A setting method for factory-made pre-camber of a large-span underpass type steel truss girder bridge

Abstract

The invention discloses a method for setting the factory-made pre-camber of a large-span underpass type steel truss girder bridge, and relates to the technical field of setting of the pre-camber of the large-span steel truss girder bridge. The method comprises the following steps of: preparing a substrate; SS01, arch camber of the underpass type steel truss girder is carried out; the actual lengths of the longitudinal beams and the lower chord members of the underpass type steel truss beam are kept unchanged; The purpose of arching is achieved by stretching the length of the upper chord, the intersection point of the inclined rods and the upper chord is still intersected with the center of an upper chord node, and the structure of the lower bearing type steel truss girder is shown as SS02when the pre-camber is not set: when the pre-camber is not set, the design lengths of the upper chord and the lower chord are consistent. According to the invention, a finite element method is adopted; The method comprises the following steps: calculating theoretical relative pre-camber as an input load parameter, deducing a telescopic formula of rod piece prefabrication blanking, compiling the calculation formula into a MATLAB program, and making a contrast table, so as to quickly and accurately obtain a line shape which is consistent with the theoretical pre-camber, namely obtain the factorypre-camber, thereby guiding the prefabrication of the rod piece.

Description

technical field [0001] The invention belongs to the technical field of pre-camber setting of long-span steel truss girder bridges, and in particular relates to a factory-made pre-camber setting method for large-span under-supported steel truss girder bridges. Background technique [0002] The design of long-span railway steel truss bridges is a complicated process. In order to make the trains pass the bridge smoothly, passengers are comfortable, and improve the running quality of the line. The upper camber of the span structure should be pre-set to offset the deflection of the dead load and half of the live load on the bridge. [0003] The structure of long-span continuous steel truss girders is complex, especially after the integral joint technology is adopted, the setting of pre-camber directly affects the shape of the structural system, and has a great influence on the design of joints and the length of members. Properly, it will not only affect the use function of the b...

AI Technical Summary

Problems solved by technology

Therefore, the complex problem of factory-made pre-camber setting for long-span under-supported steel truss girder bridges is solved

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