• 토지주택연구
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• 제13권3호
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• pp.83-102
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• 2022

경주·포항 지진이후 국내 건축물의 내진성능에 대한 국민들의 관심이 고조되고 있으며, 특히 지진하중에 취약한 필로티형 건축물의 내진성능확보에 대한 시의성이 높아지고 있다. 이 연구에서는 LH가 보유한 필로티형 건축물의 유형별 내진보강방안을 제시하였다. 내진보강방안에는 내진보강우선순위, 코어의 위치에 따른 내진보강방안이 제시되어있다. 제시된 내진보강방안의 유효성을 검증하기 위하여 필로티형 건축물의 코어의 유형에 따라 전산해석을 수행하였으며, 그 결과 제시된 내진보강방안으로 내진보강을 수행 할 경우, 내진성능이 향상됨을 확인하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.36-37
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• 2020

The government seismic retrofit project for educational facilities is progressing more actively due to the 2018 Pohang earthquake. It is most important that seismic retrofit constructions are conformed to seismic design to achieve the desired purpose of the project as reduce direct damage caused by earthquake. However, the construction supervision system is not mandatory for the retrofit construction site of small buildings including school buildings according to applicable laws and regulations. The purpose of this study was to develop a guide for constructions management of school building seismic retrofit. In order to achieve this goal, the survey on the construction site was conducted and various problems related to the construction site of school building seismic retrofit was derived Additionally, the systematic checklist was presented according to the user and seismic reinforcement method.

• Steel and Composite Structures
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• 제25권4호
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• pp.473-484
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• 2017

In this study a seismic retrofit scheme for a building structure was presented using steel plate slit dampers. The energy dissipation capacity of the slit damper used in the retrofit was verified by cyclic loading test. Genetic algorithm was applied to find out the optimum locations of the slit dampers satisfying the target displacement. The seismic retrofit of the model structure using the slit dampers was compared with the retrofit with enlarging shear walls. A simple damper distribution method was proposed using the capacity spectrum method along with the damper distribution pattern proportional to the inter-story drifts. The validity of the simple story-wise damper distribution procedure was verified by comparing the results of genetic algorithm. It was observed that the capacity-spectrum method combined with the simple damper distribution pattern leaded to satisfactory story-wise distribution of dampers compatible with the optimum solution obtained from genetic algorithm.

• 교육시설 논문지
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• 제19권4호
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• pp.29-38
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• 2012

Recently large scale earthquake s are occurred around the world following the damage of buildings. So the interest of preparing for earthquake seismic design and seismic performance has becoming high. School buildings are though used for educational purpose; they are also used as emergency shelter for local residents during earthquake disaster. However, the current seismic design ratio of our country (Korea) is 3.7% and if massive earthquake is occurred it follows a serious damage. In order to overcome this situation, seismic performance evaluation is carried out for existing school building and an accurate and appropriate seismic retrofit is required based on performance evaluation to upgrade the existing school buildings. In this paper, nonlinear static analysis on existing school buildings for ATC-40 and FEMA-356 are carried out using the capacity spectrum method to evaluate seismic performance and to determine the need for retrofitting. In addition, after reinforcement to verify the effect of retrofit enhance the seismic performance is applied the seismic performance evaluation is carried out to verify the effect of seismic retrofit time history analysis using nonlinear dynamic analysis is also performed and nonlinear behavior of earthquake load of seismic retrofit of structures was also investigated.

• 도시과학
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• 제7권2호
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• pp.29-36
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• 2018

The demand for reinforcement in accordance with remodeling, seismic retrofit, and change of use of the existing structure is increasing. Originally, shear wall new and extension method has been adopted a lot as seismic retrofit methods. Recently, dry seismic retrofit method that uses structural steel is mostly adopted in order to minimize spatiotemporal aspect and underpinning that occurs when a construct shear wall. We redesigned the form of old and new concrete joint high-shear ring anchor that was developed according to recent reinforcement method and determined construction method. Shear tests were performed on High-Shear Ring Anchor for steel-concrete connection. Comparison with 4 tests shows that the average of test-to-prediction ratios is 1.01.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.129-134
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• 2002

The seismic performance evaluation and retrofit process are very important for old bridge. If the result is not appropriate, a retrofit process requires. Among the various retrofit methods, this paper selects a seismic isolator and evaluates a seismic performance of bridge. In case of applied seismic isolators to bridge, it proved that seismic capacity is increased by isolators A period of bridge is increased, and a seismic response is decreased. A method of evaluation is capacity spectrum method. By means of a graphical procedure, capacity spectrum estimates a performance level of structure by comparing the capacity of structure with the demand of earthquake ground motion on the structure. The objective of this study is to compare a seismic performance of a non-seismic designed bridge and seismic isolated bridge and to verify a effect of seismic isolator

• 한국지진공학회논문집
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• 제18권5호
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• pp.241-251
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• 2014

In this study, shaking table test was carried out to evaluate the seismic behavior and performance of low-rise reinforced concrete (RC) piloti structures with and without retrofit. The specimens were designed considering the characteristics of existing building with pilotis such as natural period, distribution factor of strength and stiffness between columns and core wall on the first soft story. The test for the non-retrofit specimen showed that damage was concentrated on the stiffer member on the same floor as the core wall failed by shear fracture whereas columns experienced slight flexural cracks. Considering the failure mode of the non-retrofit specimen, the retrofit method using steel rod damper was presented for improving the seismic performance of piloti structures. The results of the test for retrofit specimen revealed that the retrofit method was effective for controlling the damage as the main RC structural members were not destroyed and most of input energy was dissipated by hysteretic behavior of the damper.

• 한국공간구조학회논문집
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• 제22권3호
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• pp.73-80
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• 2022

Unlike the CFT retrofit method, The EPFT retrofit method, which fills the steel tube with engineering plastic, does not require a separate concrete forming work and is a lightweight seismic Retrofit Method. In this study, an prototype model of the EPFT was proposed, and to analyze the seismic performance, an independent specimens and a reinforced concrete column were fabricated to conduct a seismic performance test. As a result of loading test of the independent specimens, the strength was increased compared to the steel tube column without internal filling, and the ductility ratio did not significantly increase due to the falling off of the weld. As a result of loading test of the concrete reinforcement specimen, the strength, ductility ratio, and energy dissipation were increased, and the number of cracks by loading step decreased compared to the non-reinforced specimen.

• 한국지진공학회논문집
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• 제17권1호
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• pp.33-41
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• 2013

Due to a high level of system ductility, steel moment resisting frames have been widely used for lateral force resisting structural systems in high seismic zones. Earthquake field investigations after Northridge earthquake in 1994 and Kobe earthquake in 1995 have reported that many steel moment resisting frames designed before 1990's had suffered significant damages and structural collapse. In this research, seismic performance assessment of steel moment resisting frames designed in accordance with the previous seismic provisions before 1990's was performed. Buckling-restrained braces and shear walls are considered for seismic retrofit of the reference buildings. Increasing stiffness and strength of the buildings using buckling-restrained braces and shear walls are considered as options to rehabilitate the damaged buildings. Probabilistic seismic performance assessment using fragility analysis results is used for the criteria for determining an appropriate seismic retrofit strategy. The fragility contour method can be used to provide an intial guideline to structural engineers when various structural retrofit options for the damaged buildings are available.

• Computers and Concrete
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• 제6권2호
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• pp.95-108
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• 2009

In the current research, a displacement-based seismic design scheme to retrofit reinforced concrete columns using FRP composite materials has been proposed. An accurate prediction for the nonlinear flexural analysis of FRP jacketed concrete members has been presented under multiaxial constitutive laws of concrete and composite materials. Through modification of the displacement coefficient method (DCM) and the direct displacement-based design method (DDM) of reinforced concrete structures, two algorithms for a performance-based seismic retrofit design of reinforced concrete columns with a FRP jacket have been newly introduced. From applications to retrofit design it is known that two methods are easy to apply in retrofit design and the DCM procedure underestimates the target displacement to compare with the DDM procedure.