Box girder shear lag effect analysis method and box girder structure

Abstract

The invention belongs to the technical field of bridge construction control and discloses a box girder shear lag effect analysis method. An identification module, an acquisition module and a processing module are included. The identification module is used for identifying the shape and size of a cross section of a box girder, and the identification module mainly acquires data of four areas throughthe acquisition module. A section identification module collects data of the four areas and then uploads the data to the processing module. The processing module is mainly used for a reasonable shearlag warping displacement mode, the mutual coupling between vertical displacement and shear lag displacement is considered, two shear lag freedom degrees are adopted in each section of the box girder,and the adaption to different shear lag displacement boundary conditions can be achieved. According to the analysis method provided by the invention, the shear lag phenomenon is analyzed after the influence of the dead weight of the box girder on the shear stress distribution on the cross section is eliminated, a dangerous working condition of the box girder structure under a construction load ora use load is scientifically analyzed, and the box girder structure applicable to the analysis method is provided.

Description

technical field [0001] The invention belongs to the technical field of bridge construction control, and specifically relates to a box girder shear lag effect analysis method and a box girder structure. Background technique [0002] The shear lag effect is a ubiquitous mechanical phenomenon in structural engineering, as small as a component, as large as a super high-rise building, there will be a shear lag phenomenon. Shear lag, sometimes called shear lag, is essentially St. Venant's principle in terms of mechanics, which strictly conforms to the three major equations of elastic mechanics, namely, geometric equations, physical equations, and equilibrium equations. The specific manifestation is that in a certain local range, the shear force can play a limited role, so the distribution of normal stress is uneven, and this phenomenon of uneven distribution of normal stress is called shear hysteresis. [0003] The shear lag effect usually appears in T-shaped, I-shaped and closed...

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Problems solved by technology

[0006] For box girders, due to the concentrated bending moment of the main beam (cable anchor point eccentricity and prestressed anchorage eccentricity), the shear lag displacement boundary condition mutation problem occurs, and the load and shear lag displacement boundary conditions are constantly changing during the dynamic construction process. None of the above methods can completely solve the problem of changing

Since the existing technology is limited to simple structural analysis under a single working condition, it cannot solve the construction error problem caused by the shear lag effect in the dynamic process of cable-stayed bridge construction

[0007] In addition, the previous test methods did not eliminate the influence of the self-weight of the box girder on the distribution of shear stress on the section, which interfered with the understanding of the phenomenon of shear lag

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