The method of using prestress to improve the integrity and durability of hollow slab frame bridge

Abstract

The invention discloses a method for improving the integrality and the durability of a hollow slab frame bridge by adopting prestressing force. The method comprises the following steps: top-slab longitudinal prestressing tendons are arranged at a positive bending region of a multi-hole or single-hole top slab of the hollow slab frame bridge in the traveling direction of the top slab, and bottom-slab longitudinal prestressing tendons are arranged at a positive bending region of a multi-hole or single-hole bottom slab of the hollow slab frame bridge in the traveling direction of the top slab; when the ratio of a transverse span to a longitudinal span is greater than 0.5, top-slab transverse prestressing tendons are transversely arranged on the top slab, the top-slab longitudinal prestressing tendons are arranged at midspan straightly, the top-slab longitudinal prestressing tendons are arranged at two bent ends, or two layers of top-slab longitudinal prestressing tendons are respectively arranged at the upper edge and the lower edge of the top slab, and the top-slab transverse prestressing tendons are arranged straightly. According to the method disclosed by the invention, on the basis of a conventional common hollow slab frame bridge made of reinforced concrete, the prestressing tendons are arranged on the top slab, the bottom slab and in side walls according to the distributing situation of force in the frame bridge, so that the defects that a conventional structure is poor in crack resistance, durability, integrality and the like are overcome.

Description

technical field [0001] The invention relates to the field of bridge engineering, in particular to a method for a hollow plate frame bridge which adopts prestress to improve integrity and durability. Background technique [0002] Frame bridge is a kind of overpass structure form of road and railway or road and road. This kind of frame bridge structure is mainly used in changing the level crossing of existing railways or highways into the form of underpassing overpasses, and most of them are constructed by jacking method. Jacking frame bridges have been put into use in my country for more than 50 years. This structure adopts reinforced concrete, which has high rigidity and convenient construction, so it is widely used. According to statistics, along with the requirements of railway speed-up in recent years, our country still needs to change original a large amount of level crossings into overpasses, and every year there are thousands of places where level crossings are chang...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the reinforced concrete hollow slab frame bridge along the span direction, which is easy to produce cracks and fatigue damage damage in the concrete tension area, avoid the corrosion caused by the rainwater penetration of the structural steel bars under the external action, improve the overall rigidity of the frame bridge, and resist Disadvantages such as poor fatigue

Images