CN106638324B - A kind of construction method of ultra-high performance concrete corrugated steel web plate composite box girder bridge - Google Patents

Abstract

This invention discloses a construction method for an ultra-high performance concrete corrugated steel web composite box girder bridge: First, U-shaped channel structural components for each span of the box girder are prefabricated according to design requirements; then, the bridge deck slab is prefabricated based on the prefabricated U-shaped channel structural components; the abutments and piers are constructed, and the prefabricated U-shaped channel structural components and bridge deck slabs are hoisted into place, transverse connecting reinforcement is tied, and transverse wet joints are poured to form a complete box girder; the next pier is constructed, the second box girder is hoisted into place, the corrugated steel webs of adjacent box girders are welded, longitudinal connecting reinforcement between adjacent box girders is tied, and longitudinal wet joints or cast-in-place crossbeams are poured between adjacent box girder segments to form a continuous bridge structure; after the wet joint concrete reaches the design strength value, the prestressed steel strands of the top slab are tensioned; the above steps are repeated to complete a multi-span continuous bridge structure. The box girder of this invention has a light self-weight, small torsional distortion, good load distribution capacity of the bridge deck, and is convenient for construction and erection, and has broad application prospects in medium and large span bridges.

Description

Construction method of ultra-high performance concrete corrugated steel web composite box girder bridge

technical field

The invention relates to highway and urban road bridge technology, in particular to a construction method of an ultra-high performance concrete corrugated steel web composite box girder bridge.

Background technique

The corrugated steel web is used to replace the concrete thick web of the traditional concrete box girder to form a corrugated steel web box girder. Not only the overall shape of the structure is beautiful, but also the problem of cracking of the traditional concrete box girder web is avoided, and the durability is good. Widely used in large and medium span bridges.

Compared with the traditional concrete box girder, the width of the corrugated steel web box girder should not be too wide because the torsional stiffness and anti-distortion stiffness of the section of the corrugated steel web box girder are reduced. Generally speaking, the maximum width of a single-box single-chamber cast-in-situ concrete box girder or a corrugated steel web composite box girder does not exceed 5m, and a wider single-box box girder must be formed by increasing the number of webs to form a single box with double rooms or a single box with multiple Chamber section, or apply transverse prestressed steel beams to meet the requirements of bridge width and avoid excessive force on the bridge deck, which will lead to problems such as increased beam weight, increased construction difficulty, and difficult pouring of concrete.

UHPC (Ultra High Performance Concrete) is a new type of concrete material with high strength (tensile strength greater than 7MPa, compressive strength greater than 150MPa) and high durability. The high performance of UHPC is mainly characterized by the hardening of stress and tensile strain, that is, the behavior similar to the yielding of steel under tensile stress, and the mechanical properties of UHPC with proper reinforcement are close to steel structures. At the current level, the advantages of being used in major structural projects such as bridges have been shown, making the appearance of the overall structure lighter, reducing the amount of steel bars, and some projects even cancel the steel bars.

Using UHPC materials, bridge components can reduce the structural size and tend to be thinner and thinner, thereby reducing the self-weight, improving the efficiency of the structure to resist loads and increasing the spanning capacity of the bridge, and at the same time, it is convenient for hoisting and erection. Therefore, the traditional corrugated steel web box girder is combined with ultra-high performance concrete (UHPC) to form a prestressed UHPC continuous box girder with corrugated steel web, which is helpful to solve the problems of web cracking and cracking in existing prestressed concrete continuous box girder bridges The problems such as heavy weight and complex construction are of great significance.

Contents of the invention

The object of the present invention is to provide a construction method for an ultra-high performance concrete corrugated steel web composite box girder bridge. The composite box girder bridge of the present invention not only possesses the advantages of traditional corrugated steel web A series of advantages such as good load distribution capacity of the panel and small torsional distortion effect of the box girder make the total width of the bridge deck of a single box room more than 10m, and the main components of the box girder can be completed in the prefabricated field, with less on-site construction work.

To achieve the above object, the present invention can take the following technical solutions:

The construction method of the ultra-high performance concrete corrugated steel web composite box girder bridge of the present invention comprises the following steps:

The first step is to prefabricate the U-shaped channel structure of each span box girder according to the design requirements of the bridge: put the corrugated steel web in place in the prefabrication field, and weld the stud connectors on its upper and lower flanges, and then Fix the prestressed reinforcement of the bottom plate of the box girder at the predetermined position on the pedestal and stretch it to the design value, then bind the steel mesh, pre-bury the prestressed pipe on the roof, erect the formwork, pour ultra-high performance concrete, and prefabricate the side plate of the bridge deck and the box girder The bottom plate, corrugated steel web, and U-shaped groove structural parts of the transverse diaphragm, among which the suspension rings are pre-embedded on the side plate of the bridge deck; then cured with steam, and the formwork is removed after 48 hours;

The second step is to prefabricate the middle plate of the bridge deck according to the distance between the bridge deck side plates of the U-shaped groove structural parts prefabricated in the first step: bind the steel mesh, pre-bury the prestressed pipe on the top plate, erect the formwork, and pre-bury it Hanging rings, horizontal connecting steel bars, and longitudinal connecting steel bars, then cast ultra-high performance concrete, cure with steam, and remove the formwork after 48 hours; T-shaped ribs;

The third step is to construct the abutment and bridge piers, hoist the prefabricated U-shaped groove structural parts and the middle plate of the bridge deck in sequence, bind the horizontal connecting steel bars, and form a complete box girder after pouring the horizontal wet joints;

The fourth step is to construct the next pier, then hoist the second box girder into place, weld the corrugated steel webs of the adjacent box girders into one, bind the longitudinal connecting steel bars between adjacent box girders, and then pour the corresponding The longitudinal wet joints or cast-in-place beams between adjacent box girders form a continuous bridge structure; after the poured concrete reaches the design strength value, the prestressed steel strands installed in the roof prestressed pipe are stretched;

In the fifth step, repeat the fourth step to complete the multi-span continuous bridge structure.

When prefabricating the U-shaped groove structural members of each span box girder in the first step, the distance between two adjacent diaphragms is less than 5m.

Compared with the prior art, the construction method of the present invention has the advantages of:

1) The present invention adopts ultra-high performance concrete (UHPC), and the structural size of the members tends to be thinner, and the dead weight is about 15-25% lower than that of the traditional corrugated steel web box girder;

2) The top plate of the box girder (middle plate of the bridge deck) and the bottom plate of the box girder of the present invention are made of ultra-high performance concrete materials, which can make full use of the high tensile and compressive properties of UHPC; the web of the box girder is made of corrugated steel web, Can make full use of its excellent shear performance.

3) The box girder roof (middle deck of the bridge deck) of the present invention adopts a bridge deck structure with T-shaped short longitudinal ribs and T-shaped short transverse ribs, and its load-bearing efficiency is higher than that of the traditional rectangular-section box girder roof, and its load distribution capacity is good. The transverse width of the box girder can reach more than 10m;

4) In the present invention, relatively dense transverse diaphragms are arranged in each span of the box girder, so that the integrity of the box girder structure is good, and the torsional distortion effect of the box girder is small;

5) The box girder bridge of the present invention adopts the construction technology of prefabrication and assembly. On the one hand, due to the use of ultra-high performance concrete materials, the concrete members of the box girder are relatively light and thin, which is convenient for hoisting construction; on the other hand, the main components of the box girder (U-shaped groove structural parts and bridge deck middle plate) can be completed in the prefabricated field, with less on-site formwork and cast-in-place construction work, which is convenient for the rapid erection of the bridge;

6) The prestressing of the box girder bottom plate of the present invention adopts the pretensioning method, which is less than the traditional post-tensioning prestressed corrugated steel web box girder on-site steel beam tensioning work, and the construction is convenient.

In summary, the present invention has a series of advantages such as light weight of the box girder, small torsional distortion, good load distribution capacity of the bridge deck, and convenient construction and erection. The box girder is poured with high-durability ultra-high-performance concrete, and the structure has good durability, especially in large and medium-span bridges, which has broad application prospects.

Description of drawings

Fig. 1 is a schematic structural view of the prefabricated U-shaped groove structure of the present invention.

Fig. 2 is a structural diagram of the prefabricated bridge deck middle plate of the present invention.

FIG. 3 is a bottom view of FIG. 2 .

Figure 4 is a structural diagram of a box girder in place.

Fig. 5 is a longitudinal sectional view of the box girder in Fig. 4 .

Figure 6 is a structural diagram of two box girders in place.

FIG. 7 is a top structural view of FIG. 6 .

Detailed ways

The construction method of the ultra-high performance concrete corrugated steel web composite box girder bridge of the present invention comprises the following steps:

The first step is to prefabricate the U-shaped groove structural parts of each span box girder according to the bridge design requirements: place the corrugated steel webs 1.1 and 1.2 on both sides in the prefabrication field, and weld studs on the upper and lower flanges Connectors 2.1, 2.2, 2.3, 2.4, then fix the pre-tensioned prestressed reinforcement 12 of the bottom plate of the box girder at a predetermined position on the tensioning platform, and stretch it to the design value, then bind the reinforcement mesh, and pre-embed the roof prestressed pipe 13, Erect formwork, pour ultra-high-performance concrete, and prefabricate U-shaped groove structural parts including bridge deck side plates 3.1, 3.2, box girder bottom plate 4, corrugated steel webs 1.1, 1.2, and transverse diaphragm 5, of which bridge deck side plates 3.1, Embed rings 6.1 and 6.2 respectively on 3.2; then use steam to cure, and remove the mold after 48 hours. The inner diaphragms should be densely arranged. Generally, the distance between two adjacent diaphragms is less than 5m, so as to ensure the integrity of the box girder and reduce the effect of torsional distortion; the corrugated steel webs 1.1 and 1.2 adopt industrial Font corrugated steel plate;

The second step is to prefabricate the bridge deck middle plate 7 according to the distance between the bridge deck side plates 3.1 and 3.2 of the U-shaped groove structure prefabricated in the first step: bind the steel mesh, erect the formwork, and pre-embed the suspension ring 7.1, Horizontal connecting steel bar 7.2, vertical connecting steel bar 7.3, then pour ultra-high performance concrete, and steam curing, remove the formwork after 48 hours; the total thickness of the formed bridge deck middle plate 7 is 0.3m (according to the width of the bridge, it can be between 0.2m~0.5 m), the bottom has T-shaped stiffening ribs 7.4 (shorter) that intersect vertically and horizontally, as shown in Figure 2 and Figure 3;

The third step is to construct the abutment 8 and the bridge pier 9, hoist the prefabricated U-shaped groove structural parts and the bridge deck mid-slab 7 in place in sequence, bind the transverse connecting steel bars 7.2, and pour the transverse wet joints 10 to form a complete box girder , as shown in Figure 4 and Figure 5;

The fourth step is to construct the next pier 9, then hoist the second box girder into place, weld the corrugated steel webs of the adjacent box girders into one, and bind the longitudinal connecting steel bars 7.3 between adjacent box girders, and then Pouring the longitudinal wet joints or cast-in-place beams 11 between adjacent box girders to form a continuous bridge structure; after the concrete to be poured reaches the design strength value, stretch the prestressed steel strands in the roof prestressed pipe 13 ; As shown in Figure 6 and Figure 7;

The fifth step is to repeat the fourth step to complete the multi-span continuous bridge structure, and finally remove the formwork to complete the bridge erection.

Claims (2)

1. A kind of 1. construction method of ultra-high performance concrete corrugated steel web plate composite box girder bridge, it is characterised in that：Including following steps Suddenly：

   The first step, it is prefabricated often across the U groove structure part of box beam by Bridge Design requirement：It is in precasting yard that Wavelike steel webplate is in place, And thereon, weld stud connector on lower flange, then the prestressing force of box beam bottom plate is fixed in precalculated position on stretching bed seat Reinforcing bar is simultaneously stretched to design load, then assembling reinforcement net, pre-buried top plate prestress pipe, sets up template, pours into a mould very-high performance coagulation Soil, it is prefabricated including bridge floor side plate, box beam bottom plate, Wavelike steel webplate, diaphragm plate U groove structure part, it is pre- wherein on bridge floor side plate Bury suspension ring；Then steam curing, form removal after 48 hours are used；

   Second step, according to plate in the distance between the prefabricated bridge floor side plate of U groove structure part of the first step prefabricated bridge floor：Colligation steel Muscle net, pre-buried top plate prestress pipe, template is set up, and in pre-buried suspension ring thereon, lateral connection reinforcing bar, longitudinally connected reinforcing bar, Then ultra-high performance concrete is poured into a mould, and with steam curing, form removal after 48 hours；Plate total thickness 0.2m in bridge floor after shaping ~ 0.5m, bottom is with longitudinal and transverse T-shaped ribs staggeredly；

   3rd step, construction abutment, bridge pier, successively lifts plate in prefabricated U groove structure part and bridge floor in place, colligation laterally connects Reinforcing bar is connect, a complete box beam is formed after pouring laterally wet seam；

   4th step, next bridge pier of constructing is then in place by second box beam lifting, and the Wavelike steel webplate of adjacent box beam is welded It is integrated, and the longitudinally connected reinforcing bar between the adjacent box beam of colligation, then pour the longitudinal wet joint or cast-in-place between adjacent box beam Crossbeam, form continuous bridge structure；After the concrete poured reaches design strength value, tensioning is located in top plate prestressed pipe Prestressed strand in road；

   5th step, the 4th step is repeated, complete the continuous bridge structure of multispan.
2. 2. the construction method of ultra-high performance concrete corrugated steel web plate composite box girder bridge according to claim 1, its feature It is：The first step is prefabricated often when the U groove structure part of box beam, and 5m is smaller than between adjacent two diaphragm plate.