Application of R&W CPT-based Method for Liquefaction Evaluation at Yuanlin

• Main Authors: Hsin-cheng Liu, 劉欣政
• Other Authors: Chih-Sheng Ku
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/94781732173294732030

碩士 === 義守大學 === 土木與生態工程學系碩士班 === 93 === Taiwan is situated on the juncture between the continental Eurasian Plate and the oceanic Philippine Sea Plate. Taiwan is a typical mobile belt and is seismically very active (Ho, 1982). Liquefaction phenomenon could be induced by a large earthquake. During the 1999 Chi-Chi, Taiwan earthquake, many sand boiling phenomena were observed in central Taiwan, which caused severe ground settlement and structure damages. The method by Iwasaki et al. (1982) for evaluating the liquefaction failure potential is widely used in Japan, Taiwan. In this method, an index, called the Liquefaction Potential Index (IL), is calculated based on an integration of the calculated factor of safety (Fs) over depth with a weighting function. Iwasaki et al. (1982) provided a set of criteria to interpret the calculated index IL based on a calibration with his dataset of field performance cases. However, in their method, the factor of safety (Fs) is based on the SPT method. Whether other liquefaction evaluation methods can be used in conjunction with the index IL or not needs further investigation. In this thesis, the Cone Penetration Test (CPT) data from Yuanlin, Taiwan, the area suffered the most from liquefaction in the 1999 Chi-Chi, Taiwan, earthquake, are analyzed. Robertson and Wride CPT-based method (1998) is used for the calculation of the factor of safety for these cases derived from the Chi-Chi earthquake. These factors of safety are used to define the liquefaction potential and risk indexes. The calculated indexes are then used to construct the failure potential maps, and these maps are checked with the field observations.