STABILITY ANALYSIS OF GABION CRUSHED ROCK AS A COASTAL PROTECTION STRUCTURE DUE TO SEA LEVEL RISE USING TWODIMENSIONAL PHYSICAL MODEL
Indonesia as a country in the tropics made up of thousands of island experiences climate pattern changes. The major threat as result of climate change impact in relation to Indonesia’s geographical condition is sea level rise. The threat of sea level rise and islands subsidence into the sea in the future will be made worse by the incident of high sea waves along the coastal areas. The subsidence of several small islands in the outermost borderline of Indonesia’s territory has also become a serious threat due to sea level rise. Coastal protection structures are commonly constructed to reduce the effects of wave action due to sea level rise. In this study, the coastal protection structure is built using material that is readily available in Indonesia, namely gabion crushed rock. Two dimensional physical modeling of gabion crushed rock as a coastal protection structure are conducted in a flume with dimensions length 8 m, width 0.4 m, water depths 0.6 m. A scaled-down model of the structure and the beach profile are put into the flume and subjected to appropriately scaled unidirectional wave conditions. Two models of Gabion crushed rock are applied, and each model is run using two slopes of sea bed. Analysis is conducted to evaluate the geotechnical stability (overturning, sliding, and bearing capacity) of the coastal protection structure. Combined between experimental and numerical results provide a safety factor of the gabion crushed rock is stable and secure. Based on the analysis of the stability of coastal protection structures, is expected to reduce the level of damage to coastal structures and other buildings in the vicinity.