Comparison of Wind and Seismic Forces on Tall Buildings. Optimum Seismic Protection for New Building Construction in Eastern Metropolitan Areas

摘要

A comprehensive study of the effects of wind and seismic shear forces on tall, rectangular Boston buildings is reported. It has been generally assumed that the Boston Building Code's rather severe wind load requirements provide a significant degree of earthquake protection. The current investigation serves to evaluate this contention. It is well established that seismic forces and story shears become less critical as the height of a building increases. This study reveals that the relative importance of seismic, as compared to wind, forces depends primarily on the weight of the building per square foot of elevation exposed to the design wind pressure. For a typical case the seismic base shear is critical in significant upper portions of the structure for buildings less than about 400 feet in height. For rectangular buildings, seismic forces are relatively more important in the longe directions. Calculations and conclusions are developed for an actual 42-story frame building. A bibliography and graphs are included.