끼움벽 보강 골조의 내진성능

김선우(Kim Sun-Woo),이영오(Lee Young-Oh),윤현도(Yun Hyun-Do) 대한건축학회 2007 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.27 No.1

Many reinforced concrete moment resisting frame buildings in seismic zones lack strength and ductility. A infill wall system may provide an economic advantage for the retrofit of these structures. The objective of this research is to evaluate structural strengthening performance of lightly reinforced concrete frame retrofitted with infill wall experimentally. In order to evaluate the performance of this type of system, four one story-one bay non-ductile frame were constructed and rehabilitated with a recycled concrete block masonry wall and two CIP(cast-in-place) walls. Especially, HPFRCC (High performance fiber-reinforced cement composite) was used in infill wall to improve ductility of infill wall-frame system. From the test results, infill wall-frame specimen exhibited a marked increase in shear strength compared to non-ductile RC frame specimen. But the ductility and story-drift at maximum load were decreased when shear strength of infill wall larger than that of existing RC frame except for IWF-H specimen retrofitted with HPFRCC infill wall. Therefore, it is difficult for RC infill wall-frame to satisfy requirement condition of maximum story-drift and ductility capacity in view of failure mode of all infill-wall frame specimens. Based on the seismic performance of test infill-wall specimen, it is confirmed that adequate reinforcement is added to assure sufficient seismic performance.

Shear Capacity of Cold-Formed Light-Gauge Steel Framed Shear-Wall Panels with Fiber Cement Board Sheathing

Wasim Khaliq,Ahmed Moghis 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.4

Being light in weight, cold-formed steel shear wall panels (SWPs) made with light gauge steel are extensively used in residential and office buildings (low to mid-rise), particularly in structures under seismic loadings. Many design practices involve the use of fiber cement board (FCB) as sheathing material both for hollow and infilled walls. FCB is a preferred choice as cladding material due to many advantages it provides such as water resistance, lower cost, withstand temperature variation, resistance to humidity and termite attack, better acoustic insulation, and superior fire resistance properties. In the absence of design guidelines, based on cold-formed light gauge steel shear walls with FCB sheathing, the designers resolve to use the guideline available for gypsum wall board (GWB) and fiberboard (FB) available in American Iron and Steel Institute Lateral Design. As a pioneer study, an experimental program was designed to investigate the behavior of cold-formed light gauge steel shear walls, both hollow and infilled with expanded polystyrene (EPS) foam concrete, with FCB sheathing on both sides under monotonic loading. The tests were performed according to ASTM E564 standard. Results show that the strength of shear walls with FCB sheathing is much higher than GWB and FB sheathing, suggesting that substitute design practices are highly conservative. Test results can help designers choose desired lateral stiffness and load carrying capacity of light gauge steel SWPs more efficiently, by selecting appropriate framing, infill, and sheathing material.

Seismic performance of RC frame structures strengthened by HPFRCC walls

Hyun Do Yun,황진하,Mee Yeon Kim,최승호,박완신,Kang Su Kim 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.3

An infill wall made of high-performance fiber-reinforced cementitious composites (HPFRCC) was utilized in this study to strengthen the reinforced concrete (RC) frame structures that had not been designed for seismic loads. The seismic performance of the RC frame structures strengthened by the HPFRCC infill walls was investigated through the experimental tests, and the test results showed that they have improved strength and deformation capabilities compared to that strengthened by the RC infill wall. A simple numerical modeling method, called the modified longitudinal and diagonal line element model (LDLEM), was introduced to consider the seismic strengthening effect of the infill walls, in which a section aggregator approach was also utilized to reflect the effect of shear in the column members of the RC frames. The proposed model showed accurate estimations on the strength, stiffness, and failure modes of the test specimens strengthened by the infill walls with and without fibers.

기존 골조의 내진성능 향상을 위한 철근콘크리트 현장타설 끼움벽의 보강성능 평가

김선우,윤현도,김윤수,지상규,Kim. Sun-Woo,Yun. Hyun-Do,Kim. Yun-Su,Ji. Sang-Kyu 한국방재학회 2008 한국방재학회 학술발표대회논문집 Vol.2008 No.1

A reinforced concrete (RC) cast-in-place (CIP) infill wall retrofitting method may provide an improved seismic performance and economical efficiency for the non-ductile rahmen structures. In this study, four one story-one bay non-ductile frame were constructed and retrofitted with CIP infill wall to evaluate seismic performance of CIP infill wall-frame. From the test results, infill wall-frame exhibited a marked increase in shear strength compared to non-ductile RC frame specimen. But the ductility and story-drift at maximum load were decreased when shear strength of infill wall larger than that of existing RC frame. Therefore, it is confirmed that adequate reinforcement detail is required to assure sufficient seismic performance.

보-기둥 접합부 비탄성 전단거동을 고려한 조적벽체를 가진 5층 철근콘크리트 중간모멘트골조의 푸쉬오버해석

강석봉(Kang Suk-Bong),임병진(Lim Byeong-Jin) 대한건축학회 2012 大韓建築學會論文集 : 構造系 Vol.28 No.8

In this study, the effects of the inelastic shear behavior of beam-column joint, the vertical distribution of lateral load considering higher modes and masonry infill walls on the response of RC IMRF are evaluated in the pushover analysis, where 5-story structures were designed in accordance with KBC2009. M-φ relationship for beam and column was identified with fiber model. An analytical model for inelastic beam-column joint was suggested and the behavior of the joint was reproduced with simple and unified joint shear behavior model. An inelastic masonry infill wall was simulated with two diagonal braces. Negligence of inelastic shear behavior of the joint caused overestimate of the maximum strength of the structures. The structures with masonry infill walls showed greater initial stiffness and maximum strength than those for the structure without the walls and the differences disappeared after the failure of the walls.

국내 기존 학교건축물의 내진보강 후 비선형 거동특성

류승현,윤현도,김선우,이강석,김용철 한국구조물진단유지관리공학회 2011 한국구조물진단유지관리공학회 논문집 Vol.15 No.1

본 논문은 내진설계규정이 적용되지 않은 국내 철근콘크리트 학교 건물에 관한 해석적 연구이다. 일본의 내진진단과 비선형정적 및 동적 해석을 통하여 대상 건축물의 내진 성능을 평가하였다. 일본의 내진진단 방법에 기초하여 철근 콘크리트 학교 건물의 부족한 내진 성능을 파악하였다. 또한, 횡하중을 받는 학교 건물의 내진거동이 해석적으로 평가되었다. 건축물의 내진 보강을 위하여 1,300kN의 내력을 받는 전단벽과 K형 가새골조가 사용되었다. 비선형 정적해석 결과, 보강에 의한 전단내력은 보강 전에 비하여 30%이상의 향상을 보이는 것으로 나타났으며, 전단벽 보강 시 최대 하중 이후에서 가새골조 보강에 비해 큰강성저하를 나타내었다. 또한, 성능점 산정 결과에서 가새골조로 보강된 건축물이 전단벽으로 보강된 건축물에 비해 30% 이상의 변형능력을 보였다. 한편 비선형 동적해석의 시간이력해석 결과에서는 가새골조와 전단벽에 의해 보강된 건축물의 최대 변위가 보강량이 증가할수록 감소하는 경향을 나타내었다. 본 연구는 이 외에도 지진 지역에서의 건축물의 내진성능 향상을 위해다양한 지반 조건과 지진파를 고려되어야 한다고 판단된다. This paper describes an analytical study on seismic performance of domestic reinforced concrete (RC) school building not designed by seismic provision. The seismic index and the seismic performance of the building were evaluated through Japanese standard and Midas Gen, respectively. Seismic index (Is) of the RC school buildings in the X-direction is below 0.4. Based on the seismic index, for seismic-strengthening the building, infill shear wall or steel brace with a capacity of 1,300 kN was used. According to nonlinear static analysis results, the contribution of the seismic-strengthening to the shear resistance of the school building was measured to be greater than 30%. However, as expected, shear strength of school building strengthened with infill wall dropt rapidly after peak load and much narrower ductile behavior range was observed compared to steel brace strengthened building. Also, the building strengthened with steel brace showed 30%larger spectral displacement than that strengthened with infill shear wall. In nonlinear dynamic analysis, for the time history analysis, the maximum displacement showed tendency to decrease as amount of reinforcement increased,regardless of strengthening method. It was recommended that variable soil properties and earthquake record should be considered for improving seismic performance of buildings in seismic zone.

철근콘크리트 전단벽의 접합방식과 대각보강에 따른 내진성능 평가 및 개선

신종학,하기주,안준석,주정준,Shin, Jong-Hack,Ha, Gee-Joo,An, Joon-Suk,Ju, Jung-Jun 한국구조물진단유지관리공학회 1999 한국구조물진단유지관리공학회 논문집 Vol.3 No.3

Six reinforced concrete shear wall, constructured with fully rigid, slit, and infilled types, were tested under both vertical and cyclic loadings. Experimental programs were carried out to evaluate the seismic performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility, under load reversals. All the specimens were modeled in one-third scale size. Based on the test results, the following conclusions can be made. For the diagonal reinforced slit and infilled shear wall specimens, it was found that the failure mode shows very effective crack control and crushing due to slippage prevention of boundary region and reduction of diagonal tension rathar than the brittle shear and diagonal tension failure. The ductility of specimens designed by the diagonal reinforcement for the slit and infilled shear wall was increased 1.72~1.81 times in comparison with the fully rigid shear wall frame. Maximum horizontal load-carrying capacity of specimens designed by the diagonal reinforcement ratio the slit and infilled shear wall was increased respectively by l.14 times and l.49 times in comparison with the standard fully rigid shear wall frame.

U형 프리캐스트 콘크리트 벽패널로 채운 기존 철근 콘크리트 보-기둥 구조물의 전단 거동 분석

하수경,손국원,유승룡,주호성 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 논문집 Vol.19 No.6

The purpose of this study is to develop a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were performed on one unreinforced beam-column specimen and two reinforced specimens with U-type precast wall panels. The results were analyzed to find that the specimen with anchored connection experienced shear failure, while the other specimen with steel plate connection principally manifested flexural failure. The ultimate strength of the specimens was determined to be the weaker of the shear strength of top connection and flexural strength at the critical section of precast panel. In this setup of U-type panel specimens, if a push loading is applied to the reinforced concrete column on one side and push the precast concrete panel, a pull loading from upper shear connection is to be applied to the other side of the top shear connection of precast panel. Since the composite flexural behavior of the two members govern the total behavior during the push loading process, the ultimate horizontal resistance of this specimen was not directly influenced by shear strength at the top connection of precast panel. However, the RC column and PC wall panel member mainly exhibited non-composite behavior during the pull loading process. The ultimate horizontal resistance was directly influenced by the shear strength of top connection because the pull loading from the beam applied directly to the upper shear connection. The analytical result for the internal shear resistance at the connection pursuant to the anchor shear design of ACI 318M-11 Appendix-D, agreed with the experimental result based on the elastic analysis of Midas-Zen by using the largest loading from experiment. 이 연구의 목표는 학교 건물과 같은 저층 보-기둥 철근콘크리트 구조 건물에서 프리캐스트 벽패널을 사용한 새로운 내진보강 방법을 개발하는데 있다. 1개의 무 보강 보-기둥 실험체와 U형 PC 패널로 보강한 2개의 보강 보-기둥 실험체에 대한 정적 이력 하중실험을 진행하였다. 앵커 접합부 실험체는 전단 파괴될 것으로 해석되었고 철판 용접 접합부 실험체는 휨 파괴할 것으로 예측되었다. 실험체의 종국 내력은상부 접합부의 전단 내력과 PC 패널 절곡 부 휨 위험단면에서 휨 내력 중 약한 것으로 결정되었다. 이 실험체에서, 한쪽 RC기둥이 가 하중(미는실험 하중)을 받아 PC 패널 부재를 밀게 된다면, 다른 쪽 내부 수직부재는 상부 전단 접합부로부터 부 하중(당기는 실험 하중)을 받게 되어있었다. 가 하중을 받는 2개의 부재는 합성 휨 거동이 지배적이므로 합성단면의 휨 내력이 실험체의 최종 내력을 결정하게 되지만, 이 경우 최종 내력에 대하여 상부 전단 접합부 강도의 직접적인 영향은 없다고 볼 수 있다. 그러나 부 하중(당기는 하중)을 받는 RC 기둥과 PC 패널 부재는 비합성 거동이 지배적이고 실험체의 최종 내력은 상부 전단 접합부 전단내력의 크기에서 직접 영향을 받는 것으로 파악되었다. ACI 318M-11 Appendix-D 앵커 전단설계에 기초한 전단내력 그리고 실험에서 얻은 최대하중을 적용하여 마이다스 젠 탄성설계에 의하여 계산한 전단 외력에 대한 비교 해석결과는 실험결과와 일치하는 해석결과를 보여주었다.

L형 프리캐스트 콘크리트 벽패널로 채운 기존 철근 콘크리트 골조 구조물의 전단 거동 분석

유승룡 ( Sung Yong Yu ),주호성 ( Ho Seong Ju ),하수경 ( Soo Kyoung Ha ) 한국복합신소재구조학회 2015 복합신소재학회논문집 Vol.6 No.2

The purpose of this study is to develop a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were experimentally performed on one unreinforced beam-column specimen and two reinforced specimens with L-type precast wall panels. The results were analyzed to find that the specimen with anchored connection experienced shear failure, while the other specimen with steel plate connection principally manifested flexural failure. The ultimate strength of the specimens was determined to be the weaker of the shear strength of top connection and flexural strength at the critical section of precast panel. In this setup of L-type panel specimens, if a push loading is applied to the reinforced concrete column on one side and push the precast concrete panel, a pull loading from upper shear connection is to be applied to the other side of the top shear connection of precast panel. Since the composite flexural behavior of the two members govern the total behavior during the push loading process, the ultimate horizontal resistance of this specimen was not directly influenced by shear strength at the top connection of precast panel. However, the RC column and PC wall panel member mainly exhibited non-composite behavior during the pull loading process. The ultimate horizontal resistance was directly influenced by the shear strength of top connection because the pull loading from the beam applied directly to the upper shear connection. The analytical result for the internal shear resistance at the connection pursuant to the anchor shear design of ACI 318M-11 Appendix-D except for the equation to predict the concrete breakout failure strength at the concrete side, principally agreed with the experimental result based on the elastic analysis of Midas-Zen by using the largest loading from experiment.

L형 프리캐스트 콘크리트 벽패널로 채운기존 철근 콘크리트 골조 구조물의 전단 거동 분석

유승룡,주호성,하수경 한국복합신소재구조학회 2015 복합신소재구조학회논문집 Vol.6 No.2

The purpose of this study is to develop a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were experimentally performed on one unreinforced beam-column specimen and two reinforced specimens with L-type precast wall panels. The results were analyzed to find that the specimen with anchored connection experienced shear failure, while the other specimen with steel plate connection principally manifested flexural failure. The ultimate strength of the specimens was determined to be the weaker of the shear strength of top connection and flexural strength at the critical section of precast panel. In this setup of L-type panel specimens, if a push loading is applied to the reinforced concrete column on one side and push the precast concrete panel, a pull loading from upper shear connection is to be applied to the other side of the top shear connection of precast panel. Since the composite flexural behavior of the two members govern the total behavior during the push loading process, the ultimate horizontal resistance of this specimen was not directly influenced by shear strength at the top connection of precast panel. However, the RC column and PC wall panel member mainly exhibited non-composite behavior during the pull loading process. The ultimate horizontal resistance was directly influenced by the shear strength of top connection because the pull loading from the beam applied directly to the upper shear connection. The analytical result for the internal shear resistance at the connection pursuant to the anchor shear design of ACI 318M-11 Appendix-D except for the equation to predict the concrete breakout failure strength at the concrete side, principally agreed with the experimental result based on the elastic analysis of Midas-Zen by using the largest loading from experiment.