Seısmıc Behavıor of Buıldıngs Wıth a Common Isolatıon Basemat The seismic isolation technology is being used in commonly as an earthquake resistant design technique all over the world and also in Turkey. While a building has its own isolation system, buildings horizontally exceeding a certain length must be separated with expansion joints. As a result, dynamically independent buildings on a common seismic isolation basemat come into scene. A smilar case may be appear when the attached buildings are wanted to reinforce with common seicmic isolation system. Expansion joints are so small that they do not allow each building to have its own seismic isolation base. One of the approaches in the analysis of these systems could be that by ignoring dynamic interaction of buildings above the isolation floor, these buildings can be analyzed independently. On the other hand, the effects of aforementioned dynamic interaction on seismic behavior could be at such a high level that it cannot be ignored. Moreover, it is necessary to investigate the performences of seismic isolation system that has multiple superstructures as correlative fixed base buildings. In this study, modeling of structural systems which include several buildings with a common seismic isolation basemat is described and a parametric study is conducted by taking the effects of dynamic interaction on the seismic behavior of the buildings into consideration. Seismic behaviors of the prototype structural systems are examined under the 1989 Loma Prieta-LGPC, the 1994 Northridge-Sylmar and the 1995 Kobe-KJMA earthquakes, and also the findings are presented comparatively. In the study, superstructure eccentricity, plan layout of the superstructures, total number of floors and the isolation system periods are taken into consideration as different parameters.
