Prestress lengthening device and prestress lengthening method

Abstract

The invention discloses a prestress lengthening device and a prestress lengthening method, and relates to the technical field of bridge construction, the lengthening device is arranged in an area withthe minimum hogging moment of a continuous beam bridge, the two sides of the lengthening device are a first area and a second area respectively, and the lengthening device comprises a plurality of first prestress ribs and second prestress ribs; bridge decks which are connected in sequence, at least one first prestressed rib is anchored on one side, far away from the first area, of each bridge deck, and at least one second prestressed rib is anchored on one side, far away from the second area, of each bridge deck; meanwhile, the first prestressed tendons are arranged on the first area and thebridge deck slab in a penetrating mode, the ends, on the bridge deck slab, of the first prestressed tendons are first tensioning ends, and the other ends of the first prestressed tendons are first anchoring ends; the second prestressed tendons are arranged on the bridge deck slab and the second area in a penetrating mode, one ends of the second prestressed tendons on the bridge deck slab are second anchoring ends, and the other ends of the second prestressed tendons are second tensioning ends. Anchoring points and tensioning points can be arranged in a segmented and scattered mode, the purposeof lengthening prestress is achieved, and meanwhile the requirement for the thickness of the bridge deck slab is lowered.

Description

technical field [0001] The application relates to the technical field of bridge construction, in particular to a prestressed extension device and an extension method. Background technique [0002] In the span-by-span construction of concrete continuous beams, the prestressed tendons are usually tensioned at both ends of the first span, and single-end tensioned at the other spans. Traditional steel truss-concrete composite beams and steel box-concrete composite beams are only set in the negative moment area. Longitudinal prestress, the positive bending moment area does not set longitudinal prestress, and the negative bending moment area with prestress often sets sawtooth blocks. [0003] Among them, longer prestressed tendons are usually extended by using extenders. When the longitudinal prestressed tendons set in the negative moment area need to be lengthened and stretched, generally prestressed extenders are used on bridge decks that meet the thickness requirements for len...

AI Technical Summary

Problems solved by technology

The installation of prestressed extenders also requires a wide notch on the longitudinal bridge side of the bridge deck, and the steel bars in the transverse bridge direction need to be disconnected, which will affect the force on the bridge deck, and too many sawtooth blocks will not cause problems. It is beneficial to the prefabrication of the bridge deck and affects the structural beauty

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