니켈-크롬 합금강바를 이용한 교각부 내진보강 성능개선

장일영,김성수,박종권,김성겸,Jang. Il-Young,Kim. Sung-Soo,Park. Jong-Kwon,Kim. Seong-Kyum 한국방재학회 2011 한국방재학회논문집 Vol.11 No.5

The newly bridge, as amended by the Highway Bridge Seismic design standards and by performing the construction. But, prior to the construction standards apply seismic. Reinforced concrete piers may be vulnerable to an earthquake by the lateral loads. In this study, modeling performed seismic reinforcement and reinforcement techniques through experiments of various types of best seismic reinforcement techniques. It has not been applied Seismic techniques to apply to the existing bridge seismic reinforcement. So, It will be able to performance. In this paper, reinforced through the numerical modeling for the pier reinforcement. The results compared to the after reinforcement against. Displacement was confirmed that more reduction. A non-seismic design for a circular pier models produced. It subject to reduction as a high seismic reinforcement material properties of nickel-chrome alloy using a strip, spiral, horizontal and vertical mixed-seismic reinforcement. It was applied to the experimental. As a result, that the form of a spiral is better than the horizontal and vertical mixed stripes type and strip shape in seismic reinforcement performance was confirmed. 신설된 교량의 경우 최근 개정된 도로교 설계기준에 의하여 내진설계를 수행하여 시공되고 있으나, 내진설계규정이 적용되기 이전에 시공되어 사용 중인 철근콘크리트 교각의 경우에는 지진에 의한 횡하중에 대해 취약할 수 있다. 본 연구에서 수행한 내진보강 모델링 및 실내실험을 통해 여러 형태의 보강기법 중에서 가장 우수한 내진보강 성능을 발휘하는 보강기법을 도출하고, 그 기법을 내진설계가 적용되지 않은 기존교량에 적용시켜 우수한 내진보강 성능을 발휘할 수 있을 것이다. 본 논문에서는 내진보강된 교각에 대하여 모델링을 통한 수치해석결과 보강전에 비하여 보강후 변위에 대하여 감소하는 것을 확인하였다. 실제 비내진 설계된 원형 교각모델에 대하여 축소실험체를 제작하고 내진보강 재료로써 우수한 성질의 니켈-크롬 합금강바를 이용하여 띠형, 나선형, 수평수직 혼합형의 보강을 내진보강에 적용하여 실험하였으며, 그 결과 띠형과 띠, 수직 혼합형의 보강 형태보다는 나선형태의 내진보강이 가장 우수한 내진보강 성능을 나타냄을 확인 하였다.

반복 횡하중을 받는 원형 철근콘크리트 기둥의 Helical Bar 보강효과에 대한 연구

김성겸,박종권,한상희,김병철,장일영 한국구조물진단유지관리공학회 2014 한국구조물진단유지관리공학회 논문집 Vol.18 No.1

본 연구에서는 1992년 도로교설계기준의 내진설계도입 이전 규정에 따라 설계, 시공된 교각의 축소 모델을 실험체로 제작하여 원형기둥의 변위비에 따른 횡하중을 변위제어 방식으로 입력하여 준정적 방법을 통해 실험을 실시하였다. 연구에 적용한 보강재는 성능을 향상시킨무기계 합금강인 Helical Bar로써 원형기둥 외부에 보강 후 실내실험을 통하여 파괴거동, 하중-변위 관계, 연성도 평가 및 에너지 평가를실시하였다. 실험변수로는 위험단면 내에서 나선으로 보강한 보강재의 단면력의 크기와 나선보강의 간격, 보강형태로 두었으며, 준정적 실험을 통해 보강성능의 차이와 효과를 확인하였다. 실험결과 보강대상 부재의 성능에 따라 적절한 보강재의 단면력 크기결정과 보강간격 및형식의 선정이 필요하며 기계적 보강재뿐만 아니라 고강도 콘크리트 피복으로의 치환으로도 보강성능이 향상됨을 확인할 수 있었다. In this study, quasi-static according to the displacement-controlled (strain control) method tests on RC columns for seismic reinforcement performance in accordance with the provisions of the seismic design and construction before 1992 design code forhighway bridges in korea. Used reinforcement that improves the performance of Inorganic Helical Bar, a kind of alloy steel, circular columns were tested outside the seismic reinforcing. In the experiment, fracture behavior, lateral load-displacement relation, ductility and energy assessment evaluation was performed through tests. The variables in experimental are section force of reinforcement, spiral reinforcement spacing, reinforcement method. Improved seismic performance and effect were confirmed through quasi-static test experiments. The results of study confirmed determination the appropriate size of reinforcement, reinforcement forces, spacing and selection of the type required, furthermore, not only mechanical reinforcement but also substitution of high-strength concrete reinforced with concrete cover improved seismic performance.

조적조 내진보강용 섬유보강 모르타르의 분사특성 평가

황병일,박종필,유병현,이동규 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.11

The seismic reinforcement ratio of SOC facilities, such as domestic roads and railroads, is 96%. Out of approximately 7 million buildings as of 2016, only 0.51 million buildings with seismic performance were secured. Although the proportion of masonry structures is 38.8% of the total buildings, there is almost no seismic resistance, only 2.0%. To solve the problem in Korea, government-level seismic measures are being promoted, but the situation is insufficient. Overseas, the UBC research team in Vancouver, Canada, has developed and used EDCC to reinforce the seismic performance of masonry buildings. EDCC is a construction material that can secure concrete ductility capability by mixing fibers and secure deformation resistance of concrete through bridging action. It is necessary to examine various materials because EDCC is not used as a spray type of secure seismic reinforcement. In this study, as part of the research and development of spraying materials to improve the durability of masonry buildings, this study examined the spraying characteristics of fiber-reinforced mortar according to fiber use and the viscosity change according to the use of thickener. As a result, the working performance of the fiber-reinforced mortar for seismic reinforcement was improved when using 1% fiber and 1% thickener. 국내 도로, 철도 등 SOC 시설의 내진보강율은 2017년 기준 96%이며 건축물은 2016년 기준 약 7백만동 중 내진성능이 확보된 건축물은 51만동에 불과하다. 조적조 건축물은 전체 건축물의 38.8%를 차지할 만큼 비중이 크지만 내진성능이 확보된 것은 2.0% 내외로 거의 전무한 실정이다. 이러한 문제를 해결 하기 위해국내에서는 정부차원의 내진대책이 추진되고 있으나 현재까지 미비한 상황이다. 국외의 캐나다 벤쿠버 UBC 연구팀은 조적조 내진성능 보강을 위해 EDCC를 개발하여 사용하고 있다. EDCC는 섬유혼입으로 콘크리트 연성능력 확보 및 가교작용으로 콘크리트의 변형 저항능력을 확보 할 수 있는 건설재료이다. 그러나 내진성능 확보를 위해 EDCC를 분사형으로 사용하지 않기 때문에 다양한 재료의 검토가 필요하다. 이에 본 연구에서는 조적조의 내구성능 향상을 위한 뿜칠재료 연구개발의 일환으로 내진보강용 섬유보강 모르타르의 분사특성을 평가하고자 하였으며, 섬유보강 모르타르의 섬유사용량에 따른 분사특성 및 증점제 사용량에 따른 점도변화를 검토하였다. 조적조 내진보강용 섬유보강 모르타르의 부착성능 및 시공성능을 검토한 결과 섬유의 사용량은 1%, 증점제의 사용량은 1%로 최적 사용량을 도출할 수 있었다.

조적채움벽의 내진성능향상을 위한 외부보강법 개발

박병태(Park, Byungtae),권기혁(Kwon, Kihyuk) 한국방재학회 2017 한국방재학회논문집 Vol.17 No.3

Interest on the seismic reinforcement has increased because of the earthquake occurred in Korea recently, but supplying is quite difficult due to the high expense and construction method. This report offers simple and less expensive seismic reinforcement compared to the past methods by using the twisted bar. Twisted bar is made by twisting a steel bar in a fixed rate and is developed for the purpose of strength improvement. We have conducted the behavior of structure through an experiment when twist bar is applied. The experiment subject was based on the unreinforced material, evaluation of twist bar by its reinforcement (vertical, cross type) was performed. As a result, an increase of resisting force and dissipation energy was observed when twisted bars are used to reinforce the masonry infilled wall. By showing the stable failure, the result was satisfied but there was a decrease in ductility depending on how the reinforcement was applied. An inspection is required before applying on seismic reinforcement. 최근 국내지진발생의 증가로 내진보강에 관한 관심이 높아지고 있으나, 경제성과 시공성의 문제로 보급에는 어려움이 있다. 본 연구에서는 기존 보강법 대비 설치가 간편하고 경제성을 확보한 트위스트바를 활용한 내진보강법을 제시하였다. 구조물의 내력향상을 목적으로 개발된 트위스트바는 강봉을 일정한 비율로 꼬아서 만든 형태이며, 실험을 통해 적용에 따른 구조물의 거동을 확인하고자 하였다. 실험체는 비보강 시험체를 기준시험체로 하여, 트위스트 바의 보강형태(수직, 교차형)별 내진성능을평가하였다. 실험결과, 트위스트바를 이용하여 조적채움벽을 보강시 내력 및 소산에너지의 증가, 안정적인 파괴유형을 보여 우수한 내진성능향상을 보였으나, 보강형태별로 일부 연성이 감소하는 경향을 보여 내진보강에 적용시 보강형태에 대한 검토가 필요하다.

Seismic performances of RC columns reinforced with screw ribbed reinforcements connected by mechanical splice

이세정,이득행,김강수,오재열,박민국,양일승 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.2

Various types of reinforcement splicing methods have been developed and implemented in reinforced concrete construction projects for achieving the continuity of reinforcements. Due to the complicated reinforcement arrangements and the difficulties in securing bar spacing, the traditional lap splicing method, which has been widely used in reinforced concrete constructions, often shows low constructability and difficulties in quality control. Also, lap spliced regions are likely to be over-reinforced, which may not be desirable in seismic design. On the other hand, mechanical splicing methods can offer simple and clear arrangements of reinforcement. In order to utilize the couplers for the ribbed-deformed bars, however, additional screw processing at the ends of reinforcing bars is typically required, which often lead to performance degradations of reinforced concrete members due to the lack of workmanship in screw processing or in adjusting the length of reinforcing bars. On the contrary, the use of screw-ribbed reinforcements can easily solve these issues on the mechanical splicing methods, because it does not require the screw process on the bar. In this study, the mechanical coupler suitable for the screw-ribbed reinforcements has been developed, in which any gap between the reinforcements and sleeve device can be removed by grouting high-flow inorganic mortar. This study presents the uniaxial tension tests on the screw-ribbed reinforcement with the mechanical sleeve devices and the cyclic loading tests on RC columns with the developed coupler. The test results show that the mechanical sleeve connection developed in this study has an excellent splicing performance,and that it is applicable to reinforced concrete columns with a proper confinement by hoop reinforcement.

노후도를 고려한 실크기 원형단면 교각의 내진성능 휨실험

이승건 ( Seung-geon Lee ),이수형 ( Soo-hyung Lee ),이혜린 ( Hyerin Lee ),홍기증 ( Kee-jeung Hong ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 논문집 Vol.25 No.6

노후 교각은 내진설계가 적용되지 않아 소성힌지구역에 겹침이음이 대다수 존재한다. 철근부식은 철근 단면적 감소 및 겹침이음부의 거동저하를 유발하여 교각의 내진성능을 저하시킨다. 본 연구에서는 이러한 노후교각의 특성에 따라 철근부식, 겹침이음, 내진설계 및 내진보강 여부를 고려하여 실험체를 설계 및 제작하고 실험을 통해 그 영향을 조사하였다. 실험결과, 겹침이음 또는 철근부식은 변위연성도를 감소시킨다. 내진설계 상세 또는 강판 내진보강을 적용하면 충분한 변위연성도가 확보됨을 확인하였다. 모든 비내진실험체는 소성힌지구역 내의 횡철근 겹침이음부의 풀림으로 인해 주철근 좌굴과 심부콘크리트 압축파쇄가 발생하였다. 내진설계된 실험체는 철근부식에 의한 소성힌지구역 내 횡철근의 단면감소와 갈고리 풀림에 의해 주철근 좌굴 및 심부콘크리트 압축파쇄가 발생하였다. For old piers constructed when seismic design code had not been developed, lap splices usually exist in plastic hinge region. Corrosion of rebars causes decreasement in cross-sectional area of rebar and deterioration of lap-splice behaviour, thereby reducing the seismic performance of the old piers. In this research, according to these characteristics of old piers, test specimens are designed and manufactured considering rebar corrosion, lap splice, seismic design details, and seismic reinforcement. These effects are investigated through experiments. As a result of these experiment, rebar corrosion as well as lap splice reduces displacement ductility. When seismic design details or steel-plate reinforcement are applied, sufficient displacement ductility is expressed. For non-seismically designed specimens, loosening of the lap splice of transverse rebars caused buckling of longitudinal rebars and crushing of core concrete in plastic hinge region . For seismically designed specimen, area-reducing and untying of transverse rebars due to corrosion of rebars caused buckling of longitudinal rebars and crushing of core concrete.

내진보강 단면형상에 따른 국내 저수지 제방의 안전율에 대한 검토

임성훈 ( Seonghun Lim ),김대현 ( Daehyeon Kim ) 대한지질공학회 2021 지질공학 Vol.31 No.3

농업용저수지는 농업용수를 공급함과 동시에 수해효과 및 휴식터를 제공함으로써 인간의 편의성을 추구하지만 노후 저수지 및 지진으로 인한 피해가 발생될 수 있으며 이에 따른 예방이 중요하다. 제방의 안전성은 제방을 구성하는 세분화된 재료의 토양 매개변수 값과 같은 현장재료 특성에 의해 영향을 받지만 정밀안전진단이나 일반 문헌값이 전용되기 때문에 최종제반의 안전인자를 물질적 특성만으로 판단하기에는 한계가 있다. 안전요인은 물리적 특성값과 제방 형태에 의의 결정되며 안전 요인에 상당한 영향을 미치기 때문에 보강된 횡단면을 검토할 때 정확한 사색이 필요하다. 따라서 본 연구에서는 GEP-SLOPE 프로그램을 활용하여 전남 고흥근 ‘○○저수지’ 내진설계 시 합리적이고 경제적인 보강교차로 사례를 분석함으로써 반복적인 검토를 통해 보강교차로에 대한 합리적 경제적 설계가 가능하도록 분석하였다. 제방의 1, 2, 3차 내진보강을 감소하여 분석한 결과, 3차 보강단면에서도 상류, 하류사면 모두 설계기준 1.20 이상을 얻음으로써 1. 2차에 비해 현저히 적은 보강물 보강물량으로도 안전율 확보가 되는 것을 확인하였다. 또한 제반의 내진보강 단면 형상을 결정할 때 사면의 상부측, 사면전체에 사석을 보강하는 것 보다 하부측에만 보강하는 형상이 단면보강을 최소화 시키며 경제적인 것을 확인하였다. Agricultural reservoirs seek human convenience by supplying agricultural water and providing flood damage effects and rest areas at the same time, but preventing them from aging reservoirs and earthquakes is important. The safety of levees is influenced by field material properties such as soil parameter values of the granular materials that make up the levees, but since precision safety diagnosis or general literature values are diverted, the final safety factors are limited to material properties alone. Since safety factors are determined by physical characteristic values and embankment shapes and have a significant impact on safety factors, accurate contemplation is required when examining reinforced cross sections. Therefore, this study analyzed the case of reasonable and economical reinforcement intersections when designing ‘○○reservoir’ in Goheung-geun, Jeollanam-do using the GEP-SLOPE program to enable rational economic design of reinforcement intersections through repeated reviews. As a result of reducing and analyzing the first, second, and third seismic reinforcement of the levees, it was confirmed that the safety ratio was secured even with a significantly smaller amount of reinforcement than the first, second, and lower slopes by obtaining design standards of 1.20. In addition, when determining all seismic reinforcement cross-sectional shapes, it was confirmed that the shape that reinforces only the lower side rather than the upper side of the slope and the entire slope was economical with minimized cross-sectional reinforcement.

고성능 철근콘크리트 골조면내 전단벽 보강시스템을 활용한 성능설계기반 건축물의 내진성능 평가

하기주,조효식,이동렬 대한건축학회지회연합회 2020 대한건축학회연합논문집 Vol.22 No.6

In this study, specimens, designed by reinforced concrete infilled shear wall using the advanced seismic retrofitting technology, were constructed and tested to improve the seismic performance of reinforced concrete buildings subjected to earthquake-tpye loadings, Six-story existing buildings, applying the advanced seismic retrofitting technology were carried out to evaluate the seismic performance based on performance design. In the evaluation of seismic performance of the existing reinforced concrete buildings using the advanced seismic retrofitting technology by the performance based design, as a result of nonlinear static analysis of reinforced concrete structures, the story drift angle in the x- direction showed up to 16% reduction when applying the advanced seismic retrofitting technology(RWXHC) compared to before reinforcement.

내진성능평가에 따른 정밀안전진단 및 내진 보수보강 조치의 개선방안 연구

김장욱 ( Kim Jang-ook ) 한국건축시공학회 2022 한국건축시공학회 학술발표대회 논문집 Vol.22 No.1

For an earthquake-safe urban environment, the Republic of Korea conducts seismic performance evaluation in accordance with laws and guidelines to assign safety ratings and implement necessary management measures such as repairs and reinforcements. In the seismic performance evaluation result, structures lacking in preparation for earthquakes are prioritized and classified into measures such as repair, reinforcement, or careful observation to respond to physical risks such as earthquakes. Such repair and reinforcement work is not a one-time thing, but it is necessary to further enhance the effect through continuous follow-up observation. In this study, the location of the vertical and horizontal displacement measuring part of the construction part is displayed so that the post-construction status of the reinforcement construction part can be visually checked by identifying the problems in the process of post-monitoring in 2022 for the maintenance and reinforcement work of local governments' public facilities carried out in 2021. We propose a plan to institutionalize the installation of, inspection tools, and crack gauges at certain locations in the construction department, and to have facility managers periodically inspect and manage them with a smartphone program or the 'Facility Autonomous Safety Inspection' app.

사인파형 웨브주름 보강재를 이용한 저층건물의 내진보강에 관한 연구

정동조,김진 한국농촌건축학회 2022 농촌건축 : 한국농촌건축학회논문집 Vol.24 No.2

In this study, a general low-rise building was selected to compare the new shear wall reinforcement method, which is a general method among the existing reinforcement methods, and the reinforcement method using sinusoidal corrugated web reinforcement. And it was confirmed that the following effects can be expected. Sinusoidal corrugated web members can be carried out in a short period of time as it does not require the removal of the masonry filling wall, the reinforcement of reinforcing bars, and the curing period of the concrete. It is effective in preventing damage that may occur when masonry filling wall is overturned in the out-of-plane direction, and the burden of the foundation is also reduced, and thus the construction period and cost required for reinforcement can greatly be reduced. By adjusting the number of sinusoidal corrugated web member, details of joints, and reinforcement positions, the flow of load can be induced to have an advantageous effect on the building. It can be considered as the most suitable reinforcement plan in terms of life safety. Unlike the shear wall that fills between the columns, the sinusoidal corrugated web members, which has a width of 1.5m, can install openings between two columns depending on the purpose of use, and can be expected to have a great effect in terms of usability due to its free installation location. As mentioned above, the seismic reinforcement using a sinusoidal corrugated web members, can expect great effect compared to conventional reinforcement methods in terms of usability, economic feasibility, and stability.