基于脉冲激励的地铁运营引起邻近建筑物内振动预测方法

根据振动系统传递特性,提出一种新的环境振动预测方法——实测脉冲传递函数预测方法。通过脉冲试验测得振源与邻近建筑物内测点的振动加速度,计算得到振动系统的振动响应传递函数;将实测的地铁运营振源的振动加速度代入传递函数公式,实现对建筑物内测点的振动加速度时程、频谱、1/3倍频程和z振级的预测。应用该方法预测隧道中心楼内测点振动加速度结果表明:隧道结构与隧道中心楼内测点振动加速度传递函数峰值频段为30～50Hz,隧道中心楼内振动加速度峰值频段为40～60Hz;土层和隧道中心楼基础结构对60Hz以上频段的振动具有很强的衰减作用,楼房基础结构有效地隔断了70Hz以上的高频振动。该方法可用于预测地铁运营引起的建筑物内振动。

The Prediction Method of Metro Trains Induced Vibration inside Adjacent Buildings Based on Pulse Excitation

Based on the transfer characteristics of vibration system,the paper presents a new environmental vibration prediction method: the measured pulse transfer function prediction method.The vibration accelerations of vibration source and the measured points inside adjacent buildings were obtained via pulse excitation.The vibration response transfer function of the vibration system was calculated.The measured vibration acceleration of the vibration source induced by metro operation was substituted into the transfer function formula to predict the vibration acceleration time history,frequency spectrum,1/3 octave and z vibration level of the measured points inside buildings.This method was used to predict the vibration acceleration of the measured points inside the tunnel center building.The results indicate that the frequency range of the vibration acceleration transfer function at the measured points of tunnel structure and inside tunnel center building is 30～50 Hz,and the frequency range of the vibration acceleration inside tunnel center building is 40～60 Hz.The soil layer and the infrastructure of tunnel center building have strong attenuation effect on the vibration above 60 Hz.The building infrastructure effectively cuts off high-frequency vibration above 70 Hz.This method can be used for vibration prediction inside buildings induced by metro trains operation.