Research On Dynamic Performance Of Prestressing Combined Box Girder With Corrugated Steel Webs

Externally prestressed box girder with corrugated steel webs is a new composite structure. This type of structure attracts wide attention as it has a great deal of advantages, such as light self-weight, excellent anti-seismic performance, high effective prestressing system, etc. The dynamic characteristics and performance of box girder with corrugated steel webs is researched by theoretical calculation, experimental study and finite element modelling. The main work is listed as follows:(1)Considering the effect of shear deformation and prestress improving section stiffness, the formula for natural frequency of externally prestressed box girder with corrugated steel webs is given. The availability of the formula is verified by an example. And then the influence of prestressing loss and concrete ages on the frequency of box girder with corrugated steel webs is studied.(2) At the prestress stretching stage, dynamic characteristics of three box girder models with corrugated steel webs are tested. The results indicate that the primary frequency of test beams improve with tensile stress of external tensions increasing. Compared with general beam theory and method of Miyamoto, the availability of given formula in this article is verified as the results calculated agree well with the test results.(3)Test models of rigid frame bridge with corrugated steel webs and concrete rigid frame bridge are designed and constructed. The longitudinal dynamic characteristics of test models with different piers are tested, theoretical calculated and finite element analyzed. The results show the primary longitudinal frequency of rigid frame bridge with corrugated steel webs is smaller than the one of concrete rigid frame bridge with the same piers. And rigidity ratio of beam-pier should be considered when calculating the primary frequency of rigid frame bridge.(4)The finite element model of a rigid frame bridge with corrugated steel webs is established. The effects of pier parameters on the dynamic characteristics and seismic response of rigid frame bridge are analyzed and the results show that compared to single-wall pier, the seismic response of superstructure with double-wall piers can be effectively reduced, but at the cost of increasing axial force at the bottom of piers; different constructional measures and double-wall pier distance have a significant impact on internal force of rigid frame bridge.