南京地铁盾构隧道纵横断面结构安全评估研究

Structure Safety Assessment on Longitudinal and Cross Section of Shield Tunnel in Nanjing Metro

南京地铁河西地区盾构隧道长期运营后,因地下水位变化、地面超载、周边基坑土方开挖、列车振动荷载等各种外部因素,造成了隧道纵断面不均匀沉降、横断面变形、管片错台及开裂、管片间渗漏等病害,基于纵断面曲率半径、横断面收敛、防水极限及螺栓强度极限的理论推算,结合与实测数值的对比,判断隧道防水性能及结构状态,为隧道的安全运营维护提供决策依据。

The shield tunnel of Nanjing Metro in Hexi area has suffered from a series of destructions after a long-term operation. These damages include uneven settlement of the tunnel＇s longitudinal profile,cross-sectional deformation,segment displacement and cracking,leakage between the segments and so on. The consequences are related to various external factors such as changes in ground water levels,ground overload,soil excavation surrounding the substratum,and oscillation and load of trains. We can judge the tunnel water-proof properties and its structure states based on the curvature radius of longitudinal profile and the theoretical calculations of the cross-sectional convergence,water-proof limit and bolt strength. It is noted that,in the process,the measured values were compared with the calculations. This work can provide the basis for decision making with respect to the tunnel＇s operation and maintenance.