AN ADAPTIVE SELECTION SYSTEM OF BASE-ISOLATION DEVICESEVALUATED BY USING A SOFT COMPUTING METHOD THATCONSIDERS SEISMIC PERFORMANCE

摘要

An arrangement of base-isolation devices is required in the design of base-isolated structures.Determining the arrangement of isolators during the design phase, however, is a time-consuming job.Furthermore, generally the arrangement currently depends heavily on the skill and experience of thedesign engineer. To overcome these drawbacks, an adaptive selection system for isolators based on theirseismic performance was developed.The main purpose of this study was to develop an adaptive selection system in which a hybrid method isused to determine the arrangement of isolators. In this system, the arrangement is determined based on the(1) maximum response displacement of the base-isolation layer, (2) maximum response acceleration ofthe superstructure, (3) natural period of the base-isolated structure, (4) eccentricity of the base-isolationlayer, (5) vertical load for each isolator, (6) wind performance, (7) living comfort of inhabitants, and (8)cost of base-isolation devices.First, our adaptive selection system was applied to actual structures and evaluated. The evaluation resultsshow that our system is superior for the different arrangements and that an arrangement that adapts to acertain type of earthquake motion does not always adapt to another type. Therefore, several types ofearthquake motion must be considered when determining the specific arrangement. The results also showthat the adaptive arrangement for wind performance differs from that for seismic performance. Next, theliving comfort for the inhabitants of a building that contained the arrangement determined by the adaptiveselection system was evaluated. The results show that achieving a certain living comfort by using oursystem was difficult but attainable. Finally, there is a trade-off between initial cost and performance inbase-isolated structures.In conclusion, by using our adaptive selection system, multi-objective selection that satisfies safety,comfort, and cost can be achieved.