Quantitative Shaking Evaluation of Bracing-Strengthened and Base-Isolated Buildings Using Seismic Intensity Level

Abstract

In current design practice, the seismic strength design of buildings is commonly based on the strength concept, lacking a quantitative evaluation tool that can show the performance of the buildings during earthquakes. This paper demonstrates the application of seismic intensity level (SIL) as a quantitative evaluation tool for aseismic building performance. A simulation test is conducted on three categories of building-frame: non-strengthened (NA), bracing-strengthened (BS), and base-isolated (BI), subjected to a north-south (N-S) 1940 El Centro seismic wave. The criteria evaluated include maximum acceleration, energy dissipation, and the measured seismic intensity level (m-SIL). The effect of strengthening methods is compared based on those criteria. The results show that despite the apparent reduction in structural response metrics, the SIL value diminishes more substantially for base isolators (4.5 level decrease) than bracing (0.4 level decrease). This confirms that SIL provides higher consistency results and is straightforward to comprehend.