مهندسی دریا
Sina Gharavi; Seyed Mostafa Siadatmousavi; Ali Khoshk holgh
Abstract
Sedimentation and erosion are among the most significant issues that pose serious challenges in coastal areas. The consequences of these phenomena include reduced lifespan of ports, continuous dredging, and high costs. When ports experience sedimentation, engineering solutions are required. Predicting ...
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Sedimentation and erosion are among the most significant issues that pose serious challenges in coastal areas. The consequences of these phenomena include reduced lifespan of ports, continuous dredging, and high costs. When ports experience sedimentation, engineering solutions are required. Predicting the rate and pattern of sediment deposition in the access channel and the basin of ports enables better cost management. The objective of this study is to numerically model the hydrodynamic and morphological effects using the open-source numerical model TELEMAC in the Strait of Khuran and Shahid Rajaei Port, located in the Persian Gulf. For this purpose, water surface elevations at open boundaries were provided to the model, obtained from a calibrated MIKE21 model. The hydrodynamic model was executed, and the output included velocity and water surface elevation. Additionally, the sediment transport model GAIA was coupled with the hydrodynamic model and executed. The sediment model output includes bed level changes and suspended sediment concentrations. Finally, the simulated model was validated using measurement data, confirming that the dominant flow is tidal, parallel to the coast, and reaches a maximum velocity of 2 meters per second. The water surface elevation modeled by TELEMAC indicates that localized maximum water levels reach up to 4 meters. Wind speeds rarely reach 5 meters per second in the Khuran channel, and therefore, their influence on the currents is minimal. The results from the sediment model demonstrate that the intensity of sediment deposition in the port area and the access channel is higher in the central and eastern parts of the Strait of Khuran, as well as in the western area of Shahid Rajaei Port.
مهندسی دریا
MORTEZA BAKHTIARI; AMIR ASHTARILARKI; Samer adnan
Abstract
Estimation of sediment transportation is one of the significant factors in river engineering. This is especially important in rivers that are used and exploited in many ways. The problem of sediment transport itself has some complexities and will be much more complex in tidal rivers. In the present study ...
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Estimation of sediment transportation is one of the significant factors in river engineering. This is especially important in rivers that are used and exploited in many ways. The problem of sediment transport itself has some complexities and will be much more complex in tidal rivers. In the present study using MIKE 21 model, particle velocity fall, erosion and sedimentation critical shear stress, Transition parameter between layers, Vertical diffusion coefficient and Roughness of bed stream are investigated. The results showed that particle velocity fall and sedimentation critical shear stress has no significant effect on sediment transport and the slope of the suspended load changes at different speeds is approximately the same. The results also show that by increasing the coefficient of transfer between layers, the concentration of suspended charge increases slightly.
مهندسی دریا
Mohammad Taghi Mansouri Kia; Hamid Reza Sheybani; Elham Rajabi
Abstract
The only navigable river is the Karun River in Iran. Karun shipping history dates back to Nasser al-Din Qajar Shah. Climate change and drought, harvests more water and reduce its capacity, the existence of new railways and highways as the main competitors of cargo from the port of Mahshahr and Khorramshahr ...
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The only navigable river is the Karun River in Iran. Karun shipping history dates back to Nasser al-Din Qajar Shah. Climate change and drought, harvests more water and reduce its capacity, the existence of new railways and highways as the main competitors of cargo from the port of Mahshahr and Khorramshahr to Ahvaz due to the boom in river water transport has been falling.There are few studies on water transport in Karun river. In this study, some of their results are discussed in general. Then, based on the acceptance of the latest research, the most important physical barriers to river transportation have been identified and their remediation strategies adapted to the current situation. Then shipping Signs required of navigation and auxiliary's equipment for sailing have also been offered.Previous studies included :(Iranian structural consulting engineers, 2004; Adabdanan Consulting Engineers, 2004) and Especially (Scott Wilson and Piesold, 2005) It has been attributed to the heavy losses of water transportation, especially in the high tonnage of annual freight. The most recent study, ongoing surveys at the Khuzestan Water and Power Organization (Mansouri Kia, 2018) show that the transport medium (in the pessimistic scenario optimistic scenario about 700 thousand tons and 2133 thousand tons in the target year 1425), together with previous studies is the development of tourism can be no economic losses. Water transport is the base year 2020. Heavy financial losses were previously assumed for river transportation. The most important results of recent research suggest that these losses are reduced by modifying the design vessel dimensions.Another important result of the present study is identifying the physical problems for the Iranian rivers transportation and to provide solutions (except for the sediment removal problem that is being investigated at another study). Applying the research results on solving physical barriers and financial support by private investment (or other financing options), revive water transportation in Karun it is possible.
مهندسی دریا
Mohammad Taghi Serajian; Alireza Masjedi; Mohammad Heidarnejad; Hooshang Hasonizadeh
Abstract
In this study, experiments are carried out to determine the deviation flow into the intake in a 90º convergent bend, aiming to investigate the effect of flow characteristics on deviation flow with and without submerged vanes. The effective variables include Froude number, convergence, and submerged ...
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In this study, experiments are carried out to determine the deviation flow into the intake in a 90º convergent bend, aiming to investigate the effect of flow characteristics on deviation flow with and without submerged vanes. The effective variables include Froude number, convergence, and submerged vanes’ angle. For this research, a Rectangular channel with a 90º arc was used, which was studied using four different discharges, four different angles of submerged vanes and four degrees of convergence of the end of the channel. According to the results, the deviation flow to the intake increases by converging the laboratory flume. As the end of the flume is converged, the deviation flow is further increased. As the flume is converged (b/B) from 0 to 0.75, the deviation flow is increased from 64.9 to 81.4%, showing a 16.5% increase. Deviation flow is decreased by installing submerged vanes. A decrease in submerged vanes’ angle reduces the deviation flow. Compared to the model without a submerged vane, deviation flow is decreased by 14.9, 9.9, 6.8, and 2.3% by installing submerged vanes at angles of 25, 30, 45 and 60º, respectively. Deviation flow is also decreased by increasing the Froude number, such that it decreases by 5.3% with the increase of Froude number from 0.14 to 0.23.
مهندسی دریا
Mohammad Hosseini; Mohammad Hadi Fattahi; Saeid Eslamian
Abstract
The density current, as a part of the gravity currents, is the flow of one fluid within another caused by the density difference between two fluids. The density current consists of the nose, head, and body regions within the ambient fluid. In the present study, a flume with 8m length, 35cm width, and ...
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The density current, as a part of the gravity currents, is the flow of one fluid within another caused by the density difference between two fluids. The density current consists of the nose, head, and body regions within the ambient fluid. In the present study, a flume with 8m length, 35cm width, and 40cm height was used. The experiments were performed in 28 different states by changing the bed slope, density, and discharge. The results indicated that by increasing the bed slope, the concentration of the density current decreased by 12% and 19% after continuous and local narrowing, respectively, compared to the non-narrowing state. Further, the entrainment ratio increased by narrowing the flume wall, as the Richardson number decreased by 80% and the entrainment ratio increased by 5 times after narrowing. In addition, the profile formation pattern of the current velocity and concentration enhanced by increasing the inlet density and the pattern indicated more scattering in the jet region compared to the wall region.
مهندسی دریا
Hamed Jalil Masir; Rohollah Fattahi; Elham Ghanbari Adivi
Abstract
Sediment transport phenomenon is considered as one of the important and Effective factors in hydraulic performance and morphological structure of the coasts. In addition, stable development, engineering proceedings and the selection of the most appropriate protection method for organization and stabilization ...
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Sediment transport phenomenon is considered as one of the important and Effective factors in hydraulic performance and morphological structure of the coasts. In addition, stable development, engineering proceedings and the selection of the most appropriate protection method for organization and stabilization of the coast, are depends on the quantity of sediment load. Therefore, the focus of this study is generally to estimate sediment transport rate, assess the impact of coastal forest cover (Green Belt) on decreasing sediment transport rate exposed to tsunami wave trend and to obtain the parametric model to each coastal area using SPSS software. Experiments were performed on the effectiveness of a mangrove tree to reduce tsunami energy, by a simulated polyethylene synthetic shrub structure, for two rectangular and triangular tree layouts, 3 input wave height of 6, 9 and 12 cm, constant and horizontal slope of the coast, 0.35 mm sediment diameter and in terms of presence and absence of cover.. The results of this study show that despite forest cover, 41.17% of coastal erosion and scour are prevented and it helps to stabilization and restoration the coasts. Also considering conditions such as triangular layout selection and increasing cover density, 7.57% and 11.20% respectively, leading to the improvement of the coastal condition. Finally, the parametric model and the experimental equation for estimating the sediment transport rate with the correlation coefficient equal to 0.95, proposed as well.
مهندسی دریا
Amir Zarepour; Mehdi Behdarvandi Askar; Saham-eddin Cheraghi; vahid Zareii
Abstract
The aim of this research is to investigate the hydrodynamic status of Mahshahr export port. Initially, the modeling of tidal streams in the starting point of Khurmousa by the tidal inputs of Rahnamaian station was performed in logical manner and the results obtained from the inner point of Khurmousa ...
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The aim of this research is to investigate the hydrodynamic status of Mahshahr export port. Initially, the modeling of tidal streams in the starting point of Khurmousa by the tidal inputs of Rahnamaian station was performed in logical manner and the results obtained from the inner point of Khurmousa was calibrated with inputs from Imam Khomeini station port and satisfactory results were achieved. During the next stage, by considering the main aim of this research, a model specific to the area of export port of Mahshar was developed. Based on the results from field measurements and the results obtained from the model, the tidal amplitude balance in export port of Mahshahr is 4.25 meters, the maximum annual ebb is 2.25 meters and the annual minimum is 2 meters. The velocity of tidal streams in Mahshahr export port parallel to the channel and during the most part of the year is between 0.5 to 1 meters per second. The pattern of tidal streams is constant throughout the year and experiences no changes
مهندسی دریا
mohammad ghanbar dezfouli; masoud dehghani; adel asakereh; behzad kalantari
Abstract
In the coastal areas and especially in the harbors, due to the presence of loose sandy sediments and structures under high lateral and vertical loads, the use of pile raft is a suitable choice for the foundation of these infrastructures. In this system, raft and piles are separated and a cushion is used ...
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In the coastal areas and especially in the harbors, due to the presence of loose sandy sediments and structures under high lateral and vertical loads, the use of pile raft is a suitable choice for the foundation of these infrastructures. In this system, raft and piles are separated and a cushion is used in the distance between the raft and the piles. The existence of reinforcement layers in the cushion such as the geogrid changes the behavior of the pile raft system. In this paper, the behavior of reinforced nonconnected pile raft with geogrid under vertical loading in sandy soils has been investigated by a laboratory studies. An automatic hydraulic jack were used in the load application and LVDT is used to measuring the settlement. The strain gages are installed at the tip of the piles to calculate the force applied to the piles. Tests were carried out under reinforced and non-reinforced condition. In non-reinforced case, the optimum thickness and pile spacing of the cushion and in the reinforced case, the optimal location of the first and second layer of the geogrid and the effect of the geogrid layers length on the load-settlement behavior and the share of the piles from the total load were evaluated. The results shows that the thickness of the cushion and the pile spacing have a significant effect on the behavior of the pile raft. The presence of geogrid layers in the cushion increases the bearing pressure and the share of piles from loads.
مهندسی دریا
gholam abbas Boroujerdi; Amir Abbas kamanbedast
Abstract
One of the most important issues related to arc ducts is the erosion of the river bank in the outer arc, which is largely due to the existence of secondary currents, in which the mechanism of these currents was elaborated in the previous section. Protecting and fixing the river walls generally involves ...
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One of the most important issues related to arc ducts is the erosion of the river bank in the outer arc, which is largely due to the existence of secondary currents, in which the mechanism of these currents was elaborated in the previous section. Protecting and fixing the river walls generally involves both direct and indirect methods (relaxants and deviators). One of the most important diversion protection structures is river flows. In this research, hexapod materials were evaluated for scouring in permeable spills. The results obtained from the simulation show that the use of Hexapod spray with 12, 20, 27 and 35% permeability reduced scours by 17, 27.9, 38 and 45.3%, respectively, compared to the control without permeability. Increasing the permeability of the hexapod spoil reduces scouring around the spillway. Increasing the permeability of Hexapod spray guns from 12 to 35 percent resulted in a reduction of sputum by 34.1 percent. This phenomenon is due to the easier flow of water through the hexapod sprayer and creates less pollen, which reduces scouring. Also, with an increase in the landing value from 0.2 to 0.36, the scour is 11.8 times higher. Of course, it should be noted that increasing the landing number increases the permeability of the spillway to increase scouring. So that with the installation of permeable sprinkler 35% in the number of 0.2 and 0.36, respectively, we saw a decrease of 20 and 61% scouring compared to the control model, respectively.
مهندسی دریا
Morteza Bakhtiari; Ehsan Kamal pour asl; Javad Ahadiyan
Abstract
There is a different method for increasing the resistance and quality of engineering of soils, one of the most suitable ones is dynamic compaction. In this method, weights are released from the specified height and, as a result of collision with the ground, the soil will be compacted. In this research, ...
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There is a different method for increasing the resistance and quality of engineering of soils, one of the most suitable ones is dynamic compaction. In this method, weights are released from the specified height and, as a result of collision with the ground, the soil will be compacted. In this research, field experiments were initially initiated. Then using the results obtained in this section, the soil dynamic compaction was modeled. In order to do the modeling, the present study was conducted using FLAC two-dimensional software. Due to the implementation of various designs in the city of Abadan, the area was selected as the site of the project After field experiments, mechanical properties of the soil were extracted and then modeled with the definition of test patterns. The result of this research show that For all conditions of modeling, the maximum deformation of soil was observed in the hammer Cutoff area, which decreased in depth of soil. Also, the results indicate that effective stress in soil under dynamic density decreases with increasing depth.
مهندسی دریا
Meysam Salarijazi
Abstract
Estimation of the water level in river’s tidal limit is a suitable tool for the tidal flood management for rivers that are located in coastal areas. In this limit, propagation of tidal waves along the river to the upstream and combination of these waves and upstream flood discharge leads to an ...
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Estimation of the water level in river’s tidal limit is a suitable tool for the tidal flood management for rivers that are located in coastal areas. In this limit, propagation of tidal waves along the river to the upstream and combination of these waves and upstream flood discharge leads to an increase in flood plain limit and risk of damage. In this study, the reach between Ahvaz and Khorramshahr in Karun River is selected as case study and different linear and non-linear models are investigated for prediction of water level as a function of flood discharge of upstream. The analysis is performed for two cases considering the nature of tidal flood. In first case, total recorded data is investigated while in second case tidal flood data is extracted based on peak over threshold series analysis. Analysis of residuals of models in two cases show that the linear models are not acceptable, therefore the transformed nonlinear models that are a form of linear models are considered for modeling too. The power equations with improved coefficient of determination, relatively constant variance and normal distribution of residuals of models are concluded from detailed analysis in calibration parts for two cases. These selected models are used for validation part for two cases. The results confirm the acceptability of these models considering their simplicity and better efficiency for first case than second case.
مهندسی دریا
Morteza Bakhtiari; Shahriyar Shemshaki; Masoud Sadri nasab
Abstract
With the advent of technology and the expansion of human needs, the use of water platforms such as seas, oceans, and the recognition of methods and solutions for the design and implementation of marine structures is becoming increasingly clear.The semi-submerged platform is one of a variety of submarine ...
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With the advent of technology and the expansion of human needs, the use of water platforms such as seas, oceans, and the recognition of methods and solutions for the design and implementation of marine structures is becoming increasingly clear.The semi-submerged platform is one of a variety of submarine platform platforms, which, according to the features of the platform, is mainly used for extracting deep-sea oil and gas resources. In this research a semi- submersible platform under performance condition using ANSYS finite element software is numerical modeling and It is under regular waves. The platform's geometry is based on a platform built in 2012, and the data used in this study is about the average 20 years of Caspian waves.The degree of displacement, rotation, and force of diffusion has been obtained in degrees of freedom and are compared with each other. to apply regular waves Airy theory has been used. The result of this study show that In the loading of regular waves, the two parameters of the wave period and the wave propagation angle were the determining factor in the displacement and the platform time, as well as the dispersion force resulting from the collision of the wave with the platform. Also, the results show that at a 90 degree angle of the wave with the platform, the motion state at 2 degrees Z, Ry was close to zero and was the largest amount of time around the X axis.
مهندسی دریا
hossein bahrami; samad emamgholi zadeh
Abstract
Accurate estimation of sediment concentrations in hydraulic sediment transport from different viewpoint such as sediment discharge estimation of river, selection of hydraulic structures and etc. are important. With respect to importance of this issue in this study for prediction of sediment concentration ...
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Accurate estimation of sediment concentrations in hydraulic sediment transport from different viewpoint such as sediment discharge estimation of river, selection of hydraulic structures and etc. are important. With respect to importance of this issue in this study for prediction of sediment concentration of Karun river multi-layer perceptron artificial neural network (ANN / MLP) was used.For this purpose 125 field data including bottom concentration, flow velocity, nearest distance from the beach, and thetotal depth of flow and flow depth was used.Three statistical metrics namely mean absolute error (MAE), root mean square error (RMSE) and coefficient of determination (R2) were used to evaluate the performance of ANN model. The result shows that MLP model with one hidden layer, Sigmoid transfer function and 5 neurons have best structure in the modeling of sediment concentration of Kroon River. The R2 and RMSE value is equal to 0.953 and 63.37 mg/l in training stage and 0.752 and 203.02 mg/l in testing stage, respectively. Finally, the sensitive analysis also showed that the nearest distance from the beachand flow depth had the most and the least effect on the sediment concentration, respectively.
مهندسی دریا
Parisa Koochak; Seyed Mahmood Kashefipour; Mehdi Ghomeshi; Ahmad Fathi
Abstract
One of the ways to control the erosion in the outer bend of rivers is to use spur dikes. In recent years, the efficiency, affordability and environmental suitability of traditional spur dikes has been criticized. Therefore the importance of adopting methods which are both cost-effective and eco-friendly ...
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One of the ways to control the erosion in the outer bend of rivers is to use spur dikes. In recent years, the efficiency, affordability and environmental suitability of traditional spur dikes has been criticized. Therefore the importance of adopting methods which are both cost-effective and eco-friendly has been addressed. The bandal-like spur dike is a combination of a permeable and an impermeable spur dike, which is usually used in Indian Sub-Continents for riverbank protection and improvement of navigation conditions in alluvial rivers. It is made of bamboo therefore it is inexpensive and environmental friendly. In this research the effect of the permeability percentage of the bandal-like structure on the maximum scour depth around it in a 90 degree mild bend flume and in submerged condition is investigated. Therefore a series of impermeable spur dikes (0% permeability) and bandal-like structures with (33,50 and 64) percent permeability are placed in the flume and examined under four different Froude numbers (0.21, 0.23, 0.26, 0.29). The results showed that the maximum scour depth around the bandal-like structure is considerably less than the maximum scour depth around impermeable spur dikes. Also by increasing the permeability percentage of the bandal-like structures the maximum scour depth around it decreases.
مهندسی دریا
Tooba Heidari; nima shahni karamzadeh; Javad Ahadiyan
Abstract
In this study, results of experiments about the trajectory and the advance velocity of inclined and convergent rectangular surface jet into stagnant ambient have been presented. In order to discharge process simulation was used a flume with 3.2 m length, 0.6 m width and 0.9 m height and a rectangular ...
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In this study, results of experiments about the trajectory and the advance velocity of inclined and convergent rectangular surface jet into stagnant ambient have been presented. In order to discharge process simulation was used a flume with 3.2 m length, 0.6 m width and 0.9 m height and a rectangular channel with 6 cm width. Discharge channel was designed in the four angle of convergence 12.5, 25, 45 and 90 degree. This channel injected the jet stream to form of tangent to the surface of ambient and in three different slopes 0, 4 and 8 percent. Receiving fluid had been prepared from urban water. As well as the jet fluid had been prepared from the salt liquidation in water and in three concentrations 5, 15 and 45 gr/l. After running the experiments and using of images routing process were analyzed the data. In this regard, hydraulic and geometric parameters on the trajectory and the advance velocity of jet was investigated. According to the results, increase the slope and decrease the angle of convergence causes increase in length of trajectory and decrease in the advance velocity of jet. Reduce the densimetric froude number causes decrease in length of trajectory. Also, in order to investigate of influence of convergence on the movement path of flow, by comparison of trajectory in convergent channel and simple channel, More relative advance was seen in convergent channel. Finally, using of the data analysis, relation between advance velocity of jet and dependent parameters was determined with RMSE=0.034.
مهندسی دریا
maryam yaghoubzadeh; Afshin Danehkar; Bahman jabbarian amiri; Sohrab ashrafi
Abstract
We used 6 criteria and 29 indicators for determination environmental sensitivity of geomorphologic aspects of the coastal area in Hormozgan. Identification and determination of the important coefficient showed exclusivity and wilderness are the most important coefficients and industrial dependency had ...
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We used 6 criteria and 29 indicators for determination environmental sensitivity of geomorphologic aspects of the coastal area in Hormozgan. Identification and determination of the important coefficient showed exclusivity and wilderness are the most important coefficients and industrial dependency had the lowest priority for determination of the environmental sensitivity in this regard.Moreover, in order to, determine importance and priority of sensitivity of ecosystems in the study area 9 physical structure were studied in both shore and coastal zone (include: 4 structure in coastal area and 5 structure in shore area). According to the results, Inundated mudflat and in shore area and Low flat land in coastal area are of the most important sensitivity .After reviewing the physical structure and preparation map of overlaying this structure, sensitivity zoning was developed coastline in Hormozgan province on 5 class of sensitivity, Very low sensitivity, low sensitivity, moderate sensitivity, high sensitivity and very high sensitivity. Zoning of sensitive physical structure in coastal zone shows the lowest extent areas are in Low sensitive degree and the most extent areas are in moderate sensitive degree in physical sensitivity classes.According to the results, shore area in Hormozgan province that includes 11.35% of coastal zone has high physical sensitivity. In shore area Inundated Mudflat, Rocky shore and Inundate beach have most physical sensitivity and inundated process is the most important phenomena on the structures mentioned the shores. The most sensitive of coastal area is Low flat land.
مهندسی دریا
morteza Bakhtiari; FARZAD ORAK
Abstract
Sea Walls are constructed to protect coastal against of waves and prevent water to coastal. In order to properly understand the behavior of these structures must have proper information of loads to the structure. One of the main significance loads over the seawall is wave’s loads. Weight forces ...
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Sea Walls are constructed to protect coastal against of waves and prevent water to coastal. In order to properly understand the behavior of these structures must have proper information of loads to the structure. One of the main significance loads over the seawall is wave’s loads. Weight forces the walls, Weight backfill, Seawater weight on the heel wall and Forces exerted on the beach other forces that enters the coastal wall. Considering the importance of seawalls study on the stability of these structures has been the subject of study. In order to achieve the objectives of the study, three scenarios include changes in the geometry of the wall and Soil properties. In present study four geometry vertical, inclined, convex, concave, are considered and modeling with Flac 3D software. The results of this study showed that the minimum of horizontal and vertical displacement are about convex seawalls and the maximum of them is about vertical concave seawalls. Also the results showed that in the higher shear strength of soils the minimum of horizontal and vertical displacements occurred.
مهندسی دریا
ahmad rezaie mazyak; mehdi sanayei
Abstract
The main goal of using floating breakwaters is to provide the sheltered area of calm water in the coastal zone. In present research, for analyzing hydrodynamic modeling of pontoon floating breakwaters the AQWA module of ANSYS software has been selected. The main parameters that have been considered in ...
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The main goal of using floating breakwaters is to provide the sheltered area of calm water in the coastal zone. In present research, for analyzing hydrodynamic modeling of pontoon floating breakwaters the AQWA module of ANSYS software has been selected. The main parameters that have been considered in this research are pattern of significant wave height, wave period, and draft and width of floating pontoon. Wave transmission coefficient can be obtained from water surface changes in any point of leeward. Results of numerical modeling demonstrate that a pontoon floating breakwater with relative width greater than 0.4 have appropriate performance. Also it has been found that the transmission coefficient of pontoon floating breakwaters will be in the range of 0.35 to 0.60 if the relative wave period changes in the range of 1.5 to 4.
مهندسی دریا
Morteza Bakhtiari; seyed mahmood kashefipour; Mehdi GHomeshi
Abstract
One application of spur dikes is ensure navigability of rivers Through regulation and stabilization of sufficient width and depth, balance changes for the development of depth and The radius of curvature.Nowadays, spurs are also employed for promoting environmental conditions along a riverbank. One of ...
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One application of spur dikes is ensure navigability of rivers Through regulation and stabilization of sufficient width and depth, balance changes for the development of depth and The radius of curvature.Nowadays, spurs are also employed for promoting environmental conditions along a riverbank. One of the important topics abut spurs is their protection against scouring that has been less studied. One of the simple and economic ways for protection of spur against scouring is using riprap. Riprap is very common because it is easily available, cheap and simple for construction.Since using, spur dikes to protect riverbanks spatially in bends is very common, This research was carried out in order to investigate the effect of the structure stability. The purpose of this study is evaluation of depth-placed riprap for protection of spur dike in 90° Bend. In order to achieve the research objectives, one riprap size of inch diameter was used. Ripraps are placed in 3 depths ( ), and used for 3 lengths of spur(15%,20% and 25% width of flume), two angles (90 and 120 degree) and three longitude distance (3,5 and 7 times of spur length). Parameters as variables in this study were selected which The results can be used in large rivers, including navigable rivers and the Gulf.The results showed that stability of ripraps are increased with increasing the depth-placed riprap and angle of spurs, whereas increasing in spur length and longitude distance decreases stability of ripraps.