Displacement Restraint Mechanism of Seismic Isolation Buildings

Displacement Restraint Mechanism of Seismic Isolation Buildings

In recent years, earthquakes have occurred more frequently around the world. On September 21, 1999, a 7.3 earthquake hit central Taiwan, which was called the Chi-Chi earthquake. Seismic codes were revised and became more restrictive in the aftermath of the disaster. However, many buildings in Taiwan that were built earlier are lacking seismic capacity and are not safe based on the revised Seismic Design Code. Therefore, building retrofits, such as seismic conventional retrofits and seismic isolation systems, are being implemented as measures to improve the safety of these old structures. The effectiveness of the isolation system has been proven by many investigators; however, some other studies have also indicated that excessive displacement response due to near-fault ground motion may cause such a system with a long period to fail. Thus, a displacement restraint mechanism is suggested to be installed between the isolated structure and the retaining wall. It is clear from the simulation results that as the isolated structure strikes the displacement restraint system, the maximum absolute acceleration of the total system is increased due to the impact. Therefore, the displacement restraint system should be properly designed to maintain the design target. In addition, the corresponding displacement restraint system of different structures with different damping ratios and periods should be properly designed.