地铁盾构隧道结构的纵向裂缝扩展规律及其失效机理研究

It is abundantly recorded that the cracking and damage of segmented lining has become one of the most common diseases of metro shield tunnels, and the longitudinal crack has the greatest impact on the performance of shield tunnel segmented lining. A lot of research has been done on the repair and strengthening of largely deformed and damaged segmented lining. In this project, aim to realize the safety assessment of shield tunnel segmented lining with existing longitudinal cracks, 1g model tests and multi-scale expanded finite element methods will be conducted to capture the propagation law of longitudinal cracks, and investigate its relationship with the final structural failure mode, to finally reveal the inherent failure mechanism of shield tunnel structure with existing longitudinal cracks. This project will establish a theoretical calculation model of shield tunnel segmented lining with existing longitudinal cracks, and put forward a measurable early-warning indicator of structural failure and evaluation parameters of structural safety. The outcome of this project will provide theoretical fundamentals and technical supports for the damage perception, evaluation, maintenance and repair of shield tunnels. Therefore, this project will have significant impact on both theoretical development and practical engineering.

据统计，管片结构裂损已成为地铁盾构隧道的常见病害之一，其中纵向裂缝对隧道结构整体性能影响最大。目前，相关研究主要集中在对大变形和裂损管片结构的修复和加固方面。本项目以实现对含纵向裂缝盾构隧道结构的安全性评估为目标，拟通过室内相似模型试验和多尺度扩展有限元数值模拟方法，对盾构隧道的纵向裂缝扩展规律及其与结构整体失稳破坏模式的联系进行研究，揭示含纵向裂缝盾构隧道结构的内在失效机理；通过建立理论计算模型，研究含纵向裂缝结构与完整结构在安全性控制因素方面的根本性差别，提出易于量测的结构整体失稳预警指标和安全性评价参数。研究成果将为盾构隧道的损伤感知、评估、维护、修复和加固提供理论基础与技术支撑，具有重要的理论和实际应用价值。