LOAD DYNAMIC METHODS TO PREVENT LIQUEFACTION AT YOGYAKARTA INTERNATIONAL AIRPORT INDONESIA

Liquefaction is a phenomenon loss the strength of the soil due to a cyclic load, like the load caused by an earthquake, which causes the soil to deform from solid to liquid. occurs in saturated soil due to increased pore water pressure and effective reduction of soil stress and also reduces the shear strength of the soil. This researchhas purpose to determine the potential of liquefaction that can occur and how to prevention it with Dynamic Compaction. This research is located in the Yogyakarta International Airport Development Project (YIA). This research starts from collect of SPT and CPT soil data and laboratory data runway, Development Project for testing CSR (Cyclic Stress Ratio) and CRR (Cyclic Resistance Ratio) and comparing results before and after compaction. The results showed that there was before soil reinforcement, some soil layers at each review point still have the potential for liquefaction. However, after soil compaction with dynamic compaction, it can be concluded that all points of observation are safe from liquefaction potential because all points have a Safety Factor > 1 and has a value (N1) 60 ≥ 30 classified as unliquefied soil. The liquefaction zone is at varying depths ranging from 2 - 6 meters. Dynamic load method test can prevent liquefaction on sandy soil