An investigation on the formation of submerged bar under surges in sandy coastal region


Demirci M., AKÖZ M. S.

CHINA OCEAN ENGINEERING, cilt.26, ss.535-546, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 26 Konu: 3
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1007/s13344-012-0040-2
  • Dergi Adı: CHINA OCEAN ENGINEERING
  • Sayfa Sayıları: ss.535-546

Özet

Cross-shore sediment transport rate exposed to waves is very important for coastal morphology, the design of marine structures such as seawalls, jetties, breakwaters etc, and the prevention of coastal erosion and accretion due to onoff shore sediment transportation. In the present study, the experiments on cross-shore sediment transport are carried out in a laboratory wave channel with initial beach slopes of 1/8, 1/10 and 1/15. By using the regular waves with different deep-water wave steepnesses generated by a pedal-type wave generator, the geometrical characteristics of beach profiles under storm conditions and the parameters affecting on-off shore sediment transport are investigated for the beach materials with medium diameters of d (50)=0.25, 0.32, 0.45, 0.62 and 0.80 mm. The offshore bar geometric characteristics are the horizontal distances from the shoreline to the bar beginning (X (b)), crest (X (t)), and ending (X (s)) points, the depth from the bar crest to the still water level (h (t)), and the bar volume (V (bar)). The experimental results have indicated that when the deep-water steepness (H (0)/L (0)) increased, the net movement to seaside increased. With the increasing wave steepness, the bars moved to widen herewith the vertical distances from still water level to the bar beginning (X (b)), crest (X (t)) and ending (X (s)) points and the horizontal distances from the coast line to the bar beginning, crest and ending points increased. It was also shown from experimental results that the horizontal distances from the bar beginning and ending points to the coast line increased with the decrease of the beach slope. The experimental results obtained from this study are compared with previous experimental work and found to be of the same magnitude as the experimental measurements and followed the expected basic trend.