地铁车辆段上盖建筑振动传播规律及预测方法研究

The train induced vibrations in the metro depot and over-track buildings has an impact on human's daily life and physical and mental health, which is the key obstacle to the construction and promotion of over-track building complex. To reveal the coupling mechanism between the soil layer and the building foundation, and break through the vibration prediction accuracy of over-track buildings in the frequency domain is an important prerequisite and necessary basis for studying of the vibration transmission and prediction of metro depot and over-track buildings. This project aims to study the vibration transmission and prediction in the metro depot and over-track buildings through a three-step research: 1) establish vibration transfer function; 2) derive impedance function; 3) propose prediction method. The train induced vertical vibration transmission in the test line region and throat area is studied systematically by field measurement, and the transfer functions of vibration source, transmission path and over-track buildings are built. On this basis, the dynamic impedance model of "soil layer-building foundation-over-track platform-over-track building" is constructed based on the impedance function. By combining with measured transfer function of the rail system and soil layer, a new hybrid vibration prediction method of the metro depot and over-track buildings is proposed, which breaks through the limitations of the existing traditional vibration prediction model, such as the large calculation and the inaccuracy of frequency domain response prediction. The study will provide a highly efficient and accurate as well as convenient vibration prediction method in the frequency domain for the early planning and design stage of the development of metro depot and over-track building complex, and provide reliable theoretical guidance and technical support for the practical engineering application.

地铁车辆段上盖建筑环境振动影响人们正常生活与身心健康，是制约地铁车辆段上盖综合体建设与推广的关键障碍。如何揭示土层与建筑基础耦合作用机理，并突破上盖建筑振动在频域内的预测精度，是研究地铁车辆段上盖建筑振动传播规律与预测方法的重要前提与必要基础。本项目基于“传播规律分析-阻抗模型构建-预测方法研究”的研究主线，通过现场试验研究地铁车辆段试车线、咽喉区列车运行引起竖向振动在上盖建筑中的传播规律，构建振源、传播途径、上盖建筑间振动传递函数；在此基础上，基于阻抗函数构建“土层-建筑基础-上盖平台-上盖建筑”动力阻抗模型，结合现场实测车轨系统-土层耦合振动传递函数，提出一种新的地铁车辆段上盖建筑振动“三阶段”混合预测方法，突破现有振动预测模型计算工作量大和对频域响应预测不够精确的局限，为地铁车辆段上盖建筑在前期规划和设计阶段提供一种高效、精确、便捷的预测方法，为该类工程设计提供理论依据和技术支撑。

公共交通的迅猛发展为人们的日常出行提供了极大的便利。然而，地铁列车运行引起的振动经由周围土层最终传播至建筑物内部，引起结构振动及二次噪声，严重影响着人们工作与生活。因此，在地铁车辆段的设计阶段，需对建筑振动响应精确合理地预测，从而支撑经济适用的减振降噪设计。列车引起的建筑振动响应预测追求高效率和高精度。然而在实际工程中，高效和高精度的预测往往难以同时实现，需要在效率和精度之间寻求平衡。基于此，本项目在多个地铁车辆段出入段线、咽喉区、试车线等区域选择临近轨道的自由场地、1层建筑、4层建筑、14层建筑的地面、基础、转换层、上盖建筑物内开展现场振动测试，阐明了振动在振源、传播途径、建筑物内的传播规律，一定程度上获得了建筑物建造前后的振动变化规律。在此基础上，为了快速得到列车荷载下上盖建筑的振动响应，结合现场实测，基于阻抗函数构建了“场地土—建筑基础—转换层—上盖建筑”动力阻抗模型，该模型以修正后的自由场振动作为输入，从而计算建筑结构的振动响应。通过结合现场实测数据进行验证，该模型能快速、准确地计算列车荷载下上盖建筑的振动响应，为地铁车辆段上盖建筑开发在前期规划和初步设计阶段提供了一种频域内高效、精确、便捷的振动预测方法。此外，该方法也可用于地铁车站、隧道临近建筑振动响应预测，为环境振动控制措施优化设计提供科学依据。