铁路桥梁段环境振动分频段预测方法  

Forecasting method for the dividing frequency bands as to the environmental vibrations in the railway bridge section

作　　者：张光明[1] 贺玉龙[1] 梅昌艮[1] 杨立中[1] 

机构地区：[1]西南交通大学地球科学与环境工程学院,成都610031

出　　处：《安全与环境学报》2015年第1期285-288,共4页Journal of Safety and Environment

基　　金：国家自然科学基金项目(41272322);教育部新世纪优秀人才支持计划项目(NCET-11-0710);中央高校基本科研业务费专项(SWJTU12CX003)

摘　　要：针对铁路环境振动,在考虑振动频率对振动传播衰减的影响下,将桥梁荷载视为点列式荷载,提出适合桥梁段环境振动的分频段预测方法。为考察该方法在铁路桥梁段环境振动预测中的适用性,分别采用该方法和现行的铁路环境振动常用预测方法对成灌快速铁路某桥梁段10-40 m范围内的地面环境振动进行预测,并将两种方法的预测结果与实测结果进行对比。结果表明,铁路桥梁段环境振动分频段预测方法在实际桥梁段环境振动预测中能够取得很好的预测效果,且相对于现行铁路环境振动的常用预测方法,其预测精度更高。In this paper,we have presented the dividing frequency bands by using the forecasting method,which is suitable for the environmental vibration forecast particularly for the railway bridge section. In addition,we would like to introduce a frequency-dividing bands forecast method applicable for dividing the ground vibration into many small frequency bands according to the one-third-octave. To be accurate,the method can be used to forecast the vibration accelerating rate of each frequency band based on the Bornitz model. In addition,we have also calculated the Zvibration level VLZvalue of the environmental vibration by using the frequency weighing factors and the forecast value of the vibration-accelerated levels in each frequency band. Therefore,the source loads of vibration can be regarded as the point range load.In hoping to analyze and define the applicability of this forecast method,it is necessary to induce the idea of the train moving manners on the railway bridge surface so as to forecast and measure the environmental vibration via the ground vibration. It is just for this purpose that we have attempted to take Chengdu-Dujiangyan fast railway bridge section as the case study sample,in which the measuring range has been taken as 10-40 m from the railway bridge central part. At the same time,we have proposed the ground vibration forecasting method accordingly. Comparing the forecasting results of Z-vibration level VLZweighed by Wk weighting factor with the value measured,we have found that the value of VLZforecasted with the dividing frequency bands forecast method turns to be lower than that has been forecasted via the currently popular-adopted forecast methods. What is more,the forecast accuracy gained from the method we have developed proves better than those gained by using other popularly used methods. In addition,we have found that in the range of 10-40 m away from bridge pier center,the value of VLZforecast by using our method is-0. 24-1. 80 d B,which is greater than the value gained on the spot measure

关 键 词：环境工程学 铁路 桥梁 环境振动 预测方法 频率段 

分 类 号：X593[环境科学与工程—环境工程]