高速列车引起半刚性节点装配式混凝土框架结构振动研究

With the development of fabricated building in our country, research on the vibration of precast concrete frame structures induced by high-speed train will be an important direction of railway environmental vibration research. The flexible connection of precast concrete frame structures is semi-rigid connection, and the dynamic characteristics of the structure are significantly changed by semi-rigid connections, then the vibration response of the structure induced by high-speed train is obviously different. Focusing on the vibration response of precast concrete frame structures with semi-rigid connections, a precast concrete frame structure with semi-rigid connections will be designed and manufactured nearby the high-speed railway in the Rail Transit Experiment Center, the behavior of semi-rigid connections and the vibration response rules of the structure will be studied in tests. Based on the comprehensive analysis of the mechanical properties of semi-rigid connections, a calculation model of connections for railway environmental vibration will be presented, and a three-dimension theoretical calculation model of soil-foundation-precast concrete frame structures with semi-rigid connections will be established using finite element method and continuum wave theory. On the basis of experiment results and theoretical analysis, the interaction mechanism of soil-foundation-precast concrete frame structures with semi-rigid connections will be explored under the vibration of high-speed train, and the vibration response rules of the structure will be achieved. The work will lay a theoretical foundation for predicting and evaluating the vibration of precast concrete frame structures with semi-rigid connections induced by high-speed train.

随着我国装配式建筑的大力发展，高速列车引起装配式混凝土框架结构的振动问题将成为铁路环境振动研究的重要方向。柔性连接的装配式混凝土框架结构的节点具有半刚性，这种节点半刚性会显著改变结构的动力特性，进而会导致高速列车振动作用下的结构振动响应明显不同。本课题针对这一问题，通过在我校轨道交通实验中心的高铁线路旁设计制作半刚性节点装配式混凝土框架结构，试验研究节点半刚性特征和结构的振动响应规律；利用有限元和连续介质波动理论，在综合分析半刚性节点力学特征的基础上，提出适于铁路环境振动的节点计算模型，建立地基-基础-半刚性节点装配式混凝土框架结构振动响应的三维理论分析模型；结合试验成果和理论分析，研究高速列车振动作用下地基-基础-半刚性节点装配式混凝土框架结构相互作用机理，探索半刚性节点装配式混凝土框架结构的振动响应规律，为准确预测、评价高速列车引起半刚性节点装配式混凝土框架结构的振动奠定理论基础。

随着我国装配式建筑和铁路事业的大力发展，运行列车对邻近装配式框架结构正常使用及结构内人体健康、精密仪器和设备正常使用的影响日益突出和严重。相较于现浇结构，装配式框架结构由于诸多构造的不同，会改变结构的动力特性，从而导致结构的振动响应不同，开展本项目的研究对于准确预测这一铁路环境振动具有重要意义。本项目围绕运行列车引起装配式结构的环境振动问题，开展了钢筋桁架混凝土楼板、压型钢板-混凝土组合楼板两种装配式楼板的振动试验研究，并基于小挠度弯曲薄板理论，提出了装配式楼板的简化等效计算模型，显著提高了计算效率，研究了装配式楼板的铁路环境振动特性，发现钢筋桁架混凝土楼板的振动响应较小；然后利用有限元和连续介质波动理论，引入节点平动刚度系数与转动刚度系数模拟节点半刚性，建立了列车振动作用下地基-基础-半刚性节点装配式框架结构相互作用体系的三维理论分析模型，探索了列车振动作用下地基-基础-半刚性节点装配式框架结构相互作用机理，研究了半刚性节点装配式框架结构的振动响应规律，发现半刚性节点装配式框架结构的振动响应受节点转动刚度影响为主，总体上水平方向振动响应随着节点转动刚度的增大而增大，而竖向振动响应随节点转动刚度改变而变化较小，当节点转动刚度达到刚接80%时，可近似看成刚接；同时研究了复杂地形条件对铁路环境振动的影响规律，发现起伏地形的存在降低了铁路环境振动，振动频率也发生了明显衰减，基于这一效应提出了针对铁路环境振动的隔振堤。本项目成果不仅发展了铁路环境振动的相关基础理论,而且为准确预测、评价以及控制列车对装配式框架结构的振动影响、评价装配式框架结构的适用性提供了理论支持，具有重要的理论意义和实用价值。