Jack-up heightening method for single-column large cantilever cap beam

Abstract

This invention proposes a method for lifting and raising a single-column cantilever cap beam, belonging to the field of building construction technology, including the following steps: S1: Clear the soil covering the pier cap location to expose the side of the pier cap; S2: Install reinforcing bars on the side of the pier cap to expand the pier cap; S3: Install the beam bottom support and clamp beam formwork under the cap beam, and construct the clamp beam around the pier column; S4: After the clamp beam construction is completed, remove the clamp beam formwork and beam bottom support; S5: Install steel pipe columns and lifting equipment on the pier cap; S6: Cut the pier column to form an upper pier column and a lower pier column; S7: Operate the lifting equipment to lift the clamp beam, and cyclically lift the upper pier column and the cap beam; S8: Extend the pier column height; S9: Remove the clamp beam; S10: Remove the lifting equipment and steel pipe columns. A clamp beam is constructed at the bottom of the cap beam to support the bottom of the cap beam. Steel pipe columns and jacking equipment are arranged around the outer side of the pier column below the clamp beam. During jacking, the stress on the cap beam is basically the same as the normal stress, and cracking will not occur, thus ensuring the quality of the project.

Description

Technical Field

[0001] This invention belongs to the field of building construction technology, specifically relating to a method for lifting and raising a single-column cantilever cap beam. Background Technology

[0002] With urban development, the clearance under some elevated bridges can no longer meet traffic requirements, affecting urban development. Demolishing the bridges and building new ones would take a long time, be costly, and not conform to green and low-carbon development. The solution is to lift and raise the bridges and add higher piers, which is cheaper and faster to construct.

[0003] Currently, the traditional construction process is as follows: construct the foundation → construct the leveling layer on the bottom slope of the cap beam → install steel pipe columns and jacks → cut off the pier column → cyclically lift it into place → connect the pier column reinforcement and pour concrete → dismantle the lifting equipment.

[0004] The above-mentioned construction process has the following technical problems: the single-column cantilever cap beam has a large cantilever length on both sides. Simply using steel pipe columns and jacks to support the bottom of the cantilever for jacking can easily cause cracks at the bottom of the cap beam due to the large cantilever, resulting in project abandonment. Summary of the Invention

[0005] To address the problems existing in the prior art, a method for jacking up a single-column cantilever cap beam is provided. A clamping beam is constructed at the bottom of the cap beam to support it. Steel pipe columns and jacking equipment are arranged around the outer perimeter of the lower pier column of the clamping beam. During jacking, the stress on the cap beam is essentially the same as under normal stress, preventing cracking and ensuring project quality.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] This technical solution proposes a method for lifting and raising a single-column cantilever cap beam, including the following steps:

[0008] S1: Clear the backfill soil at the location of the pile cap to expose the side of the pile cap;

[0009] S2: Install reinforcing bars on the side of the foundation, tie the reinforcing bars, erect formwork, pour concrete, and expand the foundation during construction;

[0010] S3: Install the beam bottom support and clamp beam formwork below the cap beam, and carry out clamp beam construction around the pier column;

[0011] S4: After the construction of the clamp beam is completed, remove the clamp beam formwork and the bottom support of the beam;

[0012] S5: Install steel pipe columns and jacking equipment on the pier;

[0013] S6: Cut off the pier column to form an upper pier column and a lower pier column;

[0014] S7: Operate the jacking equipment to jack up the clamp beam, and cyclically jack up the upper pier and cap beam to the design elevation; S8: Plug the height;

[0015] S9: Remove the clamp beam;

[0016] S10: Dismantle the jacking equipment and steel pipe columns.

[0017] Preferred construction process for extending the height of pier columns in S8:

[0018] S81: Mark lines on the pier column to determine the area for rebar stripping;

[0019] S82: The pier column is cut using a wire saw to form the upper pier column and the lower pier column;

[0020] S83: Remove the concrete between the cutting lines and peel out the joint reinforcement.

[0021] S84: Prepare several main bars and connect the corresponding splice bars at the upper and lower positions through the main bars;

[0022] S85: Tie the stirrups;

[0023] S86: Erecting formwork;

[0024] S87: Pour concrete to form a raised pier column;

[0025] S88: Apply anti-corrosion coating to the outer wall of the pier above ground.

[0026] Preferably, the stripping range in S81 is 20cm above and below the cut line.

[0027] Preferably, the clamp beam in S3 is an integral reinforced concrete structure.

[0028] The preferred construction process for the clamp beam in S3 is as follows:

[0029] S31: Apply release agent to the outer side of the pier column and the bottom surface of the cap beam respectively;

[0030] S32: Erect the bottom support of the clamp beam;

[0031] S33: Binding the reinforcing bars of the beam with clamps;

[0032] S34: Formwork for erecting clamp beams;

[0033] S35: Pour concrete to form a hoop beam.

[0034] Preferably, the specific method for removing the clamp beam in S9 is as follows:

[0035] S91: Erect the bottom support frame for the clamp beam;

[0036] S92: Manual demolition of concrete;

[0037] S93: Stripping the reinforcing bars of the clamp beam;

[0038] S94: Demolition complete.

[0039] Preferably, the clamp beam in S3 is a split-combination structure, which includes a reinforced concrete base surrounding the pier column, the reinforced concrete base forming an inner ring structure; a supporting steel plate is connected to the bottom surface of the reinforced concrete base, and several triangular brackets are connected to the circumferential sidewalls of the reinforced concrete base, the bottom of the triangular brackets being connected to the supporting steel plate; the triangular brackets and the supporting steel plate forming an outer ring structure.

[0040] Preferably, the construction method for the clamp beam in S3 is as follows:

[0041] S31: Apply release agent to the outer side of the pier column and the bottom surface of the cap beam respectively;

[0042] S32: Erect the bottom support of the clamp beam;

[0043] S33: Binding the reinforcing bars of the beam with clamps;

[0044] S34: Formwork for erecting clamp beams;

[0045] S35: Pour concrete and pre-embed bolts at the designed locations to form a reinforced concrete base with bolts on the bottom and circumferential sides;

[0046] S36: Remove the beam bottom support and clamp beam formwork;

[0047] S37: Install a triangular bracket on the circumferential side of the reinforced concrete base using bolts;

[0048] S38: A supporting steel plate is installed on the bottom surface of a reinforced concrete base using bolts;

[0049] S39: Connect the bottom of the triangular bracket to the supporting steel plate by bolting and / or welding.

[0050] Preferably, the specific method for removing the clamp beam in S9 is as follows:

[0051] S91: Erect the bottom support frame for the clamp beam;

[0052] S92: Remove the supporting steel plate and triangular bracket;

[0053] S93: Manual demolition of concrete;

[0054] S93: Stripping the reinforcing bars of the clamp beam;

[0055] S94: Demolition complete.

[0056] Compared with the prior art, the present invention has the following advantages:

[0057] 1. This invention involves constructing a clamp beam at the bottom of the cap beam. The clamp beam supports the bottom of the cap beam. Steel pipe columns and jacking equipment are arranged around the outer perimeter of the pier column below the clamp beam. During jacking, the stress on the cap beam is basically the same as the normal stress, and cracking will not occur, thus ensuring the quality of the project.

[0058] 2. The clamp beam can be made of integral reinforced concrete, which can better fit the size of the jacked pier and cap beam, and is convenient for construction.

[0059] 3. The clamp beam has high rigidity, which can better balance the lifting force of the jack and avoid uneven stress and cracking of the concrete.

[0060] 4. The large longitudinal and transverse planar areas of the clamp beam provide a large working space and facilitate construction.

[0061] 5. The clamp beam is a reinforced concrete structure, which has a low cost.

[0062] 6. The design of the clamp beam will not damage the original pier column, and there is no need to carry out destructive operations such as drilling on the original pier column. The concrete structure of the original pier column will not be damaged and its service life will not be affected.

[0063] 7. The clamp beam in this invention can also adopt a split structure. The clamp beam includes a reinforced concrete base surrounding the pier column, forming an inner ring structure. A supporting steel plate is connected to the bottom surface of the reinforced concrete base, and triangular brackets are connected to the circumferential sidewalls. The triangular brackets are connected to the supporting steel plate to form an integral structure. The triangular brackets and the supporting steel plate form an outer ring structure. This method can ensure that the stress on the cap beam during jacking is basically the same as the normal stress. During dismantling, since part of the structure is a steel structure, it can be dismantled quickly. Compared with an integral concrete structure, dismantling is more convenient and can improve work efficiency. Attached Figure Description

[0064] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0065] Figure 1 This is the main view of a single-column cantilever cap beam structure in the existing technology.

[0066] Figure 2 This is a side view of a single-column cantilever cap beam structure in the existing technology.

[0067] Figure 3 This is a structural diagram of a single-column cantilever cap beam when extended using traditional construction techniques.

[0068] Figure 4 This is a schematic diagram of the structure when the height-increasing method of this invention is used.

[0069] Figure 5 yes Figure 4 Side view of the overall structure.

[0070] Figure 6 This is a cross-sectional view of the structure of the hoop beam after casting in this invention.

[0071] Figure 7 This is a schematic diagram of the connection structure between the splice reinforcement and the main reinforcement when the pier column is extended.

[0072] Figure 8 yes Figure 7 Cross-sectional view along the AA direction.

[0073] Figure 9 This is a schematic diagram of the connection between the main reinforcement and the splice reinforcement.

[0074] Figure 10 A schematic diagram of the structure of the clamp beam in Embodiment 2 of the present invention.

[0075] Explanation of reference numerals in the attached figures:

[0076] 1-Pier column; 101-Joint reinforcement; 102-Main reinforcement; 103-Extrusion sleeve; 2-Cap beam; 3-Beam; 4-Leveling layer; 5-Pile cap; 51-Pile cap extension area; 6-Steel pipe column; 7-Piercing equipment; 8-Beam clamp; 81-Reinforced concrete base; 82-Supporting steel plate; 83-Triangular bracket; 9-Extended pier column; 10-Beam bottom support; 11-Clamp beam formwork; 12-Threaded rod; 13-High-strength bolt; 14-Anti-corrosion coating layer. Detailed Implementation

[0077] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0078] Example 1

[0079] like Figure 1-2 As shown, the existing single-column cantilever cap beam structure includes pier 1, cap beam 2 and beam 3. When lifting and extending the single-column cantilever cap beam, the traditional construction process is as follows: construct the foundation 5 → construct the bottom sloping leveling layer 4 of the cap beam 2 → install the steel pipe column 6 and the lifting equipment 7 (jacks) → cut off the pier 1 → cyclically lift to the position → connect the pier reinforcement and pour concrete → dismantle the lifting equipment 7.

[0080] However, the above construction process has the following technical problems: For a single-column cantilever cap beam, with large cantilever lengths on both sides, simply using steel pipe columns 6 and jacks for support at the bottom of the cantilever for jacking can easily cause cracks at the bottom of the cap beam 2 due to the large cantilever size, leading to project abandonment. (See attached diagram). Figure 3 .

[0081] In response to this technical problem, the applicant has conducted in-depth research and made the following improvements:

[0082] Reference Appendix Figure 4-9 This embodiment proposes a method for lifting and raising a single-column cantilever cap beam, including the following steps:

[0083] S1: Clear the backfill soil at position 5 of the foundation, exposing side 5 of the foundation;

[0084] S2: Install reinforcing bars on the side of the pier cap 5, tie the reinforcing bars, erect formwork, pour concrete, and expand the pier cap to form the pier cap expansion area 51, in preparation for subsequent jacking.

[0085] S3: Install the beam bottom support 10 and the clamp beam formwork 11 below the cap beam 2, and carry out the clamp beam 8 construction around the pier column 1; the clamp beam 8 is located at the bottom of the cap beam 2, and the clamp beam 8 supports the bottom of the cap beam 2.

[0086] S4: After the construction of the clamp beam 8 is completed, remove the clamp beam formwork 11 and the beam bottom support 10.

[0087] S5: Install steel pipe columns 6 and jacking equipment 7 on the foundation 5. The jacking equipment 7 uses jacks.

[0088] S6: Cut off pier 1 to form the upper pier and the lower pier.

[0089] S7: Operate the jacking device 7 to jack up the clamp beam 8, and cyclically jack up the upper pier column and cap beam 2 to the design elevation.

[0090] S8: Pier 1 height extension.

[0091] S9: Remove the clamp beam 8.

[0092] S10: Remove the jacking equipment 7 and the steel pipe column 6.

[0093] Using the improved method described above, a clamp beam 8 is constructed at the bottom of the cap beam 2. The clamp beam 8 can support the bottom of the cap beam 2. Steel pipe columns 6 and jacking equipment 7 are arranged around the outer side of the lower pier column 1 of the clamp beam 8. During jacking, the stress on the cap beam 2 is basically the same as the normal stress, and cracking will not occur, thus ensuring the quality of the project.

[0094] The following section further elaborates on the specific details of each step in the above method:

[0095] Construction process for extending the height of pier 1 in S8:

[0096] S81: Draw a line on pier 1 to determine the area to be stripped of the reinforcing steel; the stripping area is 20cm above and below the cut line.

[0097] S82: Use a wire saw to cut pier column 1 to form the upper pier column and the lower pier column.

[0098] S83: Remove the concrete between the cutting lines to expose the joint reinforcement 101 (i.e., expose the rebar joint).

[0099] S84: Prepare the same number of main reinforcement bars 102 as pier column 1, and connect the corresponding splice bars 101 at the upper and lower positions through the main reinforcement bars 102; the main reinforcement bars 102 are connected to the splice bars 101 through the extrusion sleeve 103.

[0100] S85: Tie the stirrups.

[0101] S86: Erecting formwork; erecting formwork and supports in elevated areas.

[0102] S87: Pour concrete to form the extended pier column 9.

[0103] S88: Apply anti-corrosion coating to the outer wall of the pier 1 above ground to form an anti-corrosion coating layer 14.

[0104] It should be noted that, in this embodiment, the clamp beam 8 in step S3 is an integral reinforced concrete structure, and the construction process for using an integral reinforced concrete structure is as follows:

[0105] The construction process for hoop beam 8 in S3 is as follows:

[0106] S31: Apply release agent to the outer side of pier 1 and the bottom surface of cap beam 2 respectively;

[0107] S32: Erect 8 clamp beams and 10 beam bottom supports;

[0108] S33: Binding the reinforcing bars of the beam with clamps;

[0109] S34: Erecting formwork for the hoop beam 11;

[0110] S35: Pour concrete to form the hoop beam 8.

[0111] The above-described structure of the clamp beam 8 offers the following advantages:

[0112] Firstly, the clamp beam 8 adopts an integral reinforced concrete structure, which can better adapt to the dimensions of the jacked pier column 1 and cap beam 2, making construction convenient.

[0113] Secondly, the high stiffness of the clamp beam 8 can better balance the lifting force of the jack and avoid uneven stress and cracking of the concrete.

[0114] Thirdly, the large longitudinal and transverse planar areas of the clamp beam 8 provide a larger working space, facilitating construction.

[0115] Fourth, the hoop beam 8 is a reinforced concrete structure, which has a low cost.

[0116] Fifth, the design of the clamp beam 8 will not damage the original pier column 1. There is no need to carry out destructive operations such as drilling on the original pier column 1. The concrete structure of the original pier column 1 will not be damaged and its service life will not be affected.

[0117] In this embodiment, the clamp beam 8 is an integral reinforced concrete structure. Therefore, the specific method for removing the clamp beam 8 in S9 is as follows:

[0118] S91: Erect 8 clamp beams and 10 beam bottom supports;

[0119] S92: Manual demolition of concrete;

[0120] S93: Stripping the reinforcing bars of the clamp beam;

[0121] S94: Demolition complete.

[0122] Example 2

[0123] Reference Appendix Figure 10 Considering that while the integral reinforced concrete structure of the clamp beam 8 has the advantage of easy construction, the subsequent demolition work is quite troublesome, requiring manual dismantling piece by piece, which is time-consuming and labor-intensive; to address this issue, the applicant has made further improvements. Other structures and methods are the same as in Embodiment 1, except that in this embodiment, the clamp beam 8 in S3 is a modular structure:

[0124] The clamp beam 8 includes a reinforced concrete base 81 surrounding the pier column 1, forming an inner ring structure; a supporting steel plate 82 is connected to the bottom surface of the reinforced concrete base 81, and several triangular brackets 83 are connected to the circumferential sidewalls of the reinforced concrete base 81, with the bottom of the triangular brackets 83 connected to the supporting steel plate 82; the triangular brackets 83 and the supporting steel plate 82 form an outer ring structure.

[0125] The triangular bracket 83 has multiple mounting holes; the supporting steel plate 82 also has multiple through holes, and the supporting steel plate 82 and the triangular bracket 83 can be connected by bolting and / or welding.

[0126] In this embodiment, the reinforced concrete base 81 is relatively small in volume. While meeting the requirements for jacking and support, the outer ring structure adopts a partial steel structure, which facilitates subsequent dismantling. The steel structure is easier to dismantle.

[0127] Correspondingly, when the clamp beam 8 is a modular structure, the construction method for clamp beam 8 in S3 is as follows:

[0128] S31: Apply release agent to the outer side of pier 1 and the bottom surface of cap beam 2 respectively.

[0129] S32: Erect 8 clamp beams and 10 beam bottom supports. The beam bottom supports 10 are full-span supports.

[0130] S33: Binding the reinforcing bars of the hoop beam.

[0131] S34: Erecting the formwork for the hoop beam 11.

[0132] S35: Pour concrete and pre-embed bolts at the design position to form a reinforced concrete base 81 with bolts on the bottom and circumferential sides; drill holes in the supporting steel plate 82 and the triangular bracket 83 in advance at the design position to form installation holes and through holes.

[0133] S36: Remove the beam bottom support 10 and the clamp beam formwork 11.

[0134] S37: Triangular brackets 83 are installed on the circumferential side of the reinforced concrete base 81 using bolts;

[0135] S38: The supporting steel plate 82 is installed on the bottom surface of the reinforced concrete base 81 by means of bolts;

[0136] S39: The bottom of the triangular bracket 83 is connected to the supporting steel plate 82 by bolting and / or welding to form a whole; the triangular bracket 83 and the supporting steel plate 82 are connected by high-strength bolts 13.

[0137] Correspondingly, the specific method for removing the clamp beam 8 in S9 is as follows:

[0138] S91: Erect 8 clamp beams and 10 beam bottom supports;

[0139] S92: Remove the supporting steel plate 82 and the triangular bracket 83;

[0140] S93: Manual demolition of concrete;

[0141] S93: Stripping the reinforcing bars of the clamp beam;

[0142] S94: Demolition complete.

[0143] This method ensures that the stress on the cap beam 2 is basically the same as the normal stress during jacking. During dismantling, since part of the structure is steel, it can be dismantled quickly. Compared with monolithic concrete structures, dismantling is more convenient and can improve work efficiency.

[0144] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for lifting and raising a single-column cantilever cap beam, characterized in that, Includes the following steps: S1: Clear the backfill soil at the location of the pile cap to expose the side of the pile cap; S2: Install reinforcing bars on the side of the foundation, tie the reinforcing bars, erect formwork, pour concrete, and expand the foundation during construction; S3: Install the beam bottom support and clamp beam formwork below the cap beam, and carry out clamp beam construction around the pier column. The clamp beam supports the bottom of the cap beam. S4: After the construction of the clamp beam is completed, remove the clamp beam formwork and the bottom support of the beam; S5: Install steel pipe columns and jacking equipment on the pier; S6: Cut off the pier column to form an upper pier column and a lower pier column; S7: Operate the jacking equipment to jack up the clamp beam, and cyclically jack up the upper pier column and cap beam to the design elevation; S8: Pier column height extension; S9: Remove the clamp beam; S10: Dismantle the jacking equipment and steel pipe columns.

2. The method for lifting and raising a single-column cantilever cap beam according to claim 1, characterized in that, Construction process for extending the height of piers in S8: S81: Mark lines on the pier column to determine the area for rebar stripping; S82: The pier column is cut using a wire saw to form the upper pier column and the lower pier column; S83: Remove the concrete between the cutting lines and peel out the joint reinforcement. S84: Prepare several main bars and connect the corresponding splice bars at the upper and lower positions through the main bars; S85: Tie the stirrups; S86: Erecting formwork; S87: Pour concrete to form a raised pier column; S88: Apply anti-corrosion coating to the outer wall of the pier above ground.

3. The method for lifting and raising a single-column cantilever cap beam according to claim 2, characterized in that, In S81, the stripping range is 20 cm above and below the cut line.

4. The method for lifting and raising a single-column cantilever cap beam according to claim 1, characterized in that, The hoop beam in S3 is an integral reinforced concrete structure.

5. The method for lifting and raising a single-column cantilever cap beam according to claim 4, characterized in that, The construction process for the S3 clamp beam is as follows: S31: Apply release agent to the outer side of the pier column and the bottom surface of the cap beam respectively; S32: Erect the bottom support of the clamp beam; S33: Binding the reinforcing bars of the beam with clamps; S34: Formwork for erecting clamp beams; S35: Pour concrete to form a hoop beam.

6. The method for lifting and raising a single-column cantilever cap beam according to claim 5, characterized in that, The specific method for removing the clamp beam in S9 is as follows: S91: Erect the bottom support frame for the clamp beam; S92: Manual demolition of concrete; S93: Stripping the reinforcing bars of the hoop beam; S94: Demolition complete.

7. The method for lifting and raising a single-column cantilever cap beam according to claim 1, characterized in that, The clamp beam in S3 is a split-combination structure. The clamp beam includes a reinforced concrete base surrounding the pier column, which forms an inner ring structure. A supporting steel plate is connected to the bottom surface of the reinforced concrete base, and several triangular brackets are connected to the circumferential sidewalls of the reinforced concrete base. The bottom of the triangular brackets is connected to the supporting steel plate. The triangular brackets and the supporting steel plate form an outer ring structure.

8. The method for lifting and raising a single-column cantilever cap beam according to claim 7, characterized in that, The construction method for the clamp beam in S3 is as follows: S31: Apply release agent to the outer side of the pier column and the bottom surface of the cap beam respectively; S32: Erect the bottom support of the clamp beam; S33: Binding the reinforcing bars of the beam with clamps; S34: Formwork for erecting clamp beams; S35: Pour concrete and pre-embed bolts at the designed locations to form a reinforced concrete base with bolts on the bottom and circumferential sides; S36: Remove the beam bottom support and clamp beam formwork; S37: Install a triangular bracket on the circumferential side of the reinforced concrete base using bolts; S38: A supporting steel plate is installed on the bottom surface of a reinforced concrete base using bolts; S39: Connect the bottom of the triangular bracket to the supporting steel plate by bolting and / or welding.

9. The method for lifting and raising a single-column cantilever cap beam according to claim 7, characterized in that, The specific method for removing the clamp beam in S9 is as follows: S91: Erect the bottom support frame for the clamp beam; S92: Remove the supporting steel plate and triangular bracket; S93: Manual demolition of concrete; S94: Stripping the reinforcing bars of the hoop beam; S95: Demolition complete.

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