AASHTO Seismic Isolation Design Requirements for Highway Bridges

In October 1990, the American Association of State Highway and Transportation Officials (AASHTO) adopted Guide Specifications for the Seismic Isolation Design of Highway Bridges. This paper overviews the basic concepts and design principles of seismic isolation and discusses the objectives and philosophy of the provisions. A summary of the provisions is presented, and the paper concludes with a procedure to compare the performance of isolation systems with different damping values.