Potential Map and Zonation of Soil Liquefaction in Taiwan

Soil liquefaction has been a major cause of damage to lifelines, facilities and building foundations in past earthquakes and clearly poses a significant threat to the integrity of structures and facilities during future earthquake. If the liquefaction potential areas could be predicted in advance, it would be possible to plan for earthquake disasters mitigation program. Zonation for liquefaction thus becomes an important goal for recent work. The purpose of this project is to compile the liquefaction potential map of Taiwan based on appropriate evaluation methods and to provide as a basic reference for drafting of hazard mitigation policy. In the past years, data from more than 14000 boreholes were collected and analyzed by joining researchers from various universities. The borehole data were extracted from geotechnical investigation reports for public construction works, and the geotechnical database of the collected data was constructed. Liquefaction potential of each area was evaluated using modified Seed's, Tokimatsu & Yoshimi's and NJRA's methods, and the liquefaction potential maps were developed based on calculated liquefaction potential index. The GIS system for display and query of the liquefaction maps as well as the database were constructed. By overlaying of related attribute data and basic maps, the thematic map could be produced and microzonation of soil liquefaction could be done.