• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.3
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• pp.229-242
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• 2009

Numerical analysis has been performed to estimate maximum settlement, maximum horizontal displacement and total settlement volume at the ground surface due to tunnel excavation varying ground condition, tunnel depth and diameter, and construction condition (volume loss at excavation face). The maximum surface settlement from the numerical analysis has been compared with the maximum settlement at tunnel crown considering ground condition, tunnel depth and diameter, and construction condition, and it has been also compared with the maximum horizontal displacement. In addition, the volume loss ($V_L$) at tunnel excavation face has been compared with the total surface settlement volume ($V_s$) with the variation of ground condition, tunnel depth, and tunnel diameter. The results from the numerical analysis have been compared with field measurements to confirm the applicability and validity of the results and by this comparison it is believed that the numerical results in this study can be utilized practically in analyzing the ground movements due to tunnel excavation.

• Tunnel and Underground Space
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• v.14 no.6 s.53
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• pp.429-439
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• 2004

The deep underground High Level Waste (HLW) repository to dispose of 36,000tons of spent fuel from the reactors in Korea needs about $4km^2$ repository area. In this study, the deep undergrond repository layout was optimized to minimize the excavation rock volume as well as underground repository area. In the optimization, the results from thermal analysis were used to define the influence of tunnel and deposition hole spacings on repository layout. The repository area and excavation rock volume could be reduced with longer disposal tunnel length. When it is necessary to reduce the repository area with satisfying thermal criteria, it is better to reduce tunnel spacing and increase deposition hole spacing. In contrast, the excavation rock volume can be reduced by increasing the tunnel spacing and decreasing the hole spacing.

• International Journal of Railway
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• v.6 no.2
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• pp.69-77
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• 2013

In this study, numerical analysis and model experiments were conducted to analyze behavioral characteristics acting on the track roadbed with excavation through steel pipe injection, a non-exclusive method of crossing construction under railroad as primary target. In model experiments that simulate injection excavation behaviors with an increase in the depth of soil cover, the upper displacement was measured by construction of the first and the second pipes in order to predict actual behaviors, and the behavior characteristics were verified through numerical analysis. The investigation results showed that surface displacement was smaller under the condition of higher soil cover. In the case of injecting two pipes, when the first pipe was injected, deformation of the surface increased linearly in both settlement and uplift experiments. However, when the second pipe was injected, the amount of change was found to be very small due to the relaxation and plastic zones around the first pipe. In addition, the results of numerical analysis on the same cross section with the model experiment found that the results of investigation into settlement ratio and volume loss were in very good agreement with those obtained by the model experiment.

• Journal of the Korean Geotechnical Society
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• v.22 no.2
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• pp.19-28
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• 2006

Long-term field observations were performed in three excavation sites in order to investigate the displacement behavior of adjacent ground during overall excavation procedure, where the depths of deep excavations were 15 m$\∼$29 m. In this study, ground settlements and lateral displacements of braced wall measured during installation of retaining wall and removal of bracing were specially focused to evaluate the behavior quantitatively according to three-stage-divided procedure, i.e. pre-excavation, main excavation, and removal of bracing. Through field measurements on three excavation sites, lateral displacements induced during removal of bracing are approximate to 40$\%$ of the amount found during main excavation stage and additional adjacent ground deformation during post-excavation procedure ranges from 18$\%$ to 33$\%$ of that found during main excavation stage, based on the settlement volume. In conclusion, it was quantitatively identified in this study that the deformations of adjacent ground during pre- and post-excavation stage were not negligible.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.257-271
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• 1997

The calculation of earthwork plays a major role in plan or design of many civil engineering projects and thus it has become very important to advanced the accuracy of earthwork calculation. The purpose of this paper is to calculate the excavation volume of terrain using a proposal area formular in eathwork volume determination for reclamation of the harbor. A proposal area formular by first and third equation is compared with end area, middle area, prismoidal formula by trapezoidal, simpson formular to excavation volume for an experimental terrian $1\sim12$. As a result of this study, algorithm of a proposal area formula by prismoidal formula should provide a better accuracy than end area, middle area, prismoidal formula by trapezoidal formular, simpson formular.

• Tunnel and Underground Space
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• v.5 no.1
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• pp.48-56
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• 1995

Recently, most of the underground excavation works are adopting heavy duty mobile diesel equipments which have outstanding merits in view of efficiency. However, these equipments are causing hygienic problems to the workers due to the various hazardous exhaust contaminants. Considering that there are always dead end workings in underground excavation sites, it is very important how to supply enough airflow to the workings to dilute diesel exhaust contaminants. This paper introduced the theoritical mechanism and actual trends of exhaust contaminants of diesel equipments under operation at local mines and suggested the design method of intake air volume in underground excavation workings using diesel equipments.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.65-72
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• 2001

Since Pyoungtaek thermal power plant began using natural gas in 1986, the annual using volume has rapidly increased and reached 12.7 million tons in 1999. When the natural gas is cooled to a temperature of approximately -162$^{\circ}$C at atmospheric pressure, it condenses to a liquid called liquefied natural gas(LNG). LNG has a special characters such as odorless, colorless, non-corrosive, and non-toxic. So, LNG storage tank, tanker ship, transfer pipelines are required the special storage and transportation systems and technology. The presently operating LNG terminals are Pyongtaek and Inchon terminals. A total of 19 above-ground LNG storage tanks(100 thousand ㎘ grade) are currently in operation with a sendout capacity of 4,360tons/hour. To meet the growing domestic demand of LNG supply, the Inchon receiving terminal is expanding(six in-ground tank) and constructing a third LNG terminal at Tongyong. In this paper, case study on seepage analysis and countermeasure against increasing the seepage volume of in-ground LNG storage tank excavation work is reported. The results of an additional seepage analysis are presented to verify the design seepage volume of assumption section and seepage volume after curtain-grouting in the slurry wall.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.5-12
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• 2010

It is very important to get the accurate calculation of pit-excavation volume in many civil engineering projects. There have been common drawbacks to earlier methods of ground profiling, such dealing with sharp corners or the grid points any two straight lines. There are several papers of using spline surfaces to obtain more accurate calculations of the earthwork. In this paper, we propose an algorithm of finding a spline surface without boundary conditions which interpolates the given data and an appropriate method to calculate the earthwork. We present some computational results showing that our proposed method provides good accuracy.

• Journal of Ocean Engineering and Technology
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• v.16 no.4
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• pp.19-24
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• 2002

항만공사같은 대규모의 매립공사에서 토공작업은 총공사비의 상당한 비중을 차지하므로 경제적인 시공을 위하여 절.성토량은 정확하게 계산되어야 한다. 따라서 본 연구는 주어진 3차원 표고데이터를 지나는 스플라인 곡면을 구하는 알고리즘을 제시함으로써 좀더 정확한 토공량 계산식의 결정을 목표로 한다. 스플라인에 대한 흥미로운 수학적 결과는 무척 많지만 본 연구에서는 스플라인 곡면을 기술하고 또, 그것을 이용하여 토공량 계산을 위한 알고리즘개발을 목표로 하기 때문에 알고리즘과 프로그래밍에 필요한 수학적 내용을 기술하며 그 수치적 계산결과는 Maple 프로그램을 이용하였다. 그리고 정확도를 비교하기 위하여 기존의 방법인 선형점고법, Chamber법, Chen과 Lin의 이론을 컴퓨터프로그램하여 본 연구에서 제시된 방법과 정확도를 비교, 분석한다. 아울러 각 이론식의 결과에 대한 보다 정확한 검사를 위하여 x, y 함수식을 이용한 실험지형을 인위적으로 만들었으며 그 때의 값을 기준값으로 하였다. 따라서 실험수치지형에 대한 기준값이 절대값에 가까우므로 각 토공량식들의 오차규명을 보다 명확하고 확실하게 비교할 수 있도록 하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.3
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• pp.265-272
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• 2002

By this time, many methods have been developed for computing the pit excavation volumes, ranging from a simple formula to more complicated numerical methods. Earlier the standard methods for pit excavation volume computation requires that the considered area be divided the boundary ranges of x and y directions into a rectangular grid. whereas these methods may not calculate the estimation of pit excavation volume that is often required in many surveying situation exactly. In Easa methods(1998), the rectangular grid is divided into the same linear in the range x and y directions respectively. This method employs a cubic Hermite polynomial for individual intervals in both directions of the grid. Because the height data over the same boundary of x and y interval ranges have to be exist, it is not possible to choose the governing points of the terrain boundary such as points of maximum and minimum height. In this study, a method of volume computation, that combines the advantages of Easa methods(1998) and avoids the drawbacks of it, is presented. The proposed method employs a cubic Hermite polynomial for individual intervals in both directions of the non-grid, the all over intervals of it may be unequal grid x in width and y in length y, partially. The new proposed method should produce better accuracy than the other conventional methods.