Journal of Waterway, Port, Coastal, and Ocean Engineering

In a time span of over 3,000 years, the function of harbor breakwaters has remained the same (i.e., the energy dissipation), with differences depending on the general breakwater configurations: rubble mound breakwaters or caisson breakwaters. The recent demands of the sea level rise and the intensification of extreme events related to climate change issues are requiring new replacement schemes and, in most cases, will not be easy to achieve with a simple modification in seawall height. Moreover, the international community recognizes the importance of investing in reliable and reasonable energy sources, which are alternative to the traditional ones. In this context, the combination wave energy converters–harbor breakwaters represent the coastal engineering response to these issues, creating a smart alternative and a path of innovation. This paper presents a review of innovative harbor breakwaters for wave-energy conversion, developing a coconstructed description of the criticality and benefits of such innovation.

Existing studies on the distribution of individual wave overtopping over sea dikes have not taken the effects of the berm into consideration. In this study, a series of physical experiments have been conducted on smooth sea dikes with intermediate berm and low-crested slopes, aiming to gain the knowledge of the berm effects on the probability of wave overtopping $P_{ow}$ and the probability distribution of individual wave overtopping (characterized by a shape factor $b$ and a scale factor $a$, which are related to the probability of wave overtopping $P_{ow}$). Two prediction equations have been derived based on the new experiment data to account for the reduction effects of the berm on the parameters $P_{ow}$ and $b$. In both equations, the relative berm length appears to be more effective in reducing the two parameters in contrast to the relative water depth on the berm, and both parameters decrease with an increase in the relative berm length and a decrease in the relative water depth on the berm in an exponential manner. The equations give an insight into the influence of the berm on the probability distribution of individual wave overtopping and provide good predictions of the berm effects.

Floating breakwaters are recognized as effective wave-attenuation structures for protecting shorelines and marine facilities. However, most common single-row floating breakwaters are unable to effectively attenuate the waves that accompany adverse sea conditions. The double-row floating breakwater was evaluated in order to improve the wave-attenuation performance of floating breakwater technology in adverse seas. A series of scaled experiments in a two-dimensional wave flume was conducted to compare the effectiveness of single- and double-row floating breakwaters. The resulting wave transmission coefficients, reflection coefficients, motion responses, and mooring forces were measured to quantify the hydrodynamic performance of the breakwaters. The double-row floating breakwater exhibited superior wave-attenuation performance when compared with the single-row floating breakwater, especially when subjected to short-period, high-amplitude waves.

In this study, a model was developed to simulate waterway operations in the Houston Ship Channel to estimate vessel waiting time during waterway closures and to determine the optimal closure scenarios. The model allows the decision makers to evaluate and to compare different closure scenarios, and select the one with minimum waiting time. Two years’ of vessel traffic data were analyzed to provide the model input parameters, such as vessel arrival rates, demand at each terminal, loading/unloading process times, and travel time to the destination terminal. Multiple daytime and nighttime closure scenarios for a construction project were evaluated based on the simulation model and recommendations were made based on the results. Results were extended to determine the effect of closures on liquefied petroleum gas (LPG) tankers with daylight navigation restriction.

The main objective of this research was to contribute to the comprehension of actual physical processes responsible for sand accumulations at the Cap Djinet harbor entrance and its immediate surroundings. This maritime infrastructure was implemented at the nearshore area of a sandy cap situated between the mouths of two wadis and bordered by sandy barred beaches classified in the microtidal intermediate beaches category. This stretch of coastline had never been investigated before, and given the importance of sedimentary transfer, an original dual experimental and modeling approach was adopted by using fluorescent tracers to identify sedimentary rates and flux directions under variable wave-energy conditions and testing the adaptability of four well-known formulas for longshore sediment transport predicting local sediment transport conditions. Offshore wave data covering the experimental period were extracted from the Wavewatch III database and input into a two-dimensional (2D) refraction–diffraction model to predict the nearshore wave conditions. The fluorescent tracing results revealed a convergence of sedimentary transfers toward the harbor for any offshore swell regime, with transfer rates reflecting conditions of low and high energy but remaining site specific to the morphodynamic state of each beach. A comparison of results of measured and predicted sedimentary fluxes indicated that the Coastal Engineering Research Center (CERC) model yielded satisfactory results under high-energy conditions and that the Kamphuis model was valid under low-energy conditions.