Showing papers in "Coastal Engineering Journal in 2017"
TL;DR: Several different forms of correction on the first-order derivative of ISPH formulation aiming to find one optimum kernel approximation are compared to achieve much more promising results as compared with experimental data and other numerical approaches.
Abstract: The smoothed particle hydrodynamics (SPH) method is a meshless numerical modeling technique. It has been applied in many different research fields in coastal engineering. Due to the drawback of its kernel approximation, however, the accuracy of SPH simulation results still needs to be improved in the prediction of violent wave impact. This paper compares several different forms of correction on the first-order derivative of ISPH formulation aiming to find one optimum kernel approximation. Based on four benchmark case analysis, we explored different kernel corrections and compared their accuracies. Furthermore, we applied them to one solitary wave and two dam-break flows with violent wave impact. The recommended method has been found to achieve much more promising results as compared with experimental data and other numerical approaches.
71 citations
TL;DR: In this article, a new Artificial Neural Network (ANN) is presented that is able to predict the main parameters describing the wave-structure interaction processes: the mean wave overtopping disc.
Abstract: This contribution presents a new Artificial Neural Network (ANN) tool that is able to predict the main parameters describing the wave-structure interaction processes: the mean wave overtopping disc...
37 citations
TL;DR: In this paper, the authors projected the future beach loss in Japan's 77 coastal zones due to sea-level rise (SLR) based on representative concentration pathway (RCP) scenarios and 21 models of the Coupled Model Intercomparison Project Phase 5 (CMIP5).
Abstract: In this study, we projected the future beach loss in Japan’s 77 coastal zones due to sea-level rise (SLR) based on representative concentration pathway (RCP) scenarios and 21 models of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The beach-loss curve for SLR in Japan was constructed, and uncertainties associated with SLR projections and sediment sizes were evaluated. Beach-loss rates in the future (2081–2100) were projected to be 62% for the ensemble mean RCP2.6 scenario, 71% for RCP4.5, 73% for RCP6.0, and 83% for RCP8.5, and the rates projected by the CMIP5 models for RCP4.5 ranged widely from 61% to 87%. The effect of the spatial distribution of SLR in each CMIP5 model on beach-loss rate in Japan is insignificant, while the effects of differences in the SLR values among RCP scenario and CMIP5 models are significant. The maximum uncertainties associated with sediment sizes (0.2–0.6mm) against the same SLR were assessed to be 38%. Despite significant uncertainties in the projected beach los...
29 citations
TL;DR: In this article, the authors used synthetic tropical cyclones to characterize present and future wave climate associated with tropical cyclone in the Gulf of Mexico, and used the NCEP/NCAR atmospheric reanalysis and the Coupled Model Intercomparison Project Phase 5 models to derive the wave climate under RCPs 45 and 85 scenarios.
Abstract: To generate projections of wave climate associated to tropical cyclones is a challenge due to their short historical record of events, their low occurrence, and the poor wind field resolution in General Circulation Models Hence, synthetic tropical cyclones provide an alternative to overcome such limitations, improving robust statistics under both present and future climates We use synthetic events to characterize present and future wave climate associated with tropical cyclones in the Gulf of Mexico The NCEP/NCAR atmospheric reanalysis and the Coupled Model Intercomparison Project Phase 5 models NOAA/GFDL CM3 and UK Met Office HADGEM2-ES, were used to derive present and future wave climate under RCPs 45 and 85 scenarios The GFDL model shows less bias in the present climate with respect to NCEP/NCAR results Furthermore, the numerical results suggest an increase in wave activity for the future climate in the Caribbean Sea and Northern Gulf of Mexico, whereas some areas are expected to decrease the wave energy, as the stretch of the Gulf of Mexico between Yucatan and Southern Texas The results have practical implications on the design of offshore structures The 100-year design wave based on the present climate might result in under/over design of structures, owing to the lifespan of a structure that is within the future wave climate period
26 citations
TL;DR: In a free-surface flow, a sudden increase in water depth induces a positive surge, also called compression wave or bore as mentioned in this paper, and a physical study was conducted in relatively large-size rectangular c...
Abstract: In a free-surface flow, a sudden increase in water depth induces a positive surge, also called compression wave or bore. Herein a physical study was conducted in relatively large-size rectangular c...
21 citations
TL;DR: In this article, the authors report the post-disaster survey results of storm surge and waves due to Super Typhoon Meranti (local name: Ferdie), along the coastline of the province of Batanes, Philippines.
Abstract: This paper reports the post-disaster survey results of storm surge and waves due to Super Typhoon Meranti (local name: Ferdie), along the coastline of the province of Batanes, Philippines. The surv...
21 citations
TL;DR: In this article, a two-dimensional Lagrangian model based on the weakly compressible smoothed particle hydrodynamics (WCSPH) was developed to explore the hydroynamics of standing waves impinge on a...
Abstract: In this paper, a two-dimensional Lagrangian model based on the weakly compressible smoothed particle hydrodynamics (WCSPH) was developed to explore the hydrodynamics of standing waves impinge on a ...
19 citations
TL;DR: In this article, an experimental study was performed to examine multiple debris entrainment and transport in tsunami-like flow conditions at Waseda University in Tokyo, Japan, in order to examine the effect of tsunami wave conditions on multiple types of materials.
Abstract: An experimental study was performed to examine multiple debris entrainment and transport in tsunami-like flow conditions. The study was performed in the Tsunami Wave Basin at Waseda University. The...
19 citations
TL;DR: In this article, an adapted methodology to evaluate coastal erosion vulnerability, which provides a basis for decision-making concerning risk management strategies, is described, and the vulnerability of coastal erosion is evaluated.
Abstract: In this paper, an adapted methodology to evaluate coastal erosion vulnerability, which provides a basis for decision-making concerning risk management strategies, is described. The vulnerability ev...
18 citations
TL;DR: Experiments were conducted at a 1:20 length scale in a large tsunami flume to measure wave evolution and pressures on and around structural elements as discussed by the authors, and the water surface profiles of waves propagating...
Abstract: Experiments were conducted at a 1:20 length scale in a large tsunami flume to measure wave evolution and pressures on and around structural elements. The water surface profiles of waves propagating...
16 citations
TL;DR: In this paper, the authors present an experimental investigation of local scour beneath two identical pipelines placed in a tandem arrangement, showing that changes in the equilibrium scour depth and time scale of scour due to t...
Abstract: This paper presents an experimental investigation of local scour beneath two identical pipelines placed in a tandem arrangement. Changes in the equilibrium scour depth and time scale of scour due t...
TL;DR: In this paper, the authors applied various methods to analyze the wave runup on fixed columns, including linear and higher order diffraction theories and semi-empirical correlations, but none of the methods applied to fixed columns is considered in this paper.
Abstract: Previous studies have applied various methods to analyze the wave runup on fixed columns, including linear and higher order diffraction theories and semi-empirical correlations However, none of th
TL;DR: The authors evaluated future changes in storm surge caused by global warming, dynamical downscaling was conducted using the Weather Research and Forecasting model for Typhoon Vera under present-and future-c...
Abstract: To evaluate future changes in storm surge caused by global warming, dynamical downscaling was conducted using the Weather Research and Forecasting model for Typhoon Vera under present- and future-c...
TL;DR: In this paper, a first-order upwind scheme FDM is applied to model sedimentation, which provides the solution to equations describing changes in bathymetry in time and space coupled with simultaneous changes of bed sediment distribution.
Abstract: The proposed formula for modeling sedimentation is based on a concept of hydrodynamic equilibrium in sediment transport. Hydrodynamic equilibrium occurs when the sediment transport is in a form of grain jumps with the distance traveled dx smaller than the one established in the numerical modeling. A first-order upwind scheme FDM is applied. It provides the solution to equations describing changes in bathymetry in time and space coupled with simultaneous changes of bed sediment distribution. A clear-cut division of sediment transport into those during wave crest and wave trough is proposed. The results of bathymetry modeling coincided satisfactorily with the laboratory data. Moreover, the longer the experiments run, the more the results of measurements are compliant with the calculations. A certain time is needed for sediment transport to reach the hydrodynamic equilibrium, especially when the suspended load is significant. It is reached after going through the initial stages of bed level changes coupled w...
TL;DR: In this paper, a two-dimensional compound model is developed to simulate coastal sediment transport and bed morphology evolution due to wave action, which is valid under combined waves and currents including the wave asymmetry and phase-lag effects.
Abstract: A two horizontal dimensional compound model is developed to simulate coastal sediment transport and bed morphology evolution due to wave action. The wave module is a higher-order Boussinesq-type model. The bed load in the surf zone is computed from an advanced semi-empirical formula while the suspended load can be calculated through the solution of the advection-diffusion equation for the sediment or alternatively from a simplified formula. The estimation of the sediment transport in the swash zone is based on the ballistic theory. The unified sediment transport module is valid under combined waves and currents including the wave asymmetry and phase-lag effects. The bathymetry is updated through the sediment conservation equation and the morphological accelerator factor technique accounts for extended simulation time. The model is validated against a number of short-term tests in one horizontal dimension. The response is generally good with most of the morphological features being reproduced in the cross-shore direction. A comparison between various sediment transport formulae and a sensitivity analysis are also performed illustrating the need for inclusion of the phase-lag effects.
TL;DR: Hamanako is an economically and culturally important tidal lake on the Pacific coast of Honshu, Japan as discussed by the authors, and entrance works were constructed to regulate the channel to the lake.
Abstract: Hamanako is an economically and culturally important tidal lake on the Pacific coast of Honshu, Japan. Between 1954 and 1973, entrance works were constructed to regulate the channel to the lake. In...
TL;DR: The forces and loading resulting from shallow water breaking waves are one of the most important drivers in coastal engineering design and morphological change and the importance of accurately and pre-planned coastal engineering is emphasized.
Abstract: The forces and loading resulting from shallow water breaking waves are one of the most important drivers in coastal engineering design and morphological change. The importance of accurately and pre...
TL;DR: In this paper, a bottom-tilting wave maker has been designed and investigated in order to generate very long waves in the laboratory, motivated by recent field observations of tsunamis.
Abstract: Motivated by recent field observations of tsunamis, a new wave maker, namely bottom-tilting wave maker, has been designed and investigated in order to generate very long waves in the laboratory. Th...
TL;DR: In this paper, a new concrete armor unit has been developed and applied as single layer armo-straps in the design of rubble mound breakwaters, which are used in the construction of concrete breakwaters.
Abstract: Single layer concrete armor systems are being widely used nowadays in the design of rubble mound breakwaters. Recently, a new concrete armor unit has been developed and applied as single layer armo...
TL;DR: Results indicate that the multi-objective optimization approach can be effectively applied for the optimal design of a vertical cellular breakwater.
Abstract: In this paper, a methodology based on multi-objective optimization is proposed for the optimal design of a vertical cellular breakwater, consisting of prefabricated rectangular cells with two verti...
TL;DR: Some experts believe that Hong Kong will probably be subjected to more extreme weather conditions due to climate change as mentioned in this paper, and to better understand the potential implications of the effects of climate ch...
Abstract: Some experts believe that Hong Kong will probably be subjected to more extreme weather conditions due to climate change. To better understand the potential implications of the effects of climate ch...
TL;DR: In this paper, the mean values and the standard deviations of the surface Stokes drift and the Stokes transport were used to estimate the drift within sea states based on long-term variation of wind conditions.
Abstract: This paper provides a simple analytical method which can be used to give estimates of the Stokes drift within sea states based on long-term variation of wind conditions. This is exemplified by using long-term wind statistics from the Northern North Sea and the Northwest Shelf of Australia. The paper presents the mean values and the standard deviations of the surface Stokes drift and the Stokes transport. Based on, for example, global wind statistics, the present analytical results can be used to make estimates of the Stokes drift.
TL;DR: In this article, the main recommendations and technical criteria along the world, the design project of a breakwater must address the verification of the different failure modes that can affect the bre....
Abstract: According to the main recommendations and technical criteria along the world, the design project of a breakwater must address the verification of the different failure modes that can affect the bre...
TL;DR: In this paper, the authors assess the climate change impact on local storm surges along the coasts of the Korean Peninsula and Tottori Prefecture, Japan, and conduct a series of storm surge simulations.
Abstract: The present study assesses the climate change impact on local storm surges along the coasts of the Korean Peninsula and Tottori Prefecture, Japan. A series of storm surge simulations are conducted ...
TL;DR: In this article, a wave flume with a sand beach was used to examine the movement of 10 wooden blocks (floatable objects) placed on the foreshore and berm as well as on short and long pilings.
Abstract: Shore protection projects require the prediction of coastal storm damage and economic loss but the damage processes are not well understood. An exploratory experiment consisting of 11 tests was conducted in a wave flume with a sand beach to examine the movement of 10 wooden blocks (floatable objects) placed on the foreshore and berm as well as on short and long pilings. The still water level was varied to create accretional and erosional profile changes. The cross-shore wave transformation on the beach and the wave overtopping and overwash of the berm were measured in 101 runs of irregular waves where each run lasted 400s. The initial block elevation above the sand surface had little effect on the hydrodynamics, sediment transport, and profile evolution in this experiment with widely-spaced blocks. The block floating and sliding on the sand surface and the block falling from the pilings depended on the swash hydrodynamics and block clearance above the foreshore and berm whose profile varied during each te...
TL;DR: A Markov chain Monte Carlo simulation is developed to increase the quantity of historical data from Taiwan followed by the use of the least squares support vector machine (LS-SVM) to estimate the probability density function (PDF) of random variables.
Abstract: This study proposes a safety evaluation process for a prevention structure against tsunamis, in which the most updated guideline (i.e. FEMA P-646) is used as the deterministic analysis and a probab...
TL;DR: In this paper, the authors developed a one-dimensional topographical model of an estuary delta as the first step of assessing climate change effects, including three major effects: tidal flow, waves and sediment supply from the river.
Abstract: Predicting the long-term topographical change based on results of a time-slice experiment using a General Circulation Model (GCM) is difficult because actual change is a result of the continuum of events occurring in succession leading from the past to the future We developed a one-dimensional topographical model of an estuary delta as the first step of assessing climate change effects Three major effects, ie tidal flow, waves and sediment supply from the river, were included in this model In order to estimate the sensitivity of these effects, simulations with virtual conditions were conducted These simulations show equilibrium profiles that are close to the results of Roberts et al 2000] “Predicting the profile of intertidal mudflats formed by cross-shore tidal currents,” Proc Marine Sci 3, 263–285] The simulation results were validated with observation data from the Shirakawa River delta As a long-term prediction (about 37 years), the propagation of the rollover point was less than the actual data showed The gradient of the subtidal zone was gentler than that observed However, the short-term prediction (about 17 years) agrees with the observation data These results show that old, unreliable, observation data used as a boundary condition significantly affects the reproducibility of the actual tidal flat profile Finally, the effect of continuous Sea Level Rise (SLR) over 100 years from the present was investigated As expected, the simulation results show a shift of the shoreline landward The water depths in the intertidal and subtidal zones increase compared to a no-SLR condition Therefore, the topset area grows as a consequence of SLR Additionally, it was shown that future accumulation in the subtidal zone is reduced with SLR