• 한국구조물진단유지관리공학회 논문집
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• 제6권1호
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• pp.95-102
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• 2002

The flexural behavior of the reinforced concrete (RC) structure upgraded by external reinforcements was examined in this study. It is well known that the incorporation of carbon fiber sheet (CFS) with concrete is one of the most effective ways to strengthen the RC structure. Complete bonding is required between CFS and concrete in order to make the RC structure provide its full function until the time the Re structures serve. Many studies have reported that construction deficiencies have caused the debonding of the CFS from concrete before the RC structure with CFS reaches its ultimate capacity. This research took a systematic look at the failure mechanism, macroscopic load-deformation characteristics, the maximum load applied, and maximum bending moment when construction deficiencies exist. The results of the experiment conducted were compared with theoretically derived values. In the future, the results of this investigation will help minimize the factors of construction deficiencies, which may occur when CFS is used to reinforce a RC structure. The experiment was manipulated with steel reinforcement ratio and piles of CFS on a total of 14 beams ($20cm{\times}30cm{\times}240cm$). The results showed that internal moment capacity increased even when construction deficiencies existed. However, RC structures with CFS in the field still contain a considerable level of potential risks.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.235-236
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• 2010

Since many structures in the sea environment are damaged by chloride, appropriate repair strategy is required. Therefore in the paper, optimum period for the RC structure's repair is calculated with consideration of economic efficiency. Moreover, when the concrete members are repaired with the other material such as polymer mortar forr section restoration, their expected service life also calculated to predict more accurate repair period during the life span.

• 한국철도학회논문집
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• 제1권1호
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• pp.20-29
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• 1998

State of the art and current issues related with the RC and PSC structure system for the German magnetic levitation train "Transrapid" were investigated. The German magnetic levitation train adopted a new kind of a structure to enable high-speed transportation, which allows the use of the space over a ground. The loading from Transrapid is light-weight compared with a regular train due to load distribution to a supporting structure. Therefore, Transrapid is considered an economical and efficient transportation system, and is also an environmentally-sustainable structure. In this paper, the structural design and construction technology specific to a magnetic levitation train were discussed, and structural considerations related with an actual operation of the train were pointed out. In addition, the future research area of a magnetic levitation train was proposed.

• 한국안전학회지
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• 제21권6호
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• pp.96-100
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• 2006

In this thesis, the crack investigation, the damage investigation, the drawing check, and the structural analysis were performed on a curved hollow RC(reinforced concrete) slab bridge structure to assess the structural safety of that. From the crack investigation result, main reason of crack occurrence is guessed with travelling of the large truck. Therefore reinforcement of slab structure is necessary by using the steel plate. When structural analysis, the straight beam model, the curved beam model, and the curved plate model is used. From the results of structural analysis for curved hollow RC slab bridge, the maximum bending moment and the maximum shear force was not a difference in each models. But the vertical displacement of mid span using the curved beam model was greater than that using the other models.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.166-167
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• 2021

The purpose of this study is to evaluate the viscosity and flowability of polymer-cement composites for repairing cracks of RC structures. The viscosity and flowability of the polymer cement composites differed greatly depending on the type of polymer and the polymer cement ratio, and the polymer cement composites could be produced that could repair fine cracks in the RC structure without material separation by adjusting the proper water-cement ratio. In particular, the mixing of high viscosity EVA-modified polymer composites could be adjusted.

• Earthquakes and Structures
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• 제26권4호
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• pp.269-283
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• 2024

When a reinforced concrete (RC) structure is exposed to a corrosive environment for an extended period of time, the material qualities deteriorate, resulting in a loss in seismic performance. Engineered Cementitious Composites (ECC) have been used to reinforce the corroded RC structure, which can achieve reinforcement effectiveness for a small change in cross-section size. In this work, finite element models of unjacketed RC pier and ECC jacketed pier were established and verified by experimental tests, with the buckling effect of longitudinal reinforcement considered. Compared with the unjacketed pier, the displacement of the pier top of the ECC jacketed pier was reduced by about 9.52% under earthquake action. In the case of moderate and major earthquakes, the probability of exceedance of ECC jacketed pier is significantly reduced. For the case of rare earthquake loading, with the ECC jacket, the e of the pier experiencing serious damage and complete damage states is reduced by 10.29% and 29.78%, respectively.

• 한국전산구조공학회논문집
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• 제24권2호
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• pp.223-233
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• 2011

본 논문에서는 수직하중, 풍하중 및 지진하중에 의해 발생하는 변위 관련 구속조건을 만족하면서 RC(Reinforced Concrete) 빌딩 구조의 부피를 최소화하기 위한 설계문제를 정식화하였다. 구조해석 절차 자동화의 어려움으로 인해 실험 계획법과 근사화기법, 최적화기법을 이용한 근사모델기반 최적설계를 수행하였다. 특히, 만족할 만한 설계 결과를 얻을 때까지 설계변수의 범위와 구속조건의 허용값을 조정하는 단계적 최적설계 방법을 제안하였다. 제안된 단계적 최적설계 방법을 통해 주어진 구속조건을 모두 만족하면서 RC 빌딩 구조의 부피를 초기 설계 대비 53.3% 감소시키는 결과를 얻음으로 써 본 논문에서 보인 단계적 최적설계 방법의 타당성을 보였다.

• Structural Engineering and Mechanics
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• 제85권4호
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• pp.485-500
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• 2023

The non-linear static analysis of reinforced concrete (RC) structures using the three-dimensional (3D) finite element method is a time-consuming and challenging task. Moreover, this type of analysis encounters numerical problems such as the lack of convergence of results in the stages of growth and propagation of cracks in the structure. The time integration analysis along with the mass scaling (MS) technique is usually used to overcome these limitations. Despite the use of this method in the 3D finite element analysis of RC structures, a comprehensive study has not been conducted so far to assess the effects of the MS method on the accuracy of results. This study aims to evaluate the accuracy of the MS method in the non-linear quasi-static finite element analysis of RC structures. To this aim, different types of RC structures were simulated using the finite element approach based on the implicit time integration method and the mass scaling technique. The influences of effective parameters of the MS method (i.e., the allowable values of increase in the mass of the RC structure, the relationship between the duration of the applied load and fundamental vibration period of the RC structure, and the pattern of applied loads) on the accuracy of the simulated results were investigated. The accuracy of numerical simulation results has been evaluated through comparison with existing experimental data. The results of this study show that the achievement of accurate structural responses in the implicit time integration analyses using the MS method involves the appropriate selection of the effective parameters of the MS method.

• Structural Engineering and Mechanics
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• 제41권1호
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• pp.1-24
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• 2012

A reinforced concrete (RC) framed structure detailed according to non-seismic detailing provisions as per Indian Standard was tested on shake table under dynamic loads. The structure had 3 main storeys and an additional storey to simulate the footing to plinth level. In plan the structure was symmetric with 2 bays in each direction. In order to optimize the information obtained from the tests, tests were planned in three different stages. In the first stage, tests were done with masonry infill panels in one direction to obtain information on the stiffness increase due to addition of infill panels. In second stage, the infills were removed and tests were conducted on the structure without and with tuned liquid dampers (TLD) on the roof of the structure to investigate the effect of TLD on seismic response of the structure. In the third stage, tests were conducted on bare frame structure under biaxial time histories with gradually increasing peak ground acceleration (PGA) till failure. The simulated earthquakes represented low, moderate and severe seismic ground motions. The effects of masonry infill panels on dynamic characteristics of the structure, effectiveness of TLD in reducing the seismic response of structure and the failure patterns of non-seismically detailed structures, are clearly brought out. Details of design and similitude are also discussed.

• 터널과지하공간
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• 제19권1호
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• pp.43-51
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• 2009

구조물의 비선형 적인 대변위 붕괴거동을 해석하기 위해 다양한 수치 해석에 대한 연구가 진행되어 왔다. 본 연구에서는 새로운 수치해석 기법인 Applied Element Method (AEM)를 이용하여 철근 콘크리트 모형 구조물의 발파해체 붕괴거동을 모사하였다. 보형 구조물의 발파해체 붕괴거동과 수치해석으로 모사된 구조물의 붕괴거동을 X 방향(수평방향)의 변위와 Z 방향(수직방향)의 변위에 대해 비교한 결과, 수치해석에서 모사된 구조물의 붕괴거동은 실제 모형 구조물은 붕괴거동을 사실적으로 모사할 수 있음을 확인하였다.