Construction method of external prestressed reinforcement and repair of concrete cap beam

Abstract

The present invention relates to a construction method for reinforcing and repairing a concrete cap beam with external prestressing, comprising the following steps: bridge reinforcement construction, installation of a suspended construction platform, fixing of anchor steel plates, installation of upper steel strands, installation of transverse prestressing, and removal of the construction platform. The present invention has the following beneficial effects: reinforcing the original bridge with a new foundation and reinforced steel pipe columns, improving the overall stability of the bridge through temporary support and span reduction technology; using a suspended construction platform to provide a construction platform for the cap beam reinforcement operation, thereby improving construction safety; and reinforcing the cap beam with a combination of local transverse prestressing and longitudinal prestressing, thereby improving the overall strength of the cap beam structure.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering, and in particular relates to a construction method for reinforcing and repairing a concrete cap beam with external prestressing. Background Art

[0002] Some existing bridges, due to limitations in their construction period, have low load-bearing capacities. With the increasing volume of heavy traffic, cracks are becoming more common in their superstructures. Similarly, when vertical loads exceeding the design allowable value are applied to the cap beams in the substructure, vertical cracking can also occur, particularly at the base of the cantilever. Traditional external prestressed concrete cap beam reinforcement and repair methods suffer from shortcomings such as difficulty ensuring quality and low efficiency. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a construction method for reinforcing and repairing a concrete cap beam structure with external prestressing.

[0004] The construction method of the external prestressed reinforcement and repair concrete cap beam comprises the following steps:

[0005] Step 1: Bridge reinforcement construction: construct a new foundation under the original bridge and reinforce the bridge with reinforced steel pipe columns;

[0006] Step 2: Installation of hanging construction platform: Install the upper span bracket on the upper part of the cap beam to install the hanging construction platform;

[0007] Step 3: Fix the anchor plate and transverse steel anchor plate on the cap beam using anchor screws;

[0008] Step 4: Install the upper steel strand: Use a temporary auxiliary stabilizing hanger to assist in positioning the upper steel strand, and then anchor and fix the upper steel strand through the end steel anchor beam;

[0009] Step 5: Installation of lower steel strands: A temporary auxiliary stabilizing hanger is used to assist in positioning the lower steel strands, and then the lower steel strands are anchored and fixed through the side steel anchor beams;

[0010] Step 6: Transverse prestressing installation: Fix the transverse prestressing tendons at the bottom of the cap beam through the transverse steel anchor plate;

[0011] Step 7. Dismantling of the construction platform: Use a crane to dismantle the suspended construction platform.

[0012] Preferably, in step 2, distribution beams are laid on the lower part of the suspended construction platform, and the distribution beams are spliced ​​to form a steel plate platform.

[0013] Preferably, in step 2, a temporary auxiliary stabilizing hanger for assisting in positioning the longitudinal prestressed tendons is provided on the upper portion of the hanging construction platform.

[0014] Preferably, in step three, the setting position of the anchoring plate corresponds to the anchoring position of the lower steel strand; the setting position of the transverse steel anchor plate corresponds to the anchoring position of the transverse prestressed tendons.

[0015] Preferably, in step four, the end steel anchor beam is provided with an end anchor steel plate and a support steel, the upper steel strand is anchored through the end steel anchor beam, and a protective cover is provided outside the end steel anchor beam.

[0016] Preferably, in step five, the side steel anchor beam is provided with a side anchor steel plate, an anchor positioning plate and an anchor, the lower steel strand is fixedly connected with a clamp, and a protective cover is provided outside the side steel anchor beam.

[0017] Preferably, in step one, the newly added foundation and the reinforced steel pipe column are arranged between the piers of the original bridge, and the reinforced steel pipe column is arranged above the newly added foundation.

[0018] The external prestressed reinforced and repaired concrete cap beam is obtained by any of the above methods.

[0019] The beneficial effects of the present invention are:

[0020] 1) The original bridge was reinforced by adding a new foundation and reinforcing steel pipe columns, and the overall stability of the bridge was improved through temporary support and span reduction technology.

[0021] 2) A suspended construction platform is used to provide a construction platform for cap beam reinforcement operations to improve construction safety.

[0022] 3) The cap beam is reinforced by combining local transverse prestressing and longitudinal prestressing to improve the overall strength of the cap beam structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the structural diagram of the concrete cap beam reinforced and repaired with external prestressing;

[0024] Figure 2 This is the structural elevation of the suspended construction platform;

[0025] Figure 3 This is the structural diagram of the suspended construction platform;

[0026] Figure 4 This is a diagram of the connection structure of the externally prestressed reinforced concrete cap beam;

[0027] Figure 5 This is the structural diagram of the end steel anchor beam;

[0028] Figure 6 This is the side steel anchor beam structure diagram.

[0029] In the figure: 1, new foundation; 2, pedestal; 3, reinforced steel pipe column; 4, pier column; 5, hanging construction platform; 6, end steel anchor beam; 7, side steel anchor beam; 8, longitudinal prestressed tendons; 9, cap beam; 10, transverse prestressed device; 11, temporary auxiliary stabilization hanger; 12, steel plate platform; 13, bottom cross beam; 14, side column; 15, upper span support; 16, wire rope; 17, distribution beam; 18, lower Steel strand; 19, transverse prestressed tendons; 20, transverse steel anchor plate; 21, support steel; 22, end anchor steel plate; 23, upper span steel bracket; 24, upper steel strand; 25, anchoring plate; 26, anchor; 27, protective cover; 28, clamp; 29, anchor screw; 30, side anchor steel plate; 31, fixing plate; 32, reinforcing rib; 33, anchor steel plate; 34, fixed beam; 35, reinforced steel beam. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0031] Example 1

[0032] As an embodiment, a construction method for reinforcing and repairing a concrete cap beam with external prestressing comprises the following steps:

[0033] Step 1: Bridge reinforcement construction: construct a new foundation 1 at the bottom of the original bridge, and use reinforced steel pipe columns 3 to reinforce the bridge; the new foundation 1 and the reinforced steel pipe columns 3 are arranged between the piers 4 of the original bridge, and the reinforced steel pipe columns 3 are arranged above the new foundation 1.

[0034] Step 2: Install the suspended construction platform: Install the upper span bracket 15 on top of the cap beam 9 to install the suspended construction platform 5. Distribution beams 17 are laid below the suspended construction platform 5, and these beams 17 are spliced ​​together to form the steel plate platform 12. A temporary auxiliary stabilization hanger 11 is installed above the suspended construction platform 5 to assist in positioning the longitudinal prestressed tendons 8.

[0035] Step 3. Fix the anchor steel plate: fix the anchor plate 25 and the transverse steel anchor plate 20 on the cap beam 9 by means of anchor screws 29; the setting position of the anchor plate 25 corresponds to the anchor position of the lower steel strand 18; the setting position of the transverse steel anchor plate 20 corresponds to the anchor position of the transverse prestressed tendon 19.

[0036] Step 4. Installation of upper steel strand: A temporary auxiliary stabilizing hanger 11 assists in positioning the upper steel strand 24, and then anchors and fixes the upper steel strand 24 through the end steel anchor beam 6; the end steel anchor beam 6 is provided with an end anchor steel plate 22 and a support steel 21, the upper steel strand 24 is anchored through the end steel anchor beam 6, and a protective cover 27 is provided outside the end steel anchor beam 6.

[0037] Step 5. Installation of the lower steel strand: A temporary auxiliary stabilizing hanger 11 assists in positioning the lower steel strand 18, and then anchors and fixes the lower steel strand 18 through the side steel anchor beam 7; the side steel anchor beam 7 is provided with a side anchor steel plate 30, an anchor positioning plate 25 and an anchor 26, the lower steel strand 18 is fixedly connected with a clamp 28, and a protective cover 27 is provided outside the side steel anchor beam 7.

[0038] Step 6: Installation of transverse prestressing: Fix the transverse prestressing tendons 19 at the lower part of the cap beam 9 through the transverse steel anchor plate 20.

[0039] Step 7: Dismantling the construction platform: Use a crane to dismantle the suspended construction platform 5.

[0040] Example 2

[0041] As another embodiment, the external prestressed reinforced and repaired concrete cap beam obtained by the construction method of the external prestressed reinforced and repaired concrete cap beam in embodiment 1 is as follows: Figures 1 to 6 As shown, it includes a cap beam 9, a pier column 4, a cap 2, a newly added foundation 1, a reinforced steel pipe column 3, a hanging construction platform 5, longitudinal prestressed tendons 8 and a transverse prestressed device 10;

[0042] like Figure 1 and Figure 3 As shown, the newly added foundation 1 and reinforced steel pipe columns 3 are installed below the existing bridge. A suspended construction platform 5 is installed on the cap beam 9 and secured to the cap beam 9 via an overhang bracket 15. A distribution beam 17 is laid beneath the suspended construction platform 5 to form a steel plate platform 12, providing a platform for reinforcing the cap beam 9 and improving construction safety. The existing bridge is equipped with piers 4 and abutments 2 below. The newly added foundation 1 and reinforced steel pipe columns 3 are installed between these piers 4.

[0043] like Figure 2 and Figure 4As shown, a temporary auxiliary stabilizing hanger 11 for assisting in positioning the longitudinal prestressed tendons 8 is provided on the upper portion of the suspended construction platform 5. The cap beam 9 is reinforced by the longitudinal prestressed tendons 8 and the transverse prestressing device 10. The transverse prestressing device 10 includes transverse prestressed tendons 19. The cap beam 9 is also fixed with a transverse steel anchor plate 20 via anchor screws 29. The transverse prestressed tendons 19 are fixed to the lower portion of the cap beam 9 via the transverse steel anchor plate 20. The longitudinal prestressed tendons 8 include lower steel strands 18 and upper steel strands 24. The longitudinal prestressed tendons 8 are anchored by end steel anchor beams 6 and side steel anchor beams 7.

[0044] like Figure 6 As shown, the end steel anchor beam 6 is provided with an end anchor steel plate 22 and a support steel 21 , the upper steel strand 24 is anchored through the end steel anchor beam 6 , and a protective cover 27 is provided outside the end steel anchor beam 6 .

[0045] like Figure 5 As shown, the lower steel strand 18 is anchored by the side steel anchor beam 7, the side steel anchor beam 7 is provided with a side anchor steel plate 30, an anchor positioning plate 25 and an anchor 26, the lower steel strand 18 is fixedly connected with a clamp 28, a protective cover 27 is provided outside the side steel anchor beam 7, and the anchor positioning plate 25 is fixed to the cap beam 9 by an anchor screw 29.

Claims

1. A construction method for reinforcing and repairing a concrete cap beam with external prestressing, characterized in that , including the following steps: Step 1: Bridge reinforcement construction: construct a new foundation (1) at the bottom of the original bridge, and use a reinforced steel pipe column (3) to reinforce the bridge; the new foundation (1) and the reinforced steel pipe column (3) are arranged between the piers (4) of the original bridge, and the reinforced steel pipe column (3) is arranged above the new foundation (1); Step 2: Installation of the hanging construction platform: Install an upper cross bracket (15) on the upper part of the cap beam (9) to install the hanging construction platform (5); a temporary auxiliary stabilizing hanger (11) for assisting the positioning of the longitudinal prestressed tendons (8) is provided on the upper part of the hanging construction platform (5); a distribution beam (17) is laid on the lower part of the hanging construction platform (5), and the distribution beams (17) are spliced ​​to form a steel plate platform (12); Step 3: Fixing the anchoring steel plate: Fixing the anchoring plate (25) and the transverse steel anchor plate (20) on the cap beam (9) by means of anchoring screws (29); Step 4: Installation of the upper steel strand: A temporary auxiliary stabilizing hanger (11) is used to assist in positioning the upper steel strand (24), and then the upper steel strand (24) is anchored and fixed by the end steel anchor beam (6); Step 5: Installation of the lower steel strand: A temporary auxiliary stabilizing hanger (11) is used to assist in positioning the lower steel strand (18), and then the lower steel strand (18) is anchored and fixed by the side steel anchor beam (7); Step 6: Transverse prestressing installation: fix the transverse prestressing tendons (19) at the lower part of the cap beam (9) through the transverse steel anchor plate (20); Step 7: Dismantling the construction platform: Use a crane to dismantle the suspended construction platform (5).

2. The construction method for reinforcing and repairing a concrete cap beam with external prestressing according to claim 1 is characterized in that: In step three, the setting position of the anchoring plate (25) corresponds to the anchoring position of the lower steel strand (18); the setting position of the transverse steel anchor plate (20) corresponds to the anchoring position of the transverse prestressed tendon (19).

3. The construction method for reinforcing and repairing a concrete cap beam with external prestressing according to claim 1 is characterized in that: In step 4, the end steel anchor beam (6) is provided with an end anchor steel plate (22) and a support steel (21), the upper steel strand (24) is anchored through the end steel anchor beam (6), and a protective cover (27) is provided outside the end steel anchor beam (6).

4. The construction method for reinforcing and repairing a concrete cap beam with external prestressing according to claim 1 is characterized in that: In step five, the side steel anchor beam (7) is provided with a side anchor steel plate (30), an anchoring plate (25) and an anchor (26), the lower steel strand (18) is fixedly connected with a clamp (28), and a protective cover (27) is provided outside the side steel anchor beam (7).

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