• 한국안전학회지
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• 제24권4호
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• pp.74-81
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• 2009

In this study, the seismic performance of RC school buildings which were not designed according to earthquake-resistance design code were evaluated by using response spectrum and push-over analyses. The torsional amplification effect due to plan irregularity is considered and then the efficiency of seismic retrofitting methods such as RC shear wall, steel frame, RC frame and PC wing wall was investigated. The analysis result indicate that the inter-story drift concentrated in the first floor and most plastic hinge forms at the column of the first story. Among the retrofitting methods, the PC wing wall has the highest seismic performance in strength and story drift aspect. Especially, it can make building ductile behavior due to the concentrated inter-story drift at the first column hinge is distributed overall stories. The axial force, shear force and moment magnitude of existing elements significantly decreased after retrofitting. However, the axial and shear force of the elements connected to the additional retrofitting elements increased, and especially the boundary columns at the end of the retrofitting shear wall should be reinforced for assuring the enhancement of seismic performance.

• 한국산학기술학회논문지
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• 제18권7호
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• pp.611-617
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• 2017

최근 수십년간 세계 각국에서 예측 불가능한 형태의 지진발생이 증가하여 중국 쓰촨대지진, 아이티지진, 동일본대지진 등 대규모 피해가 발생하였으며, 비교적 지진에 안전한 것으로 인식되어 온 국내에서도 규모 5.0이상의 지진이 수차례 발생함에 따라 지진 안전성에 대한 사회적 요구가 증가하고 있다. 과거 발생한 지진 및 피해사례로부터 전문가들은 건축물의 내진성능 확보가 가장 효과적인 피해저감 대책으로 지목하고 있고, 이에 따라 미국, 일본 등 선진각국에서는 내진보강 지원제도를 실시하고 있다. 국외에서 실시중인 대표적인 내진보강 지원제도는 정부의 비용보조, 세제혜택, 보험료 할인 등으로 나타났으며, 국내에서는 2013년부터 내진보강 지원제도 중 하나인 세제혜택을 실시하고 있지만 민간건축물 소유자들로부터 외면받고 있는 실정이다. 이러한 문제의 해결방안으로서 본 논문은 국내외 건축물 내진보강 지원제도를 검토 및 분석하였으며, 그 결과 민간건축물 소유자의 부담을 최소화할 수 있는 방안이 마련되어야 함을 확인하였으며, 이를 바탕으로 민간건축물의 내진보강 활성화를 위한 정책 및 지원제도의 개선방안을 위하여 정부차원의 지원금 조성, 조세경감과 보험료 인하, 홍보 및 교육을 통한 국민의식 제고방안이 필요함을 제시하였다.

• 한국해양환경ㆍ에너지학회지
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• 제18권1호
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• pp.15-21
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• 2015

본 연구에서는 이산화탄소 해양지중저장을 위한 운송 수단으로 활용될 $CO_2$ 운송선의 타당성조사 결과에 대하여 논한다. 중고 화물선 개조에 의한 $CO_2$ 운송선 확보와 신조에 의한 운송선 확보를 위한 개념 설계를 수행하였고, 이를 토대로 $CO_2$ 운송선의 획득 비용을 추정하였다. 마지막으로 가정한 시나리오에 대한 운용 방안을 검토하여 연간 운송량을 수송할 수 있는 필요 척수와 소요 비용을 함께 추정하였다.

• Earthquakes and Structures
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• 제9권1호
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• pp.29-48
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• 2015

The main purpose of this work is to compare different criteria for the seismic strengthening of RC framed buildings in order to find the optimal combinations of these retrofitting techniques. To this end, a numerical investigation is carried out with reference to the town hall of Spilinga (Italy), an RC framed structure with an L-shaped plan built at the beginning of the 1960s. Five structures are considered, derived from the first by incorporating: carbon fibre reinforced polymer (FRP)-wrapping of all columns; base-isolation, with high-damping-laminated-rubber bearings (HDLRBs); added damping, with hysteretic damped braces (HYDBs); FRP-wrapping of the first storey columns combined with base-isolation or added damping. A three-dimensional fibre model of the primary and retrofitted structures is considered; bilinear and trilinear laws idealize, respectively, the behaviour of the HYDB, providing that the buckling be prevented, and the FRP-wrapping, without resistance in compression, while the response of the HDLRB is simulated by using a viscoelastic linear model. The effectiveness of the retrofitting solutions is tested with nonlinear dynamic analyses based on biaxial accelerograms, whose response spectra match those in the Italian seismic code.

• 한국지진공학회논문집
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• 제26권1호
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• pp.31-38
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• 2022

Based on the nonlinear static analysis and the approximate seismic evaluation method adopted in "Guidelines for seismic performance evaluation for existing buildings, two methods to calculate strength demand for retrofitting individual structural walls in unreinforced masonry buildings are proposed." The displacement coefficient method to determine displacement demand from nonlinear static analysis results is used for the inverse calculation of overall strength demand required to reduce the displacement demand to a target value meeting the performance objective of the unreinforced masonry building to retrofit. A preliminary seismic evaluation method to screen out vulnerable buildings, of which detailed evaluation is necessary, is utilized to calculate overall strength demand without structural analysis based on the difference between the seismic demand and capacity. A system modification factor is introduced to the preliminary seismic evaluation method to reduce the strength demand considering inelastic deformation. The overall strength demand is distributed to the structural walls to retrofit based on the wall stiffness, including the remaining walls or otherwise. Four detached residential houses are modeled and analyzed using the nonlinear static and preliminary evaluation procedures to examine the proposed method.

• Steel and Composite Structures
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• 제47권4호
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• pp.467-488
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• 2023

Seismic retrofit of an existing steel-reinforced concrete hospital building that features innovative use of a continuous energy-dissipative steel column (CEDC) system is presented in this paper. The special system has been adopted to provide an efficient solution taking into account the difficulties of applying traditional intervention techniques to minimize the impact on architectural functionality and avoid the loss of building function and evacuation during the retrofit implementation. The lateral stiffness and strength of the CEDC system were defined based on the geometric and mechanical properties of the steel strip dampers. The hysteretic behavior under cyclic loadings was defined using a simplified numerical model. Its effectiveness was validated by comparing the results of full-scale experimental data available from the literature. All the main design considerations of the retrofitting plan are described in detail. The effectiveness of the proposed retrofitting system was demonstrated by nonlinear time-history analyses under different sets of earthquake-strong ground motions. The analysis results show that the CEDC system is effective in controlling the deformation pattern and significantly reducing damage to the existing structure during major earthquakes.

• 한국재난관리표준학회지
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• 제3권1호
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• pp.67-73
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• 2010

학교는 지진재해시 학생 및 교직원의 안전을 확보하고 지역주민의 대피소로서 기능을 수행할 수 있도록 방재교육과 대피소에 필요한 방재기능 및 내진성능을 확보해야 한다. 학생 및 교직원의 지진방재능력 향상을 위해서는 도덕, 과학, 체육 등 교과과목에 지진방재에 관한 내용을 수록하여 지도하고, 지역주민과 교직원이 학교 방재시설 및 대피소를 효과적으로 활용할 수 있도록 방재계획과 매뉴얼 개발이 필요하다. 학교시설 내진화 및 내진보강은 내진설계가 적용되지 않은 건축물을 우선적으로 선정하여 철골브레이스와 내진벽체 공법 중심으로 추진하되, 사회적 합의를 위해 노후시설의 개축 등 교육환경 개선사업과 병행해야 한다. 또한, 학교시설을 대피소로 활용하기 위해서는 필요한 방재시설을 갖추고 방재기능 개선이 필요함을 제시하였다.

• 토지주택연구
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• 제11권1호
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• pp.95-101
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• 2020

In the past few decades, the global population growth and rapid economic development have resulted in significant increases in building energy consumption. To reduce greenhouse-gas emissions and building energy consumption, building materials and energy technologies must be optimized. Building retrofitting is a more efficient method than reconstruction to improve the building energy performance. In order to improve the energy performance of existing buildings, this study proposed energy-efficiency retrofit plans and derived cost-effective retrofit plan. The energy efficient retrofit method is achieved through the packaging of energy technology and the energy and cost reduction effect of the energy efficiency retrofit package are analyzed. As a result of the study, the energy-efficiency retrofit package showed an energy reduction effect of up to 60% or more and a construction cost reduction of about 30%. This study argues that optimal energy and construction cost reduction of existing buildings are possible through the packaging of energy efficiency technology.

• 한국터널지하공간학회 논문집
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• 제14권6호
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• pp.653-666
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• 2012

본 연구는 터널의 단면변화구간에서 발생한 손상 미케니즘에 대하여 이루어졌다. 이를 위해 단면변화 구간을 대상으로 다양한 현장조사 및 시험을 실시하였으며, 이를 바탕으로 2차원 및 3차원 수치해석을 수행하였다. 현장조사 및 시험 결과, 슬래브 손상에 대한 직접적인 원인을 찾을 수 없었으며, 2차원 수치해석을 수행한 결과 기준 안전율(1.0)을 만족하는 것으로 분석되었다. 추가로 수행한 3차원 수치해석 결과, 기둥 간격의 변화에 따라 슬래브 휨응력 변화를 전달시키지 못해 손상이 발생한 것으로 분석되었다. 보강을 위해 터널내 기둥을 추가하는 방안을 적용하였으며 그 결과, 상부 슬래브 비틀림 형상이 완화되어 보강 효과를 확인할 수 있었다. 단면 변화 구간의 경우 2차원 뿐만 아니라, 3차원으로 영향범위를 고려하여 설계에 반영한다면, 합리적이고 안정적으로 건설 및 유지관리가 가능할 것으로 판단된다. 추후에는 개착터널내 단면변화 구간에서 구조물에 영향을 최소화할 수 있는 보강방안에 대해 연구를 계속하고자 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.343-346
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• 2005

Earthquake resistance design has been developed many countries like Japan, USA, Mexico, New Zealand etc., which countries have experienced many earthquakes. Nowadays, earthquake resistance design has come into worldwide use. In Korea, the seismic design regulations have been established since 1988 in order to minimize the economic losses. Recently performance based design method has been adopted as a new Earthquake resistance design method. These regulations, however, are targeted for newly constructed buildings, In Korea, there are no regulations for existing buildings that built before 1988. So, we need to prepare the regulations that evaluate the seismic performance, furthermore proper retrofitting design guideline needs to be proposed when remodeling old buildings. This study was performed that many existing apartments is being a Remodeling object when considering the present condition of existing apartment and the problems of cost and environment in the future plan. When Remodeling construction is reviewed by former the Seismic Performance Evaluation Method, generating problems is evaluation by using Push-over. According to this, it provides the appropriate method of calculating the Seismic Ship Performance Index.