• 대한조선학회논문집
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• 제44권5호
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• pp.482-487
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• 2007

The container mobilization of material resources has increased continually owing to international economy growth and overseas trade increase in recent years. There are large amounts of order received for container carriers which are the biggest in the world ranging from 8,000 TEU to 10,000 TEU or above The very large container carriers have minimum thickness of sheer strake, upper deck and hatch coaming about $65mm{\sim}90mm$. Therefore, this study is performed in order to develop vertical welding process with high deposition rates applicable to thick plate above 65mm thickness. Electrogas welding process with 1 pole and 2 poles has been developed to apply to vertical joint with thick plates in the shipyard. In this paper, it was explained that the relationship of cross section to various groove types and executed that electrogas welding for thick plates. The mechanical tests were carried out to verify the soundness and effectiveness of EGW.

• 한국건설순환자원학회논문집
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• 제2권3호
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• pp.233-238
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• 2014

합벽, 옹벽, 교량 주탑과 같이 세장한 매스콘크리트 구조물의 경우 온도균열 제어를 위해 저발열 콘크리트 배합의 적용 및 균열유발줄눈의 설치 등이 주로 적용되고 있다. 하지만 이러한 대책이 적용되어도 세장한 매스 구조물들은 내부구속에 비해 외부구속이 크기 때문에 완벽한 균열제어가 불가능하고, 특히 균열이 발생하게 되면 거의 관통을 하기 때문에 온도균열제어를 위한 특별한 관리가 필요하다. 합벽, 옹벽, 교량 주탑과 같이 세장한 매스콘크리트 구조물의 적극적인 온도균열 제어를 위하여 기존의 파이프쿨링 공법을 개선시킨 연직파이프쿨링 공법을 개발하였으며, 현장 우수조/중수조 합벽 콘크리트에 적용이 되었다. 그 결과 합벽의 중심부 최고 온도를 10도 이상 낮츨 수 있는 것으로 나타났으며, 균열은 50% 이상 감소시킬 수 있는 것으로 나타났다.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.655-661
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• 2005

For a hydro power plant project, the headrace tunnel having a finished diameter of 3.3m was constructed in volcanic rocks with well-developed vertical joint and high groundwater table. The intake facility was located 20.3 km upstream of the powerhouse and headrace tunnel of 20 km in length and penstock of 440 m in height connected the intake and the powerhouse. The typical caldera lake, Lake Toba set the geology at the site; the caving of the ground caused tension cracks in the vertical direction to be developed and initial stresses at the ground to be released. High groundwater table(the maximum head of 20 bar) in the area of well-connected vertical joints delayed the progress of tunnel excavation severely due to the excessive inflow of groundwater. The excavation of tunnel was made using open-shield type TBM and mucking cars on the rail. High volume of water inflow raised the water level inside tunnel to 70 cm, 17% of tunnel diameter (3.9 m) and hindered the mucking of spoil under water. To improve the productivity, several adjustments such as modification of TBM and mucking cars and increase in the number of submersible pumps were made for the excavation of severe water inflow zone. Since the ground condition encountered during excavation turned out to be much worse, it was decided to adopt PC segment lining instead of RC lining. Besides, depending on the conditions of the water inflow, rock mass condition and internal water pressure, one of the invert PC segment lining with in-situ RC lining, RC lining and steel lining was applied to meet the site specific condition. With the adoption of PC segment lining, modification of TBM and other improvement, the excavation of the tunnel under severe groundwater condition was successfully completed.

• Journal of Welding and Joining
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• 제26권5호
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• pp.66-73
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• 2008

Welding work in pre-erection or erection stage of shipbuilding construction to be carried out in flat and vertical upward position mostly and Electrogas welding(EGW) is actively applied especially for vertical butt joint of thicker steel plate recently. In this study considered how to develope and improve mechanical properties of weld metal and HAZ in high heat input welding processes such as EGW and Electroslag welding(ESW) with its welding equipment in order to extend the application range to the longitudinal members and hatch coaming parts of container ship. Some components of welding system and parameters were modified to get the faster travel speed and reduce weld heat input, and also by adding additional filler rods or tubes increase the amount of deposited weld metal. With the test get some good date can apply to actual fabrication work and recommend items to manufacture welding materials make better. Above all things it's a fruition that to prepare the possibility of application of ESW to shipbuilding construction which fill up the gap of stoppage days of more than 20 years.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.577-581
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• 1998

Recent trends in the construction of building frame feature the increase use of composite steel concrete members functioning together in what terms of mixed structural systems. One of such systems, RCS(reinforced concrete column and steel beam) system, is known to make use of type of member in the most efficient manner to maximize the structural and economic benifits. Based on the results, joint behavior and design were described in terms of two primary modes of failure ; joint panel shear and vertical bearing. In test specimen, joint deformation is observed at internal region greater than at external region.

• 한국지반공학회논문집
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• 제34권3호
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• pp.43-56
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• 2018

해상처분장의 호안구조물 및 연직차수공으로 강관시트파일이 주로 사용되며, 강관시트파일은 이음부를 연결하여 주열식으로 설치가 되는 만큼 해상 고유의 횡방향 외력에 대한 구조적인 안정성이 확보되어야 한다. 본 연구의 목적은 새로 개발된 연직차수공 이음부의 구조적인 성능을 평가하는 것이다. 먼저 기존 연직차수공 이음부의 문제점을 고찰하고 시공 및 유지보수 측면에서 기존 이음부 형식과의 차별성을 갖도록 새로운 형태의 DHLT(Double H with L-T) 연직차수공 이음부를 개발하였다. 개발된 DHLT 이음부의 실규모 모형을 제작하고 이음부에 그라우트를 채워 양생시킨 후 압축 및 인장강도실험을 수행하고 그 결과를 기존 연구결과와 비교하였다. 실험결과, DHLT 이음부의 압축강도와 인장강도는 그라우트와 강재의 영향으로 인해 기존 이음부 연구결과에 비해 다소 과소평가되었다. 특히 압축강도 실험의 경우 DHLT 이음부의 비대칭 형상으로 인해 그라우트에 균열이 발생하기 전에 강재에서 먼저 항복이 발생하는 결과를 나타내었다. 본 연구를 통해 연직차수공 개발시 이음부 강도발현에 영향을 끼칠 수 있는 요인을 파악할 수 있었으며, 이를 근거로 더 향상된 연직차수공을 개발할 수 있을 것으로 기대된다.

• 한국강구조학회 논문집
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• 제14권1호
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• pp.121-130
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• 2002

This paper presents the tensile behavior of a Concrete-Filled Square Steel Tubular (CFT) column to H-beam welded connections. These connections were externally reinforced with T-shaped stiffeners at the junction of CFT column and beam. The tensile loading tests of eighteen tee-joint connections and finite element analysis using ANSYS were carried out. The main parameters of tests are as follows: 1) the thickness of Square Steel Tubular Column : 6 mm, 9 mm, 2) the strength ratios of tensile strength of horizontal stiffeners to tensile strength of beam flange : 70 %, 100 %, 150 %, 3) the strength ratios of shear strength of vertical stiffeners to tensile strength of beam flange : 80 %, 115 %, 160 %. The results of the tests demonstrate that overall behavior and failure modes of all the specimens are governed mainly by the horizontal stiffeners rather than the vertical stiffeners, and the vertical stiffener played only a role in transferring load introduced from beam to column.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.721-728
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• 2007

The prediction of quality characteristics during the design phase of a construction project was fragmented, because no particular method exists. One of the most important key responses is the total displacements (horizontal and vertical). A brainstorming session produces the quality parameters i.e. the control factors which here are identified as: the steel joint, the pile's length, the excavation depth and angle, the distance between the piles, the anchor stretch and length to name just some of the most engaging in the design. The purpose of this study is to optimise these parameters to minimize the total displacements following a methodology based on Taguchi method. For this reason, a 2-level, L₈ orthogonal array has been employed to organize the experimentation. Data is obtained from a real-life excavation project designed on the Plaxis v.8 CAE package. Taguchi analysis is performed in the statistical package Minitab.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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• pp.61-62
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• 2011

In recent years, domestic construction companies have developed a 200MPa grade high-strength concrete and promoting the superiority of each technique. However, applying design and construction practices of developed high-strength concrete are weak. Most applications is limited to partial use and then the actual examples only used as a layer of high-rise building outrigger with casting some test on basement' vertical structures. In this study, developed materials for separation casting through joint research have been examined economy and others by field application and improving the workability.

• 한국강구조학회 논문집
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• 제24권2호
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• pp.137-147
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• 2012

본 연구는 L형, I형 실험체에 강판 콘크리트 구조와 철근콘크리트 구조를 적용하여 이질접합부를 만들고, 실험체에 반복하중을 파괴 시 까지 가력하여 면외 휨 내력 및 면내 전단 내력을 평가하고 구조특성을 검토하기 위해서 실험연구를 수행하였다.본 연구에서 면외 휨 성능실험은 접합부에서 정착부 수직철근이 인발되면서 파괴되었고, 면내 전단성능실험은 기초부에서의 휨 균열이 발생하여 파괴되었으며, 이론식과의 비교결과 최대 내력이 실험값/이론값의 결과가 면외 휨성능실험은 96%, 면내 전단성능실험은 82%의 값을 나타내었다.