2-D and 3-D Subsurface Liquefaction Potential Profiling Using Tomography Surface Waves Method

Abstract

A 6.3 Mw earthquake struck Yogyakarta region in 2006 causing many geotechnical damages, e.g., ground cracks, surface displacement, landslides and local liquefactions and soil billings occurred in some regions. From field observations, it was shown that most minor to major structural damages in buildings and bridges were identified near to liquefaction locations. Consequently, a site investigation and advanced analysis for providing the subsurface liquefaction potential information plays important rule in infrastructure design related to structural damage analysis. The aim of this paper is to use of the tomography surface waves method in order to investigate the liquefaction potential in 2-D and 3-D subsurface profile. These seismic surveys were conducted on deep loose sand and sandy soil deposit located inside Universitas Muhammadiyah Yogyakarta (UMY)’s campus, Indonesia which consists of. The liquefaction potential profile was analyzed and generated from combination of the shear wave velocity and soil properties information. Two earthquake scenarios, 6.3 and 8 Mw, were used to simulate the sensitivity of 2-D profile for identifying the liquefaction potential in each soil layer. The results show that the liquefaction potential widely occurs in observed sandy soil and sand deposit layer for stronger earthquake. Finally, the tomography surface waves method is becoming an effective tool for observing liquefaction potential profile in the site investigation, particularly for the purpose of geohazards analysis in the concept of sustainable environmental development.