Catenary type variable height steel truss beam and its construction method

Abstract

The invention discloses a catenary variable-height steel truss beam, which relates to the technical field of steel truss girder structures, including a horizontal chord, a catenary chord and a plurality of vertical bars, one end of the catenary chord is connected to the horizontal chord, The other end is connected with the main tower of the bridge to form a catenary structure. Multiple vertical rods are arranged between the catenary chord and the horizontal chord, from the connecting end of the horizontal chord and the catenary chord to the catenary chord and the main tower The length of the vertical bar increases successively, and the two ends of the vertical bar are respectively connected to the catenary chord and the horizontal chord through at least one hinged structure. The invention also discloses a construction method of the catenary variable-height steel truss girder. The invention can eliminate the bending moment effect on the vertical bar and reduce the cross-sectional area of ​​the vertical bar.

Description

technical field [0001] The invention relates to the technical field of steel truss girder structures, in particular to a catenary variable-height steel truss girder and a construction method thereof. Background technique [0002] In roads, railways, construction and other fields, a large number of steel truss structures are used. The steel truss members are thin and long, usually mainly bear the axial force, and have poor bending resistance. In the structural design, the steel truss members need to avoid large bending moments. [0003] However, in the catenary variable-height steel truss girder, the catenary chord and the horizontal chord will be gradually tangent or intersected. The chain chord and the horizontal chord tend to be tangent or intersecting and gradually become shorter. Since the catenary chord is a curve, under the load of the horizontal chord, each vertical bar will deform, causing the two ends of the vertical bar to be subjected to bending moments. , the c...

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Problems solved by technology

However, as the thickness of the steel plate of the vertical bar increases, the cross-sectional area and moment of inertia of the vertical bar also increase. Although the section resistance is improved, the linear stiffness of the vertical bar will further increase with the increase of the moment of inertia, that is, increase The thickness of the vertical bar steel plate has very limited improvement on the stress at the end of the vertical bar. In practical applications, it is often necessary to increase the thickness of the vertical bar steel plate to 4 or 5 times the cross-sectional area of ​​the original vertical bar to meet the requirements.

In addition, excessive plate thickness will make welding and installation more difficult, and it will also increase the amount of steel and increase the project cost.

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