隧道内货车篷布绳索拉力实车测试与分析

Tensile force test and analysis of freight tarpaulin cord in tunnels

针对D型与X型篷布的有绳网和无绳网4种不同装载与加固方案,在不同时速下进行货车过隧道时篷布绳索拉力测试和全程跟踪监控摄像的实车试验。研究结果表明:篷布迎风面端部两侧晃动较大,背风面兜风严重;有网篷布顶部在隧道内起伏较小,无网篷布顶部起伏较大,速度较高时起伏明显加大;列车进隧道时篷布绳索受力突然增大,在隧道中逐渐减小,在隧道出口恢复明线水平;随着列车速度的提高,绳索受力逐渐增大;当列车速度为120km/h时,D型篷布绳索最大拉力为609N,X型篷布最大拉力为722N;在相同工况下,D型篷布使用性能优于X型篷布的使用性能;篷布绳网在降低篷布绳索拉力中发挥了重要作用,有绳网篷布绳索受到的平均拉力比无绳网篷布受到的平均拉力小20%～60%。

At different level velocities,the tensile forces of tarpaulin cord under four different loadings and reinforcing projects were tested using D-type and X-type tarpaulin with and without cord net when the freight cars run in tunnel,and the full running course was photographed.The results show that the two sides of the tarpaulin end windward shake hardly and catching wind leeward is serious,and in tunnel the top of the tarpaulin with net cord undulates less but more without net cord,which undulates larger with the increase of the velocity.The tensile force increases abruptly while the train comes into tunnel and decreases gradually in tunnel and recovers open wire level at the exits of tunnel.When freight car is at 80 120 km/h,the maximum tensile force of D-type tarpaulin is 609 N and X-type tarpaulin is 722 N.Therefore the D-type tarpaulin has better performance than small-sheet tarpaulin under the same condition,and the tensile force of cord with net is 20% 60%less than that without net,so cord net has an important role.