对高架轨道交通系统引起的环境振动影响进行理论分析和数值计算,建立了车一桥和墩一土两个子系统模型,通过车.桥子系统模型得到作用在墩.土子系统上的动荷载,然后利用墩.土子系统模型计算出在该荷载作用下周围环境的动力响应;进一步通过参数分析研究了各种因素对环境振动的影响规律。结果表明:高架轨道交通引起的环境振动随振源距离的增大而逐渐减小,并且受到桥梁跨度、桥梁质量、桥墩基础埋深、车辆轴重、列车速度、土的性质及支座刚度的影响。根据计算结果运用回归的方法提出了高架轨道交通引起环境振动的预测公式,并通过与北京地铁5号线的实测结果和其他预测公式的比较进行了验证,表明所提出的预测公式具有较高的准确度和适应性。
The environmental vibration induced by trains on elevated bridges is studied through theoretical analysis and numerical calculation. Two subsystem models, the vehicle-bridge model and the pier-soil model, are established. The dynamic responses of the environment are calculated using the pier-soil model, with the dynamic load obtained from the vehicle-bridge model. The influences of different parameters upon the environmental vibration are analyzed via parameter analysis. The results show that the environmental vibration induced by nmning trains on an elevated bridge attenuates with the distance to the bridge, and is influenced by the mass and span of the bridge, the buried depth of pier, the axis load of vehicle, the running speed of train, the properties of soil and the stiffness of bearings. The prediction formula for environmental vibration induced by urban rail transit is established based on the results of regression analysis, and is then validated through a comparison with the data measured on Beijing Metro Line 5 and other prediction formulas, where the proposed formulas show more accuracy and suitability.