Civil Engineering Association

MULTI-HAZARD DESIGN OF MID- TO HIGH-RISE STRUCTURES

The importance of multi-hazard design of structures has emerged in the last decade, as extensive media coverage of natural disasters have increased public awareness of the catastrophic damage that hurricanes and earthquakes can wreak on buildings and infrastructure. Current design codes treat hurricanes and earthquakes as completely independent, which, while true in the physical sense, does not account for the increased risk to structures in regions where both hazards are present. The application of multi- hazard design to mid- to high-rise structures is advantageous, as they have the potential of being governed by either load and have high costs and large occupancy. This study, which develops multi-hazard design, is essential for improving the safety of structures, reducing building life cycle costs, and increasing efficiency in design.
Presently, experts in the fields of seismic and wind structural engineering conduct research autonomously and possess only basic knowledge in the other area of study. To encourage an interdisciplinary approach to multi-hazard design, this thesis presents a comprehensive review of the characteristics of hurricanes and earthquakes along with an explanation of how physical features of the hazards are represented in design codes. With a knowledge baseline established, an analytical model representing earthquake design and one representing wind design can be created and assessed for structural behavior under various loading. With the use of eigenvalue, static pushover, and dynamic time history analyses, it is possible to evaluate the structural response of each model to wind and earthquake loading and compare the behavior of each at a global, intermediate, and local level.
Results of this thesis research show that structural response differs significantly for buildings designed for different hazards. Wind designed buildings are more flexible than those designed for earthquake due to lower lateral load demands, however earthquake designed structures have much greater strength and ductility due to its capacity for substantial plastic hinge development before structural failure. The findings on the variation in structural behavior from the analyses provide a unique understanding of the effects of wind and earthquake is necessary for the advancement of multi-hazard design.