scholarly journals Experimental Investigation of Horizontal Wave Pressure on the Caisson Protected by Armor Blocks on the Rubble-Mounted Core

2020 ◽  
Vol 8 (9) ◽  
pp. 691
Author(s):  
Sang-Ho Oh ◽  
Jae-Sung Lee
Keyword(s):  
Coverage Rate ◽  
Front Wall ◽  
Regular Waves ◽  
Wave Pressure ◽  
Physical Experiments ◽  
Adjustment Factors ◽  
Horizontal Wave ◽  
Exposed Part ◽  
Series Of Experiments ◽  
Model Setup

The horizontal wave pressure on the front wall of the caisson protected by armor blocks on the rubble-mounted core is investigated by carrying out physical experiments. There have been few previous studies regarding this type of structure, and the characteristics of horizontal wave pressure on the structure are still unclear. Considering this, a series of experiments were performed by changing the configuration of the coverage rate in front of the caisson and the shoulder width of the armor blocks. For each of the different configurations of the model setup, wave pressure on the caisson was measured under 20 regular waves of different wave periods and heights. By analyzing the obtained experimental data, it was possible to quantify the effects of the coverage rate and the shoulder width on the wave pressure. The wave pressure tended to increase up to maximally 1.5 to 2 times at the exposed part of the caisson if it was incompletely protected. In addition, the wave pressure at the top part of the caisson was substantially reduced with the increase of the shoulder width of the armor layer. Based on these results, adjustment factors for evaluating such effects have been suggested, which can be applicable for the practical design of the caisson covered with armor blocks on the rubble-mounted core.

scholarly journals Horizontal Wave Pressures on the Crown Wall of Rubble Mound Breakwater under Non-Breaking Condition

2021 ◽  
Vol 33 (6) ◽  
pp. 321-332
Author(s):  
Jong-In Lee ◽  
Geum Yong Lee ◽  
Young-Taek Kim
Keyword(s):  
Physical Model ◽  
Model Test ◽  
Efficient Solution ◽  
Physical Model Test ◽  
Wave Loads ◽  
Wave Pressure ◽  
Practical Design ◽  
Horizontal Wave ◽  
Series Of Experiments ◽  
Rubble Mound

The crown wall with parapet on top of the rubble mound breakwater represents a relatively economic and efficient solution to reduce the wave overtopping discharge. However, the inclusion of parapet leads to increased wave pressure on the crown wall. The wave pressure on the crown wall is investigated by physical model test. To design the crown wall the wave loads should be available, and the horizontal wave pressure is still unclear. Regarding to the horizontal wave pressure on the crown wall, a series of experiments were conducted by changing the rubble mound type structure and the wave conditions. Based on these results, pressure modification factors of Goda’s (1974, 2010) formula have been suggested, which can be applicable for the practical design of the crown wall of the rubble-mound breakwater covered by tetrapods.

scholarly journals Influence of the Perforated Rate on the Wave Attenuation Performance of Perforated Caisson Set on a Rubble Bed

2021 ◽  
Author(s):  
Peihong Zhao ◽  
Dapeng Sun ◽  
Hao Wu
Keyword(s):  
Reflection Coefficient ◽  
Wave Attenuation ◽  
Wave Force ◽  
Wave Forces ◽  
Front Wall ◽  
Minimum Value ◽  
Physical Experiments ◽  
Horizontal Wave ◽  
Horizontal Wave Force ◽  
Perforated Caisson

A Jarlan-type perforated caisson (JTPC) was an important form of structure in offshore and coastal engineering and its wave attenuation performance was greatly affected by μ (the perforated rate). In the present research, a numerical model based on VARANS equations was tested by comparing the simulation results with physical experiments and then adopted to study the effect of a larger range of μ on wave attenuation performance which included both the horizontal wave forces and the reflection coefficients. Conclusions were drawn that the total horizontal wave force and the reflection coefficient both tended to decrease and then increase with increasing μ; when the reflection coefficient reached its minimum value as about μ=0.2, the wave force at the seaward side of the perforated front wall tended to be equal to that at the solid rear wall; the total horizontal wave force reached its minimum value as about μ=0.3.

scholarly journals CHANGE OF HORIZONTAL WAVE PRESSURES ON A CAISSON DEPENDING ON THE CREST LEVEL OF ARMOR LAYERS ON THE RUBBLE MOUNTED CORE

2020 ◽  
pp. 29
Author(s):  
Sang-Ho Oh ◽  
Jae-Sung Lee
Keyword(s):  
Water Level ◽  
Double Layer ◽  
Core Layer ◽  
Physical Experiment ◽  
Front Face ◽  
Significant Discrepancy ◽  
Wave Pressure ◽  
Horizontal Wave ◽  
Exposed Part ◽  
Impulsive Loadings

This study reports physical experiment campaign to measure horizontal wave pressure acting on a solid caisson that is protected with double-layer Tetrapods and core-layer of rubble stones. The main focus of this study was to evaluate the effects of crest level of the armor layers on the measured wave pressures. The measurements were conducted with four different models in terms of the coverage of the front face of the caisson: no coverage, full coverage up to the crest of the caisson, and two different partial coverages where the crest level of the armor layers were lower than the crest of the caisson. The wave pressures above the still water level showed significant discrepancy depending on different armor coverages, especially for the caisson that are partially protected by armor blocks. It seemed that impulsive loadings acted at times on the top exposed part of the caisson if the caisson is imperfectly protected by armor blocks.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/e8oNZrmiTjo

Wave Induced Pressures on Pipelines Near a Sloping Boundary Due to Regular Waves

2002 ◽  
Author(s):  
K. A. Roopsekhar ◽  
V. Sundar
Keyword(s):  
Time History ◽  
Wave Direction ◽  
Regular Waves ◽  
Scattering Parameter ◽  
Similarity Parameter ◽  
Experimental Procedure ◽  
Sloping Bed ◽  
Model Setup ◽  
Force Time ◽  
Wave Induced

The hydrodynamic pressures due to regular waves around the circumference of a pipeline near a sloping rigid bed and placed parallel to the wave direction have been measured. The pressures were integrated to obtain the force time history, from which the peak horizontal and vertical forces were evaluated. The effects of relative clearance of pipe from the bed and its relative position from the toe of the sloping bed on the pressures and forces on the pipeline as a function scattering parameter and wave steepness are reported. The reflection characteristics of the sloping bed in the presence of the pipeline are reported as a function of surf similarity parameter and compared with the results from existing literature. The details of the model setup, experimental procedure, results and discussion are presented in this paper.

scholarly journals RESEARCH OF THE WAVE FACTOR INFLUENCING HYDRAULIC STRUCTURES

2021 ◽  
Vol 05 (01) ◽  
pp. 81
Author(s):  
Sevda Aliyeva ◽  
Mahmud Ismayilov
Keyword(s):  
Wind Pressure ◽  
Horizontal Wind ◽  
Hydraulic Structures ◽  
Wave Loads ◽  
Floating Structures ◽  
Wave Pressure ◽  
Oil Platforms ◽  
Offshore Installations ◽  
Horizontal Wave ◽  
Design Characteristics

It is known that a large block of deep-sea foundations consists of a truss sheathed with wood, a metal beam system, floating structures and four pyramidal metal blocks with a truss structure. The design characteristics of the foundations of oil platforms depend on the conditions under which the vertical interaction, along with the calculation of permanent and temporary loads, is accompanied by the specific gravity of drilling equipment and rigs or horizontal wind pressure, as well as the influence of horizontal wave loads on the foundation blocks. Horizontal waves and wind loads can be constant and variable in different conditions, therefore the effect of each of these loads on the device must be considered separately. To determine the wave pressure acting on the support blocks of stationary offshore installations, SN-92-60 was used under the editorship of the team of authors under the leadership of Doctor of Technical Sciences, Professor N.N.Tsunkov. Keywords: hydraulic structures, wave factor, wave pressure, wave profile, pressure diagrams, 3D model.

scholarly journals Performance of Porous Breakwaters: Application of the BOUSS-2D Model

2012 ◽  
Vol 9 (1) ◽  
pp. 11
Author(s):  
R Balaji
Keyword(s):  
Reflection Coefficient ◽  
Transmission Coefficient ◽  
Numerical Study ◽  
Hydrodynamic Performance ◽  
Transmission Characteristics ◽  
Regular Waves ◽  
Reflection And Transmission ◽  
Wave Elevation ◽  
Time Histories ◽  
Model Setup

 The hydrodynamic performance of porous breakwaters was studied by numerical analysis to assess reflection and transmission characteristics. The finite-difference method on BOUSS-2D was used to test the efficiency of porous breakwaters. The effects of porosity on reflection and transmission characteristics under the action of regular waves were investigated. The wave elevation time histories obtained from the numerical study were compared to those measured during an experimental study, on the leeward and seaward sides of the porous breakwater and were found to be in close agreement. The reflection coefficient increases, whereas the transmission coefficient decreases with a decrease in the porosity. A model with a porosity of 5.9% showed a maximum reflection coefficient of about 0.7 and a minimum transmission coefficient of 0.3. The details of the numerical method, physical model, model setup and results are discussed in this paper. 

Regular Wave Experiments for Twin Circular Submerged Floating Tunnel Tethered to Sea Bottom

2017 ◽  
Author(s):  
Sang-Ho Oh ◽  
Woo Sun Park
Keyword(s):  
Hydrodynamic Performance ◽  
Hydrodynamic Characteristics ◽  
Two Dimensional ◽  
Wave Loading ◽  
Regular Waves ◽  
Wave Flume ◽  
Sea Bottom ◽  
Physical Experiments ◽  
Tensile Forces ◽  
Submerged Floating Tunnel

Assessment of hydrodynamic performance of submerged floating tunnel (SFT) under wave loading is one of important factor in the design of the structure. In this study, physical experiments were conducted in a two-dimensional wave flume to investigate hydrodynamic characteristics of a twin circular SFT model under the action of regular waves having different heights and periods. Five different configurations of the twin SFT model was tested in the experiment. The experimental results showed that the three-degree motions of the twin SFT and the associated tensile forces on the tension legs greatly vary with the configurations of the model. It was found that the CD0 configurations are most adequate for satisfactorily restricting the horizontal and vertical motions of the SFT model.

Evaluation of Tsunami Wave Loads Acting on Walls of Confined-Masonry-Brick and Concrete-Block Houses

2014 ◽  
Vol 9 (6) ◽  
pp. 976-983 ◽  
Author(s):  
Gaku Shoji ◽  
◽  
Hirofumi Shimizu ◽  
Shunichi Koshimura ◽  
Miguel Estrada ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Structural Damage ◽  
Failure Modes ◽  
Tsunami Wave ◽  
Concrete Block ◽  
Wave Loads ◽  
Wave Load ◽  
Confined Masonry ◽  
Wave Pressure ◽  
Horizontal Wave

Damage to confined-masonry-brick or concrete-block house was assessed for being subjected to a tsunami wave load. This study was prompted by recent three tsunamis – one during 2001 on the Near Coast of Peru, one in 2009 in the Samoa Islands, and one in 2010 in Maule, Chile. We analyzed 13 damaged walls from 10 single-storey houses located near the coastline. We focused on evaluating the tsunami wave pressure distribution on house walls. Based on the formula proposed by Asakura et al. (2000) to evaluate tsunami wave pressure distribution on a structural component located on land behind on-shore structures, which is used for designing a tsunami evacuation building, we identify the values of horizontal wave pressure indexain Asakura’s formula for walls and discuss the boundary value ofaat which a wall presents structural damage, such as in collapse and cracking failure modes.

scholarly journals Design Optimization of a Porous Box-Type Breakwater Subjected to Regular Waves

2018 ◽  
Vol 203 ◽  
pp. 01018 ◽  
Author(s):  
Eric Joseph Pereira ◽  
Hee Min Teh ◽  
Lachmi Sri Manoharan ◽  
Chai Heng Lim
Keyword(s):  
Water Contamination ◽  
Wave Reflection ◽  
Physical Modelling ◽  
Tube Length ◽  
Regular Waves ◽  
Geometrical Design ◽  
Wave Amplification ◽  
Series Of Experiments ◽  
Rubble Mound Breakwaters ◽  
Modelling Approach

Breakwaters are used to suppress the energy of waves for providing shelter to coastal and offshore facilities. Very often, the conventional rubble mound breakwaters result in high construction cost and several environmental problems, such as water contamination and wave amplification in front of the structures due to severe wave reflection. One way to alleviate the above-mentioned problem is to appropriately increase the porosity of the breakwaters. This paper aims at developing the optimum design of a porous box-type breakwater comprising multiple scrapped pipelines via physical modelling approach. Herein, the best geometrical design of the breakwater under the governing factors of porosity, width and internal tube length is proposed. A series of experiments have been conducted under the influence of regular wave environment through the analysis of wave transmission, reflection and energy loss. Several geometrical design criteria were derived to maximize the hydraulic performance of the breakwater, when adopted at sites. The proposed breakwater is a reasonably good wave attenuator and anti-reflection structure as well as an effective energy dissipator.

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