H. Kit Miyamoto, Amir SJ Gilani
Performance-based design with seismic protection devices such as viscous dampers have fundamentally altered the landscape of earthquake engineering and design. Structures designed and built without such devices typically use a code-prescribed design that implies extensive structural damage, loss of operation, and likely replacement at design-level earthquake. In contrast, performance-based design incorporating earthquake protection devices leads to a combination of best engineering practice and reducing life-cycle costs. These devices are robust, cost-effective, and have a proven exceptional performance record in past earthquakes. In most cases, the initial cost of their utilization is neutralized by reduction in cost of other structural members. The long-term performance is the key parameter used for evaluation. Structures properly designed with these devices will likely only require minimum post-earthquake inspection and can be fully operational within hours of a seismic event. When utilized for critical structures, such performance reduces the need for use of natural resources by eliminating post-earthquake repair or reconstruction and thus improving the community resiliency. Example cases are presented.