阅读说明：本技术 一种预应力混凝土-钢组合梁及其制备方法 (Prestressed concrete-steel composite beam and preparation method thereof ) 是由 占玉林 乔瑜 卢思吉 刘矗东 赵人达 赵硕硕 段盟君 于 2019-11-22 设计创作，主要内容包括：本发明公开了一种预应力混凝土-钢组合梁及其制备方法,包括混凝土桥面板、钢梁和预应力混凝土底板；钢梁为T型钢,钢梁上表面设置有多个栓钉；混凝土桥面板上设置有与栓钉对应的梯形台结构槽口；钢梁下缘连接压型钢板；压型钢板通过第一粘接层连接预应力混凝土底板；钢梁上表面除栓钉位置外设置有第二粘接层；槽口内充填现浇混凝土；本发明结构抗弯承载力强,整体刚度高,解决了梁体变形挠曲和易发生侧扭失稳的难题,并在一定程度上减少振动,降低噪声,利于列车的平稳行驶。(The invention discloses a prestressed concrete-steel composite beam and a preparation method thereof, wherein the prestressed concrete-steel composite beam comprises a concrete bridge deck, a steel beam and a prestressed concrete bottom plate; the steel beam is T-shaped steel, and a plurality of studs are arranged on the upper surface of the steel beam; a trapezoidal platform structure notch corresponding to the stud is formed in the concrete bridge deck; the lower edge of the steel beam is connected with a profiled steel sheet; the profiled steel sheet is connected with the prestressed concrete bottom plate through the first adhesive layer; a second bonding layer is arranged on the upper surface of the steel beam except for the stud positions; filling cast-in-place concrete in the notch; the structure of the invention has strong bending resistance bearing capacity and high integral rigidity, solves the problems of beam body deformation and deflection and easy side torsion instability, reduces vibration to a certain extent, reduces noise and is beneficial to the stable running of trains.)

1. The prestressed concrete-steel composite beam is characterized by comprising a concrete bridge deck (1), a steel beam (3) and a prestressed concrete bottom plate (5); the steel beam (3) is T-shaped steel, and a plurality of studs (2) are arranged on the upper surface of the steel beam (3); a trapezoidal platform structure notch (8) corresponding to the stud (2) is arranged on the concrete bridge deck (1); the lower edge of the steel beam (3) is connected with a profiled steel sheet (7); the profiled steel sheet (7) is connected with the prestressed concrete bottom plate (5) through a first bonding layer (401); a second bonding layer (402) is arranged on the upper surface of the steel beam (3) except the position of the stud (2); the notch (8) is filled with cast-in-place concrete.

2. The prestressed concrete-steel composite girder according to claim 1, wherein the profiled steel sheet (7) has a corrugated structure, and the surface of the prestressed concrete bottom plate (5) is fitted thereto.

3. The prestressed concrete-steel composite girder according to claim 1, wherein a first reinforcing mesh (9) is embedded in the concrete deck slab (1); a second reinforcing mesh (10) is embedded in the prestressed concrete bottom plate (5); the second reinforcing mesh (10) is internally provided with prestressed tendons (6).

4. The prestressed concrete-steel composite girder according to claim 1, wherein the stud (2) is welded to the upper surface of the steel girder (3) by arc stud welding; the length of each stud (2) is not less than four times of the rod diameter of the stud, and the distance between every two studs (2) along the axial direction of the beam is not less than five times of the rod diameter of the stud and is not less than 100 mm; the distance between every two studs (2) perpendicular to the axial direction of the beam is not less than four times of the diameter of the rod.

5. The prestressed concrete-steel composite beam as claimed in claim 1, wherein the thickness of said concrete deck slab (1) is greater than or equal to 180mm, the center line of the extended steel beam (3) is greater than or equal to 150mm, and the top flange of the extended steel beam (3) is greater than or equal to 50 mm.

6. A prestressed concrete-steel composite girder according to claim 1, wherein said steel girder (3) is provided with an anticorrosive coating on the outer surface thereof.

7. The prestressed concrete-steel composite beam as claimed in claim 1, wherein said steel beam (3) has a wing plate thickness of 16mm or more and a web plate thickness of 12mm or more; the width of the upper wing plate of the steel beam (3) is more than or equal to 250mm and not more than 24 times of the thickness of the upper wing plate.

8. The prestressed concrete-steel composite beam as claimed in claim 1, wherein said first adhesive layer (401) and said second adhesive layer (402) are epoxy structural adhesive, both of which have a thickness of 3-5 mm and a roughness of 0.7-1.0 mm.

9. A method for preparing the prestressed concrete-steel composite beam as claimed in any one of claims 1 to 8, which comprises the following steps:

step 1: manufacturing a prestressed concrete bottom plate (5) by a pre-tensioning method; the upper surface template structure is matched with the profiled steel sheet (7) structure;

step 2: respectively welding the stud (2) and the profiled steel sheet (7) on the upper and lower edges of the steel beam (3);

and step 3: coating a first bonding layer (401) on the upper surface of a prestressed concrete bottom plate (5), and arranging a steel beam (3) with a lower edge welded with a compression steel plate (7) on the first bonding layer (401);

and 4, step 4: prefabricating a concrete bridge deck (1), wherein a notch (8) is reserved in the concrete bridge deck (1);

and 5: and coating a second bonding layer (402) on the upper surface of the steel beam (3), hoisting the concrete bridge deck (1) and pouring concrete at the reserved notch (8).

Technical Field

The invention relates to the technical field of bridge structures, in particular to a prestressed concrete-steel composite beam and a preparation method thereof.

Background

The steel-concrete composite beam can fully exert the tensile property of steel and the compressive property of concrete, but the common structural form of the steel-concrete composite beam for the railway bridge consists of a concrete bridge deck, an I-shaped steel beam and a shear key, wherein the concrete bridge deck is connected to the upper flange of the I-shaped steel through mechanical shear keys such as studs or perforated steel plates and the like. However, the steel beam at the lower part of the composite beam has low rigidity, so that local or overall instability is easy to occur under the action of negative bending moment, and the I-shaped steel beam cannot be used for directly pouring concrete in a box like a box-shaped beam, so that the construction is inconvenient. On the other hand, the prestressed tendons are arranged in the bridge deck slab and can only prevent the bridge deck slab from cracking, the influence on the lifting of the whole bearing capacity of the structure is not large, the requirement of a large-span bridge cannot be met, and the external prestressed tendons are not easy to arrange in the I-shaped beam. In addition, in the design of rail transit planning, the conditions that rail transit lines, particularly urban rail transit lines, are close to buildings are often limited by factors such as geographical environment, station location selection, minimum curve radius and the like, the time interval is only a few meters or even the time interval passes through a building, when the rail transit passes through a city, an overhead structure is often adopted for saving land resources and crossing urban roads, and with the continuous improvement of train speed, the passenger capacity is gradually increased, and the vibration and noise pollution of the rail transit are further aggravated.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the prestressed concrete-steel composite beam which improves the structural rigidity and the bearing capacity and reduces the vibration and noise pollution of the structure and the preparation method thereof.

The technical scheme adopted by the invention is as follows: a prestressed concrete-steel composite beam comprises a concrete bridge deck, steel beams and a prestressed concrete bottom plate; the steel beam is T-shaped steel, and a plurality of studs are arranged on the upper surface of the steel beam; a trapezoidal platform structure notch corresponding to the stud is formed in the concrete bridge deck; the lower edge of the steel beam is connected with a profiled steel sheet; the profiled steel sheet is connected with the prestressed concrete bottom plate through the first adhesive layer; a second bonding layer is arranged on the upper surface of the steel beam except for the stud positions; cast-in-place concrete is filled in the notch.

Furthermore, the profiled steel sheet is provided with a corrugated structure, and the surface of the prestressed concrete bottom plate is matched with the corrugated structure.

Furthermore, a first reinforcing mesh is embedded in the concrete bridge deck; a second reinforcing mesh is embedded in the prestressed concrete bottom plate; the second reinforcing mesh is internally provided with prestressed tendons.

Further, the stud is welded on the upper surface of the steel beam through an arc stud; the length of the bolt pin is not less than four times of the rod diameter of the bolt pin, and the distance between every two bolt pins along the axial direction of the beam is not less than five times of the rod diameter of the bolt pin and is not less than 100 mm; the distance between every two of the studs perpendicular to the axial direction of the beam is not less than four times of the diameter of the rod.

Furthermore, the thickness of the concrete bridge deck plate is more than or equal to 180mm, the central line of the extending steel beam is more than or equal to 150mm, and the upper flange of the extending steel beam is more than or equal to 50 mm.

Furthermore, the outer surface of the steel beam is provided with an anticorrosive coating.

Furthermore, the thickness of a wing plate of the steel beam is more than or equal to 16mm, and the thickness of a web plate is more than or equal to 12 mm; the width of the upper wing plate of the steel beam is more than or equal to 250mm and not more than 24 times of the thickness of the upper wing plate of the steel beam.

Furthermore, the first bonding layer and the second bonding layer are epoxy resin structural adhesive, the thickness of the epoxy resin structural adhesive is 3-5 mm, and the roughness of the epoxy resin structural adhesive is 0.7-1.0 mm.

A preparation method of a prestressed concrete-steel composite beam comprises the following steps:

step 1: manufacturing a prestressed concrete bottom plate by a pre-tensioning method; the upper surface template structure is matched with the profiled steel sheet structure;

step 2: respectively welding the stud and the profiled steel sheet on the upper edge and the lower edge of the steel beam;

and step 3: coating a first bonding layer on the upper surface of the prestressed concrete bottom plate, and arranging a steel beam with a lower edge welded with a compression steel plate on the first bonding layer;

and 4, step 4: prefabricating a concrete bridge deck, wherein a notch is reserved on the concrete bridge deck;

and 5: and coating a second bonding layer on the upper surface of the steel beam, hoisting the concrete bridge deck and pouring concrete at the reserved notch.

The invention has the beneficial effects that:

(1) according to the invention, the profiled steel sheet is added at the lower edge of the steel beam, so that the bending resistance bearing capacity of the structure is improved, and the overall rigidity of the composite beam is increased; the advantages of the steel beam, the concrete and the prestressed tendons are fully exerted, and the difficult problems that the beam body is large in deformation and deflection and easy to generate side torsion instability are solved;

(2) the bonding layer in the steel structure and the concrete structure solves the connection problem of the two structures, adopts viscoelastic damping materials, has the functions of reducing vibration and noise to a certain extent, and is beneficial to the stable running of a train;

(3) according to the invention, the welded steel bar meshes are adopted in the concrete bridge deck and the prestressed concrete bottom plate, so that the shear strength of the structure can be improved, and the cracking of the concrete structure is reduced;

(4) the invention adopts the pretensioning method to pre-stress the end part of the concrete structure to crack, can reduce the use of steel, and accelerates the construction progress because the concrete bridge deck and the pre-stress concrete bottom plate both adopt the prefabricated assembly mode.

Drawings

Fig. 1 is a schematic elevation structure of the present invention.

FIG. 2 is a schematic side view of the present invention.

In the figure: 1-concrete bridge deck, 2-studs, 3-steel beams, 401-first adhesive layer, 402-second adhesive layer, 5-prestressed concrete bottom plate, 6-prestressed tendons, 7-profiled steel sheets, 8-notches, 9-first reinforcing mesh and 10-second reinforcing mesh.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

As shown in fig. 1 and 2, a prestressed concrete-steel composite girder includes a concrete deck 1, a steel beam 3, and a prestressed concrete floor 5; the steel beam 3 is T-shaped steel, and a plurality of studs 2 are arranged on the upper surface of the steel beam 3; a trapezoidal platform structure notch 8 corresponding to the stud 2 is arranged on the concrete bridge deck 1; the lower edge of the steel beam 3 is connected with a profiled steel sheet 7; the profiled steel sheet 7 is connected with the prestressed concrete bottom plate 5 through a first bonding layer 401; a second bonding layer 402 is arranged on the upper surface of the steel beam 3 except the position of the stud 2; the notch 8 is filled with cast-in-place concrete.

The profiled steel sheet 7 is of a corrugated structure, and the surface of the prestressed concrete bottom plate 5 is matched with the corrugated structure. A first reinforcing mesh 9 is embedded in the concrete bridge deck 1; a second reinforcing mesh 10 is embedded in the prestressed concrete bottom plate 5; the second mesh reinforcement 10 is provided with tendons 6 therein. The concrete bridge deck 1 and the prestressed concrete bottom plate 5 are prefabricated in a factory and assembled on site, and the notch 8 of the stud 2 needs to be reserved in the concrete bridge deck 1. The steel beam 3 is T-shaped steel with a lower edge welded with a profiled steel sheet 7. The prestressed concrete bottom plate 5 is prefabricated in a factory by adopting a pretensioning method, in order to increase the bonding force, the upper surface of the prestressed concrete bottom plate 5 is poured into a corrugated shape of a profiled steel plate 7, and is bonded on the profiled steel plate 7 at the lower edge of the steel beam through a cementing agent. The upper flange of the steel beam 3 is provided with a hybrid shear key formed by combining the stud 2 and the second bonding layer 402. The concrete bridge deck slab 1 is hoisted on the steel beam 3, concrete is poured in the reserved notch 8, and the steel beam 3 and the concrete bridge deck slab 1 are connected into a whole.

The rigidity of the bridge deck is lower due to the fact that the concrete bridge deck 1 is too thin, and the bridge deck is not beneficial to being paved; the thickness of the concrete bridge deck slab 1 is more than or equal to 180mm, and no bearing is arranged; the central line of the extending steel beam 3 is more than or equal to 150mm, and the upper flange of the extending steel beam 3 is more than or equal to 50 mm. The steel bar configuration in the concrete bridge deck 1 needs to meet the current effective steel-concrete composite bridge design specification, and the current effective design specification is GB50917-2013 Steel-concrete structural bridge design specification.

The stud 2 is welded on the upper surface of the steel beam 3 through an arc stud. In order to ensure that the stud 2 can fully exert the bearing capacity and avoid brittle failure, the length of the stud 2 is not less than four times of the rod diameter of the stud, and the distance between every two studs 2 along the axial direction of the beam is not less than five times of the rod diameter of the stud and is not less than 100 mm; the distance between every two studs 2 perpendicular to the axial direction of the beam is not less than four times of the diameter of the rod.

In order to improve durability, the outer surface of the steel beam 3 is provided with an anticorrosive layer. According to the invention, the T-shaped steel of the compression-type steel plate 7 is preferably welded on the lower edge of the steel beam 3, and the material of the T-shaped steel is Q235 or Q345. The thickness of a wing plate of the T-shaped steel is not less than 16mm, and the thickness of a web plate is more than or equal to 12 mm; the width of the upper wing plate of the steel beam 3 is more than or equal to 250mm and not more than 24 times of the thickness of the upper wing plate.

The first bonding layer 401 and the second bonding layer 402 are epoxy resin structural adhesive, the thickness of the epoxy resin structural adhesive is 3-5 mm, and the roughness of the epoxy resin structural adhesive is 0.7-1.0 mm.

The second reinforcing mesh 10 in the prestressed concrete bottom plate 5 is made of stranded steel wires or spiral rib steel wires, and appropriate measures are taken to ensure reliable anchoring of the steel wires in the concrete. The net spacing between the prestressed steel strands is more than or equal to 1.5 times of the nominal diameter of the prestressed steel strands, and for 1 multiplied by 7 steel strands, the net spacing is more than or equal to 25 mm; the clear distance between the prestressed steel wires is more than or equal to 15 mm. For a single prestressed reinforcement, a spiral reinforcement with the length not less than 150mm is arranged at the end part of the single prestressed reinforcement; for a plurality of prestressed reinforcements, 3-5 pieces of reinforcement meshes are required to be arranged in the range of constructing 10 times of prestressed reinforcements at the end part. In addition, the first and second steel-reinforced meshes 9 and 10 are closed type hoops with the diameter not less than 12mm, and the distance between the closed type hoops is not more than 200 mm.

The original plate of the profiled steel sheet 7 is a cold-rolled plate or a hot-rolled plate or a steel strip, the expansion length (substrate width) of the profiled steel sheet 7 is suitable for meeting the requirements of basic sizes of 600mm, 1000mm or 1200mm, the common width size is preferably 1000mm, the substrate steel is preferably 250-grade (MPa) and 350-grade (MPa) structural grade steel according to the yield strength grade, and the nominal thickness of the substrate is not less than 0.8 mm.

A preparation method of a prestressed concrete-steel composite beam comprises the following steps:

step 1: the prestressed concrete bottom plate 5 is manufactured by a pre-tensioning method: manufacturing and supposing to weld the second reinforcing mesh 10, tensioning the prestressed tendons 6 and supposing to form a template; pouring concrete, and shearing the prestressed tendons 6 after the concrete is condensed to a certain strength; the upper surface template structure is matched with the profiled steel sheet 7 structure;

step 2: respectively welding the stud 2 and the profiled steel sheet 7 on the upper and lower edges of the steel beam 3;

and step 3: coating a first bonding layer 401 on the upper surface of the prestressed concrete bottom plate 5, and arranging a steel beam 3 with a profiled steel sheet 7 welded on the lower edge on the first bonding layer 401;

and 4, step 4: prefabricating a concrete bridge deck 1, wherein a notch 8 is reserved on the concrete bridge deck 1;

and 5: and coating a second bonding layer 402 on the upper surface of the steel beam 3, hoisting the concrete bridge deck slab 1 and pouring concrete at the reserved notch (8).

According to the invention, the profiled steel sheet 7 is added at the lower edge of the steel beam 3, so that the bending resistance bearing capacity of the structure is improved, the integral rigidity of the composite beam is increased, and the advantages of the steel beam, the concrete and the prestressed tendons are fully exerted; the method solves the problems of large deformation and deflection of the beam body and easy occurrence of side torsion instability, is suitable for railway bridges and the like with high requirements on structural rigidity, and realizes the conversion to large-span bridges. The bonding layer arranged in the steel structure and the concrete structure not only solves the connection problem of the two structures, but also the cementing agent adopts viscoelastic damping material, and has the functions of reducing vibration and noise to a certain extent. The steel beam is beneficial to the stable running of the train, and in addition, the mechanical bonding force is increased by the wavy connection of the profiled steel sheet 7 on the lower edge of the steel beam and the prestressed concrete bottom plate 5. Welded reinforcing meshes are adopted in the concrete bridge deck 1 and the concrete bottom plate 5, so that the shear strength of the structure can be improved, the cracking of the concrete structure can be reduced, especially the cracking of the end part of the pretensioned prestressed concrete structure can be reduced, the steel can be reduced by about 25 percent, and the cost is reduced; the concrete bridge deck 1 and the prestressed concrete bottom plate 5 are both assembled in a prefabricating mode, so that the construction progress is accelerated.