bluuebunny/crossref_metadata_2025 huggingface dataset:
PROGEES DES FELTHODES DE ETSUPE DE LA HOULE NATURELLE AU LABORATOIRE NATIONAL D'HYRAULIQUE
Authors: Bonnefille Rene , Mormault Pierre , Valembois Jean
Published: February 2019

Le Laboratoiie National d'Hydraulique exploite et deveioppe depuis une qumzame d'annees des techniques de mesure propres 1 l1 etude du regime de la houle le long du littoral marin. Le type le plus connu de ces instruments est l'enregistreur autonome de houle (l), qui comporte dans un caisson etanche immerge, un manom-jtre differentie'1 et une camera enregistrant les fluctuations de pression a une profondeur doterminoe. Cette methode de mesure indirecte des caractoristiques de la houle naturelle est la plus generalenent adoptee ; mais elle poss^de le grave inconvenient de presenter une precision li^it^e, car dans l'etat actuel des connaissances, ll n'existe pat. de relation exacte et simple entre une grandeur caractf^ristique ae 1'agitatior de la mer en surface et une grandeur caract^ristique de la fluctuation de pression mduite -1 une profondeur donnee. Aussi le Laooratoire National d"[ydraulique s'est-il attache n creer des methodee ae mesure directes de l'agitation de la surface de la mer, netnodes que nous allons deenre ci-dessous.
THE OBITSDI RIVER WATER SCHEME AND IT'S SALINITY PROBLEMS
Authors: Miyake Yasuo , Kishi Tsutomu , Takahashi Junichi , Ikeda Tatsuya
Published: February 2019

In this paper, the authors describe the salinity problems and their solutions which were encountered in the Obitsui River Water Scheme. The salinity problems in this water scheme are caused by differnt origins; The one is seepage of the sea water through the earth embankment, and the other is the diffusion of the saline water from the reservoir bed. Laboratory experiments and field observations were performed to confirm the detailed design of the reservoir. It was found that the salinity concentration of the reservoir water could be controlled less than 500ppm m weight, when the earth embankment of 1,000m width was released. The another way of salinity control studied by the authors was the recharging channel. At the present stage of studies, the recharging channel is considered to be favourable. Finally, the wind effect on the mterfacial mixing of the salt and fresh water in a reservoir was studied. An approximate theory to calculate the mixing rate of the salt water was derived from the field observations.
PRELIMINARY RESULTS AND COMPARISON OF DYE TRACER STUDIES CONDUCTED IN HAREORS, "ESTUARIFS, AND COASTAL lfATFRS
Authors: Fisher Leo J.
Published: February 2019

Dye tracer studies have been conducted by the U. S. Naval Oceanographic Office in harbors, estuaries, and coastal waters during the past seven years. The purpose of the studies was to obtain data which could be used to (1) estimate the time (sometimes called the flushing time) required to remove or reduce to permissible concentrations the soluble part of any contaminant which may be released as a point source m a specific study area and (2) determine the temporal and spatial distribution of a contaminant released in a study area. The areas studied are listed in Table 1. Field reports (unpublished) have been prepared which describe m detail the results of each study. A brief description of the tracers, equipment, and sampling techniques used, and a discussion of some of the results are presented.
WAVE BOUNDARY LAYERS AMD FRICTION FACTORS
Authors: Jonsson Ivar G.
Published: February 2019

In the last two decades the problem of wave height damping due to bottom friction has received increasing attention among near-shore oceanographers. This fact is reflected in the wealth of papers on the subject; the list of references given herein presents a minor selection only. This paper is an attempt to re-evaluate and systematize the many observations and the rather few detailed measurements of the phenomenon. In nature the wave boundary layer will always be rough turbulent. This is not necessarily the case in a hydraulic model. The aim is therefore to make it possible to determine the proper flow regime for a pure short-period wave motion over a given bed. Values for the wave friction factor and the wave boundary layer thickness are also proposed. The main results of the study are presented in three diagrams giving flow regimes, friction factors and boundary layer thicknesses. Flow parameters are a-jjj/k and RE = U-|j_ ai~/v, a-]m and U-|m being maximum bottom amplitude and velocity according to first order potential wave theory, k is the Nikuradse roughness parameter.
WAVES AT CAMP PENDLETON, CALIFORNIA
Authors: Powers William H. , Draper Laurence , Briggs Patricia M.
Published: February 2019

Waves were recorded for nine years at Camp Pendleton, California, and the results of an analysis of records over two years are presented in this paper.
EFFECT OF BEACH SLOPE AND SHOALING ON WAVE ASYMMETRY
Authors: Adeyemo M.D.
Published: February 2019

This paper is concerned with the quantitative study of the geometrical asymmetry associated with shallow water oscillatory waves in the breaker zone. Three descriptions of wave asymmetry are defined and examined : (l) Wave vertical asymmetry i2^ Wave slope asymmetry and (3) Wave horizontal asymmetry The effects of shoaling, produced by beaches of different slope, on the wave asymmetry are examined. Six beach slopes in the range 1:4 to 1:18 were employed, and a quantitative correlation was found to exist between the wave slope asymmetry, wave horizontal asymmetry and the wave vertical asymmetry. An expression is given for the wave horizontal asymmetry based on the expression for the wave vertical asymmetry from the cnoidal wave theory. The theoretical study of wave slope asymmetry made by Biesel (1) and the results of the experimental work on the wave slope asymmetry in the present work are compared and gave a good agreement*
THE EFFECTS OF BOTTOM CONFIGURATION ON THE DEFORMATION, BREAKING AND RUN-UP OF SOLITARY WAVES
Authors: Camfield Frederick E. , Street Robert L.
Published: February 2019

Experiments were conducted to determine the various effects on the shoaling, breaking and run-up of solitary waves resulting from the bottom configuration. An initial set of experiments investigated the effect of the initial bottom slope on the breaking and run-up of a wave on a second, higher slope. A second set of experiments considered the effect of a continental shelf configuration on the transmissibility of waves in the shoreward direction, and the decomposition of the waves due to the shallower water depth on the continental shelf. It was found that, in order to make predictions at or near the shoreline for waves generated in deep water, it is necessary to consider the total configuration of the bottom leading to the shoreline.
WAVE REFLECTION AND TRANSMISSION IN CHANNELS OF VARIABLE SECTION
Authors: Bourodimos E.L. , Ippen A.T.
Published: February 2019

Reflection and transmission phenomena were investigated in a laboratory channel for transitions of linearly varying depth and/or width terminating in channels of reduced cross-section. Upstream wave characteristics were varied from deep to shallow water waves by changing wave frequencies, amplitudes and channel depths over a wide spectrum of conditions. Experimental values were corrected to correspond to transmission in an endless channel. The reflection and transmission coefficients are given as functions of the pertinent dimensionless parameters such as: group velocity ratio, channel depth ratio and wave steepness. Associated wave energies were also evaluated.
UPWIND TRAVEL OF REFLECTED WAVES
Authors: Richey E.P.
Published: February 2019

Wind waves in a lake have been observed to reflect from a barrier and to travel upwind for considerable distances. A model has been devised which provides a means of predicting the decay of these waves as a function of wind speed and direction with respect to the barrier. Two floating bridges across a deep lake have formed a convenient, full-scale test basin for the formation and observation of the reflected waves under a range of wind speeds and directions. Wave characteristics have been measured to a limited extent by photographic means, a portable wave probe and visually to provide seme verification of the results computed from the model. The measured and the predicted wave heights and the zones influenced by the waves were found to be in general qualitative agreement.
WAVES OFF BENGHAZI HARBOUK - LIBYA
Authors: Singh K.Y. , Draper L.
Published: February 2019

This paper gives details of the wave studies associated with the reconstruction of Benghazi Harbour, from the early forecasts, the installation of a recording instrument, its failures and repairs, to forecasts based on more recent techniques and subsequent analysis and presentation of results of records taken from 1961 to 1965- Conclusions have been drawn and some suggestions for future consideration have been given.
THE EFFECT OF WAVES ON THE PROFILE OF A NATURAL BEACH
Authors: Thompson Warren C. , Harlett John C.
Published: February 2019

A 60-day field study was conducted on a selected natural beach in which the beach profile was measured daily and the waves incident upon the profile were recorded continuously. Beach and wave parameters derived from the field data were empirically combined to yield: (a) quantitative relationships between the change in the profile and the-average deepwater wave steepness and wave power over a lunar day (24.8 hours) given the profile at the beginning of the period, (b) equilibrium profiles for different values of wave steepness, (c) an empirical relationship between wave steepness and wave power which agrees well with theory, and (d) rates at which the beach profile approached equilibrium for given initial conditions of non-equilibrium. Using the relationship developed between beach change and wave steepness, hindcasts were made of the day-to-day sand elevation at a selected location near the middle of the profile and were found to agree fairly well with the observed sand level.
COLLECTIVE MOVEMENT OF SEDIMENT IN LITTORAL ENVIRONMENT
Authors: Sonu Choule J.
Published: February 2019

Collective movements of sediment occur in the form of sand waves m the nearshore zone and affect beach topography to a significant extent. Bar-type sand waves move only in the onshore direction and account for various accretive profiles on the subaerial beach. When the beach is eroded, these sand waves are simply disintegrated on the subaerial beach, instead of migrating back in the form of sand waves. These characteristics of bar-type sand waves help explain dynamic behavior of beach profiles with respect to profile configuration, sediment storage, and beach width. Cusp-type sand waves are considered to be a product of interaction between longshore currents and an erodible bed. Their presence causes variability in beach profiles along the shore between those containing a prominent bar and those without a bar. Migration of these sand waves may well produce pulsational transfer of material along the shore.
SIMULATION OF HORIZONTAL TURBULENT DIFFUSION OF PARTICLES UNDER WAVES
Authors: Murray Stephen P.
Published: February 2019

By oscillation of an array of turbulence-generating grids in still water, the turbulent fluid velocity field m shoaling waves near the bottom is simulated in a laboratory channel. Solid particles with fall velocities varying between 1 and 40 mm/sec are introduced into the test volume from above. Multiple- image photography using ultraviolet lighting techniques and a suitably placed mirror allow recording of the gram trajectories as functions of time and three space dimensions simultaneously. The Lagrangian intensities of turbulence and diffusion coefficients are then directly measured from the photographic data. The scale times, scale lengths, and the frequencies of the power spectra modes can then be calculated. Properties of the fluid turbulence are inferred from the quasi-neutral particles. The analysis, which is restricted to the component of diffusion in the hori2ontal direction normal to the grid motion, shows that the turbulent velocity distributions of both fluid and heavy particles are Gaussian, and that their standard deviations (intensities of turbulence) increase regularly with increasing grid Reynolds numbers (grid speeds). Diffusion coefficients likewise generally increase with increasing grid Reynolds numbers. Diffusivities of the heavy particles relative to the fluid are a function of both particle fall velocity and the structure of the fluid turbulence itself.
LABORATORY STUDY ON OSCILLATORY BOUNDARY LAYER FLOW
Authors: Horikawa Kiyoshi , Watanabe Akira
Published: February 2019

The characteristics of oscillatory boundary layer flow have been treated with keen interest during the last decade from the various aspects. Among the previous results the theoretical treatment by K. Kajiura must be the most important and fruitful one to advance in our knowledge on the present phenomena. On the other hand the senior author has had a real interest in the behaviour of sediment particles due to oscillatory fluid motion, and has conducted his systematic investigations on the sediment movement in nearshore area. The aim of this paper is to introduce some results of the recent investigations conducted at the Coastal Engineering Laboratory, University of Tokyo, with the intention of investigating the applicability of Kajiura's theory to the oscillatory flow in the vicinity of bottom with sand ripples.
WAVE MEASUREMENTS BY A PRESSURE TYPE WAVE GAUGE
Authors: Bergan P.O , Torum A. , Tratteberg A.
Published: February 2019

The paper deals with comparative measurements of irregular model waves by a pressure type wave gauge and a continuous wire wave gauge. For the depth and wave conditions used in the study it is concluded that the height of individual waves obtained by a pressure type gauge and using the first order wave theory may be in considerable error, while wave height distributions and wave spectra are fairly good estimated.
THE DYNAMICS OP A COAST WITH A GROYNE SYSTEM
Authors: Bakker W.T.
Published: February 2019

A mathematical theory will be given about the phenomena, which occur if on a coastal area groynes are constructed. In former similar theories ( [1] , [2], [3] , [4], [5] ) the coast was schematised by one coastline. In the following theory it is presented by two lines, one line representing the beach and the other one the inshore. The theory is based upon the following assumptions- 1° the littoral drift along beach and inshore is linear dependent of the angle of wave incidence and therefore of the direction of the line of beach and inshore respectively; 2 the transport perpendicular to the coast depends on the steepness of the profile. If the distance between the line of the beach and the line of the inshore is less than a certain equilibrium distance, the profile is too steep and there is an offshore transport. In the opposite case there is an onshore transport. The relation between offshore transport and distance between the mentioned lines is linearised. Some results are shown in fig. 8, 9 and 13. It is found, dat the influence of a groyne system is threefold: they reflect short-period beach processes on the adjacent areas, they retard erosion and they give a lee-side scour. But the theory only gives one aspect: influence of diffraction and of currents is not yet taken into account.
THE EFFECT OF ARTIFICIAL SEAWEED IN PROMOTING THE BUILD-UP OF BEACHES
Authors: Price W.A. , Tomlinson K.W. , Hunt J.N.
Published: February 2019

The paper describes tests carried out m the laboratory and in the field in an attempt to discover whether a field of artificial seaweed placed offshore can promote an onshore transport of bed material and hence a build-up of beach levels. Tests in a wave tank showed that beach levels could be built up in this way - the effect of the seaweed being to increase the net drift of bed water m the direction of wave propagation i.e. towards the shore. The field trials were not as conclusive as was hoped, but nevertheless some build-up of beach levels did take place at a time when erosion of the beach due to many storms might have been anticipated. A simple hydrodynamic model is proposed to represent the effect of artificial seaweed on gravity waves. The model predicts increased wave attenuation and increased shoreward mass-transport consistent with the experimental results.
PATTERN OF WAVE-INDUCED EROSION UNDER CAISSON-TYPE BREAKWATER
Authors: Donnelly P. , Boivin Richard
Published: February 2019

When caisson-type breakwaters or wharves are built in areas exposed to severe wave attack, adequate precautions must be taken to ensure that all parts of the foundations are protected from erosion The joint between abutting caissons is a particularly vulnerable location This paper describes patterns of erosion which may be expected at joints between caissons resting on sand or gravel foundations for a number of joint configurations The results are based on model studies Criteria are given for estimating scouring velocities through joints and sizes of particles moved Suggestions are made for minimizing the risk of erosion An example of erosion under a prototype structure is given.
SCOUR OF SAND BEACHES IN FRONT OF SEAWALLS
Authors: Herbich John B. , Ko Stephen C.
Published: February 2019

Many previous studies were confined to problem of beach erosion due to waves breaking on the structure. The investigation reported here involved regular non-breaking, shallow water waves progressing toward a seawall. An analytical solution was developed and compared with laboratory- scale experiments. The shallow-water wave theory and boundary layer equations were used in theoretical development, which resulted in a mathematical model for the ultimate scour depth in front of a seawall.
DUNE EROSION AND PROTECTIVE WORKS AT PENDINE, CARMARTHENSHIRE, 1961-68
Authors: Colquhoun R.S.
Published: February 2019

The paper describes the application of a novel method of protecting parts of the sand dunes at Pendine, S.W. Wales. These dunes are subject to erosion under conditions when high tides are combined with south-westerly gales. A series of random rock-fill mounds were sited 20 feet away from the toe of the dunes in certain areas where structures erected on the dune crest were liable to damage through erosion at the toe of the dunes. The object of the mounds is to trap wind-borne sand in the area enclosed between the mounds and the dunes, and also to check wind-driven waves before they can reach the dune face. Over seven years the mounds and sand traps have operated in accordance with their design concept. Not only have the traps filled with sand but further sand accretion has occurred on the protected dunes, resulting in a flatter slope and a strong growth of self-sown pioneer vegetation on the protected face and on the sand trap surface.
DUNE EROSION DURING STORM CONDITIONS
Authors: Edelman T. Ir.
Published: February 2019

Since in the Netherlands large areas of low lands are protected against the sea by coastal dunes only, it is very important to know how far, during a storm surge, the erosion of these dunes will proceed. In order to obtain an answer to this question, the cross-section of the coast has been studied. The shape of the cross-section of a sandy coast is mainly caused by displacements of sand perpendicular to the coast-line. Obviously this transport is mainly caused by waves. Since our knowledge of the very intricate physical processes, governing the sand transport by waves is, even now, still very incomplete, we can, perhaps, obtain an insight into the behaviour of a sandy coast, if we start from some rather simplified basic assumptions which are roughly in accordance with observations in nature.
DESTRUCTION CRITERIA FOR RUBBLE-MOUND BREAKWATERS
Authors: Rogan Adelkis J.
Published: February 2019

The general purpose of the author's research undertaken in the "Laboratoxre National d'Hydraulique" was to study wave action on rubble-mound breakwaters with regular (periodic) waves on the one hand and irregular (random) wind generated waves on the other, and to compare the effects of these two types of waves by use of the storm duration t. With a first series of periodic waves experiments we have obtained the destruction of the breakwater's cover-layer for different storm durations t, by varying H and T. The mass of armor units remained constant. The angle of the slope, according to the seaward equilibrium profile could be considered as constant.
'STABIT'- A NEW ARMOUR BLOCK
Authors: Singh K.Y.
Published: February 2019

There are a number of specially shaped concrete armour units in use today. The Stabit is one of them and was first developed m I96I for use on the reconstruction of breakwaters at Benghazi Harbour, Libya. This paper describes the development of Stabits and gives the technical details relating to their use. The subjects covered include full scale and model tests, stability coefficients, wave run-up, coverage, placing patterns, moulds, casting, handling and placing.
EXPECTED DISCHARGE OP IRREGULAR WAVE OVERTOPPING
Authors: Tsuruta Senri , Goda Yoshimi
Published: February 2019

An experiment was carried out on the overtopping of mechanically generated irregular waves over vertical walls. The experimental discharge was almost in agreement with the expected discharge which had been calculated with the wave height histogram and the data of regular wave overtopping based on the principle of linear summation. The expected values of overtopping discharge were calculated for various laboratory data, which had been represented in a unified form of non-dimensional quantities. The calculation has yielded two diagrams of expected overtopping discharge, one for the sea wall of vertical wall type and the othei for the sea wall covered with artificial concrete blocks.
ON THE EFFECT OF ARMOUR BLOCK FACING ON THE QUANTITY OF WATTE OVERTOPPING
Authors: Shiraishi Naofumi , Numata Atusushi , Endo Taiji
Published: February 2019

Japan, surrounded by sea, is constantly threatened by storm surges and beach erosions, for which protection works are being vigorously undertaken. As a measure for protection, facings of various armour blocks have come to be used for the seawalls and embankments. This is a skillful utilization of characteristic functions of armour blocks to dissipate and absorb wave energy effectively. However, systematic experiments and studies on this subject have been conducted only in very few cases. This paper treats of the effect of the facing of armour blocks on wave overtopping by comparison of the quantity of waves topped over the vertical seawal] with facing and that of without facing. Furthermore, this paper attempts to compare the results of the field observation and the experiments on the quantity of wave overtopping. Based on these data, the authors present a design criterion of the crown height of seawall with armour block facing.
THE EFFECT OF WAVE CRESTS ON WAVE FORCES
Authors: Tratteberg A.
Published: February 2019

This paper deals with wave forces from short crested waves as compared with two dimensional waves. The investigation comprised measurements of wind wave forces on fixed pontoons in a model, and a comparison of wave crest characteristics of wind waves in model and prototype. The model tests showed that the wave crests have a marked influence on the wave forces. The investigation of model and prototype wave data showed that the crest characteristics of the model waves compared well with that of prototype sea.
WAVE FORCES ON PILES IN RELATION TO WAVE ENERGY SPECTRA
Authors: Paape A.
Published: February 2019

The determination of wave forces on piles is for an important part based upon data obtained with regular laboratory waves. Nonlmearities m the mechanism that underlies these forces may lead to deviations when applying the data to predict forces exerted by irregular waves. Experiments have been performed with irregular waves to investigate wave forces, more particularly to study the influence of the energy density spectrum of the waves. Within the range of conditions m the experiments, the wave motion is sufficiently characterized by its energy and the frequency (or wave period) at which the energy density is maximum to determine the probability distribution of wave forces.
EFFECTS OF BLAST LOADING ON A PIER
Authors: Kim Young C. , Karlsson Thorbjorn , Ko William L.
Published: February 2019

The effects of nuclear explosions on a pier have been investigated to study the interaction phenomena between the blast loading, induced surface waves, the beach geometry, and the depth of coastal region for purpose of damage assessment and protective design of a coastal structure. For the theoretical analysis, the diffraction pattern predicted by Whitham's theory was used. The characteristic solution for shock diffraction showed the shock front shapes, shock-shock shapes, and flow rays in the pier and beach geometry. A pier model was tested in a six foot diameter horizontal shock tube under four different test situations simulating pier on a beach with water, pier on a dry beach in a Mach reflection region, pier in deep water, and a pier on a dry beach in a region of regular reflection. The model was subjected to various shock overpressures in each of the four test situations. Transient pressure distribution on the pier was investigated and comparison between the characteristic solution and the test results was made.
DISSIPATION OF DEEP WATER WAVES BY HYDRAULIC BREAKWATERS
Authors: Nece R.E. , Richey E.P. , Rao V. Seetharama
Published: February 2019

Experimental results axe presented for a laboratory study of the effectiveness of hydraulic breakwaters in dissipating deep water waves. Test data are reported for a range of wave steepnesses for wave length: water depth ratios ranging from 0.375 to 1.343. It is shown that the effectiveness of hydraulic breakwaters depends upon the steepness of the incident wave and upon the ratio of the momentum of the opposing surface current created by the breakwater to the momentum of the incident waves. Results also are compared with the theoretical predictions of Taylor which are appropriate to deep water waves. Data are presented in a form allowing the determination of hydraulic breakwater manifold discharge characteristics in order to achieve specified attenuation for a particular incident wave. It is concluded that while the hydraulic breakwater is better adapted to deep water waves than to shallow water waves upon which prior studies of the device have concentrated, it is generally inefficient for most practical cases because of excess power requirements. Some possible field applications are indicated.
A FLOATING BREAKWATER
Authors: Harris A.J. , Webber N.B.
Published: February 2019

The breakwater consists of a floating slab of breadth comparable to the length of the wave to be obstructed. Performance is improved by various arrangements of slots and mass-damping. The breakwater acts primarily by inhibiting the vertical component of orbital motion; there is a secondary action of energy dissipation by wave-breaking and eddy-making; there is also a degree of reilection. Mooring forces are small; it seems that on an exposed ocean coast, forces of the order of 0.5T per ft. lin. should be catered for. The following series of tests have been carried out; the basic measurements being of wave reduction and mooring force; typical results are shown in diagrams. 1) On models of lengths 3*-4' in the Southampton University tank using wind generated waves. 2) Do. Do. Using .paddle generated waves of lengths up to 8'. Series (l) and (2) comprised observations on some forty different configurations. 3) In the National Physical Laboratory tank using a model hZ' x 30' overall and waves of lengths up to 35'- Bending strains and vertical displacements were measured. k) A model has been installed in Queen Mary Reservoir, Staines of 100' x k7' overall; gale force winds are awaited which are expected to produce waves of the order of ko' 1. 5) A 1/100 scale model has been installed in a harbour model at the Franzius Institute, Hanover, where the effect of the breakwater in a scaled-down natural site has been investigated. 6) Tests in development of (l) and (2) above are being carried out at the laboratories of Messrs. Taylor Woodrow Ltd. at Southall, London.
SHALLOW WATER WAVES A COMPARISON OF THEORIES AND EXPERIMENTS
Authors: Le Mahaute Bernard , Divoky David , Lin Albert
Published: February 2019

A series of experiments were performed to determine the velocity field and other characteristics of large amplitude shallow water waves. The experimental results were compared with the predictions of a variety of wave theories including those commonly used in engineering practice. While no theory was found exceptionally accurate, the cnoidal wave theory of Keulegan and Patterson appears most adequate for the range of wavelengths and water depths studied.
MODEL STUDIES OF A PERFORATED BR<-JKV.'ATER
Authors: Terrett F.L. , Osorio J.D.C. , Lean G.H.
Published: February 2019

The breakwater proposed for a yacht harbour on the Sussex coast of England comprises a solid base up to the level of low water and a cellular structure, having a perforated front wall and solid backwall, above low water level. A model of the breakwater (scale 1:48) was tested m a flume at the Hydraulics Research Station, Wallmgford, and measurements were made of wave reflections and wave forces. For comparison force measurements were also made on a solid faced breakwater. The reflection tests were carried out with waves of normal incidence and at 1+5 to the breakwater for waves (prototype) m the range h to 15 seconds and up to 15 ft. in height. The results are presented in graphical form and a simplified analysis Is put forward to explain them. The force measurements were made for 7 and 10 second waves (prototype) up to 22 ft. in height. The results are presented as a non-dimensional plot with envelope curves of maximum force. The results are also given of stability tests on a rock mound against the solid base of the breakwater.
EXPERIMENTAL STUDIES ON A FIXED PERFORATED BREAKWATER
Authors: Marks Wilbur , Jarlan Gerard E.
Published: February 2019

Model tests on a perforated breakwater system were carried out to evaluate effectiveness in different states of sea. Force measurements were made in three long-crested irregular wave systems and, by spectral analysis, the full-scale statistical characteristics of force were obtained. The effect of perforating the back wall was studied to determine the extent of further reduction of force on the structure. An interior perforated wall was also added for force reduction but was not as effective as the perforated back wall. The system was mounted on piles and imbedded in sand for a quasi-quantitative study of scouring in regular waves. In this case, the elevation of the breakwater walls above the sandy bottom was varied. Both the perforations and the elevation contributed to significant reduction in observed scour. The end result of these experiments is to provide information on the kind of improved performance that might be expected as each variation is introduced which, in turn provides input to design for particular applications.
DESIGN CRITERIA RECOMMENDED FOR MARINE FENDER SYSTEMS
Authors: Lee Theodore T.
Published: February 2019

This paper summarizes the world-wide effectiveness of marine-fender systems A design criteria is recommended as a result of an extensive research and development program executed at the U S Naval Civil Engineering Laboratory, Port Hueneme, California, under the sponsorship of Naval Facilities Engineering Command Pertinent information includes analytical treatment and experimental investigation of the effects of berthing impact on the design of berthing structures, definition, function, and types of fender systems, advantages and disadvantages of various fender systems, cost-effectiveness and design procedures for different marine environment and exposure conditions. The energy absorption characteristics, berthing velocity, and virtual mass of ship are discussed in detail Energy capacity requirements for marine fender systems are illustrated in both graph and monograph forms. This paper is intended to provide guidelines to coastal engineers who may be involved in design of fender systems for waterfront and offshore structures.
HI-DRO CUSHION CAMEL-a new floating fender concept
Authors: Young D.B. , Young B.O. , Walker G.W.
Published: February 2019

A new floating fender devise designed to absorb berthing energies of ships against piers or harbor structures is described The principles governing the design and operation of the Hi-Dro Cushion Camel are reviewed The materials used in construction and the results of testing on the prototype are also explained and illustrated. Cost data and other information are given to permit evaluation and economic comparison with other systems. The Hi-Dro Cushion Camel consists of rectangularly arranged thin-walled plastic cylinders grouped in clusters in a sandwich between two structural diaphragms The cylinders are submerged in water and are completely enclosed except for an air vent hole and pressure regulating orifice The orifice controls the pressure build up and water release as the tube walls are pushed together at varying velocities. The ability of the device to adapt to variations in vessel displacement, pier flexibility and berthing velocities, is also discussed.
CASE HISTORIES OF TWO ESTUARIES
Authors: Dobbie C.H.
Published: February 2019

The coast of Great Britain has many interesting examples of the interaction between tidal estuaries of rivers and the littoral drift of the coast. These have been described with historical detail mainly by geographers (ref.l). Two cases coming to the author's firm for action have interest for coastal engineers. For the River Spey m the Moray Firth of Scotland, a famous and vigorous river, unusual works have been undertaken with success. For Dawlish Warren, a sand spit m the Exe Estuary of Devon m South West England, a scheme of works is being prepared which has novelty in regard to British practices.
APPLICATION OF RISK CRITERIA IN COASTAL ENGINEERING
Authors: Biswas Asit K.
Published: February 2019

A design of any engineering structure may be said to be optimum when it can meet all the necessary requirements at a minimum possible cost. In all cases there is a probability, however slight (sometimes even incalculable because of lack of data), that the design load can be exceeded and, thus, damages could occur. Obviously, lower the design load, higher would be the cost of anticipated damages and vice versa. Thus, from economical standpoint alone, the ideal solution would be when the total cost of construction and anticipated damages is at its minimum. Very often, however, other factors like social, political, etc., have to be considered, and this makes the whole process a complex decision making problem - sometimes completely out of the jurisdiction of the engineers.
CONSTITUENT TRANSPORT IN ESTUARIES
Authors: Glenne Bard
Published: February 2019

During the last two decades considerable progress has been made in analyzing the diffusion process in estuaries. Unfortunately, certain difficulties (e g prediction of diffusion coefficients) still prevent common application of the diffusion method An old technique, related to the diffusion concept, can however, frequently give useful information regarding constituent mixing and transport velocities in natural estuaries.
HYPERBOLIC WAVES AND THEIR SHOALING
Authors: Iwagaki Yuichi
Published: February 2019

Is is very difficult for engineers to deal with the cnoidal wave theory for practical application, since this theory contains the Jacobian elliptic functions, their modulus k, and the complete elliptic integrals of the first and second kinds, K and E respectively. This paper firstly proposes formulae for various wave characteristics of new waves named "hyperbolic waves", which are derived from the cnoidal wave theory under the condition that k = 1 and E = 1 but K is not infinite and are a function of T/g/h and H/h, so that cnoidal waves can be approximately expressed as hyperbolic waves by primary functions only, in which T is the wave period, h the water depth and H the wave height. Secondly, as an application of the hyperbolic wave theory, the present paper deals with wave shoaling, that is, changes in the wave height, the wave crest height above still water level, and the wave velocity, when the waves proceed into shallow water from deep water.
USE OF A COMPUTATIONAL MODEL FOR TWO-DIMENSIONAL TIDAL FLOW
Authors: Leendertse Jan J.
Published: February 2019

The numerical solution of tidal hydraulic problems has been greatly facilitated In the last decade by the development of high-speed large-memory computers. Problems which only could be studied by use of hydraulic models can now readily be studied with mathematical models if the computational techniques for solutions are developed. Unfortunately the difficulties in formulating usable methods for these complicated problems in fluid dynamics are formidable, particularly if the problems are multidimensional in space. As a result the numerical solution approach to these hydraulic problems has generally been limited and has not kept pace with the increased capabilities of the presently available computers. In this paper a new approach is given to the solution of two-dimensional tidal flow in shallow water.
EFFECT OF CHANNEL DEEPENING ON SALINITY IN THE JAMES ESTUARY
Authors: Nichols Maynard M.
Published: February 2019

The effect of a 10-foot channel deepening on the salinity distribution and net flow were studied m the James Estuary to predict estuarine-wide changes that might disturb the natural conditions favorable to oyster production. A hydraulic model was employed to determine the physical changes; then the potential biological consequences were evaluated by integrating the model data with corollary field and laboratory observations.
SOME CONSIDERATIONS ON HYDRAULIC DESIGN OF BOTTOM WATER INTAKE
Authors: Senshu Shin-ichi
Published: February 2019

The selective withdrawal characteristics of bottom water intake placed on the sea bed for the condenser cooling system of steam power station are presented and several design methods are proposed The results of field observations are also shown.
SHIP WAVES IN NAVIGABLE WATERWAYS
Authors: Hay Duncan
Published: February 2019

Model tests were conducted at the University of California, Berkeley, on six ship models to determine the heights of the waves produced by ships. Measurements were made at various distances from the sailing line with the models moving at various speeds in various water depths. The results of the tests are presented in graphical form, as prototype values.
SHIP WAVES IN SHOALING WATERS
Authors: Johnson J.W.
Published: February 2019

Models of two types of vessels were towed at various speeds in water of uniform depth. On one side of the sailing line the ship waves were allowed to move over beaches of various slopes. The wave heights were measured and compared at two points equidistant from the sailing line- patterns were determined by photographs.
Complete Proceedings - Single PDF Download
Authors: O'Brien Morrough P.
Published: February 2019

The Council on Wave Research of the Engineering Foundation was the sponsor of the first nine conferences on Coastal Engineering. This Council was abolished and was replaced in 1964 by the Coastal Engineering Research Council of the American Society of Civil Engineers. However, in spite of the change of name and affiliation there has been no discontinuity in either the activity of the Council or its management, which continues to function under the able guidance of the Secretary, Professor J. W. Johnson of the University of California, Berkeley.
WAVE INVESTIGATIONS IN SHALLOW WATER
Authors: Siefert Winfried
Published: February 2019

Examination of the significant heights of zero-crossing waves in the Elbe Estuary has yielded two noteworthy results: 1 In the deeper water of the estuary, the value of the quotient relating the significant and the mean wave heights is larger than on the bordering tidal flat. 2. The value of this function is dependent on the height of the waves; on the tidal flat this dependency is considerably more sensitive than in deeper water. With increasing wave height the value of significant wave height divided by mean height becomes smaller The propagation direction of waves moving onto the tidal flat is contingent upon the position of intertidal channels Such channels sharply reduce the possible propagation directions The waves nearly always move up-channel regardless of the wind direction It is possible to derive special wave period and wave height distributions representing the conditions m very shallow water.
FORCES ON A PONTOON IN THREE DIMENSIONAL WAVES
Authors: Eie J. , Tratterberg A. , Torum A.
Published: February 2019

Wave forces on a long pontoon (floating breakwater, floating bridges etc.) depend to a large extent on the three dimensional wave pattern. There is no deterministic method for calculating wave forces for such structures in a three dimensional sea and laboratory equipment for testing long structures in irregular three dimensional waves does hardly exist.
BEHAVIOR OF A SLENDER BODY IN SHALLOW-WATER WAVES
Authors: Wang Hsiang , Hwang Li-San
Published: February 2019

The unsteady-state response of a slender body in nonlinear shallow water wave environment was studied Numerical scheme has been developed which permits rapid calculation of the following, which describe the motion of an arbitrarily shaped body in three degrees of freedom anywhere within such an environment a Unsteady-state response b Centroid locus c Forces and moments Sample calculations are given for a typical submersible Results are expressed in generalized parameters, defining the circumstances wherein various displacements, velocities, accelerations, etc , would occur.
DETERIORATION AND RESTORATION OF COASTAL WETLANDS
Authors: Gagliano Sherwood M. , Kwon Hyuck J. , Van Beek Johannes L.
Published: February 2019

Coastal Louisiana wetlands are a product of Mississippi River delta building that has occurred over a period of 5,000 years The building process was a gradual one, for riverine and marine processes were very nearly balanced In modern times man's use of the area (flood control, navigation improvement, exploitation of petroleum and other minerals, road building, etc ) has seriously altered the natural balance As a result, overbank flooding has been virtually eliminated and river flow is confined to channels discharging into the outer shelf area Most transported sediment is now deposited in the deep Gulf of Mexico or along the continental shelf Saltwater encroachment in the deltaic estuaries has been detrimental to fauna and flora Even though considerable sediment deposition has resulted from the historic Atchafalaya River diversion and growth of subdeltas, comparative map studies indicate a net land loss rate of 16 5 miles^/year during the last 25 to 30 years Land loss is only one symptom of general environmental deterioration A dynamic management plan is proposed for better utilization of combined freshwater discharge - dissolved solid and transported sediment input from the Mississippi River Controlled flow into estuaries will reduce salinity encroachment and supply badly needed nutrients Large areas of new marshland and estuarme habitat can be built by controlled subdelta diversion Studies of natural subdeltas indicate that these systems are amenable to environmental management, salinities and sediment deposition may be manipulated to enhance desired conditions.
RECIRCULATION IN SHALLOW BAYS AND RIVERS
Authors: Price R.K. , Dalrymple R.A. , Dean R.G.
Published: February 2019

A theoretical model is presented to provide an approximation of the water and temperature recirculation in a shallow bay, lake or river, between the outlet and inlet canals of the cooling system for a power plant In particular, a temperature recirculation factor relating the outlet and inlet temperatures is derived.
NATURAL FLUSHING ABILITY IN TIDAL INLETS
Authors: Ohveira Mote
Published: February 2019

The main object of this work is to study the variations of the flushing ability of tidal inlets with the degree of shoaling, assuming the natural situations in the lagoon are uniform. It was assumed thar natural f! ~r tg ar ity is p! oportie 1 o i *?ed-ioad capacity of ->-idai currents end ra; *ct s capacity c^ be cii^racx.«>
MATHEMATICAL MODEL OF MIXING IN NEW HAVEN HARBOR
Authors: Disko Michael D. , Norris Robert A. , Lutz Francis C.
Published: February 2019

A mathematical model of New Haven Harbor, a shallow embayment with approximately 8 square nautical miles of water surface within boundaries established by Long Island Sound and the mouths of the Quinnipiac, West and Mill Rivers, has been developed. The Harbor has extensive tidal flats and dredged channels which help to produce large lateral variations of velocity and mixing over a tidal cycle. In order to adequately consider these lateral variations, a two-dimensional model of mixing, dispersion, pollutant reactions, and reaeration is made by linking together 28 segments of the Harbor, using a series of mass-balance equations. Mixing, or dispersion, is a complex function of reversing tidal currents, salinity-induced circulation patterns, fresh-water inflow, and the physical boundaries of the Harbor. Field measurements of salinity, dissolved oxygen, BOD, and tidal and hydraulic factors are used, in conjunction with laboratory studies, to evaluate coefficients and rate constants for the model. The linked system of equations is solved by matrix inversion procedures on a large computer. After verification, the model was used to predict the effect of treatment levels, outfall locations, and hydrologic parameters on oxygen levels and water quality m the Harbor. An important aspect of the work is that it presents a rational evaluation of estuarine water quality as a function of tidal mixing, outfall location, and the degree of BOD removal by proposed treatment plants, rather than the acceptance of arbitrary treatment standards,
FLUSHING PATTERN OF NON-REACTIVE EFFLUENTS
Authors: Kamel Adel M.
Published: February 2019

In south central Louisiana non-reactive liquid effluents are introduced into man-made relatively straight prismatic canals which are comparatively narrow and have brackish watpr To study the flushing pattern of liquid effluents introduced into those canals (or eptuanes), a one-dimensional numerical model is considered for a simplified system consisting of a long straight gently sloping reach with a sinusoidal tidal variation at the mouth of the estuary, sinusoidal tidal v^iation with a phase lag and an attenuated amplitude at the upstream end, a variable inflow hydrograph, and a variable inflow or outflow. For this system, the continuity and momentum eauations are solved numerically by an explicit finite difference scheme. The output of the model describes the spatial and temporal variations in flow velocity (also in water depth and discharge) from which the flushing pattern is obtained for a liquid effluent introduced at any time during the tidal cycle at any section along the estuary. The numerical model is applied to Charenton drainage canal m south central Louisiana and good agreement is obtained between the velocities and stage elevations predicted from the model and recorded in the field. An IBIV 360/65 computer is utilized.
WATER CURRENT METER FOR MEAN FLOW MEASUREMENTS
Authors: Smith David , Harrison W.
Published: February 2019

A drag-sphere water current meter with a 0 to 6 ft/sec range has been developed for velocity measurements of relatively steady flows A two-component strain-gage type force transducer is mounted within a 3 7-inch-diameter perforated drag sphere Drag force measurements are related to the flow velocity around the meter Several drag sphere configurations were tested in selecting the 336-hole pattern Frequency response data have been recorded and evaluation tests were made with current meters deployed in an estuary Use of these current meters in studies of steady-state fluid processes and sediment responses is feasible They are simple, relatively inexpensive, and well suited to applications where several simultaneous measurements are needed to determine velocity profiles or map flow distributions.