Evaluation of Site Effects on Strong-Motion Records in Concepción during the 2010 Maule, Chile, Earthquake

Abstract

In the 2010 Maule, Chile, earthquake (Mw 8.8), many high-rise buildings in downtown Concepción (CONC) sustained severe damage. The accelerogram observed at CONC had large amplitudes and long periods. The spectra contained strong peaks with periods around 2s, whereas spectra from a neighboring site (CCSP) did not exhibit strong peaks. Because CONC and CCSP are located in the Concepción basin and at the edge of the basin, respectively, these observations suggest that the spectral differences are due to site geological effects. To quantitatively evaluate site effects, microtremor array observations were conducted as a surface structure survey. The different spectral characteristics of the records at CONC and CCSP could be explained by the amplification factors computed from the velocity profiles.