bluuebunny/crossref_metadata_2025 huggingface dataset:
OBSERVATIONS AND EXPERIMENTS ON SOLITARY WAVE DEFORMATION
Authors: Street Robert L. , Camfield Frederick E.
Published: February 2019

A series of experiments were run in a two-dimensional wave channel to study solitary wave deformation on plane slopes ranging from horizontal to vertical. The test objectives included verification of deformation theories, delineation of the shoaling processes associated with various beach slopes, and examination of the limit-height-wave concept. The results showed that the deformation process can be classified as a function of the ratio of initial wave height to water depth and beach slope. The deformation theory for reflection from a vertical wall was verified, but the theory for low slopes was found to be only qualitatively accurate. Finally, a redefinition of the limit-height wave on sloping beaches is suggested.
RUNUP RECIPE FOR PERIODIC WAVES ON UNIFORMLY SLOPING BEACHES
Authors: Van Dorn Wm. G.
Published: February 2019

The shoaling enhancement of small-amplitude, dispersive wave trains traveling over uniform, impermeable slopes was observed in a specially-constructed wave channel, where the reproducible wave elevation measurement accuracy was about .0005-in. These observations substantially support the enhancement predicted from linear theory (conservation of energy flux) except in very shallow water and on very steep slopes, where accelerative effects become important. On the hypothesis that small-amplitude runup theory might be similarly valid for periodic waves of finite height, provided that the positive incident wave amplitude Is replaced by the local crest height above still water, this theory was modified to include the effect of the superelevation under a wave crest due to profile asymmetry. The modified theory is shown to agree acceptably with runup observations of larger waves previously reported - both for breaking and non-breaking waves. Because solutions to the modified theory cannot conveniently be obtained by manual calculation, a nomograph chart is included, from which runup predictions can be easily made, given only the wave height, period, and water depth a wavelength or so from shore, and the beach slope.
A PETBOGRAPHIC STUDY ON LITTORAL DRIFT ALONG THE ISHIKAWA COAST, JAPAN
Authors: Aramaki Makoto , Takayama Shigemi
Published: February 2019

Based on the longitudinal variation series in various properties of beach sediments and topographic profiles along the southern coast of Ishikawa Prefecture, Japan, the prevailing direction and mechanism of littoral drift are discussed.
SUSPENDED SEDIMENT IN A TIDAL ESTUARY
Authors: Halliwell A.R. , O'Connor B.A.
Published: February 2019

A brief description is given of vork being carried out in the Mersey- Estuary, England. This work is part of a sedimentation study of the area, and has necessitated many days' field observations at stations distributed along and across the Estuary. Attention is drawn to the factors influencing the sediment movement and the variables, such as velocity, suspended solids, salinity and temperature that must be measured in order to define the sedimentation complex adequately. A study is made of the effect of variations in temperature and tidal range upon the mean concantration of suspended solids observed at stations in the Estuary; the relationship proposed is of the form
WAVE AGITATION IN BAYS AND HARBORS-METHODS OF MEASUREMENT AND ANALYSIS
Authors: Sakou Toshitsugu
Published: February 2019

Practical and effective methods for the measurement of and the determination of the type and the mode of wave action in a semi-enclosed basin are investigated. Pressure gages and flow meters are considered as instruments available for such measurement. The combination and arrangement of these instruments as well as the use of power spectral and cross spectral analyses as the basic means of data reduction are discussed. A special attention is given to the problem of estimating the contributions from the progressive and from the standing modes of oscillation separately. Significance of such estimation on engineering planning is briefly discussed. Examples are given.
ON THE EFFECT OF BREAKWATERS AGAINST TSUNAMI
Authors: Fukuuchi Hiromasa , Ito Yoshiyuki
Published: February 2019

As well known the coast of Japan is often attacked by tsunami. As a kind of disaster preventive facilities, breakwaters have been built or are now under construction in several ports in order to protect the harbour area by diminishing the energy of rushing water and by reducing the water level elevation inside the basin. The biggest work of this sort is found at the port of Ofunato, Iwate Prefecture. The effect of breakwaters against such long-period wave as tsunami was investigated by the authors, using electronic computers. The principle is to solve the equations of motion and of continuity. Not only for the stationary state but also for the transient state. One of the most important items to be studied is the response of basin water to the incoming tsunami, of which the period is variable in a wide range from several minutes to more than one hour. The result of calculation has clarified the behaviour of tsunami affected by breakwaters located in a bay open to the outer sea. The computing method, together with an approximate method divised from fundamental investigations made in advance, has also been applied to several other ports, supplying a plenty of data for harbour planning and design.
THE INFLUENCE OF PILE DIMENSION ON FORCES EXERTED BY WAVES
Authors: Paape A. , Breusers H.N.C.
Published: February 2019

The increase in applications of off-shore structures has raised a growing interest in the determination of wave forces on piles. Both theory and model experiments have been applied to establish relations between wave characteristics, shape and dimensions of piles and wave forces exerted. As far as theory and computations are involved, the wave forces are generally assumed to be the resultant of drag and inertia forces. The influence of typical features of the flow pattern around the pile on the forces exerted is expressed in coefficients of drag (C_) and inertia (C..) which are, in practice, generally assumed to be dependent on the shape of the pile only. The latter assumption is not correct, which partly explains the variety in magnitude of CD. and CM,, which is found in literature, The time-dependancy of the flow pattern leads to an influence of pile dimensions relative to those of orbital motions. The aim of the paper is to draw attention to this phenomenon and to provide a possible starting point for a more reliable approach of wave forces. The nature of forces exerted by oscillating flow is briefly discussed and illustrated by results of model experiments and computations. Subsequently model investigations on piles are described, the results of which are compared with computations for constant coefficients of drag and inertia.
ON DESIGN OF WAVM PRESSURE ACTING ON STRUCTURES OF SLOPING TYPE
Authors: V.V Krylov , L.V. Selivanov , P.S. Nikerov
Published: February 2019

In the paper some results of study of active external pressure of wind waves acting on structures of sloping type are presented in brief. The pressure developed by waves and acting on the inclined wall is divided into impact pressure and pressure remaining after shock. For determination of maximum water pressure remaining after shock a prof. N.N.Djunkovsky scheme is used (R.-I). Pressure distribution curve of water remaining after shock along the slope is determined by means of consideration of jet pressure acting on inclined wall. Design ourve is compared with the data of laboratory wave flume tests. Measurement pressure data received at test zone in reservoir is statistically treated.
THE STABILITY OF RUBBLE MOUND BREAKWATERS AGAINST IRREGULAR WAVES
Authors: Carstens Torkild , Torum Alf , Tratteberg Anton
Published: February 2019

Through extensive model tests with rubble mound breakwaters conducted in many laboratories in recent years design criteria and stability data have been collected. To our knowledge such data have been based on tests with regular waves only. It has been more or less accepted that the destructive effect of a train of regular waves corresponds to a confused sea with a significant wave height equal to the height of the regular waves. At the Rxver and Harbour Research Laboratory at the Technical University of Norway a new wave channel has been equipped with a programmed wave generator which can produce irregular waves wxth any wanted wave spectrum. This paper deals with model tests of the stability of rubble mound breakwaters against irregular waves as compared with regular waves.
SCALE EFFECTS W WAVE ACTION THROUGH POROUS STRUCTURES
Authors: Johnson J.W. , Kondo H. , Kallihan R.
Published: February 2019

The energy in waves which impinge on a porous structure, such as a rubblemound breakwater, is divided into reflected energy, transmitted energy, and the energy dissipated by turbulence within the structure. To obtain information on the reliability of using models to predict the transmission of wave energy through a rubble medium, a series of three models were constructed and tested in the 1 ft. by 3 ft. by 106 ft. wave channel at the University of California. The models consisted of rectangular, vertical-faced, wire baskets (constructed of expanded metal lath) which were filled with crushed stone. The three models were 0.5, 1.0, and 2.0 ft. in length, respectively. All models were 1 ft. wide and 3 ft. high. Each structure was installed in turn in the wave channel and subjected to wave action with the wave height being measured both seaward (H ) and leeward (Hp) by resistance-type wave gages.
WAVE TESTS OF REVETMENT USING MACHINE-PRODUCED INTERLOCKING BLOCKS
Authors: Hall Jay V.
Published: February 2019

Continued demand for relatively low-cost shore protection, in bays, estuaries, and comparable bodies of water has resulted in accelerated investigation in this area. Further, there is a great demand for a system that can be constructed by the individual property owner without recourse to a contractor or special construction equipment. Work along these lines gained impetus through the successful installation of a light-weight concrete-block revetment in 1962. This paper reports on the further development of light-weight block revetments through tests in the Large Wave Tank at Coastal Engineering Research Center (CERC). Two types of blocks were tested on a 1 on 2 slope, one a machine-produced tongue-and-groove type weighing 75 pounds, and the other a hand-produced shiplap type weighing 150 pounds, the latter having twice the surface area of the former. In all, ten tests were made with wave heights ranging from 1.5 to 6.2 feet and wave periods ranging from 3.0 to 6.0 seconds. During the tests observations were made regarding the displacement of blocks and the vertical movement of the face of the slope when attacked by waves. Data derived from the tests have provided information which has resulted in the development of a machine-produced block which remained stable under the continuous attack of 4.7-second 4.8-foot breaking waves. Comparative tests showed that the machine-produced tongue-and-groove blocks have greater stability than the hand-produced shiplap type.
OBSERVATIONS OF TIE TRANSFORMATION OF OCEAN WAVE CHARACTERISTICS NEAR COASTS BY USE OF ANCHORED BUOYS
Authors: Higuchi Haruo , Kakinuma Tadao
Published: February 2019

In order to clarify the transformation process of ocean waves in shallow water, a series of wave observations were carried out along some coasts in Japan by photographing two or three convenient buoys aligned m the direction of the waves with two 16 urn cine-cameras. The equipment and methods used in observations and analyses are here described together with some of the results obtained. By examining the motion of the buoys off the coast at Shirahama it was found that the method of wave observation by means of anchored buoys was very useful in the case of comparatively long waves.
SCOURING DUE TO WAVE ACTION AT THE TOE OF PERMEABLE COASTAL STRUCTURE
Authors: Sawaragi Toru
Published: February 2019

In this paper, the relation between a reflection coefficient of waves and a void ratio of permeable face of a structure is firstly revealed, because of the fact that there is a close relationship between the reflection coefficient and the phenomena of scouring. Before the scouring depth is investigated, the relation of the scouring depth to subsidence is made clear. Then, it is found that the scouring depth which has great influence upon subsidence of blocks, becomes larger with the increment of the coefficient of reflection. Furthermore, a composite cross section which has an imaginary uniform slope of 20 degrees, is proposed as the stable cross section against the subsidence of blocks.
USE OF PLASTIC FILTERS IN COASTAL STRUCTURES
Authors: Barrett Robert J.
Published: February 2019

It has long been the opinion of many engineers that the primary cause of failure in certain coastal structures is due to an inadequate filter system. Normally, filters for granular soils are made up of layers of graded sand, gravel and stone materials in various combinations and thickness dimensions. Very often these materials are expensive and in some cases, due to geographic location, are unavailable. Even if the required materials are easily accessible, proper placement is tedious and demands strict supervision. This paper discusses the use of "plastic filters" as a replacement for graded filter systems and filter blankets in coastal structures. While this discussion and illustrations are limited to coastal structures, plastic filters can and have been used in river, lake, canal, dam and other hydraulic structures.
CONSTRUCTION OF NAGOYA STORM-TIDE-PREVENTING BREAKWATER
Authors: Teranishi Koji
Published: February 2019

The Nagoya Storm-Tide-Preventing Breakwater is a large-scale Breakwater built as a link in the general Ise Bay Storm-Tide-Prevention Project. The entire length of this breakwater is about 8,250 meters, which extends from the mouth of the Nabeta River, transversing the northern part of Ise Bay, to the Chita town. (Pig. 4) The greater half of this breakwater was built on an extremely unstable foundation, the nature of ground being of soft clay stratum with a thickness of 10 m - JO m. The sand-drain method was adopted for improving the ground on which caissons were laid, forming a composite type section. For this reason, during the process of construction a close work control was maintained constantly by applying boring, observation on the sinking, pore water pressure and other conditions to ascertain whether the sinking by consolidation took place according to the calculations laid in the design specification. Based on the date obtained in this manner the speed of the work was regulated and the work was conducted under strict control of soil mechanics. The required volume of materials for the construction of the breakwater was so immense that a special care had to be given to ensure their smooth and efficient supply. And to speed up the work with a view to reducing the effects of wind and waves to a minimum, large machinery were employed. The present paper describes the engineering features of this great 8,250-meters breakwater project which was completed in a short period of 2 years and 8 months at a cost of 30 million dollars after overcoming numerous obstacles.
EXECUTION OP TRAINING DIKES AT THE OUTLET OP A DIVERSION CHANNEL ON THE COAST OP JAPAN SEA
Authors: Shigemi Toru , Amano Kagetoshi , Mizuno Kazuaki , Takada Tokuhiro
Published: February 2019

The record of the construction work of training dikes at an outlet of a diversion channel is presented here. The discharge in this channel is very small throughout the irrigation season and this fact makes difficult to maintain open outlet against the drift sand. Therefore the training dikes must be extended to fairly large depth. The special difficulty of execution is the limitation of construction time in summer that is a sole season of quiet sea.
WAVE-INDUCED OSCILLATIONS OF SMALL MOORED VESSELS
Authors: Raichlen Fredric
Published: February 2019

This study deals with the motions of a neutrally buoyant rectangular parallelpiped moored by a linear spring system m standing waves. The results show that a linear theory which considers the response of the body as a smgle-degree-of-freedom oscillator adequately describes the surge motion for standing waves ranging from shallow-water waves to deep-water waves and for ratios of body length to wave length of from 0.1 to 1 5. It was found that the response curves for surge motion become more selective with respect to frequency in the vicinity of resonance as the distance of the body from a reflecting surface increases. Therefore, coupling this with viscous effects, which are more important near resonance, it is possible to reduce the effect of resonance considerably for a moored body with a particular natural frequency by choosing the proper mooring location in its standing wave environment. This has possible application in the planning of berthing facilities in marinas.
SOME CONTRIBUTIONS TO HTDRAULIC MODEL EXPERIMENTS IN COASTAL ENGINEERING
Authors: Hayami Shoitiro , Ishihara Tojiro , Iwagaki Yuichi
Published: February 2019

This paper presents some aspects of the hydraulic model experiments in coastal engineering made at the Ujigawa Hydraulic Laboratory, Disaster Prevention Research Institute, Kyoto University, including the experiments performed by using an estuary model basin and a high speed wind wave channel. In particular, the problems to which attentions should be paid from view point of similitude between model and prototype will be discussed in addition to the presentation of experimental results.
SALINITY DISTRIBUTION AND EFFECT OF FRESH WATER FLOWS IN THE HOOGHLY RIVER
Authors: Gole C.V. , Vaidyaraman P.P.
Published: February 2019

An examination of the hydraulic characteristics of the Hooghly river with particular reference to the pattern of salinity intrusion and the effects of fresh water flows has been made in this contribution. It is seen that the conditions prevailing are such that during the brief period of fresh water flows the problem of salinity intrusion is absent. The beneficial effect of fresh water flows in improving the navigable depths along the river is also shown. The cessation of fresh water flows causes the deterioration of navigable depths due to the landward movement of sediment; it also results in the upstream encroachment of salinity affecting the supply of drinking water to the City of Calcutta. It has also been shown that even during the period in the freshet when the salinity profiles exist the estuary remains well-mixed. The need for augmentation of fresh water flows for improving the conditions has also been brought out. A few remarks on the comparative features of Hooghly and other tidal rivers have also been added to spotlight on the vastly different characteristics of the Hooghly.
STUDIES ON SALT WEDGE BY ULTRASONIC METHOD
Authors: Fukushima Hisao , Kashiwamura Masakazu , Yakuwa Isao
Published: February 2019

This paper presents some observational results on salt wedges obtained by the ultrasonic method at the mouth of the Ishikari River, with a description of some studies on the two-layer flow developed by the authors.
PREDICTED FLUSHING TIMES AND POLLUTION DISTRIBUTION IN THE COLUMBIA RIVER ESTUARY
Authors: Neal Victor T.
Published: February 2019

The observed salinity distribution in the Columbia River Estuary is used to predict the flushing times for various river discharge rates, varying tidal ranges, and varying salinity intrusions. Both the modified tidal prism method and the fraction of fresh water method are used, and the results are compared. The latter method predicts shorter flushing times, while both methods vary m a similar manner with changing river discharge and changing salinity intrusion. Both methods predict a relatively short flushing time for the estuary. The observed salinity distributions under varying conditions are also used to predict the distribution of conservative and non-conservative pollutants. In this case the fraction of fresh water method and the diffusion equation are used. In general, the fraction of fresh water method predicts higher concentrations. "When the lower estuary is divided into two channels, the two methods give quite different results. The diffusion equation method predicts a peak concentration upstream from the outfall rather than at the outfall, when the outfall location is arbitrarily placed at certain locations.
STUDY ON BOTTOM WATER INTAKE FOR CONDENSER COOLING SYSTEM OF POWER STATION SITED ON A BAY
Authors: Senshu Shin-ichi , Wada Akira
Published: February 2019

This report concerns study on a method of taking the cold water from bottom layer with relation to the design of the intake structure of cooling water for the power station sited on a bay. The quantity of cooling water used for condenser system increases year by year along with the construction of thermal power stations of large capacity. If the bottom sea water of low temperature is taken into the condenser cooling system, remarkable saving of fuel expenses can be expected due to the improvement of heat efficiency of turbine. Especially, in case that the location of intake structure of cooling water is chosen at the interior of the reclaimed land or the bay, it is absolutely necessary to take the colder water from the lower layer of the sea, in order to prevent taking hot water over the sea basin where the water temperature of the surface layer is raised by the evacuation of heat of released industrial water. Various hydraulic problems concerning thermal density flow phenomena were examined aiming to obtain the design method of the most effective intake works of cooling water, and the authors proposed a curtain-wall type intake structure. Some results of analysis are described in this paper.
SOME PROBLEMS CAUSED BY BUILDING THE CROSS DYKE ACROSS TOKYO BAY
Authors: Ito Takeshi , Hino Mikio
Published: February 2019

Two hydraulic problems anticipated from the construction of a dike across Tokyo Bay, i e water circulation and 'harbor paradox' are discussed from results of numerical experiments Especially, a new technique has been devised for the investigation of response characteristics of the bay to obtain all the information by only one run.
TSUNAMI HEIGHT, OAHU, HAWAII: MODEL AND NATURE
Authors: Jordaan Jan Malan , Adams William Mansfield
Published: February 2019

A 1:20,000 scale model was built of the island of Oahu and neighboring topography. The model was undistorted and rotatable so that an incoming tsunami from any direction could be easily incorporated by turning the 12' x 12' model to face the wave generator from the desired angle. The wave basin was 30' wide and 40' long; with a I-10 wave absorbing beach situated at the opposite end from the wave generator. The waves were modeled to a vertical scale of I:2000. The model was supplemented by a small-scale (1-247,500) model, also undistorted, in a transparent 6' x 12' ripple tank. This model represented the eight principal islands of the island chain and their surrounding topography. Nature data of runup height for four different tsunamis around Oahu show a strong tooal amplification effect, varying more with respect to fixed positions around the Island (prominent features, points, bays, reefs, etc.) rather than with respect to variations in deep sea direction. A less pronounced local effect was obtained in the model tests and direct point-to-point correlation of model and nature data was not very meaningful beyond a general trend agreement. The orientation effect was similar on the model as in prototype.
THE INVESTIGATION OF THE WAVES AT THE BAY OH THE MODELS WITH PIXED BED AND THE ESTIMATION OF THE SCALE EFFECT
Authors: Plakida M.E. , Perepetch N.T.
Published: February 2019

The wave model regime, in the given bay of the arbitrary outline, have been studing at the three scales 1:150, 1:300 and 1:450. The models had the fixed bed. The model of the scale 1:1^0 had been conditionally admitted as the prototype at the investigation. As a result of the study the scale effect for the present case have been found* The correction scale factors depend on the relative water depth.
LONG WAVES IN CHANNELS Of ARBITRARY CROSS-SECTION
Authors: Peregrine D.H.
Published: February 2019

This warier summarises some recent work on lone gravity waves on still water m channels of arbitrary constant cross-section. Theoretical results have been obtained for both straight and curved channels. Some experimental work has been performed m straight trapezoidal channels and shows reasonable agreement with theory. For straight channels some details of the second approximation are given, and the cases where the approximation breaks down are indicated. For curved channels it is found that the effect of channel curvature is more pronounced when the cross-sectional shane of the channel is not symmetric with resnect to its centre-line.
APPLICATION OF WAVE DIFFRACTION DATA
Authors: Silvester Richard , Lim Teck-Kong
Published: February 2019

By considering separately the two terms of the Sommerfeld solution of wave diffraction behind a semi-infinite breakwater, the influence of the wave reflection from the structure can be evaluated The diffraction coefficient at any point can be obtained from a graph or table for full, partial or no reflection by the simple addition of two coefficients From the similarity of the energy-spreading process to the dam-burst problem, it was found that wave heights decreased consistently along the near circular crests for all distances from the breakwater tip For a workable range of incident angle and distance from the breakwater, wave heights could be defined by this arc distance from the shadow line expressed in wave lengths These relationships have been verified experimentally for all but the smallest incident angle in proximity to the breakwater This can be likened to the dam model in which the dam is moving too slowly to permit normal spreading. The several theoretical solutions for the breakwater gap, when graphed on the same basis, are shown to be very similar, diverging only for small incident angles New parameters are provided which greatly simplify the presentation of information The scatter of past experimental data precludes the verification of this theory and indicates the need for further tests.
LONGSHORE TRANSPORT OF SAND
Authors: Inman Douglas L. , Komar Paul D. , Bowen Anthony J.
Published: February 2019

Simultaneous field measurements of the energy flux of breaking waves and the resulting longshore transport of sand in the surf zone have been made along three beaches and for a variety of wave conditions. The measurements indicate that the longshore transport rate of sand is directly proportional to the longshore component of wave power.
VARIABLE DISPERSION AND ITS EFFECTS ON THE MOVEMENTS OF TRACERS ON BEACHES
Authors: Price W.A.
Published: February 2019

To arrive at a quantitative assessment of sediment transport using tracers it is usual to analyse the results using the "centroid method". It is quite satisfactory to apply such a method when the dispersion from any cause is constant over the area under study. However, when tracers are used m a variable dispersive field, as on a beach, the interpretation of the results "by normal methods can give misleading results. A simple arithmetical model is used to illustrate the ideas put forward m the paper.
A FIELD INVESTIGATION OF SAND TRANSPORT IN THE SURF ZONE
Authors: Thornton Edward B.
Published: February 2019

The distribution of bed-load sand transport normal to the beach has been measured m a series of field experiments conducted in the surf zone at Fernandma Beach, Florida. Simultaneous measurements were made of the waves and water particle motion at various locations in the surf zone. The energy flux of the waves was resolved Into Its longshore component from the measured directional and energy spectra. It Is found that the bed-load transport is related to the depth of water and longshore energy flux. Insight into the mechanics of sediment transport is obtained by comparing the wave and water particle motion energy spectra, which give a direct measure of the kinetic and potential energy, at various locations in the surf zone.
WAVE PERIOD AND THE SWASH ZONE ENERGY BALANCE
Authors: Giese Graham S.
Published: February 2019

The shape sorting of pebbles in the swash zone was studied in an effort to determine the effect of the amount of foreshore infiltration per wave on the swash zone energy balance. Measurements were made of pebbles collected from the swash limit and from the step of selected sandy beaches. The pebbles were sampled on occasions when, and at locations where, the conditions of breaker height, breaker approach angle and foreshore slope fell within predetermined limits. The wave period and the foreshore infiltration rate varied among the beaches and were measured. The results of these measurements indicate that the mean shape of swash limit pebbles, and presumably, therefore, the swash zone energy balance depends upon the amount of foreshore infiltration per wave. This finding leads to the conclusion that in the study of the dynamics of the swash zone the effect of wave period and the effect of foreshore permeability must be considered together.
MEASUREMENT OF COASTAL CURRENTS
Authors: Zeigler J.M. , Tasha H.J.
Published: February 2019

Getting a drift buoy into and over the surf zone in rough weather has always been a problem. A cheap, cold propellant rocket launcher using either compressed air from aqua-lung bottles or liquid carbon dioxide is admirably suited for hurling drift bottles to ranges of over 1,000 feet. This launcher weighs less than one hundred pounds and can be easily transported to places of difficult access such as cliffed or reefy coasts. The float package can be modified to include mid-depth drogues if that is desired. An example of work done by a single field operator illustrates the versatility of this technique . Naval Mark II flares are useful for current tracing because they are easily obtained and can be set in arrays from aircraft. As they burn, however, they change their freeboard and are therefore more subject to wind drift than when they are lower in the water. Mark II flares were calibrated for wind drift with results given. A wind velocity profile between 5/8 inches and 5 inches above the water surface was obtained from floating arrays of flares with the results given.
THE EFFECT OF GROYNES ON STABLE BEACHES
Authors: Price W.A. , Tomlinson K.W.
Published: February 2019

The paper describes tests carried out in a wave basin to study the effect of groynes on a beach that was stable for a particular wave climate and a given supply of littoral material. The main conclusion was that on the part of the beach between H.W. and L.W. level the groynes produced no build up. The only build-up that occurred took place seaward of the impermeable groynes. Permeable groynes had little effect either inshore or offshore.
EXPERIMENTAL STUDY OF THE HYDRAULIC BEHAVIOUR OF GROYNE SYSTEMS
Authors: Barcelo Julio Patriarca
Published: February 2019

Results of an experimental study of the hydraulic behaviour f groyne systems, a very widespread coast erosion protection structure,are described. The characteristics of the evolution of beach stretches between groynes under the action of waves with different obliquity,heights and periods are defined. The results obtained are intended for design of systems of functional groynes which secure an adequate partition of the beach in satisfactory hydraulic conditions, and also meeting use requirements, notably from the architectural and recreation standpoints. Additionally the author briefly discusses longsh-ore drift and presents some experimental conclusions on the relations between longshore drift and the characteristics of the waves.
THE CREATION OF AN ARTIFICIAL BEACH IN LARVOTTO BAY - MONTE CARLO PRINCIPALITY OF MONACO
Authors: Tourmen Louis
Published: February 2019

One of the features of a recent big Monaco Government modernisation scheme was an artificial beach in Larvotto Bay at Monte Carlo, which was to offer first-class bathing and amenities matching the very high standard of urban development planned for the area. Most of the Monaco coast is rocky and very steep, and the only places with a gradual slope down to the sea were a few very inferior beaches the waves had formed with widely varied materials from local builders' rubble dumps.
THE CHARACTERISTICS OF WIND-WAVES GENERATED IN THE LABORATORY
Authors: Lee Theodore E.
Published: February 2019

Wind-wave characteristics were recorded in the laboratory for the primary purposes of (a) analysis of the probability distribution of wave height and wave period with wind speed, water depth, and fetch length as major parameters, and (b) comparison of the test results with existing theory and empirical formulae. An important aspect of this study was to test the validity of the Tucker and Draper method (Draper, 1966) for the presentation of ocean wave data as applicable to wave-data analysis for simulated wind waves. It was interesting to note that some corrections were necessary when the method proposed by Draper at the 10th Coastal Engineering Conference was used for analyzing waves generated in the laboratory. Approximately a positive 20% correction was necessary for this study in which the wave spectra distribution is of very narrow range, the wave width parametere = V1-(T /T ) varles from 0.25 to 0.50, where Tc and T2 represent crest wave period ana zero-crossing wave period, respectively. However, only a negative 5% correction was necessary when the method was used to analyze sea waves (e = 0 73 to 0 76) measured off the shoreline near Look Laboratory Therefore, it was concluded that the Tucker and Draper Method is quite feasible for engineering purposes in analyzing wind-waves having a spectral width parameter of 0.60 to 0.75 The experimental data were compared with those wave heights predicted by the Darbyshire formulas (Francis, 1959) developed for ocean waves. A significant correction factor was necessary for laboratory waves produced by low-speed wi nds. The "fetch graph" was prepared and compared with those developed theoretically by Hino (1966) and empirically by Ijima and Tang (1966) at the 10th Conference on Coastal Engineering, Tokyo, Japan Comparison was also made with the previous empirical formulae by Bretschneider (1951, 1957), Sverdrup and Munk (1947), and Wilson (1961,1962). The experimental results compared well with the Hino theory for both wave heights and wave periods, and fairly well with Bretschneider's fetch graph for wave heights The difference in the comparison of wave data with other investigators is illustrated in this paper. It is recommended that further study be made with emphasis on (a) theoretical and experimental studies of wind-wave characteristics on pre-existing waves, particularly moving storms, (b) wave-energy spectra involving stochastic characteristics and extreme values of wind waves
CUFF DRAINAGE AND BEACH DISTRIBUTION
Authors: Fryde W.T.
Published: February 2019

The works described m this paper are part of a large Coast Protection scheme recently completed at Clacton-on- Sea, Essex, England. The paper is m two parts, the first describing cliff drainage and the second dealing with beach distribution. The method of drainage departs from the usual one of surface rubble drains and comprises a system of auger bored vertical and inclined drains. This method of drainage does not depend on the slope of the cliff face, its most important feature being that it makes it possible to dram the water away from within the cliffs. The second section describes the effect of large impermeable groynes on beach distribution as experienced at Clacton and the remedial works carried out, including tipping of imported material to improve the beach levels, and the results achieved. Both sections of the paper refer to the specific problems encountered on the Clacton frontage and the methods adopted to deal with them. The solutions found could be applied to other frontages but thorough investigations would be necessary beforehand due to the very varying nature between one frontage and another.
MODELING OF STRUCTURES SUBJECTED TO WIND GENERATED WAVES
Authors: Plate Erich J. , Nath John H.
Published: February 2019

The difficulties inherent in the direct determination of loads on off-shore structures which are exposed simultaneously to wind and waves make it desirable to model each situation in the laboratory It is shown here that scaling of the loads and the waves is possible by using waves which are generated by blowing air over the surface of a laboratory channel, and by choosing a model material with an appropriate modulus of elasticity Wind-generated waves such as those measured m the wind water tunnel of Colorado State University have a dimensionless spectrum (Hidy and Plate (1965)) that is identical in shape to that found off the coast of Florida under hurricane conditions (Collins (1966)) Furthermore, it has been shown that hydro-elastic modeling is quite feasible (LeMehaute (1966)) These two results are combined to give modeling criteria for off-shore structures if direct wind forces are disregarded.
WIND VELOCITY PROFILE ABOVE PROGRESSIVE WATER WAVES
Authors: Shemdin Omar H.
Published: February 2019

An investigation of the air velocity profile above progressive, mechanically-generated waves was made m the wind and wave facility at Stanford University. The influence of propagating waves on the mean velocity profile was sought especially. Both the instantaneous and mean velocity profiles were obtained with the use of high response total head and static pressure probes, m conjunction with a wave height gage. Experimental evidence is presented which suggests that the air velocity field responds to the wave motion. The dependence of the mean velocity profile on wave frequency was investigated experimentally over mechanically generated waves having a constant amplitude. Also, the dependence of the mean velocity profile on wave amplitude was investigated over mechanically generated waves with a specified frequency. The theoretical results suggest that the wave influence is threefold. The first is due to the fact that a velocity-measuring instrument continuously shifts streamlines when measuring the air velocity above a perturbed water surface. The second is due to the wave-induced perturbation in the air velocity. The third is due to the interaction between the two effects just described. The results contribute towards explaining the lack of consistency in the existing data.
THE EFFECT OF STORM DURATION ON RUBBLE MOUND BREAKWATER STABILITY
Authors: Font Juan B.
Published: February 2019

Experimental data are given to aid in the selection of the wave height for the design of a rubble mound breakwater as a function of the type and duration of the wave storm, and the allowed percentage of damage in the armour layers. In these experiments the model breakwater was subjected to the attack of periodic waves of height and in number according with the known statistical distribution for actual swells. - Some noteworthy differences were found In the effects of different duration storms. Observation of the destruction process of the breakwater with double layer of armour rocks, showed that the filter layers uncovering occurred always for armour damage percentages above 5$ and thus this last value is suggested as the ma_ ximum permissible in case of a storm of very high recurrence period.
VELOCITIES IN DOWNRUSH ON RUBBLE MOUND BREAKWATERS
Authors: Brandtzaeg A. , Torum A. , Ostby O.R.
Published: February 2019

This paper is a sequence to two papers, (1) and (2), previously read at Coastal Engineering Conferences. They presented a mathematical model for estimating displacements, velocities and accelerations in a downrushmg wave on a rubble mound breakwater slope. Verification by photographic recording of displacements involved some uncertainties. In the present paper are reported measurements of velocities, which gave much more definite data. The correlation with velocities calculated from the model is shown to be good.
A MODEL STUDY OF THE DISTRIBUTION OF RUN-UP OF WIND-GENERATED WAVES ON SLOPING SEA WALLS
Authors: Webber Norman B. , Bullock Geoffrey N.
Published: February 2019

The behaviour of wind-generated waves on impermeable slopes of 1:2, 1:4 and 1:10 was investigated in a 40 ft long laboratory wind-wave flume. Apparatus for measuring instantaneous values of the run-up was devised. Wind velocities of up to 44 ft/sec were applied, producing wave heights of up to 2.5 in. Distributions were obtained for the wave and run-up characteristics. The empirical results were compared with theoretical statistical relationships. A comparison was made with the run-ups in paddle-wave experiments. The relationship between the waves and their run-ups was further investigated by a comparison of simultaneous recordings, using the methods of spectral analysis.
THE EFFECT OF WAVE ENERGY SPECTRA ON WAVE RUN-UP
Authors: Van Oorschot J.H. , D'Angremond K.
Published: February 2019

Previous investigations carried out "by the Delft Hydraulics laboratory have shown the necessity of applying irregular waves m studies on wave run-up. The installation of a wave generator driven "by hydraulic actuators has created the possibility of producing irregular waves with arbitrary wave spectra. Investigations performed with this type of wave generator show the influence of the shape of the energy spectrum on the wave run-up on smooth straight slopes of 1:4 and 1:6. The results are compared with run-up figures derived from experiments with wind generated waves and with monochromatic waves.
ON THE OVERLAND FLOW OF TSUNAMI AND EFFECTIVENESS OF WALL AS A COUNTER MEASURE
Authors: Iwasaki Toshio , Togashi Hiroyoshi
Published: February 2019

When a tsunami of large magnitude strikes a coast line, various kinds of disaster such as loss of lives, properties or public investments are caused by inundation of tsunami over nearly horizontal area. Although tsunami runup has been investigated for the sloping beach, these populated area is bordered on sea by a vertical wall such as a quaywall or a highway revetment. In this paper, transformation of tsunami waves at a vertical quaywall is analysed using U-C characteristics and overland flow is treated. Effectiveness of a vertical land dike aiming to stop running water is investigated also. Theoretical results are verified by experiments.
PRESSURES BY BREAKING WAVES ON COMPOSITE-TYPE BREAKWATERS
Authors: Nagai S. , Otsubo T.
Published: February 2019

The intensity and vertical distribution of pressures exerted by water waves on the vertical walls of composite-type breakwaters vary in a very wide range from those of high shock pressures exerted by severe breaking waves to those of low pressures similar to hydrostatic pressure due to standing waves, depending upon the shape of the composite-type breakwaters, the characteristics of incoming waves, and the depths of water where the breakwater are located. In this paper are presented the intensity and vertical distribution of pressures exerted by various kinds of breaking waves on the vertical walls of composite-type breakwaters with low and large base-rubble-mounds constructed m comparaticely deep water.
PRESSURE DISTRIBUTION OVER A MOVING WAVY BOUNDARY
Authors: Zagustin Konstantin
Published: February 2019

Experimental data on pressure distribution over a sinu^ soidal wavy boundary with a fixed and a moving condition, mea_ sured in a water tunnel, are presented for a number of flow - velocities. The model with the moving boundary condition is related to the situation prevailing in the steady state flow picture of a small amplitude wind-generated gravity wave in - which the water flow represents the air flow in nature, while the "fixed in space" moving wavy boundary corresponds to the nearly constant water particle velocity at the surface of the wave. The results show that the normal stress distribution - over a moving boundary differs from that over a fixed one by a phase-lag with respect to the wave shape, which varies with the ratio of flow velocity to the boundary velocity (wave celerity), as predicted by the recent theories of Miles and Ben_ jamin. These results provide an explanation for the energy - transfer from wind to wave due to normal stresses and show that those experiments performed on fixed boundary models can not be associated with the phenomena of water wave generation.
FIELD INVESTIGATION PRACTICES OF COASTAL STUDIES IN JAPAN
Authors: Hom-ma Masashi
Published: February 2019

This paper is a brief review of the publications on the field studies carried out in Japanese coasts. Japan has many projects of coastal works in relation with the development of industrial area, the protection of coastal land from disaster and some other purposes. Before the execution of these projects, the agencies in charge of them make field investigations for their necessary items. The results of investigations in detail are reported in their official publications and sometimes the abstracts of them are reported at the annual meeting of coastal engineering held by the Japan Society of Civil Engineers. As the official publications of the governmental organizations are distributed in strictly limited circles, they are not well known by scientists and engineers outside these organizations. The author intended to collect some of these official reports and selected some additional reports on field study from the proceedings of annual meetings of coastal engineering, and tried to make a classification of the contents and to give a brief review of them.
DUBAI CREEK ENTRANCE
Authors: Ridehalgh H.
Published: February 2019

The paper describes the works carried out to improve and stabilise the entrance to the Creek at Dubai. The Creek which is about eight miles long discharges through a heavily charged littoral zone m which large volumes of sand are transported across the entrance from west to east. The works were required urgently and this coupled with financial restrictions prevented a study of the problem on an hydraulic model or the collection of comprehensive site information before construction of the work commenced. In the event the works were carried out in stages - succeeding stages being planned and designed after the effects of the previous stages on the regime had been established. The paper presents the results which were achieved using the prototype as a model and traces the effect of each stage on the Creek and littoral regimes from the commencement of the works.
BREAKING WAVE CRITERIA; A STUDY EMPLOYING A NUMERICAL WAVE THEORY
Authors: Dean Robert G.
Published: February 2019

Although it is well recognized that wave systems in nature are irregular, comprising a spectrum of fundamental periods, there is still a need for improving our understanding of near-breaking nonlinear wave systems which contain a single fundamental period. For example, most of the shallow water design situations and other cases including forces on small diameter structures in which drag forces predominate are more directly treated in terms of a "design wave" rather than a wave spectrum. This situation is contrasted to many important engineering design problems in which the dynamics of the system are paramount; for example, in the case of a moored drilling vessel. Finally, one may reasonably expect that accurate solutions to the problem of nonlinear wave systems with a single fundamental period will lend insight regarding productive approaches to the more realistic problem of a spectrum of nonlinear waves. This paper investigates the applicability of the stream function wave theory1 for the representation of breaking and near-breaking waves. This particular problem has received little attention, although considerable progress has occurred on two related problems: 1. The development of wave theories covering a wide range of relative water depths and wave heights, and 2. The development of wave theories which apply at breaking conditions. In general, although these theories may be applicable for the limiting wave conditions, their basis of derivation is such that they cannot be extended to non-breaking waves. The purpose of the present investigation, then, is to establish whether or not the stream function wave theory can be applied to span the range extending up to breaking conditions.