摘要
对北京地铁5号线高架桥上的运行列车引起周围地面振动的影响进行了实测,将测试得到的地面振动加速度数据在时域和频域内进行了分析。得到了以下结论:普通轨枕下的地面横向振级为58 dB-100 dB,竖向振级为55dB-91 dB;梯形轨枕下的地面横向振级为62 dB-85 dB,竖向振级为60 dB-83 dB;地面横向振动随距离的衰减规律表现为先增大后减小,最大值出现在15 m处的测点,衰减呈现出一定的波动性;竖向振动的衰减规律总的趋势是随着距离的增大而逐渐减小,但有一个明显的反弹区(本试验中为距离振源15 m左右的范围处),且振动越大反弹越明显;梯形轨枕能够对一定频率范围内的振动起到减振效果,但是对另一频率范围的振动反而起到了放大作用,其原因是由于振动频率与梯形轨枕的自振频率产生共振而引起的;高频振动的衰减速度大于低频振动的衰减速度,远振源点的振动主要是由低频的振动引起的。
Field measurements were carried out at Beijing No.5 Metro Line subjected to moving trains on viaduct to study the ground vibrations.Time-domain and frequency-domain analyses were performed to the measured ground acceleration data.It was found that the ground lateral vibration level during trains running on common tracks is 58-100dB,and the vertical vibration level is 55-91dB;however,the ground lateral vibration level during trains running on ladder tracks is 62-85dB,and the vertical vibration level is 60-83dB;the lateral vibration level grows to a peak at the distance of 15m from the vibration source,and then drops fluctuantly with increase in distance.The vertical vibration level drops with increase in distance,and there is a rebound region at the distance of 15m;the rebound value raises with increase in the vibration level;the ladder track can reduce the vibration level in a certain range of frequency,but magnify the vibration level in the another range of frequency where the vibration frequencies are close to the natural ones of the ladder track and the resonances occur;the attenuation speed of the higher frequency vibration is larger than that lower of the frequency vibration;the vibration at the position far from the vibration source is induced mainly by the lower frequency excitations.
出处
《振动与冲击》
EI
CSCD
北大核心
2011年第2期159-163,共5页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(50538010)
北京市自然科学基金资助项目(8082021)
比利时-中国政府间合作项目(BIL07/07)
关键词
高架交通
列车
环境
振动
试验
viaduct traffic
train
environment
vibration
experiment
