“…Previous studies have been concerned with the simplifi ed model and experimental validation of the FPS performance (Zayas and Mahin, 1990;Mokha et al, 1991;Mokha et al, 1996) and other important aspects such as modeling of constitutive relationships and refi nement of the model of multi-story frame structures isolated by FPS (Almazan et al, 1998;Almazan and De la Llera, 2002;De la Llera and Almazan, 2003;Gilberto et al, 2004). However, studies on the seismic isolation of spatial structures with FPS have not been widely reported up to now.…”