Relationships between Strong Ground Motion Peak Values and Seismic Loss during the 1999 Chi-Chi, Taiwan Earthquake

Abstract. A better real-time assessment of earthquake effects (i.e. seismic intensity estimation) is crucial for hazard mitigation. Especially during the aftermath of a disastrous event, significant reduction of loss can usually be realized through timely execution of emergency response meas-ures. These effects include strong-ground shaking, ground failure, and their impact on man-made structures. The descriptive Modified Mercalli intensity scale, though still in common use in many poorly instrumented areas of the world, is out of date in areas of extensive strong-motion instrument-ation. It is desirable to place the earthquake intensity scale on a more quantitative basis based on the actual recorded ground-motion shaking and carefully compiled damage records. In this paper, we investigated the relationships between earthquake loss, intensity and strong motion peak values, mainly based on the Chi-Chi earthquake. Both the strong-motion peak values and the earthquake loss are related. From the results, we found that peak ground acceleration (PGA) and peak acceleration response spectra at 1 s period (1 s Sa) values are two parameters that give slightly higher correlation coefficients than other parameters for earthquake loss analysis. For intensity estimations, the peak ground velocity (PGV) values and 1 s Sa values are better parameters in the high range and PGA is not stable for smaller earthquakes. Although PGV values give a slightly lower correlation coefficien