# Recent Advancement in Assessment and Control of Structures under Multi-Hazard
## 5 Multi-Hazard Assessment and Vibration Control of Buildings
### Multi-Hazard Assessment of Buildings  
[PERSON] [129] provides a comprehensive account of the dynamic responses of high-rise buildings under multiple hazards. It presents performance assessment methods and case study investigations using high-rise buildings in Hong Kong. Various factors, such as seismic source-to-site distance, recurrence periods, ground shaking amplitude, building height, damping ratios, properties of wind forces, etc., were considered in the analysis. The results show that seismic loads result in a higher floor acceleration response and lateral forces but weaker torsional forces and a lower displacement response compared to wind forces. The height of the buildings was also found to be an important parameter, with wind response being more sensitive to variation in height than seismic response. The results also showed that wind response is more strongly influenced by the level of damping of the building than seismic response. [PERSON] [127], and [PERSON] and [PERSON] [128] report differences in the seismic and wind responses of mid-rise to high-rise buildings. [PERSON] [6], as well as [PERSON] and [PERSON] [7] present the responses of tall buildings subjected to wind and seismic forces. In these assessments, two tall buildings (76-story and 54-story) were considered for finite element analysis. They found that ground motions excite higher vibration modes in buildings, resulting in lower inter-story drift than wind forces, but higher floor accelerations last for a shorter time. Wind actions are, therefore, critical from an occupant comfort and serviceability consideration. Tall structures designed for strong wind may possess an adequate capacity against moderate ground shaking, but they might suffer non-structural losses due to high floor accelerations. A framework for life-cycle loss estimation, of non-structural damage in tall buildings under wind and seismic loads, is presented by [PERSON] et al. [9]. Their framework assumes that damaged structures are restored to their original condition after each hazardous event. Hazardous events are not simultaneous, and small maintenance costs are neglected. Their results show that for drift-dependent damages, wind forces are costlier than seismic forces. Seismic forces are costlier, in terms of non-structural damage, due to high floor accelerations. These observations are consistent with results reported in other studies, [6; 7]. [PERSON] [130] studied the performance of a 74-story building located in Miami to evaluate the expected losses associated with a multi-hazard (wind and earthquake forces). Performance-based approaches were used for earthquake, wind, and hurricane forces. Monetary losses corresponding to structural and non-structural damage, as well as occupant discomfort, was estimated. They report that losses due to facade damage are dominant for high probabilities of exceedance, whereas structural damage becomes dominant at lower probabilities of exceedance. [PERSON] et al. [131] proposed a framework for the damage risk assessment of high-rise buildings exposed to wind and seismic forces acting separately and concurrently. They used recorded earthquake and wind data, over a period of about 47 years, to estimate hazard curves for wind and seismic forces as well as copula-based bi-hazard surfaces. They then performed multi-hazard fragility assessment and estimated damage probabilities for separate and concurrent hazard models. Their results show that damage probability due to bi-hazards dominates the total damage probability in most damage states. They highlight the need for multi-hazard considerations in the design and evaluation of tall structures subjected to wind and seismic forces. Damage risk assessment and cost-benefit analysis of mitigation strategies, in residential buildings subjected to hurricane and seismic forces, are discussed in [PERSON] [132], giving a comprehensive overview of factors that are important in risk assessment, as well as their roles and impacts in hazard mitigation.