不同车流对桥梁静三分力及局部风压影响的风洞试验研究

Experimental studies on influence of vehicles on static aerodynamic forces and local pressure under different traffic flow

在风-车-桥耦合系统中,不同交通状态车辆将引起桥梁气动力和局部风压的变化。采用测压法测试了不同车流下桥梁断面三分力系数随攻角的变化情况,研究了不同车流下车辆对三分力系数以及局部风压的影响。研究结果表明:在堵车情况下车辆对桥梁断面三分力影响最大,车辆引起桥梁阻力系数和升力矩系数显著减小,使升力系数增大。在车桥耦合风场作用下,桥梁顶面迎风侧压力值产生由正到负的剧烈幅值变化。

Different traffic flow conditions will cause the change of bridge aerodynamic characteristics and local wind pressure distribution in the wind -vehicle -bridge coupling systems. Pressure measuring method was used to test the bridge aerodynamic coefficients with wind attack angle under different flow traffic conditions. The in- fluence of vehicles on the bridge aerodynamic coefficients and local pressure of the bridge under different traffic flow conditions was investigated. The results show that under traffic jams condition, the influence of vehicles on aerodynamic coefficients of bridge cross sections is the greatest, which decreases drag coefficient and moment co- efficient significantly and increases lift coefficient. In the wind -vehicle -bridge coupling systems, the pressure at windward side of the top surface of the bridge changes from positive to negative intensively.