Site effects on earthquake ground motion based on microtremor measurements for metropolitan Beijing  

作　　者：CHEN QiFu LIU LanBo WANG WeiJun ROHRBACH Eric 

机构地区：[1]Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China [2]University of Connecticut, Storrs, CT 06269-2037, USA

出　　处：《Chinese Science Bulletin》2009年第2期280-287,共8页

基　　金：Supported by the Ministry of Science and Technology of China (Grant No. 2006DFA21650);Special Scientific Research Projects on Earthquake (Grant No. 0207690229 and 200708008)

摘　　要：A campaign of microtremor measurements was conducted in summer 2007 for assessing local site effects of seismic strong ground motion in metropolitan Beijing. Using the measurements from over 600 sites with approximately 1―2 km spacing covering the entire area inside Beijing’s 5th Beltway, we present the analysis results in the form of contours of the predominant resonant frequency, the thick- ness of the uppermost soft sediments, and the ground motion amplification factor. The microtremor- derived soft sediment thickness is generally in agreement with previous results based on much sparser borehole data, with the revealing of more short-wavelength undulations, which coincide with major geomorphological and neotectonic expressions in metropolitan Beijing. This study provides additional valuable information to the earthquake-resistant design of civil infrastructures and seismic hazard response in metropolitan Beijing. It also provides a feasible geophysical approaching to explore the 3-D structure beneath metropolitan cities.A campaign of microtremor measurements was conducted in summer 2007 for assessing local site effects of seismic strong ground motion in metropolitan Beijing. Using the measurements from over 600 sites with approximately 1 --2 km spacing covering the entire area inside Beijing＇s 5th Beltway, we present the analysis results in the form of contours of the predominant resonant frequency, the thick- ness of the uppermost soft sediments, and the ground motion amplification factor. The microtremorderived soft sediment thickness is generally in agreement with previous results based on much sparser borehole data, with the revealing of more short-wavelength undulations, which coincide with major geomorphological and neotectonic expressions in metropolitan Beijing. This study provides additional valuable information to the earthquake-resistant design of civil infrastructures and seismic hazard re- sponse in metropolitan Beijing. it also provides a feasible geophysicat approaching to explore the 3-D structure beneath metropolitan cities.

关 键 词：基岩 理论分析 地脉动机制分析法 北京 

分 类 号：P58[天文地球—岩石学]