考虑衬砌劣化的软土盾构隧道结构地震易损性分析研究

我国是世界地震灾害最严重的国家之一，软土地区盾构隧道结构赋存环境极其复杂，不可避免地面临强震与衬砌劣化等不利因素的严峻威胁，引起了各界对隧道结构运营安全问题的高度关注。但是，目前考虑衬砌劣化的软土盾构隧道结构地震易损性演化规律尚不明确，缺乏合理的可恢复性控制方法，衬砌劣化条件下盾构隧道结构抗震安全问题已成为影响城市韧性的重大隐患。本项目采用室内试验、数值模拟和理论分析等综合方法，构建劣化盾构隧道结构精细化非线性动力分析模型，探明考虑衬砌劣化的盾构隧道结构地震响应规律，提出基于时变特征的隧道结构易损性指标量化方法，建立基于机理驱动和数据驱动的盾构隧道时变抗震能力与需求预测模型，利用概率密度演化理论揭示劣化盾构隧道时变地震易损性演化规律，提出基于结构易损性的盾构隧道地震可恢复性控制方法。研究成果将为我国长期运营盾构隧道结构抗震防灾工作提供科学依据和技术支撑，具有重要的理论意义和工程应用价值。

China is one of the most seismically active countries in the world. Shield tunnels in soft soils are often exposed to complex surrounding environment and are inevitably threated by adverse factors such as strong earthquakes and lining deterioration. Therefore, an intense focus has been placed on the safe operation of shield tunnels under both the earthquake and the lining deterioration threats. However, to date, the evolution of seismic vulnerability of degraded shield tunnels considering the effects of lining deterioration in soft soils is still unclear. Moreover, there is also a lack of scientific and appropriate methods to control the seismic resilience of shield tunnels. As a result, the seismic safety of degraded shield tunnels is of primary interest for any city concerning resilience. This research comprehensively adopts indoor testing, numerical simulation, and theoretical analysis to investigate the time-dependent seismic vulnerability of degraded shield tunnels in soft soils. Firstly, the dynamic response characteristics of shield tunnels subjected to earthquakes and lining deterioration are revealed by performing a series of detailed nonlinear dynamic analyses of degraded shield tunnels. Then, the structural vulnerability indices considering the time-dependent characteristics are quantitatively proposed, which are used to construct the mechanism- and data-driven models to further predict the seismic capacity and demand of shield tunnels. Finally, probability density evolution theory is applied to investigate the time-dependent seismic vulnerability of shield tunnels in soft soils, which is further applied to propose the seismic resilience control methods of shield tunnels. The research outcome shall provide both theoretical and technological support for the seismic analysis and disaster control of shield tunnels in soft soil during the long-term operation period, which is of great theoretical importance and practical significance.