Along-Wind Load Effects on Tall Buildings: Comparative Study of Major International Codes and Standards

Abstract

Most international codes and standards provide guidelines and procedures for assessing the along-wind effects on tall structures. Despite their common use of the “gust loading factor” (GLF) approach, sizeable scatter exists among the wind effects predicted by the various codes and standards under similar flow conditions. This paper presents a comprehensive assessment of the source of this scatter through a comparison of the along-wind loads and their effects on tall buildings recommended by major international codes and standards. ASCE 7-98 (United States), AS1170.2-89 (Australia), NBC-1995 (Canada), RLB-AIJ-1993 (Japan), and Eurocode-1993 (Europe) are examined in this study. The comparisons consider the definition of wind characteristics, mean wind loads, GLF, equivalent static wind loads, and attendant wind load effects. It is noted that the scatter in the predicted wind loads and their effects arises primarily from the variations in the definition of wind field characteristics in the respective codes and standards. A detailed example is presented to illustrate the overall comparison and to highlight the main findings of this paper.