Tugas Akhir Sipil
PENGARUH PEMECAH GELOMBANG AMBANG RENDAH DERPORUS DENGAN ISIAN BATU APUNG TERHADAP REDUKSI GELOMBANG REGULER
Coastal abrasion that mainly caused by the activity of the ocean waves is a problem that frequently
asked and needs a serious handling, because it can lead to the degradation of the shoreline. On the
problems mentioned above, it will require a construction of a breakwater that serves to breaks, reflects
and transmits wave energy. In this study, it will be carried out a research on submerged breakwaters or in
other words, the structure of the physical models breakwater made is lower than the surface of the water,
or better known as a low crested breakwater (PEGAR). Researched PEGAR structure will be given holes
on the side of the breakwater with different variations number of holes and will be filled by pumices to fill
the empty space in the physical model named hollow submerged breakwater filled by pumices.
Research located at the Faculty of Engineering Hydraulics and Coastal Laboratory UNRAM using a
tool equipped with artificial wave generator called the wave flume. PEGAR physical model that made with
a height of 35 cm was conditioned stacked between wave flume with variations in width (1/4L, 1/2L and
3/4L), the variation of depth (40 cm, 45 cm and 50 cm) and the variation number of holes with a diameter
of 3.5 cm (16, 32, and 48 holes). The generated waves came with a result of H1 values of the depth of 40
cm, 45 cm, and 50 cm in a row are 8.1 cm; 7,77 cm; and 8.08 cm. And for T1 values are 1.04 sec, 1.09
sec and 1.18 sec. All that depth has a value d/L is the same, namely 0.26
The results showed that the wider the PEGAR, the smaller the value of Rc (distance between peak
of breakwater and water level), the more the number of holes result on the greater the reduction wave.
The results of studies showing the greatest reduction value (smallest transmission) at each depth
contained in PEGAR width ¾ L, water depth of 40 cm (Rc = -5 cm), and number of holes 48 pieces. In the
analysis of wave height obtained the highest value of reduction of 76.10%. At wave length case, the
values obtained the highest reduction of 66.67%. In the analysis of the wave energy values obtained the
highest reduction of 94.29%. If compared with a previous study that researched about submerged
breakwater without filled by pumices with, height, length, and wave energy, value in a row, are 72.22%;
58.00%; and 92.10% with PEGAR wide water depth, and the same number of holes, it can be concluded
that the PEGAR filled by pumices has the ability to reduce the regular wave better than PEGAR without
pumices filling
Keywords: hollow
Tidak ada salinan data
Tidak tersedia versi lain