Dynamical Behaviours Research Of Continuous Bridge With Variable Cross-section Box Girder Combined With The Corrugated Steel Webs

Since 1987, France built the first corrugated steel web girder bridge-bridge-Cognac, this new structure has been developed rapidly, and attracted many experts in the study of the structure. Currently, most of the national and international researchers mainly focus on the static behaviors of corrugated steel webs, such as the structure of corrugated steel belly bending, torsion, shear and stability. However, they have not done too many researches on the dynamic characteristics of the structure. Recently, With the extensive application of this corrugated steel web girder bridge in the country, and also the span of the bridge are more and more longer, the frequently earthquakes bring a lot of problems to bridges and other structures, the engineers need to understand the unknown dynamical behaviors of this new structure,and improve the mechanics research of this structure. Under the commission of the Projet of Transport Science of ShanDong (2005Y017) and the Projet of Transport Science of HuNan (200706),This report presents the dynamical behavior of the continuous box girder bridge with various cross-section combined with the corrugated steel webs.In order to present the research results, there are mainly two parts including in this report. Firstly, this article reviews the structure and mechanical characteristics of corrugated steel web girder bridge with various cross-section, deduces the natural bending equations of the general bridge structures, and also explains the theory and generally analysis methods about the dynamic characteristics of bridge.Secondly, in this research, to obtain the results of the bridge's dynamic behavior affected by changing the the bridge span, and transverse plates'number, thickness and location. it used a finite element program ANSYS and MIDAS to establish a spatial solid/shell and beam finite element model respectively, and studied dynamic properties of this structure, including the natural vibration frequency and mode, which was based on the model of two box girder bridge with various cross-section box girder combined with the corrugated steel webs designed in the country. In addition, considering the smaller span one which is in construction at the moment, the research establish a series of finite element model by changing the span of bridge, and the number, thickness, location of transverse plates to analysis the effect of the series of changes to the dynamic behavior of the bridge.Refer to the relevant regulation and guidelines, this report uses MIDAS Finite Element program to make an earthquake response spectrum and time history respectively to analysis the box girder bridge with various cross-section combined with the corrugated steel webs. It is also studied all kinds of mechanical performances of this new structure to resist Earthquake affect. Study found that such bridge in the earthquake, the beam mainly suffer vertical and horizontal bending deformation, and larger horizontal deformation and vertical the moment appear in the middle of bridge, the performances of the beam on bridge pier is more complex.