Robustness Evaluation on Earthquake Response of Base-Isolated Buildings with Uncertain Structural Properties under Long-Period Ground Motions

Robustness of a base-isolated building with uncertain structural parameters under long-period ground motions is investigated by uncertainty analysis methodologies. It is shown that the critical combination of structural parameters maximizing the objective function can be derived by a proposed uncertainty analysis method, i.e., combining the so-called URP (Updated Reference-Point) method with a response surface method. The practical application of the proposed robustness evaluation methodology is presented through an example of a base-isolated building model with the natural rubber bearing (NRB) and lead rubber bearing (LRB) isolators. The results from the proposed methods are compared with those from the Monte Carlo simulation under various long-period ground motions. It is shown that the proposed URP method combined with the response-surface type can provide a reliable and accurate evaluation of robustness for the earthquake response bound without hard computational load.