A protective demolition method for bridge piers in confined working space

Abstract

The present invention discloses a method for protective removal of bridge piers in a restricted working space, comprising the following steps: step S1: building a temporary support frame and a full-height support work platform on the cap; step S2: transferring the support system of the main beam from the support on the cap beam to the temporary support frame; step S3: cutting the cap beam into small cap beam concrete blocks on the full-height support work platform, and removing each small cap beam concrete block located on the top layer; step S4: installing a mobile gantry on the full-height support work platform to remove the remaining small cap beam concrete blocks in the cap beam; step S5: horizontally cutting the portion above the connection between the pier column and the cap platform into a plurality of pier column segments; step S6: hoisting and removing each of the pier column segments one by one through the mobile gantry and the automobile crane; step S7: chiseling off the concrete at the connection between the pier column and the cap platform, and retaining the original steel bars of the pier column. The present invention can perform protective removal of bridge piers in a restricted working space, and has high construction efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge pier removal, and more specifically, to a method for protectively removing bridge piers in a confined working space. Background Art

[0002] In recent years, my country's construction projects have developed rapidly. Concrete structures have become the main structural form of infrastructure projects due to their advantages of low material consumption, fast construction, and good durability. After years of operation, some bridges have been in use. Due to external forces, the piers of some bridges have tilted beyond the limit, while the upper components of the bridges are relatively intact. When the piers cannot be reinforced or corrected, they can only be demolished in a protective manner (i.e., without damaging the main beams and components below the piers); therefore, the main beams on both sides of the piers to be demolished need to be temporarily supported. As a result, the demolition of the piers often faces problems such as small construction space, difficulty in using truck cranes, and limited construction, which affects the construction efficiency and cannot meet the purpose of emergency repairs. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0004] In order to achieve these purposes and other advantages according to the present invention, a method for protective removal of bridge piers in a confined working space is provided, comprising the following steps:

[0005] Step S1: constructing a temporary support frame and a full-height support work platform on the bridge cap; the temporary support frame is located below the main beam of the bridge, and the full-height support work platform is located below the cap beam of the bridge;

[0006] Step S2: installing a synchronous lifting device on the top of the temporary support frame, lifting the main beam by the synchronous lifting device, and transferring the support system of the main beam from the support on the cap beam to the temporary support frame;

[0007] Step S3: cutting the cap beam into small cap beam concrete blocks on the full-height support working platform, and moving each cap beam concrete block located on the top layer to the full-height support working platform and located outside the vertical projection of the main beam on the full-height support working platform, and then hoisting and removing each cap beam concrete block by a truck crane;

[0008] Step S4: After the top layer of the cap beam is removed, a mobile gantry is installed on the full-height support work platform, and the remaining small pieces of cap beam concrete in the cap beam are moved to the outside of the vertical projection of the main beam on the full-height support work platform by the mobile gantry, and then the small pieces of cap beam concrete are hoisted and removed by a truck crane;

[0009] Step S5: On the full-height support work platform, the portion above the connection between the pier column and the cap is horizontally cut into a plurality of pier column segments along the height direction of the pier column;

[0010] Step S6: lifting each of the pier column segments by the mobile gantry and moving them to the full-height support working platform, and located outside the vertical projection of the main beam on the full-height support working platform, and then lifting and removing each of the pier column segments one by one by the truck crane;

[0011] Step S7: Chisel away the concrete at the connection between the pier column and the cap, and retain the original steel bars of the pier column.

[0012] Preferably, in step S1, the temporary support frames are provided on both sides of the cap beam, and the bottom of the temporary support frames is fixedly connected to the base.

[0013] Preferably, the synchronous jacking device is a hydraulic synchronous jacking system, and the main beam is synchronously lifted by the synchronous jacking devices on both sides of the cap beam to transfer the beam load to the temporary support frame.

[0014] Preferably, in step S3, the cap beam is firstly divided into multiple layers in the horizontal direction, each layer is 0.5m high; and then each layer is cut into multiple cap beam concrete blocks in the vertical direction, each cap beam concrete block is 0.5-1m long.

[0015] Preferably, the full-height support working platform is built around the pier, and both ends extend out of the outside of the main beam, and the top surface of the full-height support working platform is not higher than the bottom surface of the cap beam.

[0016] Preferably, at least one temporary bracket is provided on the full-height support working platform, and the temporary bracket is arranged at the end of the cap beam and is located outside the vertical projection of the main beam on the full-height support working platform.

[0017] Preferably, each of the small pieces of cap beam concrete located on the top layer is moved horizontally to the temporary bracket by a hand winch, the hand winch is fixed on the temporary bracket, and then the small pieces of cap beam concrete on the temporary bracket are lifted and removed by the truck crane.

[0018] Preferably, the mobile gantry can be moved on the full-height support working platform along the width direction of the main beam so as to move the cap beam concrete blocks and the pier column segments to the outside of the vertical projection of the main beam on the full-height support working platform.

[0019] Preferably, the connection between the pier and the cap in step S5 and step S7 includes a pier column body located at a height of at least 1.5 m above the cap.

[0020] Preferably, step S5 further comprises drilling two blind holes in each pier column segment, wherein the two blind holes are symmetrically arranged along the center of the pier column segment.

[0021] The present invention has at least the following beneficial effects:

[0022] The protective dismantling method for bridge piers in a confined working space provided by the present invention meets the working requirements in the confined space by setting up a temporary support frame and a full-height support working platform. The temporary support frame temporarily supports the main beam, and the cap beam and pier columns are cut and removed in blocks on the full-height support working platform, thereby improving the transportation speed and thus greatly improving the overall construction efficiency, freeing up space and time for subsequent construction and repair processes, and the construction work has little impact and does not damage the main beam or the abutment, thereby achieving protective dismantling of the bridge piers.

[0023] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the temporary support frame and the full-height support work platform in one embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the side structure of the full-height support work platform described in the above embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of lifting and removing small pieces of cap beam concrete in the above embodiment of the present invention;

[0027] Figure 4 It is a schematic diagram of the structure of the mobile gantry described in the above embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0029] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0030] like Figure 1 to Figure 4 As shown, the present invention provides a method for protective removal of bridge piers in a confined working space, comprising the following steps:

[0031] Step S1: constructing a temporary support frame 2 and a full-height support work platform 3 on the bridge pier 1; the temporary support frame is located below the main beam 6 of the bridge, and the full-height support work platform 3 is located below the cap beam 5 of the bridge;

[0032] Step S2: Install a synchronous lifting device on the top of the temporary support frame 2, lift the main beam through the synchronous lifting device, and transfer the support system of the main beam 6 from the support on the cap beam 5 to the temporary support frame 2;

[0033] Step S3: cutting the cap beam 5 into small cap beam concrete blocks on the full-height support work platform 3, and moving each small cap beam concrete block to the full-height support work platform 3 and located outside the vertical projection of the main beam 6 on the full-height support work platform 3, and then hoisting and removing each small cap beam concrete block by the truck crane 9;

[0034] Step S4: After the top layer of the cap beam 5 is removed, a mobile gantry 10 is installed on the full-height support work platform 3, and the remaining small pieces of cap beam concrete in the cap beam 5 are moved to the outside of the vertical projection of the main beam 6 on the full-height support work platform 3 by the mobile gantry 10, and then the small pieces of cap beam concrete are hoisted and removed by the truck crane 9;

[0035] Step S5: On the full-height support work platform 3, the portion above the connection between the pier column 4 and the cap 1 is horizontally cut into a plurality of pier column segments along the height direction of the pier column 4;

[0036] Step S6: hoisting and moving each of the pier column segments onto the full-height support work platform 3 by the mobile gantry 10, and being located outside the vertical projection of the main beam 6 on the full-height support work platform 3, and then hoisting and removing each of the pier column segments one by one by the truck crane 9;

[0037] Step S7: chiseling away the concrete at the connection between the pier column 4 and the cap 1, and retaining the original steel bars of the pier column 4.

[0038] In this technical solution, the temporary support frame 2 and the full-height support work platform 3 need to be designed according to the structural dimensions of the pier to be demolished. Preferably, the temporary support frame 2 adopts a support with few fulcrums, and the full-height support work platform adopts a disc-type full-height support. The temporary support frame 2 and the full-height support work platform 3 are provided to meet the working requirements in a confined space. The temporary support frame 2 temporarily supports the main beam 6, and the cap beam 5 and the pier 4 are cut and removed in blocks on the full-height support work platform 3, which increases the transportation speed, thereby greatly improving the overall construction efficiency, freeing up space and time for subsequent construction repair processes, and the construction work has little impact, does not damage the main beam 6 or the pedestal 1, and achieves the purpose of protective demolition. After the cap beam 5 is cut, the small block of cap beam concrete located on the top layer is first removed to provide installation space for the mobile gantry 10. The mobile gantry 10 is straddled on the remaining cap beam 5, and the remaining small blocks of the cap beam concrete are hoisted to the full-height support work platform 3 by the mobile gantry 10. The cap beam 5 and the pier 4 in step S3 and step S5 can be cut by a conventional rope saw.

[0039] In another embodiment, in step S1, the temporary support frame 2 is provided on both sides of the cap beam 5, and the bottom of the temporary support frame 2 is fixedly connected to the cap 1. Furthermore, the synchronous jacking device is a hydraulic synchronous jacking system, and the main beam 6 is synchronously jacked by the synchronous jacking devices on both sides of the cap beam 5, and the beam load is transferred to the temporary support frame 2. The hydraulic synchronous jacking system is a synchronous jacking system conventionally used in the art, specifically including a computer control system, a hydraulic pump station, a displacement and pressure sensor, a hydraulic jack, etc.

[0040] In another embodiment, in step S3, the cap beam 5 is firstly divided into multiple layers in the horizontal direction, and the height of each layer is 0.5m; then each layer is cut into multiple cap beam concrete blocks in the vertical direction, and the length of each cap beam concrete block is 0.5 to 1m.

[0041] In another embodiment, the full-height support work platform 3 is built around the pier 4, and the two ends extend out of the main beam 6, so as to facilitate the movement of the small blocks of concrete of the cap beam and the pier segment to the outside of the vertical projection of the main beam 6 on the full-height support work platform 3, so as to facilitate the subsequent lifting and removal by the automobile crane 9. In addition, the top surface of the full-height support work platform 3 is not higher than the bottom surface of the cap beam 5, providing a working space for the cutting and removal of the cap beam 5.

[0042] In another embodiment, at least one temporary bracket 7 is provided on the full-height support working platform 3 , and the temporary bracket 7 is arranged at the end of the cap beam 5 and is located outside the vertical projection of the main beam 6 on the full-height support working platform 3 .

[0043] In order to facilitate the removal of the small pieces of cap beam concrete on the top layer of the cap beam 5, the small pieces of cap beam concrete are further moved horizontally to the temporary bracket 7 by a hand winch 8, the hand winch 8 is fixed on the temporary bracket 7, and then the small pieces of cap beam concrete on the temporary bracket 7 are lifted and removed by the automobile crane 9.

[0044] In another embodiment, the mobile gantry 10 can move along the width direction of the main beam 6 on the full-height support work platform 3, so as to move the small concrete blocks of the cap beam and the pier column segments to the outside of the vertical projection of the main beam 6 on the full-height support work platform 3. The mobile gantry 10 is a light and small lifting device conventionally used in the art, which is provided with a lifting device such as an electric or manual hoist, and universal load wheels are installed under its legs to meet the movement requirements.

[0045] In another embodiment, the connection between the pier column 4 and the cap 1 in step S5 and step S7 includes a pier column body located at least 1.5 m above the cap. In step S7, the concrete at the connection between the pier column 4 and the cap 1 is chiseled out manually or with high-pressure water, and the steel bars of the original pier are retained to ensure the connection between the cap 1 and the newly built pier column.

[0046] In another embodiment, to facilitate hoisting, step S5 further includes drilling two blind holes in each pier column segment, and the two blind holes are symmetrically arranged along the center of the pier column segment. Preferably, the blind holes can be drilled in each pier column segment by an impact drill, with a hole depth of 20 cm and a hole diameter of 20 cm. The blind holes are used to limit the hoisting wire rope when the mobile gantry 10 is hoisted to prevent the wire rope from sliding upward.

[0047] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for protective removal of bridge piers in a confined working space, characterized in that: The following steps are involved: Step S1: constructing a temporary support frame and a full-height support work platform on the bridge cap; The temporary support frame is located below the main beam of the bridge, and the full-height support work platform is located below the cap beam of the bridge; Step S2: installing a synchronous lifting device on the top of the temporary support frame, lifting the main beam by the synchronous lifting device, and transferring the support system of the main beam from the support on the cap beam to the temporary support frame; Step S3: cutting the cap beam into small cap beam concrete blocks on the full-height support working platform, and moving each cap beam concrete block located on the top layer to the full-height support working platform and located outside the vertical projection of the main beam on the full-height support working platform, and then hoisting and removing each cap beam concrete block by a truck crane; Step S4: After the top layer of the cap beam is removed, a mobile gantry is installed on the full-height support work platform, and the remaining small pieces of cap beam concrete in the cap beam are moved to the outside of the vertical projection of the main beam on the full-height support work platform by the mobile gantry, and then the small pieces of cap beam concrete are hoisted and removed by a truck crane; Step S5: On the full-height support work platform, the portion above the connection between the pier column and the cap is horizontally cut into a plurality of pier column segments along the height direction of the pier column; Step S6: lifting each of the pier column segments by the mobile gantry and moving them to the full-height support working platform, and located outside the vertical projection of the main beam on the full-height support working platform, and then lifting and removing each of the pier column segments one by one by the truck crane; Step S7: Chisel away the concrete at the connection between the pier column and the cap, and retain the original steel bars of the pier column.

2. The method for protective removal of bridge piers in a confined working space as claimed in claim 1, characterized in that: In step S1, the temporary support frames are provided on both sides of the cap beam, and the bottom of the temporary support frames is fixedly connected to the base.

3. The method for protective removal of bridge piers in a confined working space as claimed in claim 2, characterized in that: The synchronous jacking device is a hydraulic synchronous jacking system, which synchronously jacks up the main beam through the synchronous jacking devices on both sides of the cap beam, and transfers the beam load to the temporary support frame.

4. The method for protective removal of bridge piers in a confined working space as claimed in claim 1, characterized in that: In step S3, the cap beam is firstly divided into multiple layers in the horizontal direction, and the height of each layer is 0.5m; then each layer is cut into multiple cap beam concrete blocks in the vertical direction, and the length of each cap beam concrete block is 0.5-1m.

5. The method for protective removal of bridge piers in a confined working space as claimed in claim 1, characterized in that: The full-height support working platform is built around the pier, and both ends extend out of the outside of the main beam. The top surface of the full-height support working platform is not higher than the bottom surface of the cap beam.

6. The method for protective removal of bridge piers in a confined working space as claimed in claim 5, characterized in that: At least one temporary bracket is arranged on the full-height support working platform. The temporary bracket is arranged at the end of the cap beam and is located outside the vertical projection of the main beam on the full-height support working platform.

7. The method for protective removal of bridge piers in a confined working space as claimed in claim 6, characterized in that: The small blocks of cap beam concrete located on the top layer are moved horizontally to the temporary bracket by a hand chain hoist, and the hand chain hoist is fixed on the temporary bracket, and then the small blocks of cap beam concrete on the temporary bracket are lifted and removed by the automobile crane.

8. The method for protective removal of bridge piers in a confined working space as claimed in claim 1, characterized in that: The movable gantry can be moved on the full-height support working platform along the width direction of the main beam so as to move the cap beam concrete blocks and the pier column segments to the outside of the vertical projection of the main beam on the full-height support working platform.

9. The method for protective removal of bridge piers in a confined working space as claimed in claim 1, characterized in that: The connection between the pier and the cap in step S5 and step S7 includes the pier column body located at a height of at least 1.5 m above the cap.

10. The method for protective removal of bridge piers in a confined working space as claimed in claim 1, characterized in that: Step S5 also includes drilling two blind holes in each pier column segment, wherein the two blind holes are symmetrically arranged along the center of the pier column segment.

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