Abstract
The purpose of this study is to develop a new flattype armor block with large openings aiming at high stability and economical advantage. Wave force measurements were performed to investigate the effect of the size and placement pattern of openings for both horizontal and vertical wave forces. Stability tests were conducted to evaluate the stability number for use in the Hudson formula. Stability test results clearly show that the stability of new flat type armor block has improved drastically in comparison with the existing X-shaped block. New flat type armor block reduced the amount of concrete needed by 25% that of the existing X-shaped block, indicating that it can contribute to an outstanding cost reduction as well.
