摘要
列车高速通过桥上全封闭声屏障时会产生压力波,作用于全封闭声屏障引起全封闭声屏障的振动。为了探究作用于全封闭声屏障上的压力荷载的特点,以某全封闭声屏障使用线路为研究背景,通过CFD数值模拟对列车通过全封闭声屏障过程中形成压力波的特性进行了研究。在验证数值模型的基础上,考查了压力波在横向、纵向分布的特点及衰减特性,分析了最不利压力荷载出现的时刻以及位置,对比分析了车速、全封闭声屏障断面形状及双车交会的影响。结果表明,全封闭声屏障内同一断面压力荷载基本相同,压力波沿列车运行方向存在最不利的压力,单车以200 km/h行驶时,全封闭声屏障表面最大正压为758.54 Pa,最大负压为-959.56 Pa。列车驶出后,全封闭声屏障内仍有一定的压力波,其衰减周期为压力波在全封闭声屏障内传播一个循环的时间。阻塞比保持不变时,全封闭声屏障断面形状对于压力波的影响较小,双车对开时全封闭声屏障压力荷载显著增大,正压最大值为1462.72 Pa,负压最大值为-1613.08 Pa。
A closed noise barrier on a bridge would vibrate due to the pressure wave caused by high speed trains.To investigate the characteristics of the pressure load which acts on the closed noise barrier,taking one typical section of some railway of which the closed noise barrier is used as research background,the CFD simulation was utilized to explore the characteristics of pressure waves while the trains passing through the closed noise barrier.On the basis of the verification of numerical model,the transverse and longitudinal distributions as well as the free attenuation of the pressure wave were studied.The location and time of the most unfavorable pressure load were confirmed.The influence factors,such as vehicle speed,cross-section shape of closed noise barrier and two trains passing by each other,was discussed.The results indicate that the pressure waves were uniform in one cross section,and there were unfavorable positive and negative pressures along the closed noise barrier.Meanwhile,the most positive and negative pressures on the surface of closed noise barrier were 759.54 Pa and-959.56 Pa when one train has a speed of 200 km/h,respectively.The pressure wave was still existed when the train passed the closed noise barrier,and the frequency of pressure wave is the round-trip time that the pressure wave propagated in the closed noise barriers.As the blockage ration stays constant,the shape of the cross section of the closed noise barrier has little effect on the pressure wave.The pressure load of closed noise barrier would be increased obviously in the process of two trains passing by each other,and the most positive and negative pressures were 1462.72 Pa and-1613.08 Pa,respectively.
作者
何佳骏
向活跃
曾敏
李永乐
彭栋
HE Jiajun;XIANG Huoyue;ZENG Min;LI Yongle;PENG Dong(Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway SIYUAN survey and design group Co.,Ltd,Wuhan 430063,China;China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430056,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第20期175-182,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(51778544
51525804)。
关键词
高速铁路
全封闭声屏障
压力波
数值模拟
动网格
high speed railway
closed noise barrier
pressure wave
numerical simulation
dynamic mesh
