CN104831627A - Bridge deck slab longitudinal unequal strength steel-concrete composite structure bridge and construction method thereof - Google Patents

Abstract

The invention relates to a steel-concrete composite structure bridge with unequal strength in the longitudinal direction of the bridge deck and a construction method thereof, which belongs to a novel bridge structure system applied to continuous composite girder bridges or composite rigid frame bridges. The invention is composed of ultra-high performance concrete, ordinary concrete and steel beams. The invention works together as a whole through the connection of the shear connector and the upper concrete slab, thereby improving the strength and rigidity of the bridge and reducing the overall steel consumption of the bridge. The invention combines the respective advantages of ordinary composite bridge deck system and ultra-high performance concrete, and has the advantages of high strength and rigidity, good crack resistance, good durability and easy construction, and has negative bending moments in continuous girder bridges and rigid frame bridges, etc. It has broad application prospects in the composite structure bridges in the area.

Description

Steel-concrete composite structure bridge with longitudinally unequal strength of bridge deck and its construction method

technical field

The invention relates to a new type of bridge structure applied to continuous composite girder bridges or composite rigid frame bridges, and belongs to the technical field of bridge engineering.

Background technique

When the span of the bridge is large, the continuous girder bridge or rigid frame bridge scheme can significantly reduce the peak value of the bending moment under the action of the vertical load, reduce the material consumption of the bridge, and improve the comprehensive economy. For continuous composite beam bridges or composite rigid frame bridges, the composite beams at the intermediate supports or pier columns are in the negative moment zone, and the upper concrete deck is in tension, so there is a high risk of cracking. However, the composite beam after the cracked concrete slab not only reduces the stiffness, but also has serious problems in long-term service performance and durability. In order to improve the anti-crack performance of concrete slabs in the negative moment zone of continuous composite girder bridges or composite rigid frame bridges, a variety of anti-cracking measures in the negative moment zone have been developed in design and construction, such as adjusting the pouring sequence of concrete slabs on the bridge deck , Applying longitudinal prestress, adopting anti-pull and non-shear connectors, etc.

Composed of reactive powder concrete and steel fibers, ultra-high performance concrete is a cement-based composite material with ultra-high strength, ultra-high toughness and high durability. Laying ultra-high performance concrete in the negative moment area can effectively improve the crack resistance of the concrete deck in the negative moment area of the bridge, improve the mechanical performance of the bridge deck system in the negative moment area, and improve the overall stiffness of the bridge and its long-term performance and performance. Durability, so that the combined advantages of steel and concrete can be fully utilized.

Contents of the invention

The purpose of the present invention is to provide a composite structure bridge system with reasonable stress, good crack resistance, high durability and convenient construction. , so as to obtain the ideal mechanical performance, construction performance and comprehensive economic indicators.

A steel-concrete composite structure bridge with longitudinally unequal strength of the bridge deck of the present invention is composed of ultra-high performance concrete, ordinary concrete and steel girders. The positive bending moment area of the bridge is an ordinary concrete bridge deck; the steel girder includes an upper flange, a web and a bottom plate.

A shear connector is welded on the upper flange of the steel beam.

The steel bars are arranged in the ultra-high performance concrete in the negative bending moment area and/or the ordinary concrete in the positive bending moment area.

Steel fibers are arranged in the ultra-high performance concrete.

The construction method of a bridge deck longitudinally unequal strength steel-concrete composite structure bridge of the present invention is characterized in that the method comprises the following steps:

(1) Install bridge deck steel structure;

(2) Weld shear connectors on the upper flange of the steel beam;

(3) Pouring ultra-high performance concrete in the negative moment area of the bridge deck;

(4) Pour ordinary concrete in the positive bending moment area of the bridge deck.

1

The bridge deck steel structure adopts I-shaped steel cross-section main girders or box-shaped cross-section main girders.

Before the step (3) and/or step (4), the stressed reinforcement and structural reinforcement are arranged.

A certain amount of steel fibers are configured in the ultra-high performance concrete.

Compared with the prior art, the present invention has the following outstanding advantages: ① Laying ultra-high performance concrete in the negative moment area of the bridge deck can effectively improve the crack resistance of the bridge deck in the negative moment area under various load conditions, and solve problems The problem of anti-crack design in the negative moment zone in the development of composite structure bridge system can improve the long-term service performance and durability of the bridge structure; The steel girders and concrete slabs are connected to form a whole, which can effectively improve the strength and stiffness of the bridge deck system and reduce the amount of steel used in the bridge deck system; ③Ultra-high performance concrete is only used locally in the negative bending moment section, and the overall cost is low and economical The performance is better.

Description of drawings

Figure 1 is a schematic diagram of different types of concrete used in different areas of the composite girder in a steel-concrete continuous girder bridge.

Fig. 2 is a schematic diagram of different types of concrete used in different areas of composite girders in a steel-concrete rigid frame bridge.

Fig. 3 is a cross-sectional view of steel beams and ultra-high performance concrete connected by shear connectors in the negative moment zone.

Figure 4 is a cross-sectional view of a steel beam connected to ordinary concrete using shear connectors in the positive moment zone.

In the figure: 1 - ultra-high performance concrete; 2 - ordinary concrete; 3 - upper flange of steel beam; 4 - web of steel beam; 5 - bottom plate of steel beam; Build pier columns.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

The bridge deck longitudinally unequal-strength composite structure bridge provided by the present invention includes ultra-high performance concrete 1, ordinary concrete 2 and steel girder (by upper flange 3, web 4 and bottom plate 5), as shown in Fig. 1 and Fig. 2 Show.

In order to ensure the combined effect of the steel beam and the concrete slab, a connector with shear and pull resistance can be welded above the upper flange 3 of the steel beam, and the connector can use studs 6, as shown in Figure 3.

According to engineering needs, a certain number of stressed steel bars and structural steel bars 7 can be arranged in ultra-high performance concrete 1 and ordinary concrete 2, as shown in Figure 3 and Figure 4, a certain number of steel bars fibers (not shown in the figure).

Construction procedure of the present invention is:

(1) Install the steel structure of the bridge deck (I-shaped steel section main girder or box section main girder can be used);

(2) welding the shear connector 6 on the upper flange 3 of the steel beam;

(3) Pouring ultra-high performance concrete 1 in the negative moment area of the bridge deck;

(4) Pour ordinary concrete 2 in the positive bending moment area of the bridge deck.

According to engineering needs, stress reinforcement and structural reinforcement 7 can also be laid before pouring ultra-high performance concrete 1 in the negative bending moment area of the bridge deck and/or pouring ordinary concrete 2 in the positive bending moment area of the bridge deck.

According to engineering needs, a certain amount of steel fibers can also be configured in ultra-high performance concrete.

Claims (8)

1. the bridge deck longitudinally strong steel-concrete combined structure bridge such as not, be made up of ultra-high performance concrete, ordinary concrete and girder steel, it is characterized in that: be ultra-high performance concrete bridge deck in bridge hogging moment area, is ordinary concrete bridge deck in bridge positive bending moment district; Described girder steel comprises top flange, web plate and back plate.

2., according to the bridge deck according to claim 1 longitudinally strong composite bridge such as not, it is characterized in that: on girder steel top flange, weld shear connector.

3., according to the bridge deck according to claim 1 longitudinally strong composite bridge such as not, it is characterized in that: in the ordinary concrete in the ultra-high performance concrete in hogging moment area and/or positive bending moment district, lay reinforcing bar.

4., according to the bridge deck according to claim 1 longitudinally strong composite bridge such as not, it is characterized in that: in described ultra-high performance concrete, lay steel fibre.

5. the construction method of described composite bridge as claimed in one of claims 1-4, it is characterized in that, the method comprises the following steps:

(1) bridge floor steel work is installed;

(2) on girder steel top flange, shear connector is welded;

(3) ultra-high performance concrete is built in bridge floor hogging moment area;

(4) ordinary concrete is built in bridge floor positive bending moment district.

6. construction method according to claim 5, is characterized in that, described bridge floor steel work adopts i iron cross section girder or box-type section girder.

7. construction method according to claim 6, is characterized in that, described step (3) and/or step (4) front, configuration steel bar stress and distributing bar.

8. construction method according to claim 7, is characterized in that, the steel fibre of configuration some in described ultra-high performance concrete.