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

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 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 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.

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 SIMULATION OF IRREGULAR WAVE PRESSURE ON PERFORATED BREAKWATERS

2011 ◽  
Vol 1 (32) ◽  
pp. 29 ◽  
Author(s):  
Xuefeng Chen ◽  
Yucheng Li ◽  
Liu Long
Keyword(s):  
Experimental Data ◽  
Numerical Method ◽  
Water Level ◽  
Least Squares Method ◽  
Front Wall ◽  
Back Wall ◽  
Wave Pressure ◽  
Irregular Wave ◽  
The Stability ◽  
Perforated Caisson

In this paper, the wave pressures on the perforated caissons breakwaters are investigated. The front wall of the perforated caissons is usually perforated above a certain water level considering the stability of the structure, and the chamber of the perforated caisson is filled with rock. Based on the RANS and k- equations, the numerical method to simulate the interaction of the irregular wave with the perforated breakwaters is researched. Moreover, the wave pressures distribution on the front perforated wall and the back wall are discussed through the numerical calculations, respectively. Then, the simplified formulas to compute the wave pressures on the different position of perforated caisson are obtained from experimental data by using the least-squares method.

Estimation of Tsunami Force for Onshore Buildings in the Northwest Coast of Peninsular Malaysia

2015 ◽  
Vol 802 ◽  
pp. 172-177 ◽  
Author(s):  
Tze Liang Lau ◽  
Kok Keong Choong ◽  
T.A. Majid ◽  
Nor Azazi Zakaria ◽  
Aminuddin Ab. Ghani ◽  
...  
Keyword(s):  
Structural Damage ◽  
Peninsular Malaysia ◽  
Indian Ocean Tsunami ◽  
Front Face ◽  
Northwest Coast ◽  
Engineering Structures ◽  
Wave Pressure ◽  
Pressure Distributions ◽  
Building Models ◽  
The Government

The northwest coast of Peninsular Malaysia had suffered various extents of structural damage and loss of 68 lives in the unprecedented 2004 Indian Ocean tsunami. Since then, the government of Malaysia concerns about the safety of civil engineering structures and human lives in coastal area. An experimental study was embarked on the formulation of tsunami force for onshore buildings in Peninsular Malaysia. Four downscaled rigid building models with various heights were subjected to probable tsunamis with three nominal wave heights and flow velocities. The wave pressures at front and back faces of building model were measured. The findings show that the front face wave pressure measured from the experiment is in good agreement with the wave pressure predicted using the equation proposed by Japanese researchers. The back face wave pressure distribution is found to be slightly higher than the hydrostatic pressure. The pressure distributions at the front and back faces were then proposed for the estimation of tsunami force on buildings in the northwest coast of Peninsular Malaysia.

scholarly journals WAVE PRESSURE FORMULA FOR PERFORATED CAISSON WITH DOUBLE CHAMBERS

2018 ◽  
pp. 34
Author(s):  
Sang-Ho Oh ◽  
Chang-Hwan Ji
Keyword(s):  
Physical Experiment ◽  
Single Chamber ◽  
Wave Pressure ◽  
Design Load ◽  
Clear Guideline ◽  
Perforated Caisson ◽  
Double Chamber

Some of perforated caisson breakwaters have double wave chambers, for which no clear guideline for estimating design load is available. The well-known Takahashi's formula (Takahashi and Shimosako, 1994) is basically applicable to single-chamber perforated caisson. Considering this, we conducted physical experiment to develop a wave pressure formula for double-chamber perforated caisson.

scholarly journals Mechanical Behavior of Natural Fiber-Based Bi-Directional Corrugated Lattice Sandwich Structure

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2578 ◽  
Author(s):  
Shuguang Li ◽  
Yanxia Feng ◽  
Mengyuan Wang ◽  
Yingcheng Hu
Keyword(s):  
Compressive Strength ◽  
Mechanical Behavior ◽  
Young’S Modulus ◽  
Double Layer ◽  
Young's Modulus ◽  
Layer Structure ◽  
Core Layer ◽  
The Core ◽  
Fiber Angle ◽  
Double Layer Structure

In this study, 11 kinds of composite material were prepared, and the compression behavior of a bi-directional corrugated lattice sandwich structure prepared using jute fiber and epoxy resin was explored. The factors affecting the mechanical behavior of single and double-layer structures were studied separately. The results shows that the fiber angle, length-to-diameter ratio of the struts, and the type of fiber cloth have the most significant influence on the mechanical behavior of the single-layer lattice structure when preparing the core layer. When the fiber angle of the core layer jute/epoxy prepreg is (90/90) the compressive strength and Young’s modulus are 83.3% and 60.0% higher than the fiber angle of (45/45). The configuration of the core and the presence of the intermediate support plate of the double-layer structure have a large influence on the compression performance of the two-layer structure. After the configuration was optimized, the compressive strength and Young’s modulus were increased by 40.0% and 28.9%, respectively. The presence of the intermediate support plate increases the compressive strength, and Young’s modulus of the double-layer structure by 75.0% and 26.6%, respectively. The experimental failure is dominated by the buckling, fracture, and delamination of the core struts.

scholarly journals A Field Experiment on Wave Forces on an Energy-Absorbing Breakwater

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1563
Author(s):  
Pasquale G. F. Filianoti ◽  
Luana Gurnari
Keyword(s):  
Water Discharge ◽  
Wave Force ◽  
Eastern Coast ◽  
Small Scale ◽  
Wave Forces ◽  
Wave Pressure ◽  
Horizontal Wave ◽  
Caisson Breakwater ◽  
Horizontal Wave Force ◽  
Energy Absorbing

The U-OWC is a caisson breakwater embodying a device for wave energy absorption. Under the wave action, the pressure acting on the upper opening of the vertical duct fluctuates, producing a water discharge alternatively entering/exiting the plant through the U-duct, formed by the duct and the chamber. The interaction between incoming waves and the water discharge alters the wave pressure distribution along the wave-beaten wall of this breakwater compared with the pressure distributions on a vertical pure reflecting wall. As a consequence, the horizontal wave forces produced on the breakwater are also different. A small scale U-OWC breakwater was put off the eastern coast of the Strait of Messina (Southern Italy) to measure the horizontal wave force. Experimental results were compared with Boccotti’s and Goda’s wave pressure formulas, carried out for conventional upright breakwaters, to check their applicability on the U-OWC breakwaters. Both models are suitable for design of U-OWC breakwaters even if they tend to overestimate by up to 25% the actual horizontal loads on the breakwater. Indeed, the greater the absorption of the energy is, the lower the wave pressure on the breakwater wall is.

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