Peak factors of wind load for main frame design of rooftop structures

Abstract

Technology is being developed to unitize structures installed on apartment rooftops during construction. The rooftop is located at the top of a high-rise building with a flexible structure. However, the rooftop structure itself is close to a rigid body and is not integrated with the building. Therefore, it is difficult to calculate the gust effect coefficient of the rooftop structure. The peak factor provided by the Korean Design Standard (KDS) uses an equation for general buildings and may be inaccurate to a certain extent when used to calculate the wind load on rooftop structures. Therefore, in this study, wind pressure tests were conducted on three research models to calculate the appropriate peak factors for rooftop structures. For each model, the peak factor trend was analyzed according to the wind pressure coefficient, and the peak factor was presented. When the evaluation time was 10 min, the positive pressure peak factor converged to three and the negative pressure peak factor converged to four. Additionally, a formula for calculating the peak factor of rooftop structures based on the wind load evaluation time is proposed. Hence, the peak factor of rooftop structures can be calculated based on various evaluation times.

Keywords

• rooftop structure
• rooftop unit
• peak factor
• wind pressure coefficient
• gust effect factor