Analysis On The Static Characteristics Of Irregular Shaped Prestressed Concrete Bridge

With the rapid development of urban transport services and construction, especially in thecase of the growing development of traffic, a large number of overpasses and planar crossbridges are constructed, so there are a lot of plane irregular shaped bridges. At the connection ofthe main bridge leading to the ramp or the main branch line, variable slope, curvature, andwidth of the bifurcation link segments of viaducts and overpasses are usually set, which iscalled irregular shaped bridge structure. The irregular shaped bridge structure connecting themain line and branch line, not only reduces the impact of traffic on the ground, but meet therequirements of changing lines of the vehicle, which makes a smooth linear bridge structure.Though a large number of such projects have been constructed, computing theory and designmethod lags behind. So the study of irregular box girder bridge is very necessary.Relying on the practical engineering, finite element analysis software ANSYS and MIDASis applied to model and calculate the support project; the main contents are as follows:1. Based on the basic principles of finite element simulation method of the bridge structure,the problems of using ANSYS to establish the solid model, mesh, and constraint are analyzed.What’s more, grid division, stiffness values and other issues in the MIDAS established the boxbeam grillage model is discussed.2. The deformation, internal forces and support forces under weight and car load arecalculated in detail of the support projects and the results are analyzed, so as to discuss thespace effects of the support projects under weight and car loads and summarize its forcecharacteristics.3. Relying on the force properties under its own weight, the impacts of changing its beamstiffness, bending stiffness of the main beam and the main beam torsional stiffness on the webs,beams and support forces are analyzed, in order to provide some reference for the design ofsuch alien girder bridge. 4. The midspan deflection, beam bottom stress and moments of the first cross in the beamgrid model with those in the single-beam model is compared to obtain the partial loadcoefficients of each box girder web. And the conventional partial load factor of1.15is analyzedon the applicability into the webs of this type of bridge.5. According to the space solid model established by ANSYS, the normal stressdistribution plates of the first cross L/4roof, midspan roof and3L/4roof are obtained. Throughcomparison of the three cross-sectional normal stress distribution maps, the distribution laws ofshear lag in irregular shaped girder bridge are summed up. And by comparison of the normalstress distribution of the first cross midspan roof with the conventional straight box beammidspan roof, the differences of the lag shear in irregular shaped box girder bridge withconventional straight bridge are summarized.