Evaluation of Sea Wall Structure Retained Coastal Road in Tahuna City - Sangihe Island at North Sulawesi Province

摘要

The Gulf of Tahuna shore zone located on the Sangihe Island, North Sulawesi Province. Tahuna Sea Wall was built in 2006 by reclaimed area along of the shore. According to the effort of the regional development program is to enlarge the road facility by developing the water in front of the coastal road on longshore ± 3.90 km by reclamation. The design of seawall foundation used the treatment of wood pile for avoiding the settlement, quicksand and liquefaction hazard. It was due to the reason that foundation material consisted of uniform sandy gradation, and then, for reducing the earth force especially earthquake condition, the design of sea wall also provided sequgrid (combination geogrid and geotextile) reinforcement with the type uniaxial of 40/40 and limited tensile strength of 40 kN/m. Now, the sea wall structure often popular is called the boulevard of Tahuna City. The storm surge of some disaster has occurred for example in the 2012 and the last incident happened on June 21, 2016. Final condition sea wall structure quite safe to retained storm surge attacked. A little problem scours occurred toe protection sea wall, must nourishment as original design at several sections.