POTENTIALITY OF MICROTREMOR TO EVALUATE SITE EFFECTS AT SHALLOW DEPTHS IN THE DEEP BASIN OF SANTIAGO DE CHILE

摘要：

Ambient noise arrays measurements were performed in the deep basin of Santiago de Chile (Chile) where site effects were clearly revealed by the 1985 Valparaiso earthquake. The significant seismic intensities reported for one-storey houses outlined the resonance of a shallow soft sedimentary layer during the Valparaiso earthquake.We look for testing the Horizontal-to-Vertical spectral ratio (H/V) and the more complex array techniques HRFK (High Resolution Frequency-wavenumber method) as a tool to provide qualitative and quantitative information of site effects for the top most soil layers. Although we show the robustness of the H/V method to map the fundamental resonance frequency of the deep basin, we outline its limitation to identify the resonance frequency at shallow depths. We conclude by emphasizing that the H/V method alone may not be enough to assess the seismic hazard in urban area especially when there is a large variety of building type: from small-size residential houses to high rise business buildings. We also show that small-size arrays measurement are a powerful tool to provide the site effect estimates (resonance frequency and amplification factor) for the shallow sedimentary layers.

关键词： Site effects microtremor H/V arrays technique Santiago de Chile

作者: S. Bonnefoy-Claudet F. Leyton S. Baize C. Berge-Thierry L.F. Bonilla J. Campos

作者单位: Institute for Radiological Protection and Nuclear Safety IRSN, Fontenay-aux-Roses, France Dept. of Geophysics, Chile University, Santiago de Chile, Chile

会议类型: 国际会议

会议名称: 14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)

会议地点: 北京

会议语种:英文

在线出版日期: 2008-10-12（万方平台首次上网日期，不代表论文的发表时间）