Analysis of Support Reactions of RC Slab Bridges with Various Skews

Mha, Ho-Seong; Won, Jeong-Hun; Park, Inn Joon

Journal of the Korean Society of Hazard Mitigation 2012;12(3):17-22.
Published online June 30, 2012.

사각에 따른 RC슬래브교의 반력특성 분석

마호성, 원정훈, 박인준

Analysis of Support Reactions of RC Slab Bridges with Various Skews

Ho-Seong Mha, Jeong-Hun Won, Inn Joon Park

Abstract

The support reactions of two-span RC slab bridges with various skews are studied through the time history analysis for moving vehicles. Dynamic behaviors of bridges are evaluated by using the commercial FEM code and the bridge is modelled using shell elements. The analysis method is verified by comparing measured values and analysis results. Parametric analysis are performed for various skew angles. The bearing below the end slab with an obtuse angle shows the largest reaction forces. As the skew angle is reduced(a skew angle of $90^{circ}$ means a straight bridge without skew in this study), the distribution of reaction force is growing uneven and the largest reaction force is increased. In case of the model having skew angles under $70^{circ}$, the bearing located near the bearing with the largest reaction force shows the uplift force. Thus, it is concluded that the bearing in RC slab bridges with skew should be selected carefully by considering the variation of reaction force and uplift force.

Key Words: RC slab bridges; Moving vehicles; Skew; Reaction force

요지

본 연구에서는 2경간 연속 RC 슬래브교를 대상으로 차량 이동하중 시간이력해석을 수행하여 사각에 따른 받침의 반력분포 특성을 분석하였다. 계측값과 해석값의 비교를 통해 적용 시간이력해석방법을 검증하였으며, 사각을 매개변수로 판 해석을 수행한 결과, 둔각부 최외측 받침에 반력이 집중되며, 사각이 감소함에 따라(사교의 정도가 커질수록) 반력의 편차가 커져 둔각부에 반력의 크기가 증가하는 것으로 나타났다. 또한, 반력이 집중된 최외측 받침의 인접 받침에서는 사각 $70^{circ}$ 이하에서 부반력이 발생하는 것으로 분석되었다. 따라서 사각을 갖는 RC 슬래브교에서는 받침의 용량 산정 시 반력의 편차와 부반력 발생에 유의하여야 한다고 판단된다.

핵심용어: RC 슬래브교; 이동하중; 사각; 반력