行人对人行桥三分力系数的影响

以风洞试验方法为主、计算流体力学(CFD)方法为辅,研究不同角度风嘴入流、行人密度和行人横向排列位置条件下的人行桥主梁断面三分力系数的变化规律.结果表明:桥上行人的存在会改变截面周围气流的流态,从而对桥梁断面的静力三分力系数产生显著影响;风攻角在-12°~12°范围内,阻力系数均呈现先增加后减小趋势,负风攻角范围内行人密度是阻力系数变化的主导因素,而正风攻角范围内阻力系数变化受风攻角主导;当风攻角由-12°变化到12°时,小风嘴入流状态下的升力系数和扭矩系数整体逐渐减小,而大风嘴入流状态下的升力系数和扭矩系数整体呈现先增大后减小的趋势,随着行人由迎风侧移动到背风侧,阻力系数略微增大,升力系数显著减小,扭矩系数几乎不变.

Influence of Pedestrian on Tri-Component Coefficients of Footbridge

Mainly by the wind tunnel test method, and assistanty by the computational fluid dynamics(CFD)method, the variation of the tri-component force coefficients with different wind fairing angles, pedestrian densities and arrangements of pedestrian lateral position is studied. The results show that the pedestrians on the bridge change the flow pattern of the airflow around the cross section, consequently influence significantly the tri-component coefficients of the bridge section. With the wind attack angle varying from -12° to 12°, the drag coefficient increases at first and then decreases. Pedestrian density is the main factor for negative wind attack angle, while the wind attack angle plays a dominant role in drag coefficient for positive wind attack angle. With the wind attack angle varying from -12° to 12°, the lift coefficient and torque coefficient gradually decrease under small wind fairing angle, while the lift coefficient and torque coefficient show a trend of first increasing and then decreasing under large wind fairing angle. As the pedestrian moves from the windward side to the leeward side, the drag coefficient increases slightly, the lift coefficient decreases significantly, and the torque coefficient is almost unchanged.