• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.1
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• pp.19-27
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• 2015

Recently, the most of domestic high-rise residential complex buildings are constructed with reinforced concrete structures, which may bring structural problems during construction. This study is aimed to analyze structural safety and lateral load-resisting performance of RC high-rise residential complex building under construction. The tower-typed building with 60 floors is selected as a sample model, and numerical analyses are performed. The structural performances of building structures at construction stages, which are resulted form the analyses of numerical models completed up to 10th, 20th, 30th, 40th, 50th, or 60th floor, are compared to those of the completed building structure. For the comparisons of structural performances, modal shapes and fundamental periods of building structures, lateral load-resisting performances, and structural design performances of structural members are considered. The lateral displacement and story drift ratio are analyzed for lateral load-resisting performances, and comparisons of design ratios at construction and design stages are performed for structural design performances of structural members. The guideline of design loads and structural analysis schemes for checking the safety of RC high-rise building under construction is presented.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.4
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• pp.235-242
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• 2022

Compared with buildings that have already been constructed, buildings under construction may be more vulnerable to such natural disasters as earthquakes because the concrete strength is not yet sufficient. Currently, Korean design standards present minimum performance targets for each seismic grade of buildings, but the seismic load for design is based on a return period of 2400 years. However, because the construction period of the building is much shorter than the period of use of the building, the application of the earthquake return period of 2400 years to buildings under construction may be excessive. Therefore, in this study, a construction stage model of buildings with 5, 15, 25, and 60 floors was created to analyze earthquake loads during construction of residential reinforced concrete (RC) buildings. The structural stability was confirmed by applying reduced seismic loads according to the return period. As a result, the structural stability was checked for an earthquake of the return period selected according to the construction period, and the earthquake return period that can secure structural safety according to the size of the building was confirmed.

• Journal of the Korea Institute of Building Construction
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• v.21 no.4
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• pp.377-386
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• 2021

In April 2019, this study was enacted as a test method for the performance of waterproof layers in an environment where complex deterioration and structural behavior are simultaneously applied, but some existing standards were implemented to point out the errors of the method that should be supplemented. Thus, in establishing standards for (tentative) adhesive waterproofing sheets, field workability and quantification of test results were studied on the structural behavior response performance test methods included as test items. In addition, the performance evaluation of adhesive-type composite waterproof sheets was conducted based on the considered contents to review improvements such as applicability as an item of standard standards and field workability related problems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.15-16
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• 2015

해저파이프라인 및 해저케이블 설치해역이 대수심으로 이동함에 따라 육지와는 다른 열악한 시공 환경에 놓이게 된다. 이때 파이프라인 및 케이블이 매설되는 해저지반 상태와 작업이 이루어지는 해역의 해상조건 등은 작업효율에 영향을 미치기 때문에 효율적인 시공이 필요하다. 본 논문은 구조물 매설에 앞서 해저지반 굴삭 작업을 수행하기 위해 ROV 트렌쳐의 하단에 장착되는 워터젯 굴삭기의 작업효율 및 시공성능 추정에 관한 연구이다. 먼저 전산유체해석을 통해 워터젯 굴삭기의 굴삭효율을 극대화할 수 있는 노즐 수량을 정하였고, 모형실험을 수행하여 굴삭기의 시공성능을 예측할 수 있는 최대 굴삭심도 및 최대 굴삭속도를 파악하였다. 이를 바탕으로 실제 운용중인 워터젯 굴삭장비들과 시공성능을 비교 분석하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.96-103
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• 2019

Middle-rise reinforced concrete residential buildings account for a large portion of the Korea, and structural performance analysis are needed for problems that could occur during the construction of such buildings. Thus, a middle-rise reinforced concrete residential building with 25 stories are selected as a sample model for structural performance analysis. The structural analyses are performed by dividing a sample model into the construction stage models of the 5th, 10th, 15th, 20th and 25th floors and the completion stage models with the design completed. For the comparisons of structural performances, Eigenvalue analysis results and lateral-load-resisting capabilities and structural design performances of structural members are analyzed. As a result of analyses, it was confirmed that both the construction and completion stage do not exceed KBC criteria limits at the lateral displacement and story drift ratio, and structural design performances of structural members confirm structural safety in all components except for some members of the wall. Therefore, it was concluded that if structural stability is obtained during the completion stage of a middle-rise reinforced concrete residential building, structural stability is secured under construction.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.43-50
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• 2022

Even though the structural safety is confirmed in the design stage, the structural safety is not guaranteed in the construction stage because the structural system is not completed. In addition, since the construction period is shorter than the period of use of the building after completion, it is excessive to apply the same seismic load to the construction stage as in the design stage. ASCE 37-14 presents the concept of seismic load reduction factor during construction, but does not provide a clear application method. Therefore, in this study, the seismic load reduced according to the return period was applied to the example model of a residential middle-rise RC building. The construction stage of the example model was divided into five-story units, and seismic load with the change of the return period was applied to the construction stage models to analyze the change of seismic load during construction and to check the sectional performances of structural members. By comparing the design strength ratio of the shear wall at the design stage and the construction stage, the range of seismic load magnitudes that can assure the safety during construction of a residential middle-rise RC building was analyzed in terms of the return period.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.2
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• pp.85-92
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• 2023

Unlike a completed building, a building under construction may be at risk in terms of safety if a load exceeds the value considered in the design stage owing to various factors, such as a load action different from that in the design stage and insufficient concrete strength. In addition, if an earthquake occurs in a building under construction, greater damage may occur. Therefore, this study studied example models with various sizes of 5, 15, 25, and 60 floors for typical building types and analyzed the effects of seismic load on buildings under construction using construction-stage models according to frame completeness. Because the construction period of the building is much shorter than the period of use after completion, applying same earthquake loads as the design stage to buildings under construction may be excessive. Therefore, earthquakes with a return period of 50 to 2,400 years were applied to the construction stage model to review the seismic loads and analyze the structural performances of the members. Thus, we reviewed whether a load exceeding that of the design stage was applied and the return period level of the earthquake that could ensure structural safety. In addition, assuming the construction period of each example model, the earthquake return period according to the construction period was selected, and the design appropriateness with the selected return period was checked.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.89-97
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• 2013

With regard to complex-shaped tall buildings whose plans and constructions have been gradually on the increase, this study was aimed to analyze their structural behaviors during construction by applications of construction sequences analyses to prototype models. For twisted tall buildings, total 18 models of with three conditions of a lateral load-resisting system, a twisting angle, and a construction method were selected. A diagrid system and a braced tube system were applied as a lateral load-resisting system. For each lateral load-resisting system, three types of plan with $0^{\circ}$, $1^{\circ}$, and $2^{\circ}$ twisting angles and three construction methods with construction sequences of exterior tube and interior frame were assumed. The structural performances of tall buildings under constructions were analyzed with results of lateral displacements from construction sequence analyses. Also, construction performances of the construction period and the maximum lift weight were compared.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.438-441
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• 2009

휨강성이 작은 바닥시스템인 플랫 플레이트 구조는 응력조건 뿐만 아니라 사용성조건에 의하여 구조적 성능이 결정될 수 있으며, 특히 과도한 시공 하중의 작용은 시공 중 안전성에 대한 단기적인 손상 뿐만 아니라 사용성에 관련된 장기적인 손상을 발생시킬 수 있다. 이러한 플랫 플레이트의 시공하중은 동바리지지 층 수, 시공주기, 슬래브 콘크리트의 재료적인 강성 뿐만 아니라, 동바리의 강성과 슬래브에 발생하는 균열에 의한 영향에 의하여 결정된다. 본 논문에서는 다양한 설계조건에 대한 해석연구를 통하여, 동바리-슬래브의 강성비 변화 및 콘크리트 균열에 의한 단면강성저하가 슬래브들 간의 하중 분포에 미치는 영향을 분석하고, 이러한 동바리 강성 및 슬래브 균열의 영향을 고려한 시공하중 산정법을 제안한다.

• Magazine of the Korea Concrete Institute
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• v.14 no.6
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• pp.88-95
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• 2002

최근 국내에 60층을 초과하는 초고층 구조물들이 많이 건설되고 있으며, 콘크리트 품질의 향상 특히 콘크리트의 고강도화에 힘입어 이를 이용한 철근 콘크리트 고층 구조물들이 증가하고 있다. 이에 따라 이들 초고층, 초대형 구조물을 지지할 수 있는 고축력, 고연성의 기둥에 대한 설계 및 시공이 요구되고 있으며, 이에 가장 적합한 구조요소라 할 수 있는 콘크리트 충전 강관기둥(Concrete Filled Steel Tube Columns : CFT Columns)의 설계 및 시공에 관심이 높아지고 있다. 이러한 콘크리트 충전 강관기둥은 콘크리트가 강관에 의해 둘러싸여지기 때문에 축하중 저항 능력이 증가되는 장점과 동일한 단면으로 H형강을 사용한 순수 철골조 H형강 기둥의 강축(strong axis)과 약축(weak axis) 문제해결과 동시에 강성 (stiffness)을 증가시킬 수 있으며, 내화 성능이 향상되고 거푸집 대체 재료로 사용되는 등 여러 가지 장점을 지니고 있다. 한편 충전 강관기둥에 작용하는 축하중은 대부분 콘크리트가 부담하게 되는데 이러한 충전강관 기둥의 장점을 극대화하기 위해서는 보통강도 콘크리트보다는 압축강도 및 탄성계수가 큰 고강도 콘크리트의 사용은 불가피하게 된다.(중략)