高速铁路隧道洞口微气压波计算模型的修正

Revision of Calculation Model for Micro⁃pressure Wave atTunnel Portal of High Speed Railway

隧道洞口微气压波随列车运行速度提高显著提升,可能影响周围建筑及居民。隧道洞口微气压波与隧道内压力波首波压力梯度密切相关。根据实车测试数据,分析隧道内不同位置压力梯度,修正了辐射立体角模型(Radiation Solid Angle Model,RSA),给出模型关键参数空间立体角的取值方法。结果表明:列车以350 km/h通过无砟轨道隧道时,从隧道入口至隧道中心附近压力波首波压力梯度逐渐提高;采用随机森林方法分析RSA模型参数特征权重并修正模型,修正后的RSA模型相对原模型对隧道洞口微气压波压力峰值的计算精度更高。提出了采用无人机或测距仪等设备测量计算隧道洞口空间立体角的三种方法。

The micro-pressure wave significantly increases with the increase of train speed,which may affect the surrounding buildings and residents.The micro pressure wave at the tunnel portal is closely related to the pressure gradient of the first wave of the pressure wave inside the tunnel.Based on the actual vehicle test data,the pressure gradient at different positions inside the tunnel was analyzed,and the radiation solid angle(RSA)model was modified.The method for determining the spatial solid angle,a key parameter of the model,was provided.The results indicate that when the train passes through a ballastless track tunnel at a speed of 350 km/h,the pressure gradient of the first wave of the pressure wave gradually increases from the tunnel entrance to the tunnel center.The random forest method was used to analyze the parameter feature weights of the RSA model.The modified RSA model has a higher calculation accuracy for the peak micro pressure wave at the tunnel portal compared to the original RSA model.Three methods for measuring and calculating the spatial solid angle of tunnel openings by equipments such as drones or rangefinders have been proposed.