摘要
通过现场监测研究了高速铁路桥梁段以墩台为中心60 m范围监测点振动加速度的衰减变化及其频谱特征。各测点处列车运行荷载引起的地面竖向加速度响应以振源为中心随距离增大整体呈现衰减趋势,但在20~30 m处出现局部放大的现象,25 m处的Z振级相当于5~10 m处的振级。竖向1/3倍频程振级中桥梁墩台振源处达到了90 dB左右,随着距离的增加,高频振动呈现较快衰减,低频振动衰减缓慢、传播更远。1/3倍频程速度有效值除振源点外,其他测点能满足精密仪器对振动速度有效值12.5μm/s的限值要求,5~40 m的振动加速度有效值在各频段较为接近,50~60 m处低频段振动显著减弱。振动加速度局部放大段应重视高速列车运行对精密仪器生产厂区等的持续性影响。
The attenuation and spectrum characteristics of vibration acceleration at different monitoring points within a 60 m range centered on piers and abutments in high-speed railway bridge sections were studied through on-site monitoring.The ground vertical acceleration response caused by the train running load presented an overall attenuation trend with the distance increasing,however,there was a local amplification section at 20-30m and the Z vibration level at 25 m is equivalent to the vibration level at 5~10 m.The vertical 1/3 octave band vibration level of measuring point got to 90 dB at the vibration source of bridge pier.With the increase of distance,the high frequency vibration showed rapidly attenuation,while low frequency vibration attenuated slowly and spread further.The effective value of 1/3 octave band velocity at the vibration source could meet the precision instrument's effective value of 12.5μm/s except for the vibration source point.The effective value of vibration acceleration at 5~40 m was relatively close in each frequency band,and the low-frequency vibration at 50~60 m was significantly weakened.Attention should be paid to the sustained impact of high-speed train running on precision instrument production sites aiming at the local amplification section of vibration acceleration.
作者
张维成
ZHANG Weicheng(Environment and Navigation Engineering Design and Research Institute,China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 102600,China)
出处
《铁路节能环保与安全卫生》
2024年第1期14-18,60,共6页
Railway Energy Saving & Environmental Protection & Occupational Safety and Health
基金
中铁第五勘察设计院集团有限公司科研计划课题(T5Y2019-B07)。
关键词
高速铁路
振动加速度
频谱特征
环境振动
High-speed railway
Vibration acceleration
Spectrum characteristic
Environmental vibration
