PHYSICAL MODELLING OF ARTIFICIAL REEF FOR COASTAL PROTECTION

A study on the artificial reef and to propose a newly designed artificial reef is carried out
for this project. This project involves two phases where the first phase is to be carried out
in the first semester involving designing the artificial reef and preliminary experiments.
For the second phase, experiments on the proposed design of artificial reef will be
conducted as to obtain the effectiveness of the design in attenuating waves. This paper
represents the second phase of the project where the experiments and the analysis of
result for the designed artificial reef is conducted.
The reefs dissipate wave energy and at the same time act as the sandy materials that
nourishes the beach. Human intervention and activities which include sea water
pollutions, mining and exploitation of the coral reefs frequently damage natural reef and
leave the beach prone to direct wave attack
Long lasting artificial reefs are useful tools for restoring our reef systems to a natural and
productive balance. As a result, a newly designed artificial reef has been proposed for this
project named 'Trape Reef. This artificial reef is expected to reduce the wave reflection
in nearshore area. The design for this artificial reef is made in trapezoidal shape with a
hollow cross section. On the surface of the structure there are holes created to dissipate
the wave parameters and to make a path for the marine lives to get into the hollow cross
section.
The experiments on performance of newly designed artificial reef were done to observe
the effectiveness of 'Trape Reef. It can be seen that 'Trape Reef can gives Cj as low as
0.1. However, the Ct values increase through increasing water depth. Results that show
the most effectiveness of 'Trape Reef is at water depth 20 cm. The experiment on the
'Trape Reef conducted indicated that as water depth increases, the reflection and
transmission coefficient increase, while loss coefficient decreases.
n