Steel-concrete composite structure continuous box girder and manufacturing method thereof

Abstract

The invention discloses a steel-concrete combined structure continuous box girder and a manufacturing method thereof, belonging to the technical field of bridge structures. The positive bending moment area still uses flat steel webs, but in the negative bending moment area of ​​the middle fulcrum, corrugated steel webs are used instead of conventional flat steel webs, and embedded PBL shear connectors are used to connect the corrugated steel webs to the concrete roof, and The elastic material is filled between the crest section and the outer side of the trough section of the corrugated steel web and the concrete contact surface to form a reserved deformation buffer area. Once the prestress is applied in the negative bending moment area, due to the small longitudinal stiffness of the corrugated steel web, it is easy to produce compression deformation under pressure, and at the same time, the elastic material allows the corrugated steel web to produce lateral expansion deformation. By virtue of the combination of the above two factors, the prestress can be effectively applied in the concrete roof, effectively improving the efficiency of prestress application. The composite structure effectively alleviates the possibility of concrete cracking in the negative moment area and improves the safety and durability of the bridge.

Description

technical field [0001] The invention belongs to the technical field of bridge structures, and in particular relates to a steel-concrete composite structure continuous box girder and a manufacturing method thereof. Background technique [0002] The steel-concrete composite structure simply supported beam takes advantage of the compressive strength of concrete, and replaces the concrete in the mid-span tension zone with a steel structure, which effectively avoids the cracking of the lower concrete. However, the main girder in the negative moment zone of the steel-concrete composite continuous girder bridge is in an unfavorable stress state where the steel girder is under compression and the concrete bridge deck is under tension. The bridge deck concrete bears a large tensile stress and is prone to cracking, which leads to a decrease in structural stiffness. At the same time, the steel beams in the compression area also have stability problems. Therefore, in practical engineer...

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Problems solved by technology

However, the prestress applied to the roof concrete in the negative moment area increases the shear stress at the junction of the concrete and the steel beam, and since the elastic modulus of the flat steel web is greater than the concrete elastic modulus, the prestress applied in the negative moment area is large Part of it is consumed on the steel web and steel flange, and the actual effective precompression stress applied to the roof concrete is very limited, which greatly affects the crack resistance of the concrete roof

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