• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.879-884
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• 2002

The objective of this study is to investigate the seismic capacity of the non-seismically detailed RC bridge piers before and after applying a seismic retrofitting method using stainless steel wire mesh. Total nine circular section RC piers were constructed. Different lap splice longitudinal reinforcement details were adapted for four specimens and various types of stainless steel wire mesh were applied for the remaining five specimens. Harmonic cyclic lateral load was applied on each specimen under a constant axial load. The test results indicated that the existing circular piers have low seismic capacity while the stainless steel wire mesh retrofitting method improves the seismic capacity considerably. In addition, test results revealed that the circular section piers could have a considerable amount of ductility if longitudinal bars are not lap-spliced in potential plastic hinge zone. Based on this experimental study it could be concluded that the seismic performance, that is ductility and energy absorption capacity, of the non-seismically detailed RC bridge piers would be increased by applying the stainless steel wire mesh seismic retrofitting method.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.259-266
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• 2000

This study was conducted to investigate the seismic behavior assessment of circular reinforcement concrete bridge piers particularly with regard to assessing the displacement ductility curvature ductility response modification factor(R) and plastic hinge region etc, The experimental variables of bridge piers test consisted of transverse steel details amount and spacing different axial load levels etc. The test results indicated that reinforcement concrete bridge piers with confinement steel by the code specification exhibited suffcient ductile behavior and seismic performance. Also it is found that current seismic design code specification of confinement steel requirements may be revised.

• 대한토목학회논문집
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• 제26권2A호
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• pp.351-361
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• 2006

이 연구에서는 원형 철근콘크리트 교각의 횡방향 철근에 따른 내진성능평가를 위한 비선형 유한요소해석 기법을 제시하였다. 이 논문에서는 원형 철근콘크리트 교각의 이력거동의 예측에 근거한 손상지수를 제시하였다. 손상지수는 지진하중하의 원형 철근콘크리트 교각의 손상을 수치적으로 정량화하는 방법으로서 제안되었다. 제안한 해석기법을 실험된 철근콘크리트 교각에 적용하여 비교, 분석하였다. 제안된 해석기법은 조사된 실험체에 대하여 하중단계에 따라 내진성능을 정확하게 예측하였다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.187-193
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• 2001

The object of this research is to evaluate the seismic performance of existing circular reinforced concrete bridge piers by the Quasi-static test. Existing reinforced concrete bridge piers, which were non-seismical]y designed in accordance with the conventional provisions of Korea Highway Design Specification, are needed to rating evaluate seismic performance fur probable earthquake motions in future by developing a seismic analysis computer program with estimation algorithm. This study has been performed to verify the effect of lap spliced longitudinal steel, confinement steel type and confinement steel ratio for the seismic behavior of reinforced concrete bridge piers. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility, energy absorption, strength degradation etc.

• Steel and Composite Structures
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• 제12권3호
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• pp.261-273
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• 2012

This study proposes and examines a circular composite bridge pier for seismic resistance. The axial and flexural strengths of the proposed bridge pier are provided by the longitudinal reinforcing bars and the concrete, while the transverse reinforcements used in the conventional reinforced concrete pier are replaced by the steel tube. The shear strength of this composite pier relies on the steel tube and the concrete. This system is similar to the steel jacketing method which strengthens the existing reinforced concrete bridge piers. However, no transverse shear reinforcing bar is used in the proposed composite bridge pier. A series of experimental studies is conducted to investigate the seismic resistant characteristics of the proposed circular composite pier. The effects of the longitudinal reinforcing bars, the shear span-to-diameter ratio, and the thickness of the steel tube on the performance of strength, ductility, and energy dissipation of the proposed pier are discussed. The experimental results show that the strength of the proposed circular composite bridge pier can be predicted accurately by the similar method used in the reinforced concrete piers with minor modification. From these experimental studies, it is found that the proposed circular composite bridge pier not only simplifies the construction work greatly but also provides excellent ductility and energy dissipation capacity under seismic lateral force.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.364-371
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• 2000

The pseudo dynamic test has been carried out so as to investigate the seismic performance of RC bridge piers strengthened with and without glass fiber sheets. The Lessons from severe demage of many infrastructures in Kobe(1995) and Northridge(1996) earthquakes have emphasized the need to develop the retrofit measures to enhance flexural strength, ductility and shear strength of RC bridge piers nonseismically designed before 1992. Therefore, the objective of this experimental research is to investigate the seismic behavior of circular reinforced concrete bridge piers by the pseudo dynamic test. and then to enhance the ductility of concrete piers strengthening with glass fiber sheets in the plastic hinge region. 7 circular RC bridge piers were made in a 1/3.4 scale. Important test parameters are confinement steel ratio, retrofitting. load pattern, etc. The seismic behavior of circular concrete piers under artificial ground motions has been evaluated through strength and stiffness degradation, energy dissipation. It can be concluded that existing bridge piers wrapped with glass fibers in the plastic hinge regions could have enough seismic performance.

• 대한토목학회논문집
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• 제26권2A호
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• pp.339-349
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• 2006

이 연구는 원형 철근콘크리트 교각의 횡방향 철근에 따른 지진거동을 파악하고 합리적이면서 경제적인 내진설계기준의 개발을 위한 자료를 제공하는데 그 목적이 있다. 14개의 원형 철근콘크리트 교각에 일정 축하중 하에서 횡방향 반복하중을 가하는 준정적 실험을 수행하였다. 정확하고 올바른 성능평가를 위하여 신뢰성 있는 비선형 유한요소해석 프로그램을 사용하였다. 사용된 프로그램은 철근콘크리트 구조물의 해석을 위한 RCAHEST이다. 연계논문에서는 원형 철근콘크리트 교각의 횡방향 철근에 따른 내진성능평가를 위해 제안한 해석기법을 실험결과와 비교하여 그 타당성을 검증하였다.

• 한국공간구조학회논문집
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• 제7권2호
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• pp.91-96
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• 2007

최근, 복잡해진 도심지의 토지이용률을 향상시키기 위해 원형 강기둥 구조물의 건설이 점차 요구되고 있다. 원형강기둥 구조물은 유효단면적을 감소함과 동시에 내하력 증가 효과를 기대할 수 있다. 그러나 이러한 원형 강기둥 구조물은 지진 및 피로와 같은 반복하중 작용시 국부좌굴 및 대변형 현상이 발생하며 이로 인하여 대상구조물의 성능이 감소된다. 이러한 내하력 감소 현상을 방지하기 위해 최근 원형 강기둥에 환보강재(다이아프램)의 적용을 고려할 수 있다. 수직보강재의 적용으로 인한 좌굴내하력 및 내진성능의 증가효과는 이미 연구된 바 있으나 다이아프램에 관한 연구는 아직 전무한 실정이다. 단조 및 반복하중 작용시 국부좌굴 및 변형을 효과적으로 방지하기 위해서는 원형강교각에 적용된 다이아프램 설치위치가 중요한 역할을 한다. 그러나 설치위치의 변화에 따른 다이아프램의 내진성증 증가효과에 관해서는 아직 명확히 밝혀지지 않았다. 본 연구에서는 기하학적, 재료학적 비선형을 고려한 유한요소프로그램을 이용하여 탄소성해석을 수행하였다. 즉, 다이아프램 설치위치를 파라메타로하여 내진성능을 검토하였다. 본 연구에서는 각 해석모델의 내하력 및 에너지 소산효율을 비교함으로서 원형강교각에 적용된 다이아프램에 관한 내진성능을 명확히 하였다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.194-199
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• 2001

Lap splice in plastic hinge region is inevitable because of due to constructional joint between footing and column. R/C Circular columns with lap-splice in plastic hinge region are widely used in Korean highway bridges. In addition, these columns which constructed before the seismic design code have a number of structural deficiencies. It is, however, believed that there are not many experimental research works for nonlinear behavior of these columns subjected to earthquake motions. The object of this research is to evaluate the seismic performance of existing circular reinforced concrete bridge piers by the Quasi-static test. Existing reinforced concrete bridge piers were moderate seismically designed in accordance with the conventional provisions of Korea Highway Design Specification. This study has been performed to verify the effect of lap spliced longitudinal steel, confinement steel type and confinement steel ratio far the seismic behavior of reinforced concrete bridge piers. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility, energy absorption, strength degradation etc.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.369-374
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• 2000

This study was conducted to investigate the seismic behavior assessment of circlular-tied bridge piers, particularly with regard to assessing the displacement ductility. The experimental variables of bridge piers test consisted of transverse steel details, amount and spacing different axial load levels etc. The test results indicated that reinforcement concrete bridge piers with confinement steel by the code specification exhibited sufficient ductile behavior and seismic performance. Aldo, it is found that current seismic design code specification of confinement steel requirements may be revised.