Daerah Istimewa Yogyakarta (DIY) is one of the region in Indonesia that potentially have earthquake disaster. In geotechnic point of view , soil profile in DIY, especially, in the city of Yogyakarta is covered by sand layer up to the depth of 60 meter. The soil is uniformly graded sand with low of N- SPT values near the ground surface, and it gets higher on the deep elevation.
Groundwater level at the elevation of 12 meter during the dry seasons and getting higher up to the depth of 4 meters during rainy seasons. Therefore, based on the condition of soil profile, groundwater level and N-SPT value, it is possible that there will be liquefaction in DIY. The research was conducted to predict the liquefaction that may happen in DIY. In this research, the data were collected the form of boring-log, ands Standard Penetration Test (SPT). There were more than
10 boring, and 10 SPT data collected from the north of DIY. Moreover, the additional required data such as mechanical properties of the soil were tested in the Soil Laboratory Department of Civil Engineering Universitas Atma Jaya Yogyakarta. The soil data, then analyzed by means of the method developed by NCEER The results indicates that the CSR obtained from the previous
earthquake data are relatively smaller compared to the CRR for every elevation. It is probably due to
horizontal acceleration-gravitation ratio ( 0.03; 0.088;0.116; 0.123; and 0.142), and total – effective
stress ratio are very small. From CRR-CSR ratio, there were no liquefaction zone in the specific depth . However, in the future if there is earthquake that generates horizontal acceleration more than 0.2 g , there will probably be liquefaction in DIY.