Study of the sub-surface geological condition of the Sibalaya flow liquefaction using seismic refraction method

Abstract

Understanding the occurrence of flow liquefaction requires knowledge of the sub-surface condition controlling its occurrence. This paper presents the results of seismic refraction surveys conducted to evaluate the sub-surface geological condition in the Sibalaya flow liquefaction area. From the interpretation of the seismic refraction model, an inclined boundary presents between the near-surface sediment layers. Further examinations of the SRT images demonstrate the existence of localized basinal structures in the rock layer with the highest P-wave velocity. The basinal structure may be associated with a hidden normal fault system of horst-graben structures. Thus, this study indicates that such a complex sub-surface geological structure also contributed to the Sibalaya flow liquefaction occurrence.