基于多自由度耦合变形的盾构隧道纵向接头地震力学行为与抗震技术

The construction of shield tunnels, which have great significance for the economy and society, has been in the period of high-speed development in China. Therefore the safety of these projects is crucial. In fact, China is located in the area between Pacific earthquake belt and Eurasia earthquake belt where the earthquakes happen frequently. This situation motivates us to focus more on the safety of shield tunnel under seismic condition. According to the shield tunnel’s characteristic of combined structure with smaller longitudinal stiffness and easier deformation plus the rarity of relevant researches, this study investigates the seismic behavior and aseismic technology for longitudinal joints of shield tunnel based on multi-freedom coupled deformation, expecting to reveal its mechanical behavior and damage mechanism under strong earthquakes. In addition, the nonlinear relations between the stiffness of longitudinal joints and the inner force of structure is determined to build a more reasonable longitudinal dynamic analysis model for shield tunnels, which can display the multi-freedom coupled deformation of longitudinal joints and the interaction between tunnel and soil layers. Thereby, the effect caused by longitudinal joints with coupled deformation on force and deformation of tunnel are discovered. And aseismic measures about shield tunnel and key designing parameters are put on. The researches above contribute to reduce the damage of tunnels caused by earthquake, ensure their regular performance and enhance the safety as well as stability of the shield tunnel under seismic condition.

我国盾构隧道建设已步入高速发展时期，盾构隧道工程对全国或区域性国民经济和社会发展作用巨大，其安全性至关重要。而我国位于太平洋地震带和欧亚地震带之间，且这些区域近期地震活动频繁，这促使我们更加关注盾构隧道工程的地震安全性。本项研究依据盾构隧道装配式结构且纵向刚度更小、更容易发生变形以及相关研究比较薄弱的特点，着重研究基于多自由度耦合变形的盾构隧道纵向接头地震力学行为与抗震技术，以期揭示强震作用下盾构隧道纵向接头多自由度耦合变形的力学特征与损伤机理，探明纵向接头刚度与盾构隧道纵向内力之间的非线性关系，构建更加合理的反映纵向接头多自由度耦合变形以及隧道与地层相互作用的盾构隧道纵向动力分析模型，从而明确耦合变形的纵向接头对盾构隧道地震响应的影响，提出盾构隧道纵向接头抗震措施与关键设计参数，以降低隧道震害，保证其正常使用，提高盾构隧道在地震中的安全与稳定性。

随着我国交通强国战略的实施，越来越多的越江跨海隧道正在规划或建设实施中。盾构法隧道是水下交通隧道的常用的工法之一。由于我国地处太平洋地震带和欧亚地震带之间，强烈的地震活动会导致盾构隧道产生较为严重的震害，尤其是纵向接头部位。因此，本课题采用资料调研、理论分析、数值模拟和室内足尺实验等多种手段着重研究了基于多自由度耦合变形的盾构隧道纵向接头地震力学行为与抗震技术，揭示了强震作用下盾构隧道纵向接头多自由度耦合变形的力学特征与损伤机理，探明了纵向接头刚度与盾构隧道纵向内力之间的非线性关系，构建了反映纵向接头多自由度耦合变形的盾构隧道纵向动力分析模型，明确了耦合变形的纵向接头对盾构隧道地震响应的影响，提出了盾构隧道纵向接头抗震措施与关键设计参数。课题研究成果对降低盾构隧道震害，保证其正常使用，提高盾构隧道在地震中的安全性及稳定性，具有重要意义，亦有较好的学术价值、应用价值和社会价值。