Abstract:
Coastal embankment is a structural measure usually taken near coastline to protect
inland habitat and crops. This research work considers only those embankments
which are located along the coast line directly facing the sea. The general practices in
Bangladesh for the design of coastal embankment normally consider high tide level
as the design high water. Based on the design criteria it can be said that, the
consideration of periodicity of small waves while designing an embankment is one of
the most important parameter. For accurate design consideration, the main
parameters are wave height, wave direction, current and soil properties. The effects
of the above considerations might result in changes in the alignment, crest level,
slope or drainage system of the embankment. The study analyzes the effect of
dynamic loading due to wave associated with submerged, floating breakwater and
CC block condition on coastal embankment.
An experimental investigation was conducted to study the behaviour of wave
parameters with different loading conditions in the laboratory flumes of Hydraulics
and River Engineering Laboratory of the Department of Water Resources
Engineering, BUET. Test runs were conducted for different wave periods, water
depths with loading conditions such as by providing CC block, submerged
breakwater and floating breakwater. Before the test runs, instrumental setup of wave
generator had been done and pointed for individual condition runs. Total 36 test runs
were conducted. All the above performances have been done by two different slopes
of 1:2 and 1:3 against the wave action by changing the wave period, water depth and
protection work.
Wave loads, especially dynamic loads were calculated from the experimental values
of wave parameters by using Sainflou’s formulae (1928). The study shows that
presence of breakwater in front of the coastal embankment resulted in a change in the
loading distribution. Breakwater position (submerged or floating) individually affect
the wave loads further more.
