Optimization method of position of steel-concrete combined section of large-span cable-stayed bridge based on fatigue service life assessment

Abstract

The invention relates to optimization of the position of a steel-concrete combined section of a large-span cable-stayed bridge. The section bending moment of the steel-concrete combined section of thelarge-span cable-stayed bridge, the fatigue service life of a shear connecting piece of the steel-concrete combined section, the pier additional bending moment of the steel-concrete combined sectionin the construction state and the steel beam manufacturing cost are selected as four targets, the position of the steel-concrete combined section serves as a decision variable, and a multi-target function of the optimized position of the steel-concrete combined section is established; the multi-target function is solved through a genetic algorithm, and the optimized position of the steel-concretecombined section is obtained. Compared with the prior art, the optimization method of the steel-concrete combined section of the large-span cable-stayed bridge is disclosed from the perspective of structure fatigue damage, and the hidden hazard that the shear connecting piece of the steel-concrete combined section of the large-span cable-stayed bridge generates fatigue damage is eliminated.

Description

technical field [0001] The invention belongs to the technical field of civil engineering, and in particular relates to the optimization of the position of the steel-concrete joint section of the main girder of a long-span cable-stayed bridge. Background technique [0002] Cable-stayed bridge is one of the main types of long-span bridges. In order to improve the spanning capacity of the cable-stayed bridge, the mid-span of the cable-stayed bridge often adopts a light-weight and high-strength steel structure deck girder, and the side span adopts a concrete beam with high structural self-weight and rigidity, and good ballast and anchoring effects. The stiffness of the bridge deck beam junction of two different materials varies greatly, and local stress concentration is a key part of bridge design. In the overall design of the bridge, determining the reasonable position of the steel-concrete junction is a key problem to be solved. [0003] In the prior art, when determining the...

AI Technical Summary

Problems solved by technology

However, the stress on the steel-concrete joint section of the cable-stayed bridge is complex, especially the stress concentration at the shear joints of the steel-concrete joint section. Under the action of dynamic load during the operation period, the shear joints of the steel-concrete joint section inevitably have fatigue life problems.

When determining the position of the steel-concrete joint section, if only the influence of static load is considered, and the fatigue life of the shear connector is ignored, there will inevitably be safety hazards in the design, which is the deficiency of the existing technology

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