• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.135-140
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• 2001

A post-tensioned reinforced concrete slab bridge is analyzed by specially orthotropic laminate theory. Symmetrically reinforced slab with tension and compression steel is considered for convenience of analysis. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of the rule of mixture. This bridge is under uniformly distributed vertical loads, and axial loads and end moments due to post-tensioning. In this paper, finite difference method is used for numerical analysis of this bridge. Theory and analysis method of specially orthotropic laminate plates used in this paper can be used for design of new bridges, and maintenance and repair of old bridges.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.141-146
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• 2001

A post-tensioned steel plate girder bridge with cross-beams is analyzed by specially orthotropic laminate theory. The cross-sections of both girders and cross-beams are WF types. The result is compared with that of the beam theory. This bridge with simple support is under uniformly distributed vertical load, and axial loads and moment due to post-tension. In this paper, finite difference method for numerical analysis of simple supported bridge is developed. Relatively exact solution is obtained even with small number of meshes. Theory and analysis method of specially orthotropic laminate plates used in this paper can be used in design of new bridges, and maintenance and repair of old bridges.

• 한국구조물진단유지관리공학회 논문집
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• 제3권4호
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• pp.205-214
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• 1999

구조물의 동특성(고유진동수, 감쇠, 모드형상 등)의 변화는 구조물의 안전도를 평가할 수 있는 한 방법이다. 본 연구에서 콘크리트 세그먼트의 웨브 부분에 상당히 많은 균열이 진전되고 있는 상태의 Post-Tensioned Segmental 콘크리트 교량의 안전도 평가를 시도하였다. 안전도 평가를 위한 근간 데이터로 1986년 측정했던 데이터와 2차원 유한요소해석에서 얻은 결과값을 사용했다. 손상의 정도와 손상의 위치를 보다 정확히 찾아내기 위한 기술 중의 한 방법으로 Modal Test를 이용하였다. 이 방법이 Post-Tensioned Segmental 콘크리트 교량에 적용되어 교량의 안전도를 분석 평가하였다.

• 복합신소재구조학회 논문집
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• 제1권4호
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• pp.13-17
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• 2010

A post-tensioned slab bridge is analyzed by the specially orthotropic theory. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This slab bridge with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and the beam theory are used for analysis. The result of beam analysis is modified to obtain the solution of the plate analysis. The result of this paper can be used for post-tensioned slab bridge analysis by the engineers with undergraduate study in near future.

• 한국지진공학회논문집
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• 제20권3호
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• pp.135-143
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• 2016

In this paper, a design concept of post-tensioned precast bridge piers was proposed to improve seismic behavior of the bridge pier. Mild reinforcing bars are placed continuously along the height of the column. Prestressing tendons are also provided to obtain re-centering capability for seismic events. Arrangement of the axial steels to prevent buckling of rebars at plastic hinge region was suggested and enhanced seismic performance was verified by experiments. Moment-curvature analyses were performed to evaluate the effect of effective prestress on seismic behavior after verifying the calculation method by cyclic tests of the precast columns. A real bridge pier was designed to investigate the seismic performance according to different level of effective prestress. Level of effective prestress showed obvious effect on crushing displacement but negligible effect on lateral displacement at fracture of tendons and reinforcements.

• 한국강구조학회 논문집
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• 제14권1호
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• pp.105-111
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• 2002

포스트텐션된 슬래브 교량은 특별직교이방성 복합적층판 이론으로 해석할 수 있다. 슬래브 교량의 해석에 있어 단면의 기하학적, 물리적 특성이 중립축을 중심으로 휨-연계 강성 $B_{ij}=0$ 이고, $D_{16}=D_{26}=0$ 임을 고려해야 한다. 각각의 횡방향철근과 수직방향철근은 하나의 lamina로 간주하고, 재료상수는 각각의 lamina의 혼합법칙에 의해서 계산되어진다. 단순지지된 슬래브 교량은 등분포하중과 축하중을 받고 있다. 본 논문에서는 유한차분법과 보 이론에 의해서 해석하였다. 그 결과 보 이론에 의한 해석 값이 판 이론에 의한 해석 값에 근접함을 알 수 있었다. 본 논문에서 얻은 연구 결과를 이용하여 가까운 장래에 학부정도의 실력을 가진 기술자가 포스트텐션된 슬래브 교량의 해석에 있어서 유용하게 사용 할 수 있다.

• Structural Engineering and Mechanics
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• 제43권4호
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• pp.459-473
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• 2012

Post-tensioned concrete voided slab girders are widely used in highway bridge constructions. To obtain greater section hollow rate and reduce the self-weight, the plate thickness of slab girders are designed to be small with the adoption of flat anchorage system. Since large prestress is applied to the anchor end section, it was found that longitudinal shear cracks are easy to occur along the voided slab girder. The reason is the existence of great shearing effect at the junction area between web and bottom (top) plate in the anchor end section. This paper focuses on the longitudinal anti-cracking problem at the anchor end of post-tensioned concrete voided slab girders. Two possible models for longitudinal anticracking analysis are proposed. Differential element analysis method is adopted to derive the solving formula of the critical cracking state, and then the practical analysis method for longitudinal anti-cracking is established. The influence of some factors on the longitudinal anti-cracking ability is studied. Results show that the section dimensions (thickness of bottom, web and top plate) and prestress eccentricity on web plate are the main factors that influence the anti-cracking ability. Moreover, the proposed method is applied into three engineering examples to make longitudinal anti-cracking verification for the girders. According to the verification results, the design improvements for these girders are determined.

• Structural Engineering and Mechanics
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• 제42권1호
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• pp.25-38
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• 2012

Recently, investigated failures of external post-tensioned (PT) tendons have called attention to the corrosion of strands in PT bridges, and the prevention of ongoing corrosion is required to secure their structural integrity. Since voids inside ducts can be a source for the ingress of water or deleterious chemicals, the vacuum grouting (VG) method and a volumeter for estimating amount of repair grouts were employed to fill voided ducts. However, the VG method is expensive and time-consuming for infield application because it requires an air-tight condition of entire ducts. Thus, latest research assessed three different repair grouting methods, and the pressure vacuum grouting (PVG) method was recommended in the field because it showed good filling capability in voided ducts and did not require an air-tight condition. Thus, a new method is required to estimate the volume of repair grouts because the PVG method is not applied in air-tight ducts. This research assesses the relationship between voided areas on ducts identified with soundings and required grout volume for repair using experimental results. The results show that the proposed equations and assumptions for estimating repair grout volume provide a sufficient amount of repair grouts for filling voided ducts.

• 한국산학기술학회논문지
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• 제15권11호
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• pp.6898-6905
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• 2014

스트레스 리본 교량(Stress Ribbon Bridge)이란 두께가 얇은 상부구조(바닥판)가 특정한 현수 형태(catenary type)로 유지되고 긴장된 바닥판 (Post-tensioned deck)이 하중에 의해 역 아치(Reverse arch) 거동을 보이는 PSC 구조물이다. 현재 스트레스 리본 교량의 경우 국외에서 자연파괴를 최소화 하고 아름다운 구조로 인식되어 차도교, 보도교 등에 활발하게 이용되고 있으나 국내에서는 이와 관련된 연구가 매우 미흡한 실정이다. 본 연구에서 시공단계가 고려된 스트레스 리본교량의 비선형, 시간의존적 해석이 고려된 모델을 정립하는데 목표가 있다. 정립된 모델을 이용하여 시공단계에 따른 단면력을 이론에 의한 수치와 비교하여 그 타당성을 입증하였으며, 시공단계에 따른 교량의 거동을 분석하였다.

• 대한토목학회논문집
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• 제29권6A호
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• pp.587-596
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• 2009

본 연구는 외부 후 긴장력 횡분배 거동을 연구하고 일부 거더 외부 후 긴장만 으로 공용중인 강합성형교 보강 가능성을 평가하기 위한 연구이다. 실험 및 해석적 연구로부터 부분 거더 긴장만으로도 강합성형교 보강이 가능한 것으로 나타났으며, 브레이싱에 의하여 긴장력 횡분배 거동이 개선되는 것으로 평가되었다. 강성비, 거더 간격, 경간장의 영향을 받는 긴장력 횡분배 거동은 교량 형태 및 긴장되는 거더 위치에 의해 변화하는 것으로 분석되었으며, 외부 후 긴장력 횡분배 거동을 예측하는 제안식을 도출하여 합리성을 평가 하였다.