Fernando Veloso Gomes

Efficiency analysis to reflection of a new quay wall type

The effective dissipation of residual wave energy inside a harbour basin is desirable to improve its tranquillity conditions and the efficiency of port operations. The construction of gentle slopes is frequently unfeasible due to space limitations and physical constraints. Hence, other solutions such as quay walls with a perforated (dissipative) berthing face are used. This research analyses the efficiency to reflection of an innovative type of structure consisting of the superposition of unreinforced concrete blocks, with an original geometry. Physical model tests were conducted at a scale of 1/30 for irregular long-crested waves normal to the quay wall, and the results indicated that reflection can be reduced, particularly for small peak wave periods and large wave heights and water levels. This type of structure was adopted in Portuguese ports, namely in the new multipurpose terminal of the Port of Leixões.

Advanced Experimenting on Wave Interaction with Low-Crested Breakwaters

Two-dimensional scaled physical tests were carried out in the Hydraulics Laboratory wave tank of the University of Porto in order to more accurately understand the effect of submerged breakwaters on wave-induced velocities and pressure fields. The slow-varying pressures acting normally on the slope were simultaneously measured with the flow-induced velocities at the surface, and an analysis of their distribution along the whole structure-on the front slopes, rear slopes and along the crown-was done as this information is considered potentially useful for hydraulic design. Different points on the breakwater model were considered and diverse wave conditions were tested, allowing study of the dependency of pressures/velocities on model characteristics. Maximum, minimum and mean phase-averaged values of these variables were calculated, allowing the detection of potentially sensitive areas in terms of pressure and velocities at the surface. A spectral analysis of these physical variables was also perfomed in order to check the results obtained with the regular wave tests.