Geotechnical Database of Chiang Mai Basin Using GIS Approach for Soil Liquefaction Analysis

Abstract

Chiang Mai basin where the Chiang Mai city located on is susceptible to seismic activity due to its proximity to an active fault zone. One potential consequence of an earthquake in this area is soil liquefaction. This is because the topsoil in Chiang Mai basin is mostly composed of alluvium, which is a mixture of clay, sand, and silt deposited by rivers. This study gathered geotechnical data of Chiang Mai basin including boring-log, water table levels, peak ground acceleration, shear wave velocity, and geological maps. Interpolation methods such as inverse distance weighting, nearest-neighbor, natural neighbor, and kriging were implemented to create a GIS database for soil liquefaction analysis. The accuracy of the interpolation methods was evaluated using the root mean square error. The GIS database was also compared to the actual geology of the Chiang Mai basin. The results of this study can be used to prepare a soil liquefaction hazard map in the future.