The Study Of Mechanical Properties Of Wide Curved Box Girder Bridge

The curved girder bridge is one of the most important bridge forms in model road traffic system. With the rapid development of expressway and urban road in recent years, and considering the limit of geographic and geomorphic, road alignment consistency, urban landscaping,etc. at the same time, more and more curved bridges have been used in our country. Due to the factor resulted from bending-torsion coupling, make curved bridges analysis quite complicated. Compared to the finite precision of traditional grillage method, by applying 3-D finite element method to the calculation of wide curved box grider bridges is not convenient currently. Therefore, analysis method with reasonable precision and ease of use for wide curved box grider bridges still need further research. In addition, with the extensive use of wide curved bridges in civil engineering, large number of various diseases have been appeared, so the further research about catastrophic failures of wide curved box grider bridges, mechanical mechanism and influencing factors of diseases become essential.Based on the principles of grillage method, finite element analysis method and orthotropic plate simulation method, according to the characteristics of the wide curved box girder cross section, a simple practical modified method with reasonable precision brought forth, which is called simulated plate-grillage method.generalizing rules of grillage meshing and sectional characteristic of this method is presented.Simulated the actual project, building the traditional grillage model, simulated plate-grillage model and accurate soild element model of the wide curved box girder bridge with the help of finite element software:MIDAS/CIVIL and ANSYS. Under different load, studied the spatial forces, the lateral transfer mechanism of internal forces of wide curved box girder.Made a three-span continuous wide curved box girder model by using plexiglass. With the model static load test, measured the strain and deflection of the control cross-sections of curved girder, and we proposed the "uniformity coefficient" to express the uneven force of the curved bridge. Compared the finite element analysis results and experimental data, verified the accuracy and practicality of simulated plate-grillage method, meanwhile got the distribution about the stress and deflection of the wide curved continuous box girder.Relied on the first page wide curved box girder bridge of the A ramp of Junshan interchange bridge of the Dayue Expressway in Hunan Province, applying simulated plate-grillage finite element method to study the in-plane deformation behavior of concrete continuous wide curved box girder. According to mechanics characteristics of the bridge, studied the diseases may caused by the deformation of girder, and provide references for the design and construction in civil engineering.