Anti-cracking steel-concrete combined continuous girder bridge of negative moment region

Abstract

The invention relates to an anti-cracking steel-concrete combined continuous girder bridge of a negative moment region. A main girder of the bridge girder is of a steel structure; a bridge deck is of a concrete structure; and the main girder and the bridge deck are connected through shear nails, wherein the main steel girder structure and the shear nails are made of a steel product with a standard model; the bridge deck is made of two concrete materials; a base material of the negative moment region of the bridge deck is made of high-strength organic polymer fiber concrete of which the dry apparent density is not less than 2400 kg / m<3>; the base material of the other region of the bridge deck is made of high-strength common concrete of which the dry apparent density is not less than 2400 kg / m<3>, and prestressed reinforcements are arranged in the negative moment region of the bridge deck. The cracking resistance of the negative moment region of the bridge is improved and the technical problem of low anti-cracking ability of the bridge deck in the negative moment region of the steel-concrete combined continuous girder bridge can be solved by using material characteristics, such as high tensile strength and shearing strength (over 20% greater than those of common high-strength concrete) of the high-strength organic polymer fibre concrete and optimizing the arrangement mode of prestressing tendons.

Description

technical field [0001] The invention relates to the field of bridge engineering in the transportation industry, in particular to a steel-concrete composite continuous girder bridge which resists cracking in the negative moment zone. Background technique [0002] Continuous girder bridges have broad application prospects in the field of bridge engineering due to their unique advantages such as strong spanning ability, mature construction technology, comfortable driving, and low construction cost. At present, the bridge structures commonly used in continuous girder bridges are: concrete continuous girder bridge, steel structure continuous girder bridge and steel-concrete composite continuous girder bridge. [0003] Concrete continuous girder bridges are all constructed of concrete materials, and their self-weight accounts for more than 70% of the structure. The dead load of the structure is large, resulting in complex stress in the negative moment area of ​​the long-span conti...

AI Technical Summary

Problems solved by technology

[0003] Concrete continuous girder bridges are all constructed of concrete materials, and their self-weight accounts for more than 70% of the structure. The dead load of the structure is large, resulting in complex stress in the negative moment area of ​​the long-span continuous girder bridges currently built. Many long-span continuous girder bridges have negative bending Rectangular area concrete is difficult to meet the structural crack resistance requirements

The main girder of the steel structure continuous girder bridge is all made of steel structure. The steel structure has high crack resistance and light weight. Surface paving is prone to common diseases such as shifting and wrapping, and it is difficult to maintain in the later stage

The steel-concrete composite continuous girder bridge is a new type of bridge structure in which the main girder adopts a steel structure, the bridge deck is a concrete structure, and the main girder and the bridge deck are connected by shear nails to form a common stress. The structural characteristics of continuous girder bridges have the advantages of large spanning capacity, light weight, high rigidity, low cost, beautiful appearance, and convenient construction. The deck of concrete composite continuous girder bridge adopts ordinary concrete material, and its negative moment area is the same as that of concrete continuous girder bridge, which has the problem of insufficient tensile and shear resistance. Therefore, taking advantage of the structural advantages of steel-concrete composite continuous girder bridge, research A new type of steel-concrete composite continuous girder bridge structure, which overcomes the technical problem of low crack resistance in the negative moment zone, is an inevitable trend in the further development of continuous girder bridges

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