部分软土地区的盾构隧道结构出现过大的变形与严重的病害，这些带病服役的盾构隧道结构仍将长时间 服役，且其后续服役期内也将面临各类不利的服役环境。因此，有必要提出盾构隧道结构变形控制限值，在隧道 结构变形进一步发展时，为结构的养护运维及时提供判断、决策依据。以南京某 3 个地铁区间为背景，分别以实 测数据分析、三维精细化有限元模拟为手段，探究错缝拼装盾构隧道结构横断面的收敛变形与各类病害之间的相 关关系。通过两种手段相互验证与补充发现：收敛变形小于 30 mm 时，隧道结构的服役性能良好；30～60 mm， 出现渗漏水、裂缝，且螺栓开始屈服；60～80 mm，病害加剧，出现管片破损；80～100 mm，首个螺栓到达抗拉 极限状态，安全性受到极大威胁；大于 100 mm，整环结构濒临屈服。据此得到结构性能的衰退特性，进一步提 出盾构隧道横断面变形控制限值。

Excessive deformation and serious deterioration have occurred in some shield tunnel structures in soft soil areas. These structures with defects will be in service for a long time, and face various adverse service environments. Therefore, it is necessary to propose the control limit of shield tunnel structure deformation, which can be a judgment and decision-making basis for the maintenance and operation of the structure when there is further deformation. Based on the background of three subway sections in Nanjing, this study explores the correlation between cross-sectional convergence deformation and various diseases of staggered seam-assembled shield tunnels using measured data analysis and three-dimensional refined finite element simulation. The two methods verify and complement each other. The results show that the service performance of the tunnel structure is good when the convergence deformation is less than 30 mm. At 30~60 mm, water leakage and cracks appear and the bolts begin to yield. The disease intensifies and the segment is damaged at 60~80 mm; the first bolt reaches the tensile limit state and the safety is greatly threatened at 80~100 mm. The entire ring structure is on the verge of yield when thedamage is greater than 100 mm. On the structural performance degradation characteristics, the control limit of the cross-sectional deformation of the shield tunnel is proposed.

U231

国家自然科学基金(面上项目)(51978523)