Reinforcement method for pre-stress continuous beam base plate cracks

A technology of prestressing and bottom plate, applied in the direction of bridge reinforcement, bridge, bridge maintenance, etc., can solve the problems of negative, prestressed continuous beam bottom plate cracking, etc., achieve the effect of clever idea, reduce the difficulty of reinforcement construction and construction cost

Active Publication Date: 2013-07-24
CHINA RAILWAY FIRST SURVEY & DESIGN INST GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of this invention is to provide a method for strengthening the cracking of the bottom plate of prestressed continuous beams, which overcomes the existing methods that only make a fuss about reinforcement and gives the existing beams Technical problems that bring many negative effects

Method used

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  • Reinforcement method for pre-stress continuous beam base plate cracks
  • Reinforcement method for pre-stress continuous beam base plate cracks
  • Reinforcement method for pre-stress continuous beam base plate cracks

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Embodiment

[0025] After the prestressed concrete continuous beam of a passenger dedicated line was prestressed and grouted, a large area of ​​cracking occurred at the bottom of the middle hole beam. The bridge hole span layout adopts (30.15+48+56+48+30.15)m continuous box girder, the top width of the box girder is 12.0m, and the bottom width is 6.7m. The bottom plate is cracked, falling off, and there are many cracks, the width of the crack is 1mm~2mm, and the width of the crack is about 50mm at the place where the concrete falls off; the bottom plate is cracked and delaminated, and the steel mesh of the bottom plate sinks up to about 14.7cm; there are many voids under the protective layer on the top surface of the bottom plate , the steel mesh sinks, and when viewed from the inside of the box, the bottom plate cracks and delaminates from the longitudinal prestressed bellows.

[0026] After a comprehensive analysis of the reasons for the cracking, after analyzing and comparing the advant...

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Abstract

The invention relates to a reinforcement method for pre-stress continuous beam base plate cracks. A continuous beam midspan base plate is cracked after a pre-stress pipeline is grouted, so that the maintenance and the reinforcement can not be finished by using a method for re-tensioning pre-stress steel bundles in a beam body. The reinforcement method comprises the following steps of: digging off concrete formed by cracking of the base plate; symmetrically and uniformly applying a pre-stress load to layered stacks from the two sides to the middle within a midspan range; embedding new reinforcement steel bars into drilling holes, resetting steel bar meshes on the top layer and the bottom layer of the conventional base plate, binding and fixing the steel bar meshes, and cleaning floating slurry on the surfaces of the steel bars; and after the concrete achieves the strength, symmetrically and uniformly unloading from two sides to the middle until the load is zero, wherein an elastic upper arch of a beam body pressurizes the base plate, so that a top plate is decompressed; and therefore, pre-stress is applied, and a reinforcement effect is achieved. By using the mechanical characteristics of the stress on a continuous beam, the pre-stress load is applied to a cracked section, and natural pre-stress is supplied to the cracked section; and therefore, the reinforcement construction difficulty and the construction cost are reduced, and consequences caused by the high stress and high creepage are avoided.

Description

technical field [0001] The invention belongs to the technical field of traffic construction, and in particular relates to a method for reinforcing cracks in the bottom plate of a prestressed continuous beam. Background technique [0002] After the grouting of the prestressed steel beam pipeline of the continuous beam is completed, the bottom plate cracks, and the maintenance and reinforcement cannot be completed by re-tensioning the prestressed steel beam in the beam body. Traditional reinforcement methods are generally reinforcement methods, such as pasting steel plates on the bottom plate of the box girder, and adding external prestressed steel tendons to the bottom plate. [0003] In order to make the steel plate attached to the bottom plate play a role, it is necessary to ensure that the steel plate and the beam concrete are jointly stressed. The implementation of deformation coordination is very difficult, and it is very difficult technically, and the repaired concrete...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E01D22/00E04G23/02
Inventor 吴少海李承根陈举郑继平唐英张多平殷俊章彭强齐绪平刘红绪赵会平闫希文张景利张祥君邓创成姬伟力
Owner CHINA RAILWAY FIRST SURVEY & DESIGN INST GRP
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