A precast capping beam

Abstract

A precast capping beam, comprising grouting sleeves, prestressed steel strands, a group of bearing stones, retaining blocks, steel bars and concrete. The steel bars form a frame structure, and the grouting sleeves, prestressed steel strands and concrete are located within the frame structure formed by the steel bars. The group of bearing stones and retaining blocks are located at the top of the frame structure formed by the steel bars. The steel bars include framework steel bars, support steel bars and reinforcement stirrups. The framework steel bars form an overall frame structure, and the support steel bars and reinforcement stirrups are located within the framework steel bars. Multiple layers of prestressed steel strands with different heights are arranged within the frame structure formed by the steel bars, and both ends of the multiple layers of prestressed steel strands incline downward along both ends of the frame structure. Compared with the prior art, grouting sleeves are used for connection between columns, pile caps and capping beams, ensuring the accuracy requirements for splicing. The steel bar framework is tied up on the jig, and the bearing stones and retaining blocks are constructed according to the drawings, ensuring that each component bears force as required by the design, and improving the force-bearing performance and safety of the components.

Description

Technical Field

[0001] The present invention belongs to the technical field of bent caps, and particularly relates to a precast bent cap. Background Art

[0002] A bent cap refers to a cross beam arranged at the top of a row of pile piers to support, distribute, and transfer the loads of the upper structure, also known as a cap beam. A reinforced concrete or under-reinforced concrete cross beam is arranged on a bridge pier or row of piles. Its main function is to support the upper structure of the bridge and transfer all loads to the lower structure. There are cases where bridge piles are directly connected to the bent cap, and there are also cases where bridge piles are connected to columns and then to the bent cap.

[0003] Among them, precast bent cap products have wide application value in the field of bridge construction and research. However, it is difficult to ensure the accuracy requirements of components for traditional cast-in-place bent cap products. In particular, there are deviations in the positions of embedded parts such as precision rolled thread steel, and accurate splicing of the bent cap with columns and small box girders cannot be achieved. At the same time, on-site construction has a certain impact on the living conditions of surrounding residents and traffic conditions.

[0004] The existing cast-in-place bent caps have the following disadvantages: 1. It is difficult to accurately control the spacing of stirrups, the spacing of main reinforcement, the positions of embedded parts, and the positions of corrugated pipes during on-site assembly of the steel reinforcement cage, resulting in deviations between the stress conditions of the cast finished product and the design drawings, reducing the safety of the bridge; 2. The next process of the cast-in-place bent cap cannot be carried out until the concrete strength reaches the strength standard, resulting in an extended construction period and increased costs; 3. On-site tying of the steel reinforcement cage requires workers with professional knowledge, with high labor costs, slow speed, and low efficiency. Summary of the Invention

[0005] The present invention aims to overcome the above-mentioned defects in the prior art and provides a precast bent cap with high prefabrication accuracy, simple assembly, and high precision.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a precast bent cap, comprising grouting sleeves, prestressed steel strands, cushion stone groups, retaining blocks, steel bars, and concrete. The steel bars form a frame structure, and the grouting sleeves, prestressed steel strands, and concrete are located within the frame structure formed by the steel bars. The cushion stone groups and retaining blocks are located at the top of the frame structure formed by the steel bars; the steel bars include framework steel bars, support steel bars, and reinforcing stirrups. The framework steel bars form an overall frame structure, and the support steel bars and reinforcing stirrups are located within the framework steel bars; multiple layers of prestressed steel strands with different heights are arranged within the frame structure formed by the steel bars, and both ends of the multiple layers of prestressed steel strands incline downward along both ends of the frame structure.

[0007] As a preferred embodiment of the present invention, the framework steel bars include bottom steel bars, side steel bars and top steel bars connected to each other. The bottom steel bars, side steel bars and top steel bars enclose a closed frame structure. Stirrups are arranged in the radial direction on this frame structure, and transverse steel bars, vertical steel bars and longitudinal steel bars are arranged inside this frame structure. The bottom steel bars and the side steel bars partially overlap, and the side steel bars and the top steel bars partially overlap.

[0008] As a preferred embodiment of the present invention, the support steel bars are inclined and arranged inside the frame structure. The two ends of the support steel bars are respectively connected to the top steel bars and the side steel bars, and the upper part of the support steel bars inclines towards the center of the frame structure.

[0009] As a preferred embodiment of the present invention, the strengthening stirrups include a first combined stirrup and a second combined stirrup. The first combined stirrup is located on the cross-section of the top steel bars and the bottom steel bars, and the second combined stirrup is located on the cross-section of the top steel bars and the side steel bars.

[0010] As a preferred embodiment of the present invention, the first combined stirrup includes a first rectangular stirrup and two first polygonal stirrups connected to each other. The two first polygonal stirrups are located on both sides of the first rectangular stirrup, and the two first polygonal stirrups are at different horizontal heights. The two first polygonal stirrups are partially overlapped, and the outer edges of the first polygonal stirrups overlap with the stirrups.

[0011] As a preferred embodiment of the present invention, the second combined stirrup includes a second rectangular stirrup and two second polygonal stirrups connected to each other. The two first polygonal stirrups are located on both sides of the first rectangular stirrup, and the two first polygonal stirrups are at different horizontal heights. The two first polygonal stirrups are partially overlapped, and the outer edges of the first polygonal stirrups overlap with the stirrups.

[0012] As a preferred embodiment of the present invention, the bending radius R at the bent part of the stirrups, the first combined stirrups and the second combined stirrups is R=(d + 2*32)*2*0.9 / r.

[0013] As a preferred embodiment of the present invention, the multi-layer prestressed steel strands include a first-layer prestressed steel strand, a second-layer prestressed steel strand and a third-layer prestressed steel strand arranged from top to bottom. Before the concrete is poured, corrugated pipes are inserted to reserve holes for the first-layer prestressed steel strand, the second-layer prestressed steel strand and the third-layer prestressed steel strand. The two ends of the first-layer prestressed steel strand, the second-layer prestressed steel strand and the third-layer prestressed steel strand are fixed by anchor devices.

[0014] As a preferred embodiment of the present invention, embedded steel bars adapted to the retaining blocks are formed on the frame structure. The retaining blocks are located at both ends of the top of the frame structure, and the cushion stone groups are distributed on the top of the frame structure, and the cushion stone groups are located between the retaining blocks at both ends.

[0015] As a preferred embodiment of the present invention, a two-way water-dispersing longitudinal slope is formed at the top of the frame structure, and lifting points are also provided at the top of the frame structure.

[0016] The beneficial effects of the present invention are as follows compared with the prior art:

[0017] 1. The column, the bearing platform and the capping beam are connected by grouting sleeves, ensuring the accuracy requirements for splicing.

[0018] 2. The steel bar cage is tied up on the jig, and the cushion stone and the retaining block are constructed according to the drawings, ensuring that each component bears force as required by the design, and improving the force-bearing performance and safety of the components.

[0019] 3. After the capping beam is prefabricated, it can be directly hoisted to the site for assembly, and the assembly steps are simple and can be completed quickly, improving the construction efficiency and shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the front view of the present invention;

[0021] Figure 2 is the top view of the present invention;

[0022] Figure 3 is the structural schematic diagram of the framework steel bars;

[0023] Figure 4 is the structural schematic diagram of the frame structure;

[0024] Figure 5 is the exploded view of the frame structure;

[0025] Figure 6 is Figure 3 the sectional view of the A-A plane in

[0026] Figure 7 is Figure 3 the sectional view of the B-B plane in

[0027] Figure 8 is the structural schematic diagram of the first combined stirrup;

[0028] Figure 9 is the structural schematic diagram of the second combined stirrup;

[0029] Figure 10 is the layout schematic diagram of the prestressed steel strands;

[0030] Figure 11 is Figure 10 the sectional view of the A-A plane in

[0031] Figure 12 is Figure 10 the sectional view of the B-B plane in

[0032] Figure 13 yes Figure 10 Cross-section of the mid-CC plane;

[0033] Figure 14 It is a schematic diagram of the arrangement of the first layer of prestressed steel strands and the second layer of prestressed steel strands;

[0034] Figure 15 It is a schematic diagram of the arrangement of the first layer of prestressed steel strands and the third layer of prestressed steel strands;

[0035] Figure 16 It is the installation diagram of the stopper;

[0036] Figure 17 It is a schematic diagram of the connection between the stopper and the concrete;

[0037] Figure 18 This is the installation diagram of the hanging point;

[0038] The reference numerals in the figure are: frame structure 1, supporting steel bars 1-1, bottom steel bars 1-2, side steel bars 1-3, top steel bars 1-4, first combined stirrups 1-5, first polygonal stirrups 1-5-1, first rectangular stirrups 1-5-2, second combined stirrups 1-6, second polygonal stirrups 1-6-1, second rectangular stirrups 1-6-2, stirrups 1-7, grouting sleeve 2, first layer prestressed steel strand 3-1, second layer prestressed steel strand 3-2, third layer prestressed steel strand 3-3, block 4, embedded steel bars 4-1, cushion stone group 5, concrete 6, hanging point 7. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] like Figure 1-18 As shown, a prefabricated cap beam includes a grouting sleeve 2, a prestressed steel strand, a cushion stone group 5, a block 4, steel bars and concrete 6, the steel bars constitute a frame structure 1, the grouting sleeve 2, the prestressed steel strand and concrete 6 are located in the frame structure 1 composed of the steel bars, the cushion stone group 5 and the block 4 are located at the top of the frame structure 1 composed of the steel bars; the steel bars include skeleton steel bars, supporting steel bars 1-1 and reinforcing stirrups, the skeleton steel bars form an overall frame structure 1, the supporting steel bars 1-1 and the reinforcing stirrups are located in the skeleton steel bars; the frame structure 1 formed in the steel bars is provided with multiple layers of prestressed steel strands with different heights, and both ends of the multiple layers of prestressed steel strands are inclined downward along the two ends of the frame structure 1.

[0041] The steel bars are prefabricated to form the steel skeleton, supporting steel bars 1-1 and reinforcing stirrups of the cap beam. The basic structure of the cap beam is formed by welding the steel skeleton, supporting steel bars 1-1 and reinforcing stirrups. The grouting sleeve is installed at the bottom of the steel skeleton to ensure the accuracy requirements when the column and the pedestal are connected.

[0042] The framework steel bars include the bottom steel bars 1-2, the side steel bars 1-3 and the top steel bars 1-4 which are connected. The bottom steel bars 1-2, the side steel bars 1-3 and the top steel bars 1-4 enclose a closed frame structure 1. There are stirrups 1-7 arranged along the radial direction on the frame structure 1, and there are transverse steel bars, vertical steel bars and longitudinal steel bars inside the frame structure 1. The bottom steel bars 1-2 partially overlap with the side steel bars 1-3, and the side steel bars 1-3 partially overlap with the top steel bars 1-4.

[0043] The length of the top steel bars 1-4 is designed according to the required length of the capping beam, and the top steel bars 1-4 form the top surface of the capping beam. The middle part of the top steel bars 1-4 is the highest point, and both sides slope downwards. There is a two-way longitudinal slope for water drainage on the top of the frame structure 1. There are also lifting points 7 on the top of the frame structure 1. The inclination angle of the top steel bars 1-4 is consistent with the inclination angle of the longitudinal slope for water drainage. The lifting points 7 are welded on the top steel bars 1-4, and the lifting points 7 are symmetrically arranged on both sides of the top steel bars 1-4.

[0044] The bottom steel bars 1-2 are located in the middle of the bottom of the frame structure 1. The side steel bars 1-3 are symmetrically connected to both sides of the bottom steel bars 1-2, and the side steel bars 1-3 and the bottom steel bars 1-2 are fixed by welding. The side steel bars 1-3 and the bottom steel bars 1-2 partially overlap. Both ends of the bottom steel bars 1-2 form inclined sections adapted to the side steel bars 1-3. The top of the side steel bars 1-3 forms a bent section connected to the top steel bars 1-4. The welding between the top steel bars 1-4, the side steel bars 1-3 and the bottom steel bars 1-2 can be single-sided welding or double-sided welding. The length of single-sided welding is not less than 10d, and the length of double-sided welding is not less than 5d.

[0045] The supporting steel bars 1-1 are inclined and arranged inside the frame structure 1. Both ends of the supporting steel bars 1-1 are respectively connected to the top steel bars 1-4 and the side steel bars 1-3. The upper part of the supporting steel bars 1-1 slopes towards the center of the frame structure 1. The supporting steel bars 1-1 are located on both sides of the center of the frame structure 1, and the supporting steel bars 1-1 on both sides are arranged oppositely. The inclination angle of the supporting steel bars 1-1 is between 30° and 60°. Both the upper and lower ends of the supporting steel bars 1-1 form bent sections connected to the top steel bars 1-4 and the side steel bars 1-3. The bent sections face different directions. The supporting steel bars 1-1 are fixedly connected to the top steel bars 1-4 and the side steel bars 1-3 by welding, so that the supporting steel bars 1-1 play a supporting role for the top steel bars 1-4. The quantity and position of the supporting steel bars 1-1 are designed according to the length of the top steel bars 1-4.

[0046] The reinforcement stirrups include a first combined stirrup 1-5 and a second combined stirrup 1-6. The first combined stirrup 1-5 is located on the cross-section of the top reinforcement 1-4 and the bottom reinforcement 1-2, and the second combined stirrup 1-6 is located on the cross-section of the top reinforcement 1-4 and the side reinforcement 1-3. The ends of the first combined stirrup 1-5 and the second combined stirrup 1-6 are provided with 135° hooks. The adjacent stirrup joints are arranged staggeredly along the longitudinal direction, and the arrangement of the first combined stirrup 1-5 and the second combined stirrup 1-6 does not affect the position of the grouting sleeve 2.

[0047] The first combined stirrup 1-5 includes a connected first rectangular stirrup 1-5-2 and two first polygonal stirrups 1-5-1. The two first polygonal stirrups 1-5-1 are located on both sides of the first rectangular stirrup 1-5-2 and are at different horizontal heights. The two first polygonal stirrups 1-5-1 are partially overlapped, and the outer edges of the first polygonal stirrups 1-5-1 are overlapped with the stirrup 1-7.

[0048] The first combined stirrup 1-5 is located on the same plane and is arranged along the cross-section direction of the capping beam. The welding of the first rectangular stirrup 1-5-2 and the first polygonal stirrup 1-5-1 forms the first combined stirrup 1-5. The first polygonal stirrup 1-5-1 is a pentagonal structure, and the outer side of the first polygonal stirrup 1-5-1 is arranged along the arrangement direction of the stirrup 1-7, so that there is a better contact area and stability between the first polygonal stirrup 1-5-1 and the stirrup 1-7. The first rectangular stirrup 1-5-2 is welded and fixed between the two first polygonal stirrups 1-5-1.

[0049] The second combined stirrup 1-6 includes a connected second rectangular stirrup 1-6-2 and two second polygonal stirrups 1-6-1. The two first polygonal stirrups 1-5-1 are located on both sides of the first rectangular stirrup 1-5-2 and are at different horizontal heights. The two first polygonal stirrups 1-5-1 are partially overlapped, and the outer edges of the first polygonal stirrups 1-5-1 are overlapped with the stirrup 1-7.

[0050] The second combined stirrup 1-6 is located on the same plane and is arranged along the cross-section direction of the capping beam. The welding of the second polygonal stirrup 1-6-1 and the second rectangular stirrup 1-6-2 forms the second combined stirrup 1-6. The second polygonal stirrup 1-6-1 is a pentagonal structure, and the outer side of the second polygonal stirrup 1-6-1 is arranged along the arrangement direction of the stirrup 1-7, so that there is a better contact area and stability between the second polygonal stirrup 1-6-1 and the stirrup 1-7. The second rectangular stirrup 1-6-2 is welded and fixed between the two second polygonal stirrups 1-6-1.

[0051] The height relationship of the two first polygonal stirrups 1-5-1 is staggered with the second polygonal stirrup 1-6-1. For example, when the left first polygonal stirrup 1-5-1 among the two first polygonal stirrups 1-5-1 is above the right first polygonal stirrup 1-5-1, the left second polygonal stirrup 1-6-1 among the two second polygonal stirrups 1-6-1 is below the right second polygonal stirrup 1-6-1, so that the force in the first combined stirrup 1-5 and the second combined stirrup 1-6 cancels each other out, having better safety.

[0052] When the straight section of the stirrup, the first combined stirrup 1-5 and the second combined stirrup 1-6 is less than 100 mm, the arc can be used to replace the broken line for implementation. The bending radius R at the bending part of the stirrup, the first combined stirrup 1-5 and the second combined stirrup 1-6 is R=(d + 2*32)*2*0.9 / r.

[0053] The multi-layer prestressed steel strands include the first-layer prestressed steel strand 3-1, the second-layer prestressed steel strand 3-2 and the third-layer prestressed steel strand 3-3 arranged from top to bottom. Before the concrete 6 is poured, corrugated pipes are inserted to reserve holes for the first-layer prestressed steel strand 3-1, the second-layer prestressed steel strand 3-2 and the third-layer prestressed steel strand 3-3. Both ends of the first-layer prestressed steel strand 3-1, the second-layer prestressed steel strand 3-2 and the third-layer prestressed steel are fixed by anchor devices.

[0054] A bent section is formed on the second-layer prestressed steel strand 3-2. Both ends of the second-layer prestressed steel strand 3-2 are parallel to the middle part of the second-layer prestressed steel strand 3-2. The fillet at the bent section on the second-layer prestressed steel strand 3-2 has a radius R of 10000 mm. When the prestressed steel strand conflicts with the embedded steel bars of the pier column, the position of the embedded steel bars of the pier column should be adjusted appropriately.

[0055] The third-layer prestressed steel strand 3-3 includes two symmetrically arranged ends, and a fillet is also provided on the third-layer prestressed steel strand 3-3, and the fillet R is 6000 mm.

[0056] Before the concrete is poured, corrugated pipes are inserted to reserve holes for the first-layer prestressed steel strand 3-1, the second-layer prestressed steel strand 3-2 and the third-layer prestressed steel strand 3-3. The first-layer prestressed steel strand 3-1, the second-layer prestressed steel strand 3-2 and the third-layer prestressed steel strand 3-3 are fixed by anchor devices at both ends and tensioned to the specified length by a jack.

[0057] Embedded steel bars 4-1 adapted to the stoppers 4 are formed on the frame structure 1. The stoppers 4 are located at both ends of the top of the frame structure 1. The cushion stone groups 5 are distributed on the top of the frame structure 1 and are located between the stoppers 4 at both ends. The cushion stone groups 5 are constructed according to the drawings to ensure the position and eccentricity distance of the cushion stone groups 5, so as to ensure that the erection position of the small box girder is accurate without error. The stoppers 4 determine the upper and lower bottom widths and heights according to the drawings to ensure that the small box girder can just be embedded.

[0058] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0059] Although the terms such as frame structure 1, support steel bars 1-1, bottom steel bars 1-2, side steel bars 1-3, top steel bars 1-4, first combined stirrups 1-5, first polygonal stirrups 1-5-1, first rectangular stirrups 1-5-2, second combined stirrups 1-6, second polygonal stirrups 1-6-1, second rectangular stirrups 1-6-2, stirrups 1-7, grouting sleeves 2, first layer of prestressed steel strands 3-1, second layer of prestressed steel strands 3-2, third layer of prestressed steel strands 3-3, stoppers 4, embedded steel bars 4-1, cushion stone groups 5, concrete 6, lifting points 7, etc. are used more in this article, the possibility of using other terms is not excluded; these terms are only used to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A precast capping beam, comprising a grouting sleeve (2), prestressed steel strands, a cushion stone group (5), a stop block (4), steel bars and concrete (6). The steel bars form a frame structure (1), and the grouting sleeve (2), prestressed steel strands and concrete (6) are located inside the frame structure (1) formed by the steel bars. The cushion stone group (5) and the stop block (4) are located at the top of the frame structure (1) formed by the steel bars. It is characterized in that the steel bars include skeleton steel bars, support steel bars (1-1) and reinforcing stirrups. The skeleton steel bars form an overall frame structure (1), and the support steel bars (1-1) and reinforcing stirrups are located inside the skeleton steel bars. Multiple layers of prestressed steel strands with different heights are arranged inside the frame structure (1) formed by the steel bars, and both ends of the multiple layers of prestressed steel strands incline downward along both ends of the frame structure (1). The skeleton steel bars include connected bottom steel bars (1-2), side steel bars (1-3) and top steel bars (1-4). The bottom steel bars (1-2), side steel bars (1-3) and top steel bars (1-4) enclose a closed frame structure (1). Stirrups (1-7) are arranged along the radial direction on the frame structure (1), and transverse steel bars, vertical steel bars and longitudinal steel bars are arranged inside the frame structure (1). The bottom steel bars (1-2) partially overlap with the side steel bars (1-3), and the side steel bars (1-3) partially overlap with the top steel bars (1-4). The reinforcing stirrups include first combined stirrups (1-5) and second combined stirrups (1-6). The first combined stirrups (1-5) are located on the cross-section of the top steel bars (1-4) and the bottom steel bars (1-2), and the second combined stirrups (1-6) are located on the cross-section of the top steel bars (1-4) and the side steel bars (1-3). The first combined stirrups (1-5) include a connected first rectangular stirrup (1-5-2) and two first polygonal stirrups (1-5-1). The two first polygonal stirrups (1-5-1) are located on both sides of the first rectangular stirrup (1-5-2), and the two first polygonal stirrups (1-5-1) are located at different horizontal heights. The two first polygonal stirrups (1-5-1) are partially overlapped, and the outer edges of the first polygonal stirrups (1-5-1) overlap with the stirrups (1-7). The second combined stirrups (1-6) include a connected second rectangular stirrup (1-6-2) and two second polygonal stirrups (1-6-1). The two first polygonal stirrups (1-5-1) are located on both sides of the first rectangular stirrup (1-5-2), and the two first polygonal stirrups (1-5-1) are located at different horizontal heights. The two first polygonal stirrups (1-5-1) are partially overlapped, and the outer edges of the first polygonal stirrups (1-5-1) overlap with the stirrups (1-7).

2. A precast capping beam according to claim 1, It is characterized in that The supporting steel bars (1-1) are inclined and arranged inside the frame structure (1). The two ends of the supporting steel bars (1-1) are respectively connected to the top steel bars (1-4) and the side steel bars (1-3), and the upper part of the supporting steel bars (1-1) is inclined towards the center of the frame structure (1).

3. A precast capping beam according to claim 1, characterized in that the bending radius R at the bent part of the stirrups, the first combined stirrups (1-5) and the second combined stirrups (1-6) is R = (d + 2 * 32) * 2 * 0.9 / r.

4. A precast capping beam according to claim 1, characterized in that The multi-layer prestressed steel strands include the first-layer prestressed steel strands (3-1), the second-layer prestressed steel strands (3-2) and the third-layer prestressed steel strands (3-3) arranged from top to bottom. Before the concrete (6) is poured, corrugated pipes are inserted to reserve holes for the first-layer prestressed steel strands (3-1), the second-layer prestressed steel strands (3-2) and the third-layer prestressed steel strands (3-3). The two ends of the first-layer prestressed steel strands (3-1), the second-layer prestressed steel strands (3-2) and the third-layer prestressed steel strands are fixed by anchor devices.

5. A precast capping beam according to claim 1, characterized in that Embedded steel bars (4-1) adapted to the retaining blocks (4) are formed on the frame structure (1). The retaining blocks (4) are located at both ends of the top of the frame structure (1). The cushion stone groups (5) are distributed on the top of the frame structure (1), and the cushion stone groups (5) are located between the retaining blocks (4) at both ends.

6. A precast capping beam according to claim 1, characterized in that A two-way water-draining longitudinal slope is formed on the top of the frame structure (1), and lifting points (7) are also provided on the top of the frame structure (1).

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