准流线型桥梁表面压力分布研究

SURFACE PRESSURE DISTRIBUTION OF QUASI-STREAMLINE BRIDGES

桥梁的气动选型对于大跨度桥梁建设影响重大,准流线型桥梁断面具有较好的气动外形。为了进一步探究该种断面的气动特性,选取某个大跨度桥梁准流线型桥梁断面为研究对象,通过风洞试验测得模型表面风压分布,并分析其变化规律。结果表明:模型上表面前半部分存在明显的气流分离与再附;下表面仅存在分离过程,没有出现再附;模型上表面腹板和下表面左侧斜腹板存在较大脉动值,可能会对桥梁风致振动问题造成不利影响。

The aerodynamic selection of bridges has a great influence on the construction of long-span bridges.The quasi-streamline bridge section has a good aerodynamic shape.To explore the aerodynamic characteristics of this kind of cross-sections,the quasi-streamline cross-section of a large-span bridge is selected as the research object.The wind pressure distribution on the surface of the model and its variation are measured and analyzed in a wind tunnel test.The results show that there were obvious air flow separation and reattachment in the front half of the upper surface of the model,that there was only separation process in the lower surface without reattachment,and that there were large pulsation values in the webs of the upper surface and the inclined webs on the left side of the lower surface of the model,which may have an adverse effect on the wind-induced vibration of the bridge.