Strengthening Design Using Rating Factor Considering Increment of Tendon Force for Two-Span Steel-concrete Composite Bridges Strengthened by Straight External Tendons
본 논문에서는 2경간 강합성교량의 내하력을 향상시키기 위해, 외부 긴장재로 보강하는 방법을 제시하였다. 긴장재를 직선 배치하였을 경우, 외부하중으로 인한 증가 프리스트레스력을 가상일의 원리로 구하였고, 증가 프리스트레스를 고려한 내하율 산정식을 제시하였다. 제안된 내하율 산정식으로부터, 긴장재 개수와 초기 긴장력의 계산방법을 제시하였다. 본 방법을 2경간 강합성교량에 적용하여, 산정식의 타당성과 합리성을 검증하였다.
In this paper, a method of increasing in load-carrying capacity is shown in two-span steel-concrete composite bridges strengthened by external tendons. An analytic expression for the increment of tendon force under external loads is derived using virtual work method for straight external tendons and a new rating factor equation is proposed. Considering the initial tendon force and its increment under external loads, an analytic procedure has been developed to calculate the number of tendons and the initial tendon force from the proposed rating factor equation. This method is used to verify a validity and rationality for an existing two-span composite steel-concrete bridge.