RESILIENT SEISMIC DESIGN OF A SLENDER STEEL BUILDING ACCORDING TO THE SEISMIC ISOLATION GUIDELINES OF MEXICO

Abstract

Currently, worldwide applications for seismic isolation are continuously increasing, due both to the confidence and the availability that the technology has gained. Great advantages are obtained when using seismic isolation in firm soil sites in areas of low, moderate or high seismic hazard. To date, most applications worldwide have been in low-rise and industrial structures. There are relatively few applications in slender or tall buildings, most of them in Japan. In this paper, a study is reported where the application of seismic isolation in a slender steel building is evaluated. The subject building was assumed to be located on firm soils for an area of greatest seismic hazard in Mexico: Oaxaca. The building was designed using high damping rubber bearings (HDRBs). The goal of the design was to be seismically resilient to the maximum credible earthquake scenario according with the seismic isolation guidelines of the Manual of Civil Works of Mexico for the city of Juchitán, Oaxaca. The designed building was evaluated through nonlinear dynamic analyses when subjected to bidirectional and tridirectional action of the ground motions recorded during the September 7, 2017 Tehuantepec Earthquake (M_w = 8.2) and the October 9, 1995 Manzanillo earthquake (M_w = 8.0). From the resulting simulations, it is shown that resilient seismic designs of slender buildings can be achieved with HDRBs. However, particular attention must be paid to monitor that net tensile forces on the isolators and their potential uplift would be within reasonably safety margins. The demands of tension and uplift forces in the base isolators are increased by the action of the vertical component of the ground motions, so its potential impact should not be neglected in the design of slender buildings.