不同交通流状态下简支梁桥动力响应研究

Research on Dynamic Response of Simply-supported Beam Bridge under Diff erent Traffi c Flow States

为了解交通流状态对桥梁动力响应的影响,根据道路服务水平,选择车头间距与车速作为交通流状态评价指标,选用两轴平面整车车型,基于模态综合法,建立多车车桥耦合振动分析模型,分析不同交通流状态下简支梁桥的动力响应。结果表明,当车辆达到3辆时,桥梁跨中最大竖向位移最大,车辆增加到5辆时,桥梁跨中最大竖向位移趋于稳定;当车辆之间的距离增加时,车辆之间的叠加动力效应减弱,桥梁跨中最大竖向位移逐渐减小并接近单车下的数值;在不同交通流状态中,稳定流对桥梁动力响应的影响最小,限制流对桥梁动力响应影响最大。

In order to understand the influence of traffic flow state on the dynamic response of bridge,according to the road service level,the space headway and vehicle speed are selected as the evaluation indexes of traffic flow state and the two-axle plane vehicle model is selected to establish the multi-vehicle vehicle-bridge coupling vibration analysis model to analyze the dynamic response of simply-supported beam bridge under different traffic flow states based on the modal synthesis method.The results show that when the number of vehicles reaches 3,the maximum vertical displacement in the middle of the bridge span is the largest,when the number of vehicles increases to 5,the maximum vertical displacement in the middle of the bridge span tends to be stable;when the distance between vehicles increases,the superimposed dynamic eff ect between the vehicles is weakened,and the maximum vertical displacement in the middle of the bridge span gradually decreases and approaches the value under the single vehicle;in diff erent traffic flow states,the steady flow has the least infl uence on the dynamic response of the bridge,and the restricted flow has the greatest infl uence on the dynamic response of the bridge.