Accession Number : ADA307688

Title :   Use of Microtremors For Site Response Characterization.

Descriptive Note : Final rept. Jan 94-Feb 96.

Corporate Author : LEIGHTON AND ASSOCIATES INC IRVINE CA

PDF Url : ADA307688

Report Date : FEB 1996

Pagination or Media Count : 586

Abstract : The primary objective of this project was to investigate the feasibility of using microtremors to obtain information on the local site conditions for site specific ground motion analysis. Microtremors and microseisms have been used by many investigators for site response investigation. One of the old and rather neglected techniques is Aki's (1957) 'Circular Array' method. It uses microtremor data on a small scale circular array to infer information on the wave propagation properties of the local site materials. Aki successfully used this technique at a site in the University of Tokyo to obtain the information on the shear wave velocity profile for the site. The most attractive feature of this technique is its simplicity in data requirement and field operation. Theoretical, numerical, and field investigations of the Circular Array technique were conducted to evaluate its potential for site investigation. The results of this study clearly indicate that the Circular Array technique can provide general information on the seismic wave propagation properties of the local site materials. The data requirements (i.e., microtremors) and the field instrumentation are fairly simple. The data processing and interpretation can be simple or sophisticated depending upon the detail of the velocity model that is desired for a particular application. However, it is possible to automate different aspects of the data processing in order to make the interpretation the least time consuming.

Descriptors :   *SITE SELECTION, *SEISMOLOGY, DATA PROCESSING, REQUIREMENTS, DATA MANAGEMENT, FIELD TESTS, SOIL MECHANICS, PROFILES, WAVE PROPAGATION, RESPONSE, SEISMIC WAVES, EARTH MODELS, FIELD EQUIPMENT, CIRCULAR, MICROSEISMS, SEISMIC ARRAYS, SHEAR STRENGTH, SECONDARY WAVES.

Subject Categories : Civil Engineering
      Seismology

Distribution Statement : APPROVED FOR PUBLIC RELEASE