部分软土地区盾构隧道结构出现过大变形与严重病害，这些带病服役盾构隧道结构仍将长时间服役，且其后续服役期内仍将面临各类等不利服役环境。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。本文以南京某三个地铁区间为背景，分别以实测数据分析、三维精细化有限元模拟为手段探究了错缝拼装盾构隧道结构横断面收敛变形与各类病害之间的相关关系，两种手段相互验证与补足发现：收敛变形小于30 mm时，隧道结构服役性能良好；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，安全性收到极大威胁；大于100 m，整环结构濒临屈服。据此结构性能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 diseases have occurred on some shield tunnel structures in soft soil area. These shield tunnel structures in service with defects will still be in service for a long time, and they will still face various adverse service environments in the subsequent service period. Therefore, it is necessary to put forward the control limit of shield tunnel structure deformation, which can provide judgment and decision-making basis for the maintenance and operation of the structure in time when the structural deformation of the tunnel develops further. Based on the background of three subway sections in Nanjing, this paper explores the correlation between cross-sectional convergence deformation and various diseases of staggered seam assembled shield tunnel by means of 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 tunnel structure is good when the convergence deformation is less than 30 mm. The water leakage and cracks appear and the bolts begin to yield when the convergence deformation is 30-60 mm. The disease intensifies and the segment is damaged when reaches 60-80 mm., The first bolt reaches the tensile limit state and the safety is greatly threatened when reaches 80-100 mm. The whole ring structure is on the verge of yield when more than 100 m. On the basis of structural performance degradation characteristics the control limit of cross section deformation of shield tunnel is proposed.