Analysis Of Spatial Property And Design Of Variation Of Thin-walled Curved Box Girder In Urban Bridge

With rapid developing of the high grade highway and the city orbit transportation in recent years, various kinds of curve beam bridge structure are already extensively adopted by our country. The concrete thin-walled curve box beam plays the important role, because it has the good whole space property and the good stability function, adapting various modern construction methods such as the incremental launching method and the erection by protrusion method. The foundation research work such as the pattern of destruction, the designed model of section, the shear-lag, the warping, and the distortion effects of the thin-walled curved box beam which is a kind of structure system have not yet been carried on systematically so far; adopting the model of mechanical analysis and the method of designed computation in design also lack of test.This text bases on the computer simulation theory, applying the account of large-sized software, choosing a spatial unit that has 8 nodes and 24 degree of freedom compose finite element model, adopting parameters to set up the mold of method, building up the thin-walled curved box beam entity space calculation model of the true size. By changing the parameter, we can imitate various thin-walled curved box beams.This text discusses the relationships of designed parameters and endogen force of freely supported thin-walled curved box beam, mainly analyzing effect of the curvature radius, the ratio of width to span, the ratio of height to width, the thickness of box, and the boundary condition. Resolution enunciates under the dead loading, the mainly influencing factors of the freely supported thin-walled curved box beam of single span are the ratio of width to span, the ratio of height to width, and the thickness of box. Endogen force of freely supported thin-walled curved box beam of single span is gradually increasing when the ratio of width to span of curved box girder; The moment of flexure, the moment of torsion and the shear force of freely supported thin-walled curved box beam of single span is gradually increasing when the ratio of width to span of curved box girder, yet the stress of beam section is gradually falling down; Endogen force of freely supported thin-walled curved box beam of single span is gradually increasing when the thickness of curved box girder.This text also discusses the relationships of designed parameters and endogen force of continuous thin-walled curved box beam which is a tow span, mainly analyzing effect of the curvature radius, the ratio of width to span, the ratio of height to width, the thickness of box, and the boundary condition. Resolution enunciates under the dead loading, the mainly influencing factors of the continuous thin-walled curved box beam of tow span are the ratio of width to span, the ratio of height to width, and the thickness of box. Endogen force of continuous thin-walled curved box beam of tow span is gradually increasing when the ratio of width to span of curved box girder; Endogen force of continuous thin-walled curved box beam of tow span is gradually increasing when the ratio of height to width of curved box girder. Endogen force of continuous thin-walled curved box beam of tow span is gradually increasing when the thickness of curved box girder.From analyzing two upward situations, we get the main designed parameters of curved box beam to effect extent and basic effect law of construction member's force., and giving out some conclusion and designed suggest.