Analysis Of Moment Magnification Factor For Reinforced Concrete Rib Arch

Arch bridge, with extremely high aesthetic value, acting as one of the fundamental bridge types, is widely applied in engineering. In recent years, the effect of geometry and material non-linear has been considered in the design of long-span arch bridge to gain the accurate internal force. Nevertheless, for the design of mid-span and small-span arch bridge, the internal force is gained through moment magnification factor, which multiply the results from the elastic theory, to consider the effect of arch rib deformation on it. In design codes, moment magnification factor can't reflect the characteristic and mechanic of arch, so the internal force of arch can't be accurately analyzed. In order to get the more precise calculation of the internal force of the arch, this dissertation made a special analysis of reinforced concrete arch bridge and studied the moment magnification factor of arch according to its own characteristics.Firstly, this thesis introduced the characteristics of reinforced concrete arch bridge and the concept of moment magnification factor, as well as its recent research. Secondly, the calculation theory of arch was discussed, including stability, arch deflection theory and the geometric nonlinear analysis. Thirdly, the calculation of moment magnification factor in design code was discussed. Finally, using the finite element software MIDAS to analyze the internal force of reinforced concrete arch bridge with span of 60m, 70m and 80m to achieve theoretical values of moment magnification factor, and then compared them with the moment magnification factor from the old and the new Chinese highway bridge design code.