The use of aerodynamic databases for the effective estimation of wind effects in main wind-force resisting systems: application to low buildings

摘要

As a part of the ongoing National Institute of Standards and Technology research on the development of a new generation of standard provisions for wind loads, we present results of a pilot project on the estimation of wind effects in low-rise building frames. We use records of wind pressure time histories measured at a large number of taps on the building surface in the boundary layer wind tunnel of the University of Western Ontario. Time histories of bending moments in a frame are obtained by adding pressures at all taps tributary to that frame multiplied by the respective tributary areas and influence coefficients. The latter were obtained from the frame designs provided by CECO Building Systems. We compare results obtained by using the pressure time history records with results based on ASCE 7 standard provisions. The comparison suggests that provisions which use aerodynamic databases containing the type of data described in this work can result in designs that are significantly more risk-consistent as well as both safer and more economical than designs based on conventional standard provisions. We outline future research on improved design methodologies made possible by the proposed approach to the estimation of wind effects. We note that the use of the proposed methodologies is fully consistent with the ASCE 7 Standards insofar as these allow the use of wind-tunnel data for estimating wind load effects. Finally, We note that the proposed methodologies may be used for damage assessment for insurance purposes.