of the structures and longitudinal joints during the tests,the failure mechanisms of the DOT tunnel structures are revealed.The tests indicate that the failure process of the DOT tunnel subjected to the extreme surface surcharge can be divided into three typical stages:initial linear stage,rapid accumulation of plastic damage stage,and instability stage.As the convergence deformation of the long axis(from the left waist to the right waist)approaches approximately 25 mm,three negative moment joints(No.6,No.8,and No.3)enter the elastoplastic state,and the structures simultaneously enter the second stage(rapid accumulation of plastic damage stage).Subsequently,with the extrados concrete of the No.7 positive moment joint being crushed and the intrados cast iron plate of that joint being fractured,the structures enter the third stage(instability stage).Ultimately,with the bending failure of the B7 block(segment),the structures completely lose their bearing capacity.The structural robustness evaluation indicates that the DOT tunnel,compared to the quasi-rectangular tunnel,better utilizes the good load-bearing performance of circular tunnels,resulting in a higher robustness performance.The relationships between the structural convergence deformation and the joint rotation angles as well as the joint opening deformations are also investigated.It is found that the structural deformation at the first stage mainly c

关 键 词：双圆盾构隧道 原型结构试验 地表堆载 破坏机制 鲁棒性评价 监测部位 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]