高速铁路隧道壁面气动压力实车试验分析

Analysis on aerodynamic pressure of tunnel wall of high-speed railways by full-scale train test

采用实车试验方法对高速动车组穿越双线隧道引发的隧道壁面气动压力进行测试,分析不同位置测点在列车通过阶段和列车驶出阶段的压力峰值.研究结果表明:不同测点压力最大峰峰值(正峰值-负峰值)可能发生在列车通过阶段,也可能发生在列车驶出隧道后的压力衰减阶段;压力峰峰值在洞口附近较小,在隧道中部较大.在列车通过隧道阶段,壁面测点压力峰峰值随着车速的增加而迅速增大.列车驶出隧道后,压力峰峰值开始周期性衰减,衰减周期为2倍的声速在隧道内传播时间;在同一周期内,隧道入口处测点压力衰减率较大,出口次之,隧道中部最小;斜切洞门缓冲结构顶部开口对降低第一个周期压力峰峰值的效果不明显,但可以明显降低多个周期后的压力峰峰值.

The transient aerodynamic pressure was measured when a high-speed train passed a double track tunnel based on full-scale train test.The peak values of pressure at different measuring points were analyzed during the periods of passing through the tunnel and running out of the tunnel.Results showed that there appeared the maximum peak to peak(positive peak-negative peak)values of pressure at the measuring points when the train was passing through the tunnel or at the stage of pressure decayed when the train was running out of the tunnel.The peak to peak values were smaller at the measuring point near the tunnel entrance,but were larger at the measuring point in the middle of tunnel.When the train passed through the tunnel,the peak to peak values increased with the increase of the speed of the train.After the train ran out of the tunnel,the peak to peak values presented a periodic attenuation with double time of travelling in the tunnel with sound speed.During the same cycle,the pressure decay rate decreased in order of the entrance,the exit and the middle.The hole of the Bamboo-truncating portal hood can not reduce the peak to peak values of the pressure in the first cycle,but can obviously reduce the peak to peak values after several cycles.