南京地面轨道交通运行引起的大地环境振动预测研究

城市轨道交通造成环境的振动“污染”不容忽视。通过现场测试和理论分析，得到南京地面轨道交通运行引起的大地竖向振动加速度幅值、频率随距离轨道中心线不同位置的衰减规律，即随着与轨道水平距离的增加，大地竖向振动加速度幅值总的趋势表现为逐渐减弱，但在距离轨道中心线20～30 m之间振动幅值有所反弹；振动加速度的频率集中在0～ 100 Hz，最大值出现在30～80 Hz左右，随着与轨道水平距离的增加，各频率的振动信号分量总的趋势是减弱，且频率愈高衰减愈快。基于“北京交通大学”预测公式，建立包含受振点距离、地基土性质、列车速度3个参数的南京地面轨道交通运行引起大地振动的预测模型，与实测数据相比，吻合较好。

Study of ground vibration prediction caused by Nanjing rail transit operation on ground

Environmental vibration pollution caused by city rail transit can’t be ignored. By means of in-situ test and theoretical analysis, the attenuation discipline of amplitude and frequency of ground vertical vibration acceleration with distance from track center line by Nanjing rail transit operation on ground has been obtained. With the horizontal distance between the test point and rail transit track increasing, the amplitude value of ground vertical vibration acceleration fades as a whole, but rebounds slightly at 20 to 30 m off track center line. Meanwhile the frequency of ground vertical vibration acceleration ranges from 0 to 100 Hz, and the dominant one is in the range of 30 to 80 Hz. With the distance from track center line increasing, the vibration signal component of each frequency also shows a fading tendency as a whole, and decays faster at the higher frequency. In view of Beijing Jiaotong University forecasting formula, a prediction model of ground vibration caused by Nanjing rail transit operation including the parameters of receiving point distance, the property of foundation soil and train speed has been constructed, and forecasts well compared with the actual measured data.