摘要
列车风作用下的风荷载是影响全封闭声屏障结构安全的主要荷载之一。由于列车风为较复杂的三维非定常绕流,为了探究列车风作用下声屏障风压荷载问题,以某高铁线路矩形截面全封闭声屏障为研究背景,采用动模型试验方法,研究声屏障在高速列车以3种不同时速通过时的风压荷载分布。研究结果表明:高速列车通过声屏障时,压缩波传播到测点导致压力上升,膨胀波传播到测点导致压力下降,风压变化趋势与气压波传播规律相吻合;风压分布沿声屏障展向(长度方向)呈先增大后减小的趋势,建议取中间截面压力值为设计的参考压力;沿声屏障环向,跨中截面各测点压力峰值差异较小,压力变化幅值最大差异量为1.8%,风压荷载分布较均匀;出入口截面环向各测点的压力峰值差异较大,压力变化幅值最大差异量为40.8%,在声屏障进行结构设计时需要考虑出入口截面风压荷载沿环向不均匀分布的情况;沿声屏障高度方向,模型列车通过声屏障时在出入口截面引起的风压荷载不是呈线性变化,高度越高的测点压力衰减的越快;在跨中截面,高度变化对测点所受压力影响不大。
Wind load under train induced wind is one of the main loads affecting the safety of fully-enclosed sound barrier structure.Owing to the train induced wind is a complex three-dimensional unsteady flow,in order to investigate the wind pressure load of sound barrier under the train induced wind,taking a rectangular fullyenclosed sound barrier of a high-speed railway line as the research background,the moving model experiments were adopted to study the wind pressure load distribution of the sound barrier when a high-speed train passing through at three speeds.Conclusions are drawn as follows.As a train passes through the sound barrier,the pressure increases when the compression wave propagates to the measuring point,and decreases when the expansion wave propagates to the measuring point.The variation trend of wind pressure is consistent with the propagation law of pressure wave.The wind pressure distribution along the extension direction of the closed sound barrier increases first and then decreases,so it is suggested that the pressure value of the middle section should be taken as the design reference pressure.Along the circumferential direction of the sound barrier,the difference of peak pressure value at each measuring point in the mid-span section is small,and the maximum difference of pressure variation amplitude is 1.8%,so the wind pressure load distribution is relatively uniform.The peak pressure value at each measuring point along the circumferential direction of the entrance and exit section is quite different,the maximum difference of pressure variation amplitude at each measurement point is 40.8%,the uneven distribution of wind pressure load along the circumferential direction of the entrance and exit section should be taken into consideration in the structural design of the closed sound barrier.Along the height direction of the sound barrier,when the model train passes through the sound barrier,the wind pressure load caused by train induced wind on the entrance and exit section show nonlinear variation,and the higher the height of the measuring point,the faster the pressure decays;in the mid-span section,the height change has little effect on the pressure of measuring points.
作者
欧双美
邹云峰
黄永明
何旭辉
OU Shuangmei;ZOU Yunfeng;HUANG Yongming;HE Xuhui(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Laboratory for High-speed Railway Construction,Central South University,Changsha 410075,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第3期781-789,共9页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(52078504,51925808,U1934209)
湖南省科技创新计划资助项目(2021RC3016)
湖南省自然科学基金资助项目(2022JJ10082)。
关键词
全封闭声屏障
动模型试验
高速列车
列车风
风压荷载
fully-enclosed sound barrier
moving model experiment
high speed train
train induced wind
wind pressure load
