Reinforcing steel bar structure of top web node of PC prefabricated small box girder and forming method of reinforcing steel bar structure

Abstract

The invention discloses a PC prefabricated small box girder top web node reinforcing steel bar structure which comprises top plate horizontal reinforcing steel bars, web U-shaped stirrups, top plate longitudinal reinforcing steel bars, corner longitudinal reinforcing steel bars, web longitudinal reinforcing steel bars and concrete, and reinforcing steel bar arrangement of a small box girder top web node is completed in the mode that top plate reinforcing steel bar meshes and web reinforcing steel bar meshes are manufactured respectively, assembling is conducted, and finally reinforcing steel bar penetrating is conducted. The top plate horizontal steel bars and the top plate longitudinal steel bars form a top plate steel bar mesh, the web U-shaped stirrups and the web longitudinal steel bars form a web steel bar mesh, and the top plate steel bar mesh is hoisted to the web steel bar mesh and then penetrates through the corner longitudinal steel bars to complete small box girder top web node steel bar arrangement. By optimizing the inclined steel bars at the lower corner and reinforcing the longitudinal steel bars at the corner in the traditional design, the top web node steel bars are optimally arranged, the mechanical property of the top web node is improved, meanwhile, the steel bar machining and arranging difficulty is lowered, and the problems that the top web node steel bars are various in specification, low in arranging and mounting efficiency and the like are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a PC prefabricated small box girder top web node steel bar structure and a forming method. Background Art

[0002] In the process of arranging the steel bars at the top and web nodes of traditional prestressed concrete small box girders, the corner areas are often required to arrange dense and complex steel bars to enhance the structural strength due to the large concentrated stress and shear force. However, this dense steel bar arrangement not only increases the difficulty of pouring concrete, but also easily leads to the difficulty of concrete to completely fill the steel bar gaps during the pouring process, forming voids or bubbles, which in turn affects the density and overall strength of the concrete and reduces the construction quality of prestressed concrete small box girders. In addition, too many interlaced steel bars will also hinder the flow of concrete, making the pouring process more time-consuming and labor-intensive, inconvenient for construction, and reducing construction efficiency.

[0003] The diagonal steel bars at the corners are prone to deviations during positioning due to their special spatial position and angle requirements. Traditionally, these diagonal steel bars are mainly tied manually, which is not only labor-intensive and troublesome to install, but also difficult to ensure accuracy. During the tying process, due to the influence of human and environmental factors, the connection between the steel bars is prone to loosening, resulting in a large deviation between the actual construction effect and the design drawings. This deviation not only affects the construction quality of the box girder, but may also cause safety hazards.

[0004] At the same time, in the connection construction process of the steel mesh of the top web node of the traditional prestressed concrete small box girder, due to the existence of the oblique steel bars at the corners of the top web node, the connection construction process of the top plate steel mesh and the web steel mesh becomes complicated. The connection between the traditional top web node oblique steel bars and the top web node is mostly connected by manual binding. Workers need to bind the connection points one by one. The operation process is cumbersome, time-consuming and labor-intensive, and the construction efficiency is low. To a certain extent, the engineering cost of the connection construction of the steel mesh of the top web node of the traditional prestressed concrete small box girder is increased.

[0005] With the advancement of building industrialization and the continuous development of intelligent construction technology, the traditional prefabricated small box girder top web node structure has been unable to meet the needs of industrialization, intelligence, and componentization in the modern construction industry. This not only limits the improvement of construction efficiency and construction quality, but also increases the difficulty and cost of construction site management. Therefore, exploring and optimizing the layout technology and methods of the prefabricated small box girder top web node to adapt to the development trend of intelligent and componentized construction has become an urgent problem to be solved in the construction industry. Summary of the invention

[0006] In order to overcome the technical problems in the prior art, the present invention provides a PC prefabricated small box girder top web node steel bar structure, which solves the above technical problems by optimizing the specifications of the top web node steel bars of the traditional design prestressed concrete small box girder and optimizing the chamfer of the top web node concrete.

[0007] A PC prefabricated small box girder top web node reinforcement structure comprises top plate horizontal reinforcement, web U-shaped stirrups and longitudinal reinforcement, which together constitute a prestressed concrete small box girder top web node reinforcement arrangement, wherein the longitudinal reinforcement comprises top plate longitudinal reinforcement, corner longitudinal reinforcement and web longitudinal reinforcement, the corner longitudinal reinforcement is located on the outside of the top plate horizontal reinforcement and the web U-shaped stirrups, is connected with the top plate horizontal reinforcement and the web U-shaped stirrups by binding or welding, and simultaneously strengthens the corner longitudinal reinforcement.

[0008] The web longitudinal reinforcement is located outside the web U-shaped stirrups and is connected to the web U-shaped stirrups by binding or welding.

[0009] The concrete chamfer of the top web node of the small box girder adopts the method of straight line transition from the lower edge of the top plate to the web.

[0010] The above-mentioned PC prefabricated small box girder top web node steel bar structure, the web U-shaped stirrups are connected with the top plate horizontal steel bars by binding or welding to form equivalent closed stirrups and at the same time constitute the small box girder top web node steel bar skeleton.

[0011] In the above-mentioned PC prefabricated small box girder top web node steel bar structure, the web U-shaped stirrups extend out of the concrete to a certain height, which is convenient for paving the leveling layer.

[0012] A forming method for a PC prefabricated small box beam top web node steel bar structure, the forming method comprising the following construction steps:

[0013] S1: Adjust the reinforcement arrangement scheme of the top web nodes of the traditional prestressed concrete small box girder, strengthen the longitudinal reinforcement of the top corners in the traditional design, optimize the oblique reinforcement at the intersection of the top bottom layer and the web under the traditional design, and open the closed reinforcement of the web in the traditional design;

[0014] S2: Install the web U-shaped stirrups on the assembly platform according to the designed spacing;

[0015] S3: Use figure eight tie wires to tie the web longitudinal reinforcement to the web U-shaped stirrups to form a web reinforcement mesh;

[0016] S4: Tie the longitudinal reinforcements of the top plate to the horizontal reinforcements of the top plate according to the designed spacing to form a reinforcement mesh of the top plate;

[0017] S5: Accurately hoist the tied top plate steel mesh onto the web steel mesh;

[0018] S6: Connect the top plate horizontal reinforcement and the web plate U-shaped stirrups by welding;

[0019] S7: Install the longitudinal reinforcement in the corners by threading;

[0020] S8: Complete the reinforcement arrangement of the top web nodes of the precast concrete small box beam

[0021] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0022] 1. The present invention provides a PC prefabricated small box girder top web node steel bar structure, which optimizes the oblique steel bars at the corners of the traditional design and strengthens the longitudinal steel bars at the corners, so that the optimized arrangement of the top web node steel bars improves the mechanical properties of the top web node while reducing the difficulty of steel bar processing and arrangement, and solves the problems of various specifications of top web node steel bars and low arrangement and installation efficiency;

[0023] 2. The present invention optimizes the cross-sectional shape of the concrete at the corners by straightening the corners, so that the transition between the top and web concrete cross-sections is more reasonable, and the cross-sectional shape of the top and web nodes is simplified while meeting the stress requirements, so that the stress at the corners is clearer, the stress concentration at the corners is reduced, and the durability of the structure is improved;

[0024] 3. The present invention optimizes the steel bars and concrete chamfers at the top web nodes of the small box beam, which not only improves the overall stress-bearing performance of the node, but also reduces the number of templates, reduces material costs, facilitates the installation and removal of templates, improves the efficacy, and improves the construction quality of the prestressed concrete small box beam;

[0025] 4. The present invention optimizes the layout of the top and web node reinforcements, fundamentally solving the problem of low construction efficiency in the connection between the top and web reinforcement layouts of the box girder, and laying a foundation for the subsequent componentized reinforcement construction of prestressed concrete small box girders. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0027] Figure 1 It is a structural schematic diagram of a top web node steel bar structure of a PC prefabricated small box girder of the present invention;

[0028] Figure 2 It is a schematic diagram of the top plate horizontal steel bars and the web plate U-shaped steel bars of the top and web plate node steel bars of a PC prefabricated small box girder of the present invention;

[0029] Figure 3 is a schematic diagram of the web steel mesh of the present invention;

[0030] Figure 4This is a schematic diagram of the top plate steel mesh of the present invention;

[0031] Figure 5 Schematic diagram of the steel cross-section structure of the top web node of the small box girder on the assembly platform.

[0032] In the figure: 1- horizontal reinforcement of top plate, 2- U-shaped stirrups of web plate, 3- longitudinal reinforcement of top plate, 4- longitudinal reinforcement of corners, 5- longitudinal reinforcement of web plate, 6- concrete, 7- assembly platform. DETAILED DESCRIPTION

[0033] like Figure 1 The figure shows a schematic diagram of the structure of the top web node reinforcement structure of a PC prefabricated small box girder of the present invention, which includes the top plate horizontal reinforcement 1, the web U-shaped stirrups 2 and the longitudinal reinforcement, which together form the top web node reinforcement arrangement of the prestressed concrete small box girder. The web U-shaped stirrups 2 are connected to the top plate horizontal reinforcement 1 by tying or welding to form an equivalent closed stirrup and at the same time form the top web node reinforcement skeleton of the small box girder, such as Figure 2 The figure shows the connection relationship between the top plate horizontal steel bars 1 and the web plate U-shaped steel bars 2.

[0034] The web U-shaped stirrup 2 extends out of the concrete 6 to a certain height, which is convenient for paving the leveling layer. The chamfering of the small box girder top web node concrete 6 adopts a method of straight transition from the lower edge of the top plate to the web.

[0035] The longitudinal steel bars include top plate longitudinal steel bars 3, corner longitudinal steel bars 4 and web longitudinal steel bars 5. The corner longitudinal steel bars 4 are located on the outside of the top plate horizontal steel bars 1 and the web U-shaped stirrups 2, and are connected to the top plate horizontal steel bars 1 and the web U-shaped stirrups 2 by binding or welding to strengthen the corner longitudinal steel bars 4. The web longitudinal steel bars 5 are located on the outside of the web U-shaped stirrups 2, and are connected to the web U-shaped stirrups 2 by binding or welding.

[0036] A forming method for a top web node steel bar structure of a PC prefabricated small box beam comprises the following construction steps:

[0037] Step 1: Adjust the reinforcement arrangement scheme of the top web node of the traditional prestressed concrete small box girder, strengthen the longitudinal reinforcement 4 at the corner of the top plate in the traditional design, optimize the oblique reinforcement at the intersection of the bottom layer of the top plate and the web in the traditional design, and replace the closed reinforcement of the web in the traditional design with the closed reinforcement formed by the top plate horizontal reinforcement 1 and the web U-shaped stirrup 2;

[0038] Step: Install the web U-shaped stirrups 2 on the assembly platform 7 according to the designed spacing;

[0039] Step 3: Use the figure eight wire to tie the web longitudinal reinforcement 5 to the web V-shaped stirrups 2 to form a web reinforcement mesh. Figure 3As shown, it is a schematic diagram of the structure of the web steel mesh;

[0040] Step 4: Tie the top plate longitudinal steel bars 3 on the top plate horizontal steel bars 1 according to the designed spacing to form a top plate steel mesh, such as Figure 4 As shown, it is a schematic diagram of the structure of the top plate steel mesh;

[0041] Step 5: Accurately hoist the tied top plate steel mesh onto the web steel mesh;

[0042] Step 6: Connect the top plate horizontal reinforcement 1 and the web plate U-shaped stirrup 2 by welding;

[0043] Step 7: Accurately install the corner longitudinal reinforcement 4 by threading;

[0044] Step 8: Complete the reinforcement arrangement of the top web nodes of the precast concrete small box beam, such as Figure 5 The figure shows the cross-sectional structure diagram of the steel bars at the top web node of the small box girder on the assembly platform.

Claims

1. A PC prefabricated small box girder top web node steel bar structure, characterized in that: It comprises top plate horizontal steel bars (1), web plate U-shaped stirrups (2) and longitudinal steel bars, which together form a prestressed concrete small box girder top web plate node steel bar arrangement, and improve the chamfer of the small box girder top web plate node concrete (6); The longitudinal steel bars include top plate longitudinal steel bars (3), corner longitudinal steel bars (4) and web plate longitudinal steel bars (5); The corner longitudinal steel bars (4) are located outside the top plate horizontal steel bars (1) and the web U-shaped stirrups (2), and are connected to the top plate horizontal steel bars (1) and the web U-shaped stirrups (2) by binding or welding to strengthen the corner longitudinal steel bars (4); The web longitudinal steel bars (5) are located outside the web U-shaped stirrups (2) and are connected to the web U-shaped stirrups (2) by tying or welding; The chamfering of the small box girder top web node concrete (6) adopts a method of straight line transition from the lower edge of the top plate to the web.

2. A PC prefabricated small box girder top web node steel bar structure according to claim 1, characterized in that: The web U-shaped stirrups (2) are connected to the top plate horizontal steel bars (1) by binding or welding to form equivalent closed stirrups, forming a steel bar skeleton of the top web node of the small box girder.

3. A PC prefabricated small box girder top web node steel bar structure according to claim 1, characterized in that: The web U-shaped stirrups (2) extend out of the concrete (6) to a certain height.

4. The forming method of the top web node steel bar structure of a PC prefabricated small box beam according to claim 1 is characterized in that: The molding method comprises the following construction steps: S1: Adjust the reinforcement arrangement scheme of the top web node of the traditional prestressed concrete small box girder, strengthen the longitudinal reinforcement (4) at the top corner in the traditional design, optimize the oblique reinforcement at the intersection of the top bottom layer and the web in the traditional design, and open the closed reinforcement of the web in the traditional design; S2: Install the web U-shaped stirrups (2) on the assembly platform (7) according to the designed spacing; S3: Using figure eight tie wires to tie the web longitudinal reinforcement (5) to the web U-shaped stirrups (2) to form a web reinforcement mesh; S4: tying the top plate longitudinal steel bars (3) on the top plate horizontal steel bars (1) at designed spacing to form a top plate steel mesh; S5: Accurately hoist the tied top plate steel mesh onto the web steel mesh; S6: Connecting the top plate horizontal reinforcement (1) and the web plate U-shaped stirrups (2) by welding; S7: Install the longitudinal reinforcement (4) at the corner by threading; S8: Complete the reinforcement arrangement of the top web nodes of the precast concrete small box girder.

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