• Title/Summary/Keyword: harbor design

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Estimation of Erosion Damage of Armor Units of Rubble Mound Breakwaters Attacked by Typhoons (태풍에 의한 경사식 방파제의 피복재 침식 피해 산정)

  • Kim, Seung-Woo;Suh, Kyung-Duck
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.5
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    • pp.295-305
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    • 2010
  • Although the rubble mound breakwaters in Korea have been damaged by typhoons almost every year, quantification of erosion of armor block have seldomly been made. In this paper, the damage of armor units is standardized by the relative damage. In the case where the number of damaged units is reported, it is divided by the total number of units to calculate the relative damage. In the case where the rehabilitation cost is reported, the relative damage is calculated by using its relationship with the present value of the past rehabilitation cost. The relative damage is shown to have strong correlations with the typhoon parameters such as nearest central air pressure and maximum wind speed at each site. On the other hand, the existing numerical methods for calculating the cumulative damage are compared with hydraulic model tests. The method of Melby and Kobayashi (1998) is shown to give a reasonable result, and it is used to calculate the relative damage, which is compared with the measured damage. A good agreement is shown for the East Breakwater of Yeosu Harbor, while poor agreement is shown for other breakwaters. The poor agreement may be because waves of larger height than the design height occurred due to strong typhoons associated with climate change so that the relative damage increased during the last several decades.

A Basic Study on Proper Straight Route Distance under Marine Bridge using ES Model (ES모델을 이용한 해상교량 하부 적정 직선항로 길이에 대한 기초 연구)

  • Park, Young-Soo;Choi, Kwang-young;Park, Sang-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.2
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    • pp.133-139
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    • 2018
  • Keeping a proper straight route length under the marine bridge is one of the important factors for the safe passage of ships. However, according to port and harbor design standards, there is only a constant guideline of 8 times the length of the marine bridge underpass. On this study, we used the ES model to determine the ratio of risk to the route width, traffic volume, the degree of curvature of the route, and the length of the straight route in order to derive the optimal straight route distance. As a result, the risk ratio decreased by 2.27% as the route distance increased from 3L to 10L when the degree of curvature of the route was $45^{\circ}$. The risk associated with curvature was found to be 4.83% when the bending degree was changed from $0^{\circ}$ to $45^{\circ}$ in the case of 3L length. In addition, it was confirmed that the risk ratio according to the degree of curvature of the route and the straight route was reduced by 1.45% at maximum under the condition that the width of the line was 400m and the number of the vessels generated per hour was 20. It was verified that a straight route distance more than a certain length is needed depending on the congestion degree and the degree of curvature of the route when constructing the marine bridge.

A Study on Construction of Barge Transportaion System between Incheon and Gaesung (인천-개성 항로 바지 수송시스템 구축에 관한 기초적 연구)

  • Kim, Sang-Hyun;Lee, Seung-Hee;Lee, Young-Gill;Yu, Jin-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.14 no.3
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    • pp.227-233
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    • 2008
  • Recently, the transport quantity of goods between South and North Korea is rising rapidly by increasing of economical exchange between South and North Korea and growth of Gaeseoung industrial complex. In addition to a land transportation route, it is necessary to secure various logistics and transportation route for freight transportation between Incheon and Gaesung. In this paper, we investigated a construction of barge transportaion system between Incheon and Gaesung. The barge transportation system which has many merits such as a little initial investment and convenience of harbor loading/ unloading has been also used to transport freight widely in the EU and USA. Firstly, we investigated barge transport route, marine freight and barge fleet which consists of barge and pusher between Incheon and Gaesung. And next, we designed hull form and general arrangement of a barge and pusher based on shipping service condition, barge fleet, etc. Finally, a construction plans of barge transport system such as a operation of shipping service, berthing facilities, logistics center, intermodal transport are investigated.

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Numerical Simulation of Interaction between Composite Breakwater and Seabed under Regular Wave Action by olaFlow Model (olaFlow 모델에 의한 규칙파작용 하 혼성방파제-해저지반의 상호작용에 관한 수치시뮬레이션)

  • Bae, Ju-Hyun;Lee, Kwang-Ho;Jung, Uk Jin;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.6
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    • pp.270-285
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    • 2018
  • The behavior of wave-induced pore water pressure inside the rubble mound and seabed, and the resultant structure failure are investigated, which are used in design of the composite breakwater representing the coastal and harbor structures. Numerical simulation techniques have been widely used to assess these behaviors through linear and nonlinear methods in many researches. While the combination of strongly nonlinear analytical method and turbulence model have not been applied yet, which can simulate these characteristics more accurately. In this study, olaFlow model considering the wave-breaking and turbulent phenomena is applied through VOF and LES methods, which gives more exact solution by using the multiphase flow analytical method. The verification of olaFlow model is demonstrated by comparing the experimental and numerical results for the interactions of regular waves-seabed and regular waves-composite breakwater-seabed. The characteristics of the spatial distributions of horizontal wave pressure, excess-pore-water pressure, mean flow velocity and mean vorticity on the upright caisson, and inside the rubble mound and seabed are discussed, as well as the relation between the mean distribution of vorticity size and mean turbulent kinetic energy. And the stability of composite breakwater are also discussed.

A Study on the Reinforcement Effect of Low Flow Mortal Injection Method Using Field Test (현장시험을 이용한 저유동성 몰탈주입공법의 보강효과에 관한 연구)

  • Junyeong Jang;Gwangnam Lee;Daehyeon Kim
    • The Journal of Engineering Geology
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    • v.33 no.4
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    • pp.599-609
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    • 2023
  • In the seismic retrofitting of harbor breakwaters in Korea, the recovery rate is often uncertain due to site conditions and site conditions, and problems continue to arise. Therefore, in this study, we analyzed the recovery rate and compressive strength of the improved material through drilling survey by grouting confirmation method after applying low-fluidity mortar injection method, and furthermore, we checked the elastic modulus by downhole test and tomography to confirm the reinforcement effect of soft ground after ground improvement. The experimental results showed that the average shear wave velocity of the ground increased from 229 m/s to 288 m/s in BH-1 and BH-3 boreholes to a depth of 28.0 m, and the average shear wave velocity of the ground to a depth of 30.0 m tended to increase from 224 m/s to 282 m/s in the downhole test. This is believed to be a result of the increased stiffness of the ground after reinforcement. The results of the tomographic survey showed that the Vs of the soft ground of the sample at Site 1 increased from 113 m/s to 214 m/s, and the Vs of the sample at Site 2 increased from 120 m/s to 224 m/s. This shows that the stiffness of the ground after seismic reinforcement is reinforced with hard soil, as the Vs value satisfies 180 m/s to 360 m/s in the classification of rock quality according to shear wave velocity.

IPA Study of Landscape Potentiality of Agricultural and Fishery Heritages - A Focus on Cheongsando - (농어업유산의 경관 잠재력 파악을 위한 IPA 연구 - 청산도를 중심으로 -)

  • Kim, Dong-Chan;Choi, Woo-Young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.4
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    • pp.76-88
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    • 2014
  • The purpose of this study is to derive landscape characteristic elements of agricultural and fishery heritage and to classify landscape characteristic elements of Cheongsando designated as Korean agricultural and fishery heritage No.1 as well as a Globally Important Agricultural Heritage System (GIAHS). Additionally, this study was conducted to suggest priority for conservation and management of Cheongsando by grasping differences between factors which visitors deem as important and satisfying. To implement this study, the literature review was written, an on-site survey to derive landscape characteristic elements of Cheongsando and a survey on importance and satisfaction of landscape characteristic elements of Cheongsando were conducted, and reliability analysis, descriptive statistical analysis and IPA analysis were performed using SPSS 20.0. The results are as follows: The analysis showed the factors requiring persistent efforts in the first quadrant are the rape flower garden, the sea, green barley field, flat stone paddy field, breakwater and lighthouse, abalone farms, stone houses, thatched houses, a coastal road, the slow road, Stonewall Walkway of Seongseo Village, and residents' agricultural behaviors. The analysis showed the factors needing intensive management strategies in the second quadrant are the surrounding mountain area, dock, Docheong Harbor, vessels, fish market, Doksari stone wall, garish-roofed farm villages, excursion school to a slow island, pension and cafe, bus stop, shade trees, Raw Fish Street, the beach and the filming site. Analysis indicated that the factors needing management control in the third quadrant are the pine grove, the beach, tidal mudflat, the garlic fields, vinyl greenhouses, grain drying yard, sea mustard drying yard, heritage center, Choboon, Dangri exorcism, the market place, residents' fishery behaviors, residents' industrial behaviors, residents' ordinary behaviors, visitors' behaviors that visiting the dock, visitors' behaviors that walking the slow road, visitors' behaviors that eating and shopping for specialties, visitors' behaviors that experiencing agriculture and fishery. Excessive effort factors in the fourth quadrant were not derived.

Numerical Simulation of Nonlinear Interaction between Composite Breakwater and Seabed under Irregular Wave Action by olaFlow Model (olaFlow 모델에 의한 불규칙파 작용하 혼성방파제-해저지반의 비선형상호작용에 관한 수치시뮬레이션)

  • Lee, Kwang-Ho;Bae, Ju-Hyun;Jung, Uk Jin;Choi, Goon-Ho;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.3
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    • pp.129-145
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    • 2019
  • For the design of composite breakwater as representative one of the coastal and harbor structures, it has been widely discussed by the researchers about the relation between the behavior of excess-pore-water pressure inside the rubble mound and seabed caused by the wave load and its structural failure. Recently, the researchers have tried to verify its relation through the numerical simulation technique. The above researches through numerical simulation have been mostly applied by the linear and nonlinear analytic methods, but there have been no researches through the numerical simulation by the strongly nonlinear mutiphase flow analytical method considering wave-breaking phenomena by VOF method and turbulence model by LES method yet. In the preceding research of this study, olaFlow model based on the mutiphase flow analytical method was applied to the nonlinear interaction analysis of regular wave-composite breakwater-seabed. Also, the same numerical techniques as preceding research are utilized for the analysis of irregular wave-composite breakwater-seabed in this study. Through this paper, it is investigated about the horizontal wave pressures, the time variations of excess-pore-water pressure and their frequency spectra, mean flow velocities, mean vorticities, mean turbulent kinetic energies and etc. around the caisson, rubble mound of the composite breakwater and seabed according to the changes of significant wave height and period. From these results, it was found that maximum nondimensional excess-pore water pressure, mean turbulent kinetic energy and mean vorticity come to be large equally on the horizontal plane in front of rubble mound, circulation of inflow around still water level and outflow around seabed is formed in front of rubble caisson.