Urban Areas, Ground Motion Characteristics

Site response characteristic is one of the most important influencing factors of the earthquake motion distribution. It makes an important sense of setting down quake-proof countermeasure and doing the antiknock designing of the construct that to grasp the site response characteristics of the urban area. The microtremor method is one of the major methods of the study on the ground character, and it's one of the most important tools of the seismic zoning. This paper is base on the project of the estimation of the earthquake perniciousness in Kunming and Hangzhou city. We collected the microtremor data in large place with a high density to use to do our study on the ground character of the predominated period and the transfer function. The compared exact data are selected to be analyzed and concluded in the Linux system with different processing methods. Single-site spectral ratio method is adopted to analyze the data of Kunming and Hangzhou to get the distribution map of the predominated period in the ArcGIS software. Then the Golden Surfer software is used to interpolate in the target area to get the contour map of the predominated period. Simultaneous observation method is adopted to analyze the simultaneous observation data of Hangzhou to get the distribution map of the transfer function. The Golden Surfer software is also used to get the transfer function contour map. The two kinds of contour map will be adopted in the work of the seismic zoning and the construct quakeproof designing. Besides, it is expatiated that the development of the theory and the actuality of the research on the microtremor. This paper also describes the microtremor observation instrument, the selection of the observation time and the observation place and the principle of the observation line selection. Kinds of the analysis method are expounded and summarized and it makes a compared all-round presentation of the microtremor method. It is hardly any precedent in China that the microtremor be used in the work of the seismic zoning and the construct quakeproof designing, while it is adopted in Japan widely.