CN107142830B - Steel pipe web prestress steel-concrete combined girder structure and construction method - Google Patents

Abstract

The invention discloses a steel pipe web prestressed steel-concrete composite main girder structure and a construction method, comprising a concrete roof, a concrete floor, a web steel pipe, internal prestressed steel strands, external prestressed cables, and a diaphragm. The web steel pipes are buried between the concrete roof and the concrete floor, and the top and bottom ends of two adjacent web steel pipes are connected by shear key bolts to form a longitudinal triangular stable structure. Multiple steel pipes are connected to each other in turn to form a beam web. The slab bears the shear force and partial bending moment of the beam body. The internal prestressed steel strands are buried in the concrete of the top and bottom slabs. The external prestressed cables are arranged inside the steel-concrete composite beam frame. The horizontal diaphragm The slabs are located inside the steel-concrete composite beam frame, and are arranged at intervals, and are consolidated with the top and bottom slabs by pouring concrete.

Description

Steel tube web prestressed steel-concrete composite main beam structure and construction method

technical field

The invention relates to the technical field of bridges used in civil engineering, and more specifically relates to a steel pipe web prestressed steel-concrete composite main girder structure and a construction method.

Background technique

A bridge is a structure for crossing various obstacles (such as rivers or other structures) in highways, railways, urban roads, rural roads, and water conservancy construction. According to the structural form, bridges can generally be divided into girder bridges, arch bridges, cable-stayed bridges and suspension bridges; according to the type of materials used, bridges can generally be divided into wooden bridges, masonry bridges, reinforced concrete bridges, steel bridges, and steel-concrete composite structure bridges wait.

A girder bridge is a bridge in which the main girder is mainly subjected to bending as the load-bearing member. Main girders can be solid web or truss girders. The steel-concrete composite structure girder bridge is a new type of bridge structure formed by combining two main girder materials with different properties, steel and concrete. Since this type of bridge makes full use of the tensile properties of steel and the compressive properties of concrete, it can significantly improve the mechanical properties of steel structures and improve economic efficiency, and has the advantages of convenient construction, beautiful appearance, environmental protection and energy saving, so it is becoming more and more popular. It is used in the field of bridge engineering construction.

Traditional steel-concrete composite structure girder bridges generally adopt the combination of concrete bridge deck and steel plate girder, steel box girder, or steel truss girder. Due to the light weight of solid-web steel-concrete composite beams (steel plate composite beams, steel box composite beams), solid-web steel plates are easily affected by wind loads; empty-web steel-concrete composite beams (steel truss composite beams) cannot , Prestressing is applied to the top and bottom concrete to resist dead load and live load, so the spanning capacity is greatly limited; when traditional steel beams are assembled, cantilever construction is more difficult, and floor supports need to be erected for temporary support of steel beams. Generally speaking, the main disadvantages of traditional steel-concrete composite structure girder bridges are: (1) The wind resistance capacity of solid-web steel-concrete composite beams is poor; The construction is complex and the construction site occupies a large area.

Therefore, under this background, it is of great practical value to develop a new steel pipe web prestressed steel-concrete composite beam bridge structure that meets the needs of greater spanning capacity and more convenient construction.

Contents of the invention

The purpose of the present invention is to provide a steel pipe web prestressed steel-concrete composite main girder structure and construction method, improve the bearing capacity of the traditional steel-concrete composite structure beam bridge from the structural system and internal force mechanism, and the traditional construction method Well connected and easy to implement.

In order to achieve the above object, the present invention adopts the following technical measures:

A steel pipe web prestressed steel-concrete composite main girder structure, comprising a concrete roof, a concrete bottom plate, web steel pipes, internal prestressed steel strands, external prestressed cables and diaphragms, the web steel pipes are arranged on the concrete Between the top slab and the concrete bottom slab, the top and bottom of the web steel pipes are provided with shear keys, and the web steel pipes are connected with the concrete top and bottom slabs through the shear keys and steel pipe positioning steel bars to form a steel-concrete composite main beam frame. It is installed horizontally inside the steel-concrete composite beam frame, and is installed at intervals, and is integrated with the concrete top and bottom slabs to increase the lateral stiffness of the beam body; the internal prestressed steel strands are embedded in the top and bottom slabs In the concrete, the external prestressed cable is arranged inside the steel-concrete composite beam frame, one end is anchored on the diaphragm at the end of the beam, the other end is anchored on the diaphragm at the top of the pier, and the middle part passes through the diaphragm on the diaphragm. After the external prestressed steering steel casing, the designed external prestressed vertical steering is completed. Further, the concrete top slab and bottom slab are constructed in sections, and prestressed steel pipes are embedded in each section before pouring.

Further, the prestressed steel bars in the body are stretched and anchored through the prestressed steel bar pipelines of the corresponding segments, and after the pipelines are grouted, the prestressed steel bars in the body are combined with the top and bottom slab concrete as a whole, and then combined with the top and bottom slab concrete Jointly bear the construction load and the first phase dead load.

Further, the web steel pipes are hollow steel pipes, two rows of hollow steel pipes are symmetrically arranged along the longitudinal direction of the concrete roof and the concrete floor, and each row of hollow steel pipes includes a plurality of hollow steel pipes arranged obliquely and connected in sequence.

Further, the top and bottom ends of two adjacent web steel pipes are connected by shear key bolt plates to form a longitudinal triangular stable structure, and multiple steel pipes are connected to each other in turn to form a main beam web to withstand shear force and partial bending moment.

Further, according to the design bearing capacity, multiple externally prestressed cables can be arranged symmetrically in the lateral direction to bear the live load during the operation period.

Further, the diaphragm is a reinforced concrete structure, including a middle diaphragm, a pier top diaphragm and an end diaphragm, and the middle diaphragm is designed with a plurality of beams located between the pier top and the beam end. In the middle of the body, external prestressed steering steel casings are pre-embedded inside to assist the steering of external prestressed cables; the diaphragm at the top of the pier is located at the top of the pier, and the end diaphragm is located at the end of the beam, and the anchor sleeve is also pre-embedded inside , for external prestressed cable anchorage.

The construction method of the steel pipe web prestressed steel-concrete composite main beam structure includes the following steps:

Step 1: Assemble the floor formwork of the No. 0 beam section on the bracket platform of the pier top and tie the floor steel bars, arrange and pre-embed the prestressed pipes according to the design requirements, assemble the web steel pipes of this section, and temporarily install the shear keys at the bottom of the steel pipes Fixed on the corresponding design position of the bottom plate;

Step 2: Pour the No. 0 base plate concrete, and when the concrete reaches 90% of the design strength, carry out the prestressed steel strand pipeline in the base plate body, tension and anchor;

Step 3: Set up the full hall bracket and the roof construction platform on the pier top bracket platform, and carry out the construction of the No. 0 main girder roof formwork, steel bar binding, concrete pouring, and prestressed tensioning construction as in Step 1. Before concrete pouring, fine-tune the position of the shear key at the top of the steel pipe in the roof to make it meet the design requirements;

Step 4: Assemble the hanging basket system symmetrically at both ends of the top surface of the pier top beam section, and conduct a loading test;

Step 5: Assemble the 1# beam section bottom plate formwork on the bottom formwork platform of the hanging basket and bind the bottom plate steel bars, arrange and pre-embed the prestressed pipeline according to the design requirements, assemble and connect the web steel pipe of this section, and temporarily install the shear key at the bottom of the steel pipe Fixed on the corresponding design position of the bottom plate;

Step 6: Pour the concrete on the bottom plate of the beam section of No. 1 block, and when the concrete reaches 90% of the design strength, carry out the prestressed steel strand pipeline in the bottom plate body, tension and anchor;

Step 7: On the top platform of the hanging basket, the roof of the No. 1 beam section is erected, the steel bars are bound, the concrete is poured, and the prestressed tension is constructed. Before concrete pouring, fine-tune the position of the shear key at the top of the steel pipe in the roof to make it meet the design requirements;

Step 8: Move the hanging basket system forward, repeat steps 5 to 7, and enter the main girder construction of the next section until the whole bridge is closed;

Step 9: When the construction reaches the position of the diaphragm, the vertical form is bound to the reinforcement of the diaphragm, and the steering or anchoring device is pre-embedded;

Step 10: The external prestressed cable passes through the corresponding anchor block and steering block, and is tensioned to the design load for anchoring.

Compared with the prior art, the present invention has the following advantages:

(1) The roof and bottom plate adopt prestressed concrete structure, which greatly improves the bearing capacity of the beam body compared with the traditional steel truss composite beam with concrete roof

(2) The web adopts steel pipe truss, which solves the problem that the solid web steel plate concrete composite girder bridge is easily affected by wind load, and the material consumption is less, which has good engineering economy;

(3) The hanging basket cantilever construction is adopted, the construction is safe and reliable, and the construction site and equipment are saved.

(4) The structure uses roof and floor concrete and prestress to bear most of the bending moment, and the web steel pipe bears most of the shear force. The structural system is simple and the structural force is clear.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1 is a schematic elevation view of the steel pipe web prestressed steel-concrete composite main beam structure;

Figure 2 is a partially enlarged schematic diagram of the steel pipe web prestressed steel-concrete composite main beam structure;

Figure 3 is a schematic diagram of the A-A section of the steel pipe web prestressed steel-concrete composite main beam structure;

Fig. 4 is the assembly diagram of web steel pipe;

Figure 5 is a schematic diagram of the cantilever construction of the steel pipe web prestressed steel-concrete composite main beam structure;

In the figure: 1- steel pipe web prestressed steel-concrete composite main beam structure, 2- concrete roof, 3- concrete floor, 4- web steel pipe, 5- internal prestressed steel strand, 6- external prestressed cable, 7 -diaphragm, 8-shear key, 9-external prestressed steering steel casing, 10-shear key bolt plate, 11-steel steel positioning steel bar, 12-middle diaphragm, 13-pier top diaphragm, 14-end transverse partition, 15-hanging basket system, 16-bottom platform, 17-top platform.

Detailed ways

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

As introduced in the background technology, there are (1) poor wind resistance of solid-web steel-concrete composite beams in the prior art; (2) difficulty in applying prestress to empty-web steel-concrete composite beams, and small spanning capacity; (3) complex construction of supports, The construction site occupies a large area. In order to solve the above technical problems, the present application proposes a steel pipe web prestressed steel-concrete composite main girder structure and a construction method.

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

Compared with the traditional steel-concrete composite main girder structure, the invention provides a steel pipe web with higher structural stress mechanism and bearing efficiency, greater spanning capacity, superior economic performance, less on-site operation and less construction difficulty. Slab prestressed steel-concrete composite main beam structure.

As shown in Figure 1 and Figure 2, a steel pipe web prestressed steel-concrete composite main beam structure 1 includes a concrete roof 2, a concrete floor 3, web steel pipes 4, internal prestressed steel strands 5, external prestressed cables 6. Transverse partition 7.

As shown in Fig. 3 and Fig. 4, the web steel pipe 4 is arranged between the concrete roof 2 and the concrete bottom 3, the top and bottom of the web steel pipe 4 are provided with shear keys 8, and the web steel pipe 4 passes through the shear key 8, the steel pipe The positioning steel bar 11 is connected with the concrete of the roof and the floor to form a steel-concrete composite beam frame.

As shown in Fig. 1, Fig. 2 and Fig. 3, internally prestressed steel strands 5 are buried in the roof and floor concrete; externally prestressed cables 6 are arranged inside the frame of the steel-concrete composite beam, and one end is anchored to the diaphragm 14 at the end of the beam , the other end is anchored to the diaphragm 13 on the top of the pier, and after the middle part passes through the externally prestressed steering steel sleeve 9 of the diaphragm, the designed external prestressed vertical steering is completed; the diaphragm 7 is located inside the frame of the steel-concrete composite beam , set one at a certain distance, consolidated with the top and bottom concrete pouring as a whole, and used to increase the lateral rigidity of the beam body.

As shown in Fig. 1 and Fig. 2, the concrete top slab 2 and the bottom slab 3 are segmented construction, and prestressed steel pipes are embedded in each segment before pouring.

As shown in Figure 1 and Figure 2, the prestressed steel bars in the body pass through the corresponding section of the prestressed steel pipe for tension and anchoring, and after the pipeline is grouted, the internal prestressed steel strand 5 is integrated with the top and bottom slab concrete , together with the roof and floor concrete bear the construction load and the first phase dead load.

As shown in Fig. 2, Fig. 3 and Fig. 4, the web steel pipes 4 are hollow steel pipes including multiple, along the longitudinal direction along the concrete roof and the concrete floor, there are two rows of hollow steel pipes symmetrically arranged, and each row of hollow steel pipes is vertical It is arranged obliquely, and the top and bottom ends of two adjacent web steel pipes are connected by shear key bolt plates 10 to form a longitudinal triangular stable structure. Multiple steel pipes are connected to each other in turn to form the main beam web, which can withstand shear force and partial bending. moment.

As shown in Fig. 2 and Fig. 3, according to the design bearing capacity, multiple prestressed cables 6 can be installed laterally and symmetrically to bear the live load during the operation period.

As shown in Fig. 1, Fig. 2 and Fig. 3, the diaphragm 7 is a reinforced concrete structure, which is divided into a middle diaphragm 12, a pier top diaphragm 13 and an end diaphragm 14, and the middle diaphragm 12 is located at the pier top In the middle of the beam body between the beam end and the beam end, an externally prestressed steering steel casing 9 is embedded inside to assist the steering of the externally prestressed steel bar; the pier top diaphragm 13 is located at the pier top, and the end diaphragm 14 is located at the beam end , The internal embedded anchor sleeve is used for external prestressed cable anchoring.

The construction method of the steel pipe web prestressed steel-concrete composite main beam structure is described in detail, including the following steps:

Step 1: Assemble the No. 0 beam section bottom slab formwork on the pier top bracket platform and tie the bottom slab reinforcement, arrange and pre-embed the prestressed pipeline according to the design requirements, assemble and connect the web steel pipe 4 of this section, and shear the bottom of the steel pipe Key 8 is temporarily fixed at the corresponding design position of the bottom plate;

Step 2: Pour the No. 0 bottom plate concrete, and when the concrete reaches 90% of the design strength, carry out the prestressed steel strand 5 pipes in the bottom plate body, stretch and anchor;

Step 3: Set up the full hall bracket and the roof construction platform on the pier top bracket platform, and carry out the construction of the No. 0 main girder roof formwork, steel bar binding, concrete pouring, and prestressed tensioning construction as in Step 1. Before concrete pouring, fine-tune the position of the shear key 8 at the top of the steel pipe in the roof to make it meet the design requirements;

Step 4: symmetrically assemble the hanging basket system 15 on both ends of the top surface of the pier top beam section, and carry out a loading test;

Step 5: Assemble the 1# beam section bottom plate formwork on the bottom plate platform 16 of the hanging basket and bind the bottom plate steel bars, arrange and pre-embed the prestressed pipes according to the design requirements, assemble and connect the web steel pipe 4 of this section, and connect the shear key at the bottom of the steel pipe 8 Temporarily fixed at the corresponding design position of the bottom plate;

Step 6: Pour concrete for the bottom plate of the beam section of No. 1 block, and when the concrete reaches 90% of the design strength, carry out the prestressed steel strand 5 pipes in the bottom plate body, stretch and anchor;

Step 7: On the top plate platform 17 of the hanging basket, formwork for the top plate of the beam section of No. 1 block, steel bar binding, concrete pouring, and prestressed tensioning construction. Before concrete pouring, fine-tune the position of the shear key 8 at the top of the steel pipe in the roof to make it meet the design requirements;

Step 8: Move the hanging basket system 15 forward, repeat steps 5 to 7, and enter the main girder construction of the next section until the whole bridge is closed;

Step 9: When the construction reaches the position of the diaphragm 7, the steel bars of the diaphragm are bound with the vertical form, and the steering or anchoring device is pre-embedded;

Step 10: The external prestressed cable 6 passes through the corresponding anchor block and steering block, and is tensioned to the design load for anchoring.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (6)

1. The steel pipe web prestressed reinforced concrete combined girder structure is characterized by comprising a concrete top plate, a concrete bottom plate, web steel pipes, in-vivo prestressed steel strands, in-vitro prestressed cables and transverse partition plates, wherein the web steel pipes are arranged between the concrete top plate and the concrete bottom plate, shear keys are arranged at the tops and bottoms of the web steel pipes, the web steel pipes are connected with the concrete top plate and the concrete bottom plate through the shear keys and steel pipe positioning steel bars to form a reinforced concrete combined girder frame, and the transverse partition plates are transversely arranged in the reinforced concrete combined girder frame and are integrally cast and solidified with the concrete top plate and the concrete bottom plate at intervals for increasing the transverse rigidity of a girder body; the in-vivo prestress steel strand is buried in the top and bottom plate concrete, the in-vitro prestress cable is arranged in the steel-concrete composite beam frame, one end of the in-vitro prestress cable is anchored on a diaphragm plate at the beam end, the other end of the in-vivo prestress cable is anchored on a diaphragm plate at the pier top, and the middle part of the in-vivo prestress cable passes through an in-vitro prestress steering steel sleeve on the diaphragm plate to finish the design of in-vitro prestress vertical steering;

the concrete top plate and the concrete bottom plate are constructed in sections, and each section is embedded with a prestressed reinforcement pipeline before pouring;

the in-body prestressed steel strands penetrate through the corresponding segment prestressed steel bar pipelines to be tensioned and anchored, and after grouting through the pipelines, the in-body prestressed steel strands are combined with the top and bottom plate concrete into a whole, and then bear construction load and primary constant load together with the top and bottom plate concrete.

2. The steel pipe web prestressed reinforced concrete combined main girder structure according to claim 1, wherein the web steel pipes are hollow steel pipes, two rows of hollow steel pipes are symmetrically arranged along the longitudinal direction of the concrete top plate and the concrete bottom plate, and each row of hollow steel pipes comprises a plurality of hollow steel pipes which are obliquely arranged and are sequentially connected to form a longitudinal triangular stable structure; thereby forming a web plate of the main girder body to bear shearing force and partial bending moment.

3. The steel tube web prestressed reinforced concrete composite girder structure of claim 2, wherein the top ends and the bottom ends of two adjacent web steel tubes are connected by a shear key bolt plate.

4. The steel pipe web prestressed reinforced concrete combined main girder structure of claim 1, wherein the external prestressed cables are symmetrically arranged along the longitudinal direction of the reinforced concrete combined girder frame according to the designed bearing capacity, so as to bear live load in the operation period.

5. The steel pipe web prestress steel-concrete combined girder structure of claim 1, wherein the diaphragm plate is a reinforced concrete structure and comprises a middle diaphragm plate, a pier top diaphragm plate and end diaphragm plates, wherein a plurality of middle diaphragm plates are arranged in the middle of a girder body between a pier top and a girder end, and an external prestress steering steel sleeve is embedded in the middle of the girder body for assisting external prestress cable steering; the pier top diaphragm plate is positioned at the pier top position, the end diaphragm plate is positioned at the beam end, and an anchoring sleeve is also embedded in the end diaphragm plate and is used for anchoring an external prestressed cable.

6. A method of constructing a steel pipe web prestressed reinforced concrete composite girder structure as claimed in any one of claims 1 to 5, wherein: the method comprises the following steps:

step 1: assembling a No. 0 beam section bottom plate template and binding bottom plate steel bars on a pier top bracket platform, arranging and embedding prestressed pipelines according to design requirements, assembling and connecting the section web steel pipes, and temporarily fixing shear keys at the bottoms of the steel pipes at corresponding design positions of the bottom plates;

step 2: pouring No. 0 bottom plate concrete, and when the concrete reaches 90% of the design strength, carrying out beam penetration, tensioning and anchoring on prestressed steel strand pipelines in the bottom plate body;

step 3: setting up a full framing and a top plate construction platform on a pier top bracket platform, and carrying out the construction of a No. 0 main girder top plate vertical formwork, steel bar binding, concrete pouring and prestress tensioning in the same step 1; before concrete pouring, finely adjusting the position of a shear key at the top of a steel pipe in a concrete roof, so that the shear key meets the design requirement;

step 4: symmetrically assembling hanging basket systems at two ends of the top surface of the pier top beam section, and carrying out a loading test;

step 5: assembling a 1# beam section bottom plate template and binding bottom plate steel bars on a basket bottom die platform, arranging and embedding pre-stressing pipelines according to design requirements, assembling and connecting the section web steel pipes, and temporarily fixing shear keys at the bottoms of the steel pipes at corresponding design positions of the bottom plate;

step 6: pouring the bottom plate concrete of the No. 1 girder segment, and carrying out in-vivo prestress steel strand pipeline beam penetration, tensioning and anchoring when the concrete reaches 90% of the design strength;

step 7: setting a model, binding steel bars, pouring concrete and carrying out prestress tensioning construction on a No. 1 block beam Duan Dingban on a hanging basket top plate platform; before concrete pouring, finely adjusting the position of a shear key at the top of a steel pipe in the top plate to enable the shear key to meet design requirements;

step 8: the basket hanging system moves forward, the steps 5 to 7 are repeated, and the next section of girder construction is carried out until the full bridge closure is achieved;

step 9: when the construction is carried out to the diaphragm plate position, binding diaphragm plate reinforcing steel bars by the vertical mould, and embedding a steering or anchoring device;

step 10: the external prestressed cable passes through the corresponding anchoring block and the steering block and is stretched to the designed load for anchoring.

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