UHPC-NC superimposed bridge deck steel-concrete composite beam hogging moment area section checking calculation method

Abstract

The invention discloses a UHPC-NC superimposed bridge floor steel-concrete composite beam hogging moment region section checking calculation method. The method comprises the following steps: inputting the section structure size of each part of a steel-concrete composite beam; vertically layering the section of each part to form a fiber strip; determining the width of a fiber strip; determining a nonlinear stress-strain relationship of each component material; analyzing the stress state of each part in the bridge forming stage as a primary stress state, and assigning the state to the determined fiber section; taking the NC concrete layer out of work, redistributing the internal force to the remaining section part, and obtaining the stress of each fiber strip by adopting a strip stacking method; gradually loading the bending moment of secondary stress, wherein the strain increased in each loading step linearly changes in the height direction of the cross section; judging whether the stress on the cross section meets the stress requirement or not; and obtaining the stress and strain states of each fiber, and calculating the crack width of the bridge deck UHPC and NC concrete layers in the normal use limit state according to the obtained steel bar stress and the UHPC concrete material fiber strain in combination with a related specification formula.

Description

technical field [0001] The invention relates to the engineering and construction industry, in particular to a method for checking and calculating the cross-section of a steel-concrete composite beam with a UHPC-NC laminated bridge deck in a negative moment zone. Background technique [0002] Steel-concrete composite girder bridges are more and more widely used in bridge structures because of their light weight, small cross-sectional height, and strong bearing capacity. Due to the low tensile strength of NC ordinary concrete, the concrete bridge deck in the continuous steel concrete negative bending moment area is prone to cracking, resulting in reduced bearing capacity and durability of the bridge. The UHPC ultra-high-performance concrete layer has ultra-high tensile and compressive capabilities and better durability, and can be used in the negative moment area to improve the strength and durability of the composite beam structure. However, due to the high cost of UHPC at t...

AI Technical Summary

Problems solved by technology

[0005] Based on relevant literature retrieval, the current analysis and calculation software and related algorithms based on fiber cross-sections of beam-column bending moment curvature and bearing capacity only consider one loading iteration, and cannot consider the unique construction sequence calculation requirements of composite beams. After the primary force and bending moment are generated, the laminated girder deck is poured, and then the analysis and calculation of the section bearing capacity considering the secondary force is carried out

[0006] At present, the relevant bridge structure analysis and calculation software considers the secondary stress process of section forming in stages, but it cannot consider the nonlinear loading process of UHPC-NC laminated deck layered stress, and cannot directly obtain the NC ordinary concrete layer after it quits work. UHPC ultra-high performance concrete bridge deck, the section bearing capacity of bridge deck steel bars and steel box girder under the joint stress

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