• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.3
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• pp.212-221
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• 2007

This paper describes on the evaluation and management of work process in suction hopper dredger and grab bucket dredger as an application of a PC-based ECDIS system. The dynamic tracking of dredging bucket and the data logging of grab dredging information were performed by using the grab dredging vessel "Kunwoong G-18". The position and route tracking of the dredger moving toward the ocean dumping site of dredged material was performed by using the hopper dredging vessel "Samyang-7". The evaluation of wok process in the dredging field, for grab dredger, was continuously carried out on January to May, 2006, in Incheon Hang and for hopper dredger, on July to December, 2003, in Busan Hang, Korea. The dredging information, such as dredger's position, heading, dredging depth and route track which was individually time stamped during the dredging operation, was automatically processed in real-time on the ECDIS and displayed simultaneously on the S-57 ENC chart. From these results, we conclude that the ECDIS system can be applied as a tool in order to manage the work process during the dredging operation, and also in order to generate the factual record of the dredging activities that is sufficient for dredging inspector to accurately evaluate the contract performance even in the absence of a full-time onboard inspector.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.2
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• pp.140-148
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• 2007

This paper describes on the real-time monitoring of dredging information for grab bucket dredger equipped with winch control sensors and differential global positioning system(DGPS) using electronic chart display and information system(ECDIS). The experiment was carried out at Gwangyang Hang and Gangwon-do Oho-ri on board M/V Kunwoong G-16. ECDIS system monitors consecutively the dredging's position, heading and shooting point of grab bucket in real-time through 3 DGPS attached to the top bridge of the dredger and crane frame. Dredging depth was measured by 2 up/down counter fitted with crane winch of the dredger. The depth and area of dredging in each shooting point of grab bucket are displayed in color band. The efficiency of its operation can be ensured by adjusting the tidal data in real-time and displaying the depth of dredging on the ECDIS monitor. The reliance for verification of dredging operation as well as supervision of dredging process was greatly enhanced by providing three-dimensional map with variation of dredging depth in real time. The results will contribute to establishing the system which can monitor and record the whole dredging operations in real-time as well as verify the result of dredging quantitatively.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.3-12
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• 2013

In order to evaluate dredging results scientifically the system which can manage and estimate working process by monitoring dredging process in real-time needs to be constructed. We constructed real-time dredging management system for guidance of a dredging vessel and for survey of dredging construction. This system was designed to have functions of dredger location by GPS, ship direction measurement by GPS/Gyroscope combination, Grab position measurement, dredging depth measurement and correction. In addition, we developed the programs for controlling and operating the constructed system. The system could induce the vessel to accurate position and conduct dredging according to plan and the effectiveness of the system was evaluated through the results of application to actual dredging construction site.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.542-543
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• 2005

• Journal of Ocean Engineering and Technology
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• v.20 no.3 s.70
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• pp.67-76
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• 2006

Three-dimensional information of submarine topography was acquired by assembling DGPS and Echo Sounder, which is mainly used in the marine survey. However, the features of submarine topography, derived according to mechanical data, were confirmed using human eyes. Because the dredging capacity using a submarine surveying data influences harbor public affairs, analysis and the process method of surveying data is a very special element in construction costs. In this study, information on submarine topography is acquired by assembling DGPS and Echo Sounder. Moreover, the dredging capacity in harbor public affairs has been analyzed by the interpolation method: inverse distance to a power, kriging, minimum curvature, nearest neighbor, and radial basis function. Also, utilization of DGPS and Echo Sounder method in calculation of the dredging capacity have been confirmed by comparing and analyzing the dredging capacity and the actual one, as per each interpolation. According to this comparison result, in the case of applying Radial basis function interpolation and Kriging, 3.94 % and 4.61 % of error rates have been shown, respectively. In the case of the study for application of the proper interpolation, as per characteristics of submarine topography, is preceded in calculation of the dredging capacity relevant to harbor public affairs, it is expected that more speedy and correct calculation for the dredging capacity can be made.

• Spatial Information Research
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• v.14 no.1 s.36
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• pp.57-65
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• 2006

In general, the investigation for reservoir dredging are conducting a observation on the horizontal position and the depth of water by assembling GPS/Echo Sounder and Total Station/Echo Sounder, and it is computed at a section computation of riverbed, reservoir volume and dredging plan etc. at that times, the detail plane is determinated about soil volume, height for dredging. Planning has a fault that the method of sound detection using the Echo Sounder doesn't check up distribution of reservoir deposit. In this study, the author emphasizes that implementation of dredging with combined Global Positioning System(GPS) and Ground Penetration Radar(GPR) is well-done more than existed GPS/Echo Sounder. the combined equipment can be adapted to computation and dredging reffering to distribution of deposition. First of all, it is executed water tank modelling test through sampling for apply to test area and is estimated the possibility after passed far accuracy verification of equipment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.263-271
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• 2005

The most important point when we engage on waterway dredging work is supplying safe navigational passage to the vessels underway by narrowing dredge work area and removing submerged dangers. In order to meet this end it is neccessary to use auxiliary equipment for shifting actively and mooring and adopt automation of dredging work by integrating information on real time position, dredging depth, and work information. The danger with a spud control system in this study, by the way, is able to employed on continuous dredging work with the narrowest working area allowing wide and safe passages to vessels underway, by moving the dredger to the working zone with the spud controlled automatically. Furthermore, it has been improved definitely compared with the existing dredging proccess management system such that it shows the track of spud and working depth on the electronic navigation chart of window, together with the final outcome of dredging work. The test dredging work at the entrance of Busan North Port for system evaluation showed that actual working time available was twice of the one by the existing anchor system, and that it reduced 38% of time for preparation work and one man power.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.395-402
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• 2005

The most important point when we engage on waterway dredging work is supplying safe navigational passage to the vessels underway by narrowing dredge work area and removing submerged dangers. In order to meet this end it is necessary to use auxiliary equipment for shifting actively and mooring and adopt automation of dredging work by integrating information on real time position, dredging depth, and work information. The dredger with a spud control system in this study, by the way, is able to employed on continuous dredging work with the narrowest working area allowing wide and safe passages to vessels underway, by moving the dredger to the working zone with the spud controlled automatically. Furthermore, it has been improved definitely compared with the existing dredging process management system such that it shows the track of spud and working depth on the electronic navigation chart of window, together with the final outcome of dredging work. The test dredging work at the entrance of Busan North Port for system evaluation showed that actual working time available was twice of the one by the existing anchor system, and that it reduced $38\%$ of time for preparation work and one man power.

• Ocean and Polar Research
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• v.28 no.2
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• pp.129-144
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• 2006

Small-scale effects of sand mining on macrobenthic communities have been reported previously. However, little information is available as to how dredging affects the macrobenthic community structure. The objective of this study was to determine the impacts of large-scale exhibition dredging on the macrobenthic community of Gyeonggi Bay, Korea, where sand mining has continued for 20 years. Prior to dredging, the macrobenthic species composition was similar to that of areas near the dredging site, with several common dominant species found before dredging. After dredging, the number of species, density, and diversity (H') in the experimental area (sites 0 and 1) decreased significantly, but no difference was observed at other sites. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure before and after dredging. The amphipod Urothoe grimaldii japonica, which was the most dominant species at sites 0,1, and 2, decreased rapidly at sites 0 and 1 after dredging, but no difference was observed at site 2. In addition, the index of multivariate dispersion (IMD) and the relative IMD (r. IMD) were large at sites 0 and 1, suggesting that the effects of dredging were direct at site 0 and 1, but indirect at site 2. The macrobenthic communities at sites 3 and 4 were not affected by dredging, but they were affected by physical conditions and biological interactions. We suggest that benthic biotope indices such as the IMD and r.IMD may constitute a valid tool for assessing the effects of dredging on the macrobenthic community; long-term monitoring is required to verify this.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1065-1070
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• 2008

The evaluation of dredging works of pump dredger considering soil conditions is a main idea in calculating construction costs in non-cohesive soil layers. For using pump dredger, on effects of pump dredger equipment, some data of overseas code for pump dredger are different to those of results and a pump dredging capability table in the field of costs. In this study, considerations of sandy soils are described for application of construction works.