强风环境中下行式移动模架的抗风性能

Wind resistance of downward movable scaffolding system in strong wind environment

摘要:

为明确强风环境中下行式移动模架的抗风安全性,以东南沿海某50 m跨下行式移动模架为研究对象,采用气弹模型风洞试验和数值计算相结合的方式,对其颤振、涡振和抖振性能进行了较系统的研究。结果表明:结构竖向位移和扭转角分别是移动模架合模和开模工况时的控制性因素；合模工况时,移动模架主体结构能够满足8级强风(20.7 m/s)的作业要求,且能够抵抗14级风（46.1 m/s）作用；开模工况时,在措施得当的情况下主体结构能够满足8级强风的作业要求；多模态耦合频域抖振计算法和《公路桥梁抗风设计规范》中的等效静阵风荷载法均可以用于移动模架的抖振响应计算,且具有一定的精度,推荐采用精度较高的多模态耦合频域抖振计算法。

Abstract:

To clarify the safety performance of downward movable scaffolding systems (MSSs) in strong wind environment, this paper takes a downward mobile scaffolding system with span of 50 m (MSS50) in the southeast coastal area as the research object to systematically investigate its flutter, vortex, and buffeting performance by aero-elastic model wind tunnel test and numerical calculation. Results show that vertical displacement and torsion angle were critical factors of MSS in fixing and moving conditions respectively. In the fixing condition, MSS50 could meet the operation requirements of 8-level strong wind (20.7 m/s) and resist 14-level wind (46.1 m/s). In the moving condition, the main structure could meet the operation requirements of 8-level strong wind in the case of proper measures. The multi-modal coupling frequency domain buffeting calculation method and the equivalent static gust wind load method in Wind-resistant Design Specification for Highway Bridges could be used to calculate the buffeting response of MSS with acceptable accuracy. The multi-modal coupling frequency domain buffeting calculation method has higher accuracy than the equivalent static gust wind load method and is recommended to calculate the buffeting response of MSS.