기존 교량을 일체식 교대 교량과 같이 거동할 수 있도록 교대 흉벽과 상부슬래브를 일체화하는 흉 벽 일체식 교대 교량 공법에 관한 것으로, 교대 흉벽은 뒤채움 토사의 토압을 주요 하중으로 설계되기 때문에 배면부에는 휨보강 철근이 배치되지만 흉벽 일체화에 따른 흉벽 전면부에 온도팽창에 저항하 기에 부족한 철근량을 가지게 된다. 본 실험 연구는 일체화된 흉벽 구조체의 단차부 전면에 부착-정 착방식으로 제작된 FRP 보강체를 사용하여 휨 실험을 수행하고 이를 비교 분석하였다.

가설교량의 접속부 구간은 하부구조의 지지강성의 차이로 인해 부등침하가 발생할 가능성이 큰 취약구간이다. 부등침하로 인한 접속부의 단차 발생으로 노면소음, 접속슬래브 파손, 차량진동, 구조물의 충돌하중 발생 등의 문제점이 나타 나고 있으며 주기적으로 재포장을 실시하여 가설교량과 뒤채움부의 단차를 조정하고 있음을 확인하였다. 본 연구에서는 차량 우회용 가설교량의 현장 조사를 통한 분석한 결과 가설교량의 경우 뒤채움부가 폐합된 일반 교량과 달리 접속부 형상이 복잡하여 토사 유실로 인한 침하 가능성이 높고 뒤채움부 침하로 인한 접속부 단차가 발생하는 것을 확인하였다. 이에 가설교량 단부의 3차원 설계를 통해 가설교량의 특징을 고려한 뒤채움 침하 방지 방안을 연구하였다

In this study, the lap joint performance for SFRC beam with different depths was evaluated. The specimens had the lap splice details using the high-strength headed reinforcement. For the SFRC beam with different depths, the headed reinforcement which is overlapped more than 20 times of the rebar diameter has sufficient lap-splicing performance.

This paper focuses on the experimental study for investigating the performance for lap splice of hooked or headed reinforcement in beam with different depths. In the experiment, seven specimens, with its variables as the lap length of headed or hooked bar, the existence of stirrups, etc., was manufactured. Bending test was conducted. Lap strengths by test were compared with the theoretical model based on KCI2012. The result showed that the cracks at failure mode occurred along the axial direction to a headed bar. The initial stiffness and the stiffness after initial crack were similar for all specimens. For HS series specimens without stirrups, a 25% increase in lap length was increased 11.8~18.1% maximum strengths. For HH series specimens without stirrups, a increase in lap length did not affect the maximum strengths because of the pryout failure of headed bar. For HS series specimens, the theoretical lap strengths based on KCI2012 considering the B grade lap and the reduction factor for stirrup were evaluated. They are smaller than the test strengths and can ensure the safety in terms of strength capacity. For HH series specimens, the stirrups in the lap zone are needed to prevent the pryout behaviour of headed bar.

An experimental study was conducted to propose an improved joint in the beam with non-uniform depths of cross-sections. The tested joint detail consisted of headed bars and 180-degree hooked bars. The parameters are the splice length and the confinement effect of strrups in lap zone. The increase of lap length and the confinement detail of strrup reinforcement in the lap zone did not affect the initial stiffness. It can be concluded that the proposed joint detail would be applicable to practical design by using the load transfer mechanism by the effects of confinement details.

In this study, reinforced concrete flat plates with steps were analyzed to suggest stiffness modification factors for the effective beam width of flat plates with steps. The analysis revealed that the stiffness modification is related to the length, thickness, height and location of the step.