• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.60-68
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• 2010

In this study, the seepage flow monitoring method by hydaulic head loss rate graph was developed for the purpose of monitoring the seepage flow from the see side or from the lake on sea dike in which seepage force was varied periodically. The hydraulic head loss rate was defined in this method. The value of the rate is in the range from 0 to 1. the value of 0 means perfectly free flow of seepage. the value of 1 means perfect waterproofing. The value of coefficient of determination in the hydraulic head loss rate graph closer to 1 means that the seepage flow way is stable. The value of coefficient of determination in the hydraulic head loss rate graph closer to 0 means that the hole may exist or the piping may be in the progress. The pore water pressure data measured in Saemangeum sea dike was analyzed with the developed method The result showed that the variation of seepage flow state was detected sensitively by this method and the interception effect of sea dike could be estimated quantitatively.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.1-8
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• 2013

This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

• Proceedings of the Korean Society of Rural Planning Conference
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• 1998.10a
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• pp.16-18
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• 1998

Fresh water lake was developed as a result of tidal land reclamation of the Sukmoon area. Water quality of lake has been monitored before and after sea-dike construction. Water quality degradation has been observed after Sukmoon sea-dike construction. In this paper observed water quality of the Sukmoon lake is presented and possible measures to improve water quality are also discussed.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.2
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• pp.43-56
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• 1993

The laboratory tests are performed on how the liquefaction potential of the sea dike structures on the saturated sand or silty sand seabed could be affected due to earthquake before and after construction results are given as follows ; 1. Earthquake damages to sea dike structures consist of lateral deformation, settlement, minor abnormality of the structures and differential settlement of embankments, etc. It is known that severe disasters due to this type of damages are not much documented. Because of its high relative cost of the preventive measures against this type of damages, the designing engineer has much freedom for the play of judgement and ingenuity in the selection of the construction methods, that is, by comparing the cost of the preventive design cost at a design stage to reconstruction cost after minor failure. 2. The factors controlling the liquefaction potential of the hydraulic fill structure are magnitude of earthquake(max. surface velocity), N-value(relative density), gradation, consistency(plastic limit), classification of soil(G & vs), ground water level, compaction method, volumetric shear stress and strain, effective confining stress, and primary consolidation. 3. The probability of liquefaction can be evaluated by the simple method based on SPT and CPT test results or the precise method based on laboratory test results. For sandy or silty sand seabed of the concerned area of this study, it is said that evaluation of liquefaction potential can be done by the one-dimensional analysis using some geotechnical parameters of soil such as Ip, Υt' gradation, N-value, OCR and classification of soils. 4. Based on above mentioned analysis, safety factor of liquefaction potential on the sea bed at the given site is Fs =0.84 when M = 5.23 or amax= 0.12g. With sea dike structures H = 42.5m and 35.5m on the same site Fs= 3.M~2.08 and Fs = 1.74~1.31 are obtained, respectively. local liquefaction can be expected at the toe of the sea dike constructed with hydraulic fill because of lack of constrained effective stress of the area.

• Journal of Construction Engineering and Project Management
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• v.3 no.2
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• pp.49-57
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• 2013

A sea dike construction has been increased in Korea because of the actively deployed reclamation project in basis of efficient application in land. The degree of completion in sea dike construction is affected by final closing construction, which has a lot of uncertainty that often results in higher accidents rate. Therefore, this research identified risk factors of final closing construction and classified them. This research examines the likelihood and its impact for each risk factor and calculates the risk degree as to the risk matrix. Based on this, the impact and the environmental conditions that affect to risk factors are investigated and further responsive methods are established for each risk factor. Ultimately, this research attempts to provide the risk retrenchment method for inspectors by proposing risk estimation model, responsive action list, and risk management process.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.5
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• pp.78-83
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• 2000

When a sea-dike is constructed on soft soils, it is much difficult to calculate ground deformation caused by forced displacements. In this study , a series of laboratory model tests have been performed to investigate the ground deformation under a constructed sea-dike on soft soils. Construction sequence of sea-dike embankment was assumed such as constructed by quarry first and followed by soils adjacent to quarry embankment. as test data and displacement in subsoils have been analyzed, it seems that deformation is caused by general shear failure. the shape of ground deformation caused by forced displacements was well defined be parabola . Upon comparing profiles and depth of forced displacement from the model test to those based on stress-baring capacity method commonly used, it has been found that deformation prediction using stress-bearing capacity method was not exact at the edge of loading.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.159-167
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• 2014

In this study the process of normalizing hydraulic head loss rate was developed for the purpose of estimation of seepage blocking state at each seepage segment in sea dike embankment. Pore water pressure sensors were installed with some interval along seepage path, then the hydraulic head loss rate at each segment between pore water pressure sensors was calculated, and then the calculated hydraulic head loss rate was normalized based on seepage path length. The comparison of normalized hydraulic head loss rates showed that the cross section of sea dike embankment was homogeneous approximately and the width of cross section was long enough to blocking tide water.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.1
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• pp.35-45
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• 2001

The sea dike at Gun-Jang Industry Area had been constructed recently and both inside and outside areas of the dike show harmonic behaviour. To examine stability against piping, 2 dimensional seepage analysis was executed using finite element method. To investigate the harmonic motion of water level, unsteady and unsaturated flow analysis is needed, and specially harmonic motion in the both areas from the dike should be considered, Water level recorder was used to obtain tidal harmonic data, and sieve analysis has been earried out so that the distribution of grain diameter of the dike material is clearly informed. The calculated velocity was compared with critical velocity.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.169-174
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• 1999

The reclamation area of Saemangeum (Kunsan) located between 126$^{\circ}$10' -126$^{\circ}$50'E and and 35$^{\circ}$35'N -36$^{\circ}$05'N at the western coast of Korea. The construction of the 33km sea dike is building in the Saemangeum area. When the construction of the sea dike in the coastal region takes plase, there exists a certain amount of soil which is diffused by the tidal current. Behavior of the soil diffusion usually depends on its intrinsic characteristics, bathymetry, construction method and used mchinery. The amount of soil at the construction acts as a pollutant which is the cause of changing the marine environment. When the soil material is diffused , it may form a layer which obstructs the light passing into the sea and causes the extinction or alteration of the living beings on the sea bottom. The settlement of soil material could change the sea bottom deposit. The purpose of MITIGATION is to harmonize the development and the conservation of environment, to restrict environmental destruction and to reproduce the enviroment damaged by the construction in the coastal region. The purpose of this study is to find the method by which we minimize the anti-function of development in the coastal region. Tide and tidal current are calculated using a two-dimensional numerical model before the construction of sea dike in Saemangeum Bay. The numerical results are compared well with field observations. On the basis of these results, we caculated the tide and tidal current after the construction of the sea dike in order to investigate the change of the tide and tidal current after the construction of the sea dike. Moreover, we calculated the tide and tidal current after the construction of submerged breakwater in order to preserve the enviornmental condition of creature habitat . We compared the tide and tidal current before and after the construction of submerbed breakwater, to investigate the possbility of MITIGATION in the fisheries.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.925-931
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• 2004

Due to the development of Yongsan river estuary weir and Yongam-Kumho sea dike, Mokop coastal area is changed. Especially, Discharged water through Yongsan river estuary weir and Yongam-Kumho sea dike, may muse the environmental influences such as the changes of currents pattern and sedimentation in the vicinity of semi-closed Mokpo harbor. This study deals with the collection and analysis of discharge through estuary weir and sea dike, based on that, we analyzed a characteristics of a sea area from simulation. As the results of this study, it was known that discharge mused the changes of a tidal currents pattern and calculated depth variations showed close relation with tidal circulation.