Box girder bridge section design optimization method

Abstract

The invention discloses a box girder bridge section design optimization method. According to the method, the effects of factors such as box girder shear lag and shear deformation effect are considered; firstly, deformation potential energy and kinetic energy of a box girder are determined, so that a structural dynamic control differential equation and a natural boundary condition are obtained by the hamilton principle. Secondly, a related application program is compiled based on this; and a fine analysis on dynamic characteristics of the box girder bridge is expanded by Matlab software. Finally, with an inherent frequency value of the box girder bridge as a criterion, namely the inherent frequency value is large, the structure deformation potential energy is small, the section size of the box girder bridge is optimal, and the effectiveness of the box girder bridge section design optimization method is further proved by a statics analysis, so that the structure is in a good mechanical state due to the optimized box girder section; avoiding of bad diseases such as girder box cracking, stiffness reduction and local buckling is facilitated; and the box girder bridge section design optimization method is clear in mechanical concept and simple in calculation, has good application value, and is a beneficial supplement to an existing box girder bridge design theory.

Description

technical field [0001] The invention relates to a method for optimizing the section design of a box girder bridge, which belongs to the technical field of bridge construction. Background technique [0002] The box section has good structural properties such as bending resistance and torsion resistance, so it is widely used in bridge engineering. section. However, affected by factors such as the shear lag effect, the stress of this type of structure is very complicated, which brings great difficulties to the mechanical analysis of box girder bridges. Due to the unremitting efforts of domestic and foreign scholars, the mechanical analysis of this type of structure is becoming more and more perfect. Many research results have been partially applied to the design of box girder bridges. However, the design theory of box girder bridges is far from mature, and the diseases of this type of bridges in operation are still serious. [0003] In recent years, due to the excessive defl...

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Problems solved by technology

[0004] At present, box girder bridges are more widely used in high-speed railways, highways and urban overpasses in China. Especially due to the limitations of mechanical analysis of box girder bridges, many defects in current design theory and technology have been derived, resulting in box girder bridges. Many potential safety hazards of girder bridges, thus endangering the safety and durability of bridge structures

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