Derivation of equivalent gust effect factors for wind loading on low-rise buildings through Database-Assisted-Design approach

作者：Seo Dong Woo; Caracoglia Luca^*

来源：Engineering Structures, 2010, 32(1): 328-336.

DOI：10.1016/j.engstruct.2009.07.020

• Low-rise buildings
• Structural design
• Wind loading
• Database-Assisted-Design

The method for the simulation of extreme wind loading on low-rise buildings, currently adopted by most civil engineering Standards, is based on the concept of "gust effect factor" (GEF). The GEF is a dimensionless coefficient that quantifies the effect of turbulence on wind pressure distribution and enables the assessment of maximum external loading and internal forces in the structure from the analysis of the mean wind pressure scenario. The GEF is employed because a direct quantification of unsteady pressures, usually requiring detailed wind tunnel investigation, is sometimes uneconomical for a "simplified" low-rise building.
This study analyzes different methods for the assessment of wind loading, utilizing the GEF. These include the approach employed by the Standard of the American Society of Civil Engineers (ASCE-7), the guidelines of the Seventh Edition of the Massachusetts Building Code (780-CMR) and the Database-Assisted-Design (DAD) approach.The DAD, developed by the National Institute for Standard and Technology. is a rational approach for the structural design against extreme winds, which employs a large database of wind tunnel test results. A set of simulated loading scenarios on rectangular low-rise gabled-roof buildings with various floor-plan dimensions and heights was employed. Wind loading analyses were restricted to enclosed buildings and primarily based on external pressures. The performance of the main wind force resisting system was analyzed. Two-dimensional lateral frames were considered. Peak values of the bending moments at critical locations were evaluated through the DAD procedure, and transformed into "equivalent gust effect factors" (EGEF) for comparison with ASCE-7 and 780-CMR.
It was found that ASCE-7 always predicts an increment in the GEF with the height of the building, while the DAD estimations suggest that, for a large building, the EGEF should decrease with the height. Moreover, ASCE-7 can under-predict the magnitude of the gust effects is some cases. Finally, a relative increment in the EGEF was recorded between a large and a small floor-plan building, which is partially incompatible with the equivalent reduction of loading indicated by 780-CMR for "one and two family dwellings and townhouses".

• 出版日期2010-1
• 单位东北大学