窄悬索桥气动稳定性的风洞试验研究

Research on Aerodynamic Stability of Narrow Suspension Bridge Based on Wind Tunnel Test

对于处于西部山区复杂风环境中的窄悬索桥,为了确保其气动稳定性及研究提高气动稳定性的措施,制作了弹簧悬挂模型在长安大学CA-1风洞实验室中进行风洞试验。试验结果表明,该桥气动不稳定,必须改变原始设计以提高结构刚度、确保结构安全。考虑到桥梁使用功能和构造的限制,对原桥采取增加抗风缆和中央扣等措施,并对增加了措施的模型重新进行了风洞试验。试验结果表明,在桥梁原设计方案上增加了抗风缆和中央扣之后,大大提高了结构的基频和颤振临界风速,保证了气动稳定性。

For the narrow suspension bridge in complex wind climate in western mountainous area,in order to ensure the aerodynamic stability of the bridge and find out the mitigation measures for improving the aerodynamic stability,spring-support models were made for wind tunnel test in wind tunnel laboratory of Changan University.The test result indicates that the aerodynamic performance of the bridge is unstable and the original design must be changed considerably to improve the structural rigidity to ensure safety.Considering the limit of function and structure,the models with mitigation measures such as auxiliary cables and central buckles were re-tested in wind tunnel.The test result indicates that auxiliary cables and central buckles can considerably increase the fundamental frequency of the bridge and critical flutter wind speed to ensure the aerodynamic stability.