• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2011.11a
• /
• pp.105-107
• /
• 2011

국내의 플로팅 건축 사례의 경우 철근콘크리트 보다는 바지선과 같은 형식의 폰툰이 주로 사용되고 있다. 반면 유럽의 경우 철근콘크리트 폰툰의 사례가 많고 상대적으로 많은 장점을 갖고 있는 것으로 알려져 있다. 유럽 사례를 통해 철근콘크리트 폰툰의 유형을 구분하고 상부시설과의 상관성을 분석함으로써 플로팅 건축 계획에서 계획방법론으로서 활용 가능성을 검토 한다.

• Journal of the Korea Institute of Building Construction
• /
• v.19 no.6
• /
• pp.521-527
• /
• 2019

Quantity takeoff and cost estimates in Korea are carried out in practice without any clear standards or standards. Especially, quantity takeoff of Reinforcing bar and BoQ documentation process is very complex using 2D drawings. In this study, 10 case sites were analyzed for the status of inefficient quantity takeoff and how the statement was prepared. In order to solve this problem, this study presented a method for calculating the quantity of rebars through the ratio of concrete volume for schools, offices, and apartment buildings, and analyzed the accuracy of results. In the future, it is expected that the error range can be reduced by defining the factors affecting the results and calculating the correction value for them.

• Disaster Prevention Review
• /
• v.15 no.3
• /
• pp.83-93
• /
• 2013

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.2
• /
• pp.136-145
• /
• 2007

This study analyzes the current usage of SD500 high-strength re-bar in domestic construction sites. Also, an evaluation method was developed to measure economic efficiency of lap splice and coupler splice, which are most commonly used in connection SD500. The evaluation method was applied to construction sites in Seoul in December 2006, and the result revealed that coupler splice is relatively superior in terms of cost efficiency when the re-bar diameter is bigger and the concrete strength is lower.

• Journal of the Korea Institute of Building Construction
• /
• v.10 no.6
• /
• pp.7-17
• /
• 2010

Modern construction technology has been highly systemized, which has simplified the construction methods applied to construction sites. However, on reinforced concrete construction sites, there have recently been many new disasters, and these have been bigger than before due to the heavy dependency on manpower. This study investigates the cause and cases of disasters during reinforced concrete construction. In addition, the study surveyed the psychological condition of construction site personnel in relation to the safety awareness and the causes of disasters, while deriving the basic components related to disasters on construction sites in order to analyze the relationship between each component to suggest an efficient safety management measures checklist. Construction site personnel should utilize the results drawn from this study as a disaster prevention tool to use in a safety education class, and not consider this simply as statistical data, but as a checklist to ensure full awareness of the appropriate priorities for safety categories to utilize in the reinforced concrete construction in order to execute reasonable safety management.

• Tunnel and Underground Space
• /
• v.9 no.1
• /
• pp.20-26
• /
• 1999

The completion of the Bakun Diversion Tunnel is subsequently to the Main Dam construction. Therefore, the completion date is very important for the Bakun Hydroelectric Project. Generally, the tunnel lining work as a finishing phase of the tunnelling project occupies a important portion as well as an excavation and a support work of the tunnels in respect to the construction cost and period. Internal section of Bakun Diversion Tunnel is designed circular shape to reduce the roughness of the water flow with 12 meters in diameter of total length 4314.6 meters of 3 tunnels. The lining thickness is varied between 500 mm and 700 mm depending on the structural condition. From the original Tender design of the Bakun tunnels, the required quantity of steel bars was 5,985 ton designed by Reinforced Concrete (RC) through the entire tunnel linings. During the detail design stage by the consideration of the rock conditions and various load conditions, we could suggest five kinds of RC lining type including plain concrete lining type. Through the detail design modification, we could reduce the required amount of steel bars to 2,178 ton, as a half of original Bill of Quantity. Finally, this design modification give us the time and cost saving effect to catch up the construction progress in time.

• Journal of the Korea Concrete Institute
• /
• v.25 no.2
• /
• pp.165-173
• /
• 2013

Splice sleeves for HD25 and HD32 rebars with yield strength 500 MPa were studied experimentally and analytically. The shapes of sleeve was examined with nonlinear finite element analyses. A total of 18 specimens were tested with test variables of rebar types, sleeve lengths, mortar compressive strengths, and rebar development lengths. Three identical specimens per each variable were tested in order to prevent any test errors. After tests, numerical studies with a nonlinear finite element method were conducted to evaluate the test results. Experimental studies with 18 specimens showed that the sleeves of this study satisfies the code requirement. It was found that the strength of mortar and the bar development length within the sleeves did not affect to the load-carrying capacity of sleeves.

• Land and Housing Review
• /
• v.4 no.3
• /
• pp.295-301
• /
• 2013

In this study, cases of domestic tall residential buildings were investigated for the structural types, numbers of stories, total heights, type of lateral load resisting systems, and zoning of concrete strength. Based on these investigation data, the structural planning pattern of tall residential building was analyzed. SRC structure is main structural types of tall residential building at the initial stage of domestic tall residential building, but RC structure is substituted for main structural types since 2005. Retaining wall system is positioned at the core part of structural plan as a lateral load resisting system. Concrete strength zoning of vertical members like columns are divided by vertical heights of lower parts, middle parts, and upper parts. Basic data of structural planning of 40stories and 60 stories residential buildings was proposed based on case investigation.

• Journal of the Korea Concrete Institute
• /
• v.18 no.2 s.92
• /
• pp.177-188
• /
• 2006

Conventional nonlinear finite element analysis requires complicated modeling and analytical technique. Furthermore, it is difficult to interpret the analytical results presented as the stress-strain relationship. In the present study, a design-oriented analytical method using the truss model was developed. A reinforced concrete member to be analyzed was idealized by longitudinal, transverse, and diagonal line elements. Basically, each element was modeled as a composite element of concrete and re-bars. Simplified cyclic models for the concrete and re-bar elements were developed. RC beams and walls with various reinforcement details were analyzed by the proposed method. The inelastic strength, energy dissipation capacity, deformability, and failure mode predicted by the proposed method were compared with those of existing experiments. The results showed that the proposed model accurately predicted the strength and energy dissipation capacities, and to predict deformability of the members, the compression-softening model used for the concrete strut element must be improved.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.13 no.6
• /
• pp.87-98
• /
• 2009

It is well known that reinforcement details in the plastic hinge region of bridge piers give the most important effects on the seismic performance of bridges, from investigations of bridge failures in many earthquake events and in laboratory tests. Longitudinal reinforcement details give larger effects than lateral reinforcement details do. The lap-spliced longitudinal steel shows slip during earthquake events, which results in low ductility and inadequate seismic performance. However, before the issue of the earthquake design code, a considerable number of bridge piers were constructed with lap-spliced longitudinal steel in the plastic hinge region. Therefore, a large amount of research has been conducted on the seismic performance and retrofit of circular and rectangular shaped bridge columns with lap-spliced longitudinal steel. However, research on wall type piers is very limited. This paper investigates the seismic performance of a pier wall by a quasi-static test in the weak axis direction and proposes a retrofit method. From the test with variables being the longitudinal steel detail and the transverse steel amount, it is shown that the currently used definition of yield displacement is not adequate. Therefore a new definition of yield displacement for the ductility investigation for a pier wall is proposed. In addition, a retrofit method by steel plates and bolts is proposed to improve ductility, and test results show that slip of the longitudinal steel is prevented by up to a considerably large displacement.