• 한국BIM학회 논문집
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• 제9권3호
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• pp.8-18
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• 2019

Precast concrete manufacturing has proved economies of scale through the repetitive production by means of standardization, automation, and prefabrication. Advanced digital design and fabrication technologies can empower its benefits by enabling mass customization in the building design and construction. This study analyzed five case studies in terms of 1) design intent and background, 2) module development and facade construction, 3) integrated process among project stakeholder. This article has attempted to establish the following three points in conclusion: 1) Form generating digital design tools such as Rhino, CATIA, Generative Component, and Digital Project were implemented to produce parametric surface pattern and rationalization to maximize existing precast manufacturing benefits. Also, BIM program has been used to promote coordination and communication among engineering consultants and contractors, 2) In addition to traditional precast concrete materials, GFRC, RFP, brick cladding precast and 3D printed mould have been introduced to reduce the weight and cost and to comply the code from the zoning, seismic, and fireproof requirements, 3) Design-assist contract, design-assist financial support, and co-location measures have been introduced to facilitate collaboration between architect, fabricator, and contractor from the beginning of the project.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.52-55
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• 2004

Before incorporating the earthquake-resistance design in design code(998), most of existing residential buildings were built without having lateral resistance capacity in addition to their structural peculiarity such as exterior stair ways, exterior elevator room. For these reasons, the retrofitting research demands for existing buildings arise recently and many retrofitting methods are proposed. These tasks are important to reduce the enormous economic loss and environmental issues. In this study, Scaled residential buildings with/without lateral resistance were tested and monitored with external lateral load especially toward the longer side of the building. From these experiments, enhanced retrofitting methods of old shear wall system are proposed and also compared with structural analysis.

• Earthquakes and Structures
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• 제6권3호
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• pp.317-334
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• 2014

The work is concerned with an investigation of the advantages stemming from the use of lightweight aggregate concrete in earthquake-resistant reinforced concrete construction. As the aseismic clauses of current codes make no reference to lightweight aggregate concrete beams made of lightweight aggregate concrete but designed in accordance with the code specifications for normal weight aggregate concrete, together with beams made from the latter material, are tested under load mimicking seismic action. The results obtained show that beam behaviour is essentially independent of the design method adopted, with the use of lightweight aggregate concrete being found to slightly improve the post-peak structural behaviour. When considering the significant reduction in deadweight resulting from the use of lightweight aggregate concrete, the results demonstrate that the use of this material will lead to significant savings without compromising the structural performance requirements of current codes.

• 한국구조물진단유지관리공학회 논문집
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• 제6권2호
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• pp.245-253
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• 2002

This study was focused on the effect of concrete strength and lateral ties of concrete columns using high-strength concrete. Thirty-six concrete columns with 20cm square cross-section were tested. Experimental parameters included the concrete strength, the distribution of longitudinal bars and the volumetric ratio, yield strength, spacing of lateral ties. From the experiments, we found that: 1) the increasing rate of the strength and ductility of concrete columns caused by confinement of lateral ties was decreasing, as the concrete strength increased. 2) The high volumetric ratio and the reduction of tie spacing had a tendency to enhance the strength and improve the ductility. 3) The high-strength concrete columns required high volumetric ratio of lateral ties to maintain the proper strength and ductility. It was observed that the current AIK design code to specify the maximum tie spacing of high-strength concrete columns led to the poor strength and ductility for seismic design.

• Smart Structures and Systems
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• 제15권3호
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• pp.913-929
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• 2015

Hybrid simulation is increasingly being recognized as a powerful technique for laboratory testing. It offers the opportunity for global system evaluation of civil infrastructure systems subject to extreme dynamic loading, often with a significant reduction in time and cost. In this approach, a reference structure/system is partitioned into two or more substructures. The portion of the structural system designated as 'physical' or 'experimental' is tested in the laboratory, while other portions are replaced with a computational model. Many researchers have quite effectively used hybrid simulation (HS) and real-time hybrid simulation (RTHS) methods for examination and verification of existing and new design concepts and proposed structural systems or devices. This paper provides a detailed perspective of the enabling role that HS and RTHS methods have played in advancing the practice of earthquake engineering. Herein, our focus is on investigations related to earthquake engineering, those with CURATED data available in their entirety in the NEES Data Repository.

• Earthquakes and Structures
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• 제2권4호
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• pp.377-396
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• 2011

In seismic design and structural assessment using the displacement-based approach, real structures are simplified into equivalent single-degree-of-freedom systems with equivalent properties, namely period and damping. In this work, equations for the optimal pair of equivalent properties are derived using statistical procedures on equivalent linearization and defined in terms of the ductility ratio and initial period of vibration. The modified Clough hysteretic model and 30 artificial accelerograms, compatible with the acceleration spectra for firm and soft soils, defined by the Japanese Design Specifications for Highway Bridges are used in the analysis. The results obtained with the proposed equations are verified and their limitations are discussed.

• 한국전산구조공학회논문집
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• 제30권5호
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• pp.371-380
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• 2017

미국의 내진설계기준인 ASCE/SEI 7-10은 구조물 붕괴성능에 대한 불확실성을 고려하지 않는 등재해도 기반 내진설계의 문제점을 해결하기 위해 위험도 기반 내진설계 개념을 도입하였다. 하지만 현행 국내 내진설계기준의 경우 한반도 내에서 발생한 큰 규모의 지진기록과 구조물의 붕괴성능과 관련된 연구의 부족으로 위험도 기반 내진설계 개념을 반영하지 않고 있다. 본 연구에서는 철골 보통중심가새골조를 표본건물로 선정하여 위험도 기반 내진성능평가를 수행하였다. 건물이 위치한 지역, 높이, 지반조건을 변수로 바탕으로 표본건물에 대한 붕괴성능 평가를 수행하였으며, 국내 지진기록의 특성을 반영할 수 있는 경험적 스펙트럴 형상 예측 모델을 활용하여 지진재해도 곡선을 작성하였다. 이를 활용하여 국내 주요 도시에 위치한 철골 보통중심가새골조의 붕괴확률을 위험도 적분 개념에 따라 평가하였다. 국내 주요 도시에 위치한 철골 보통중심가새골조의 붕괴확률을 평가한 결과, 현행 건축구조기준에 따라 설계된 표본건물은 본 연구에서 고려한 해석 변수에 따라 붕괴확률에 상당한 차이를 보였다. 특히 국내 건축구조기준의 경우 철골 보통중심가새골조에 대한 높이제한이 없어 일부 고층표본건물에서 목표 위험도인 50년간 1%의 붕괴확률을 초과하는 것으로 평가되었다.

• 한국지진공학회논문집
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• 제16권2호
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• pp.47-60
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• 2012

우리나라의 건축법 시행령에서는 3층 미만 그리고 연면적 $1000m^2$ 미만의 건축물을 소규모 건축물로 정의하고 있으며 내진설계 적용 대상 범위에서 제외하고 있다. 하지만 소규모 건축물에 거주하는 인구의 비율이 상당하다는 사실을 고려할 때, 소규모 건축물의 내진성능을 확보하는 것은 지진 재해 경감에 있어서 중요한 부분이라고 할 수 있다. 이 논문에서는 2층 철골 건물에 비좌굴 Knee가새를 적용한 예제 연구를 통해서 소규모 건물의 내진보강 전략에 대한 연구를 수행하였다. 확률론적 내진성능 목표를 바탕으로 가새의 상세를 결정하였고, 이를 위해서 다양한 구조적 특성에 대한 취약성 분석 결과를 즉시 구해서 비교할 수 있는 취약성 등고선을 이용하였다. 기존에 수행된 실험적, 해석적 연구결과를 바탕으로 75개의 BRKB모델을 개발하였으며, 이 중에서 예제 건축물에 대한 BRKB의 가장 효과적인 보강 방안은 취약성 곡선을 이용한 내진성능의 검증과 강재의 무게를 바탕으로 결정하였다. 본 연구를 통해서 취약성 등고선을 이용한 내진성능평가 방법이 확률론적 내진성능목표를 바탕으로 한 보강전략수립에 효율적으로 사용될 수 있는 것으로 나타났다.

• 한국지진공학회논문집
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• 제15권3호
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• pp.37-43
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• 2011

구조물 내 설치된 파이프시스템은 주로 내부구성원들의 인간생활에 근간이 되는 기반시설로서 현대 도시생활의 생명선과 같은 역할을 한다. 이들 구조물 내 파이프시스템이 만약 지진발생에 의하여 손상될 경우 1차적으로 구조물 내 기능성이 저하되고 구조물 내 많은 정신적, 물질적 피해가 발생할 수 있다. 실제 내진공학에서 지진발생에 따른 비구조재요소의 거동은 크게 중요하게 고려되지 않으나 인적 및 물적 피해와 매우 밀접하게 연관되는 가스 혹은 수계파이프시스템에 대한 비구조적 요소의 거동예측 및 성능평가 연구는 보다 효과적인 구조물 유지관리를 위하여 그 필요성이 크다고 판단된다. 본 연구는 현재 일반적으로 널리 시공되어져 있는 노후 철근콘크리트 빌딩구조물 내 설치된 가스 혹은 수계파이프시스템에 대하여 실제 지진발생이 예측되는 거동을 살펴보고 이들 거동에 따른 성능평가 및 현 설계기준에 대한 검토도 병행하여 수행하고자 한다. 이를 위하여 본 연구에서는 해석적으로 발생 가능한 총 10회의 지진파에 대하여 현재 실제 건물 내 기설치된 수계파이프시스템 모델링 및 해석을 통하여 그 결과를 검증, 평가하였으며 부가적으로 실제 발생 가능한 파괴유형 분석을 통하여 현 설치된 수계파이프시스템의 설계에 대한 적절한 내진보강방법에 대하여도 제안하고자 한다.

• Structural Engineering and Mechanics
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• 제16권4호
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• pp.493-517
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• 2003

Attempts at improving beam-column joint performance has resulted in non-conventional ways of reinforcement such as the use of the crossed inclined bars in the joint area. Despite the wide accumulation of test data, the influence of the crossed inclined bars on the shear strength of the cyclically loaded exterior beam-column joints has not yet been quantified and incorporated into code recommendations. In this study, the investigation of joints has been pursued on two different fronts. In the first approach, the parameters that influence the behaviour of the cyclically loaded beam-column joints are investigated. Several parametric studies are carried out to explore the shear resisting mechanisms of cyclically loaded beam-column joints using an experimental database consisting of a large number of joint tests. In the second approach, the mechanical behaviour of joints is investigated and the equations for the principal tensile strain and the average shear stress are derived from joint mechanics. It is apparent that the predictions of these two approaches agree well with each other. A design equation that predicts the shear strength of the cyclically loaded exterior beam-column joints is proposed. The design equation proposed has three major differences from the previously suggested design equations. First, the influence of the bond conditions on the joint shear strength is considered. Second, the equation takes the influence of the shear transfer mechanisms of the crossed inclined bars into account and, third, the equation is applicable on joints with high concrete cylinder strength. The proposed equation is compared with the predictions of the other design equations. It is apparent that the proposed design equation predicts the joint shear strength accurately and is an improvement on the existing code recommendations.