某高速铁路高架线路直线与曲线段环境振动实测对比分析

摘要

For the purpose of studying environmental vibration attenuation rules and spectrum characteristics of elevated straight line and curved line of high-speed railway,this paper takes a elevated section of a domestic high-speed railway line as the research object and the vibration responses of the straight line and the curved line are tested at the speed of 300 km/h,then the vertical Z-vibration level is introduced to conduct comprehensive assessment on these two forms of lines.The vibration characteristics and attenuation rules of the pier and middle span cross section of the straight and curved sections are compared and analyzed respectively.The results show:(1) the environmental vibration of the curve section is larger than that of the straight line section,where the pier is big 6dB,and the middle span is big 3 dB;(2) the closer the distance from the center,the greater the impact on the environmental vibration of the dominant frequency in the range of 25 ～ 80 Hz,when the distance is farther,the dominant frequency is about 10 Hz;(3)compared to Z-vibration level at 30 meters,the main frequencies of the cross section of the pier on the straight line,of the middle span and the piers on the curve line tend to increase at 45 m,and the main frequencies are all low frequencies.%为了研究高速铁路高架桥线路直线和曲线段的环境振动衰减规律及其频谱特性,以广深港高铁某高架区段为研究对象,测试300 km/h速度下直线段和曲线段的振动响应,通过引入铅锤向Z振级进行综合评价,分别对直线和曲线段的桥墩和桥梁跨中断面的振动特性及衰减规律进行对比分析,结果表明:(1)曲线段的振动源强大于直线段的振动源强,桥墩处大6 dB,跨中处大3 dB;(2)当距中心距离较近时,对环境振动影响较大的主要频率为25～80 Hz的高频部分,当距离较远时,环境振动的优势频率在10 Hz左右;(3)在45m处,直线桥墩断面、曲线跨中和桥墩断面的主频振级相比30 m处都有所增大,且主频都为低频.