The current Urban Regulation in the Metropolitan Area of San Salvador (Master Plan, 2017) encourages the densification in the territory and promotes the growth in height due to the lack of land. The project developers are more interested in using new seismic response control systems. This study intends to propose a design procedure for seismically isolated buildings in El Salvador. A design of a base isolation system for the target building is conducted, applying the Capacity Spectrum Method and Time History Analysis (THA), following the Japanese Standard. The effect of the aspect ratio is analyzed by the history of axial forces of models with two aspect ratios, lower than and higher than 4, by THA and pushover. The capacity curves are associated with the tensile failure obtained by pushover, considering the "Ai" and uniform load distribution. The analysis of the history of axial forces of the two models proved the accuracy of the Japanese recommendation in terms of the aspect ratio in the isolated building. The significant effect of the type of horizontal load distribution was also analyzed on evaluating the tensile failure in the isolation devices using the capacity spectrum method. It is found that uniform load distribution is more appropriate in the capacity spectrum method.
Keywords: Design procedure, seismically isolated buildings, aspect ratio