Estudo do quebramar vertical perfurado LOWREB

Abstract

For their higher reflectivity and despite their higher complexity and cost of construction as compared to vertical structures,perforated structures are becoming more and more popular not only for quay walls inside sheltered harbors, but also for externalcaisson breakwaters, in order to partly overcome the typical drawbacks of vertical imperious structures.In order to analyze the hydraulic behavior towards reflection of perforated structures, physical modelling tests were performedon a three chambers perforated structure, in the wave tank of the Hydraulics Laboratory of the Hydraulics, Water Resources andEnvironment Division, of the Faculty of Engineering of the University of Porto (LH-FEUP).The physical model tests were carried out at a 1:50 scale. The tests' program included two tide levels (low tide and high tide),three wave heights for regular waves (5,5 m, 6,0 m and 6,5 m) and three significant wave heights for irregular waves (3,0 m, 4,0m and 5,0 m) and three wave periods (10 s, 14 s and 18 s). To analyze the influence of porosity and the slots' arrangement on theperforated walls, three models were tested under the same conditions of wave propagation. The hydraulic efficiency with respectto reflection of the perforated structure was compared with the corresponding vertical solution, under the same test conditions.The results of the experimental study indicate that the hydraulic efficiency of the structure increases with the increase of the waveheight, for the low water level, and decrease with the increase of the wave period, for the high water level, and the tested modelsshow an improvement on the hydraulic efficiency with respect to reflection for the higher tide level.