地铁和城铁引起地表振动的测试分析

通过对北京地铁二号线、十三号线沿线特定地段列车通过时引起地面振动的测试分析发现,在列车通过时引起的地表振动中高于10Hz以上的振动信号很容易被土层衰减,而在1~10Hz的振动信号难以衰减,其振动强度是无列车通过时的30~100倍。而且测试发现1~10Hz范围的振动信号在100m范围内传播几乎没有衰减。对于采用"钢弹簧浮置板道床"轨道减震装置路段,地表观测显示在1~10Hz频段上振动信号有一定减弱,但仍超出无列车通过时振动信号的10倍以上。因此,地铁低频振动引起的环境背景地面运动水平的显著提高无疑会对地铁沿线大型精密仪器设备的正常使用带来不利影响。

Testing and analysis of vibration of ground surface by metro or underground vehicles

By testing and analysis of the vibration of ground surface for some special districts of Metro line 2 and 13 in Beijing, we have found that the vibration of which the frequency is higher than 10Hz is easy to be absorbed by the soil, but the vibration of which the frequency is between 1 - 10Hz is not easy. The vibration intensity in this frequency segment is about 30 - 100 times higher than that where is no Metro or underground vehicle passed. Moreover, the vibration in the segment of 1 - 10Hz can propagate horizontally as far as 100m with almost no damping. For the district where the track is isolated with a kind of equipments, such as Steel Spring Floating slab, the vibration intensity can be decreased effectively in a certain amount. However it is still 10 times higher than that where is no Metro or underground vehicle passed. Therefore, the operating Metro or underground vehicles will induce an intensive low frequency environment vibration which is severe for the normal operation of the precise laboratory instruments nearby.