Predicton models for surface manifestation of liquefaction for the practice in Taiwan

抄録

In geotechnical earthquake engineering, evaluating the risk of liquefaction hazards is an important issue for modern seismic engineering design. In Taiwan seismic design codes of ordinary buildings, there are three indicators suggested to quantify the severity of ground manifestation or the damage of low-rise buildings due to liquefaction: the liquefaction potential indicator (LPI) proposed by Iwasaki et al. (1982), the thickness of non-liquefied surface layers (H1) proposed by Ishihara (1985), and the post-liquefaction settlements (SL) proposed by Ishihara and Yoshimine (1992). Associated with these three indicators, the criteria and principles for liquefaction risk evaluation recommended by the corresponding originators are also prevalent to be adopted as indicators for the occurrence of liquefaction in seismic design in Taiwan practice; however, these criteria were generally derived from the investigation and observations from Japan case histories of liquefaction along with calculati on procedures developed in Japan, such that their applicability to Taiwan sites and assessing methods in Taiwan seismic design codes remains unknown. To determine the indicator of occurrence of ground manifestation of liquefaction for the practice in Taiwan, this paper exploits the liquefied and non-liquefied case histories of the 1999 Chi-Chi earthquake and those of the 2016 Meinong earthquake in Taiwan and evaluates their LPI, SL, and H1 values by 4 SPT-based simplified methods which are suggested in Taiwan seismic design codes for the ordinary buildings. Based on the combinations of these values, several prediction models for the surface manifestation of liquefaction can be determined using statistical approaches. These prediction models are compared and discussed in this paper, which is believed as a reference to develop future seismic design recommendations on strategies for liquefaction prevention.