Quantitative Shaking Evaluation of Bracing-Strengthened and Base Isolated Building using Seismic Intensity Level (SIL)

Abstract

Abstract This paper presents a new and comprehensive design philosophy for evaluating earthquake-induced shaking and vibrations based on Japan Meteorological Agency (JMA) formulas. The goal of determining Seismic Intensity Level (SIL) is to identify measures or actions that can minimize the risk of human casualties during earthquakes. This study aims to assess the application of SIL as an evaluation tool for the seismic aspect of a building. Three categories of building model, which are existing building (a 15x12x18.1 m frame building without strengthening), bracing-strengthened buildings, and Base Isolated buildings, were evaluated. The evaluation criteria are the maximum acceleration of the roof, energy dissipation, and measured Seismic Intensity Level (m-SIL) according to JMA calculation. Models were subjected to the 1940 El Centro seismic wave of the North-South (N-S) orientation as the ground motion. From this study, the evaluation using Seismic Intensity Level (SIL) provides more consistency and is simpler to comprehend. The application of SIL as an evaluation tool for comparing the performance of the two strengthening methods proves that the base isolation (BI) method performs safer shaking of the building than bracing strengthening. An indicative chart is also proposed to help designers generatecost estimation of SIL.