Abstract Database

ASSESSING THE APPLICABILITY OF L-SHAPE ARRAY FOR MICROTREMOR SURVEY

MEE08156
LI Jinggang
Supervisor: Toshiaki YOKOI
Country: China
Abstractfulltext
Site effects play a major role in destructive ground motion. The effects of local geology may modify ground motion significantly on soft soils.To evaluate the site response, Microtremors methods have advantages: low cost and environment friendly for urban area and effective for low or moderate seismicity area. But standard array shape is strict circular. In urbanized area, it is usually very difficult to find an area for circular array observation due to existing buildings and other facilities. Therefore, irregular array should be investigated and in the paper L-shape array was checked by comparing the performances of circular array and L-shape array (both even and uneven interval) in the same site. The SPAC coefficients fit well with theoretical Bessel function, so the results are reliable. The results show that L-shape can have good performance in microtremors surveying. A shear wave profile was obtained by L-shape array and had good agreement with existing borehole data. The theory of Shiraishi et al.(2006) was attested by the observation data. Moreover, an effective and efficient method for the key step of SPAC analysis, frequency range selecting, was proposed.
Citation: Bulletin of IISEE, 44, 1-6.