Hubungan Kandungan Butiran Halus Tanah dan Analisa Distribusi Butiran Tanah Terhadap Potensi Likuefaksi

Abstract

Liquefaction is the loss of soil strength caused by cyclic loads that occur during earthquakes, where the soil from a solid state becomes liquid due to increased water pressure, weakening the soil's binding power. This research was conducted to determine the potential for liquefaction in Banaran Village, Galur, Kulon Progo Regency, Special Region of Yogyakarta. This area has a sandy soil type and a high earthquake potential which significantly influences the occurrence of liquefaction. This research was conducted by analyzing based on the results of soil grain distribution tests, and direct shear tests, and using secondary data in the form of SPT data that previous soil mechanics laboratories had carried out. The method used to analyze the liquefaction potential is based on the Tsuchida curve (1970) using the results of grain distribution analysisand the Seed and Idris method from the SPT test results so that the value of soil resistance to liquefaction is obtained. Liquefaction potential is obtained by comparing the values of CRR (Cyclic Resistance Ratio) and CSR (Cyclic Stress Ratio). The results showed that the finer the grain content of the soil, the higher the liquefaction potential. Based on the the analysis of grain distribution using the Tsuchida curve (1970), it is known that soils that are dominantly fine-grained (silt) show the liquefaction potential, while soils that are predominantly fine sand have a high liquefaction potential. Meanwhile, based on the SPT data, the FS value ranges from 0.3 to 0.5.