dc.description.abstract | Based on the available geologic geomorphologic data and some borehole data, and refered the 1997 Uniform Building Code (UBC) provisions, Lee et al. (2001) classified 708 free-field strong-motion station sites of Taiwan Strong-Motion Instrumentation Program (TSMIP). They also published a geologic site class map for whole Taiwan. Till year 2005, the Central Weather Bureau has finished core drilling and PS logging for 266 strong-motion sites. This study utilize the 266 drilling and logging data and more other new data to evaluate and revise the site classification, and update the site class map of Taiwan.
Because the property of the upper 30 meters soil profile is a key point to the amplification of ground-motion, most of the researches on site effect consider the average shear-wave velocity in upper 30 meters (Vs30) as an important factor. The purpose of this study was mainly on mapping the distribution of Vs30 in Taiwan. First, I collect and examine the drilling and PS logging data for the strong-motion station, and recheck these data. Second, by using these rechecked high quality shear-wave velocity data and SPT-N value, I build a model to estimate the shear-wave velocity from SPT-N value. Third, by using this model, I estimate the shear-wave velocity of each drilling data from the Central Geological Survey Engineering Geology Database. Finally, I use a geostatistical analysis method called “Kriging with verying local means method” to generate a Vs30 distribution map of Taiwan with the estimated Vs30 value from each drilling data. Furthermore, a site classification result of Taiwan’s strong-motion stations is updated base on the Vs30 map. | en_US |