Mechanical Calculation and Rational Structural System of Hybrid Beam Rigid Frame Bridge

Abstract:

On the basis of traditional concrete rigid frame bridge， the hybrid beam rigid frame bridge formed by replacing a part of the main span with steel beam has effectively achieved a breakthrough in the span of the beam bridge and an improvement in structural performance. So， it has become a very promising bridge structure and has been more and more widely applied in actual engineering. In order to explore the reasonable arrangement and simplified calculation method of the mechanical performance of the three-span steel-concrete hybrid beam rigid frame bridge structure system， the simplified mechanical model during construction and completion was derived. The calculation precision of the model was verified by the finite element models and testing results of an actual project. Based on the model， taking the internal forces of the control sections as the objective functions， the effects of λ （the ratio of side-span and mid-span） and μ （the ratio of the steel beam length and main span length or the position parameter of the steel-concrete composite segment ） on the mechanical performance of the hybrid beam rigid frame bridge were calculated and analyzed. The research results show that based on the reasonable mechanical performance of the structure， the reasonable value range of λ and μ is obtained. Considering the risk in the construction and operation of the bridge， it is suggested that λ takes 0.4 and μ takes 0.4 ~ 0.5， which can be used as the design reference of the hybrid beam rigid frame bridge.