缓和曲线段地铁运行引起地表振动的实测结果及其传播规律分析

对上海轨道交通9号线某区间缓和曲线段地铁运行引起的地表振动进行了现场测试,并对实测的地表振动加速度进行了时域、频域及1/3倍频程分析。结果表明:在缓和曲线段,地铁列车行驶引起的地表横向加速度有效值是竖向加速度有效值的0.9~3.1倍;地表加速度频率分布在30~120 Hz,其中最显著的频率为30~50 Hz;加速度振级随着与隧道中心线水平距离的增加呈减小趋势,且在距离隧道中心线5 m、30 m时出现放大区;地表土体振动加速度幅值、频谱峰值随着地铁列车速度增大基本呈增大趋势。

In-situ Measurement of Ground Vibration Caused by Metro Operation on Transition Curve Section and Analysis of the Propagation Law

The ground vibration caused by metro operation on a transition curve section of Shanghai Line 9 is tested,the acceleration data of ground vibration are analyzed in time domain,frequency domain and 1/3-octave method.The results show that the effective value of horizontal ground vibration acceleration caused by train is 0.9-3.1 times of vertical acceleration in transition curve section;the frequency of ground acceleration distribute is in a range of 30-120 Hz,in which the most significant frequency is 30-50 Hz;the acceleration vibration level decreases with the increase of horizontal distance from the tunnel center line,the acceleration enlarged areas will appear at a horizontal distance of 5-30 m from the tunnel center line;with the increase of train speed,both the vibration acceleration amplitude and frequency spectrum amplitude are basically in a trend of increase.