Downburst-Induced Vibration Coefficient of Long-Span Roof Structures

Long-span roof structures are vulnerable to being damaged by downbursts due to the sensitivity of such structures to wind loads. However, there is still no simple and practical method for the downburst-resistant design of such structures to date. Inspired by the wind-induced vibration coefficient (WVC) frequently used by engineers, this paper proposes a downburst-induced vibration coefficient (DVC) to evaluate the response of a roof structure subjected to downbursts. The proposed DVC is defined as the ratio of the total response to the mean response of the structure due to the action of downburst wind loads. The influences of different parameters on the downburst-induced vibration response of a long-span single-layer spherical reticulated structure are first analyzed in detail. Then, using a statistical approach, a design DVC, which can be practically adopted for civil engineers to evaluate the total structural response, is proposed to facilitate the structural downburst-resistant design. With the influences of different structural parameters fully taken into consideration, the design DVCs of displacement and internal force are studied through orthogonal analysis. Finally, regression models of the design DVCs are presented, and their reliability is verified via the application to a case study. The verification results indicate that the proposed regression models of the design DVCs are reliable and can be utilized to simply calculate the structural downburst-induced vibration response. The results obtained can serve as a reference for the downburst-resistant design of long-span roof structures.