Laboratory Physical Modeling of Rakuna IV Armor Block Stability and Overtopping Discharge of Patimban Port’s Rubble Mound Breakwater

Abstract

A series of 2D physical model experiment was carried out to examine the potential advantage of Rakuna IV armor block over Tetrapod blocks in term of stability, number of blocks for the same cross-section and overtopping discharge under predetermined experiment conditions. For the sea side slope armor, Rakuna IV – 2ton armor blocks perform advantageous stability in comparison to Tetrapod-2ton blocks for the case of Hmo= 1.2×Hs. For the harbor side slope armor and toe armor, rocks of 300-1000kg/pc performs high stability with very less damage, with S << 2 and S=0.11 respectively (S=2 is initial damage condition). For the crest elevation +2.5mCD, overtopping discharge over either Rakuna IV or Tetrapod armored slopes are more or less at the same amount and both are still within allowed criteria limit. For the crest elevation +2.1mCD, overtopping discharge over Rakuna IV is still within allowed criteria limit. Reduction of breakwater crest from +2.5mCD to +2.1mCD (Rakuna IV) has relatively increased overtopping discharge four times higher, but it is still within allowed criteria limit. For the present experimental design, Rakuna IV armor layer is requiring less number of fabricated blocks for the same cross-section compared to Tetrapod block.