Construction method of pre-embedded anchor bars in one-step pile construction of high cap cast-in-place pile

Abstract

The present invention discloses a method for pre-embedded anchor bars in one-time pile formation of high-capped cast-in-place piles, and relates to the technical field of cast-in-place pile construction methods. The method for pre-embedded anchor bars in one-time pile formation of high-capped cast-in-place piles comprises step one: measuring the pile position, determining and marking the position of the cast-in-place pile; step two: drilling a hole to the designed depth with a drilling rig, removing the sediment at the bottom of the hole, and ensuring that the bottom of the hole is clean; step three: lowering a steel cage, adjusting the steel cage and fixing it to a preset height at the top of the steel cage. During the implementation of the present invention, the shock-absorbing pad can be installed without secondary grouting, and high-strength grouting materials can be saved to a great extent in large-scale projects. At the same time, during the implementation of the construction method, the height of the steel cage can be determined and the steel cage can be fixed by a height positioning device, and there is no need to manually adjust the position of the steel cage frequently, thereby reducing the position deviation of the steel cage in the cast-in-place pile, saving manpower, and simplifying the grouting steps.

Description

Technical Field

[0001] The invention relates to the technical field of cast-in-place pile construction methods, in particular to a one-time pile forming and pre-embedded anchor bar construction method for high-cap cast-in-place piles. Background Art

[0002] In recent years, the construction of high-cap pile foundations for cryogenic tanks in China has increasingly adopted integrated construction technology. In areas with high seismic fortification, in order to reduce the horizontal seismic force on the pile top, the design institute has adopted the technical measure of adding seismic isolation pads on the pile top.

[0003] In the related technology, the construction process of high-capped cast-in-place piles is as follows: first, lower the steel cage into the pile foundation hole, determine the height of the steel cage, then pour concrete until it is formed to the pile top position, set a reserved hole on the pile top surface in advance, and then insert the anchor rod into the reserved hole after the seismic isolation pad and the anchor rod are installed. Finally, fill the reserved hole tightly with grouting material to combine the anchor rod and the pile body into one.

[0004] The above-mentioned existing technical solutions have the following defects: during the installation of the seismic isolation pad, the reserved holes may deviate, resulting in rework or delays in the construction period, and the reserved holes need to be grouted again when installing the rubber bearings. In order to ensure the grouting effect, the diameter of the reserved holes is relatively large, which leads to large loss of grouting materials and a long construction period. In addition, the deviation of the rubber bearings from the reserved holes when docking will also affect the accuracy of the rubber bearing installation. Summary of the invention

[0005] The object of the present invention is to provide a one-time pile construction method for high cap cast-in-place piles with pre-embedded anchor bars, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a high cap cast-in-place pile one-time pile pre-embedded anchor bar construction method, comprising the following steps:

[0007] Step 1: Measure the pile position, determine and mark the location of the cast-in-place pile;

[0008] Step 2: Use a drilling rig to drill to the designed depth, remove the sediment at the bottom of the hole, and ensure that the bottom of the hole is clean;

[0009] Step 3: lower the steel cage, adjust the height of the steel cage through the height positioning device and fix the steel cage to the preset height at the top of the steel cage;

[0010] Step 4: Pile pouring, continue pouring concrete until it reaches the ground;

[0011] Step 5: Install a positioning plate on the top of the steel cage. The positioning plate limits the upper concrete pouring height by its own height. An anchor foot is provided on the positioning plate to realize the rapid positioning of the rubber bearing. The height of the positioning plate is adjusted by the screw connection column on the positioning plate to determine the upper concrete pouring height.

[0012] Step 6: Upper formwork, set the steel jacket formwork above the ground and continue pouring concrete until the preset height;

[0013] Step 7: Install the bearings. After the concrete solidifies, remove the anchor bars on the positioning plate, blow and polish the top of the positioning plate, and then install the rubber bearings.

[0014] Further to this solution, in step 3, the top height of the steel cage is determined by a preset height positioning device, and determining the top height of the steel cage includes the following steps:

[0015] S1: Determine the height of the steel cage exposed above the ground after it is placed into the drill hole;

[0016] S2: Use a crane to lower the steel cage and adjust the height of the steel cage to a predetermined height;

[0017] S3: Connect and install the adjusting member in the height positioning device to the steel cage, and then control the height of the steel cage exposed above the ground to a predetermined height through the adjusting member;

[0018] S4: Use the surrounding parts and adjusting parts in the height positioning device to fix the steel cage.

[0019] Further regarding this scheme, the height positioning device includes two sleepers, and the adjusting member includes a screw and a screw block. The screw is rotatably installed on the sleepers, and the screw block is screwed on the surface of the screw. An articulated arm is hinged on one side of the screw block, and a hook is screwed on the other end of the articulated arm through a basket screw. The adjusting member is connected to the transverse ribs of the steel cage through the hook.

[0020] Further to this solution, a limiting groove is provided on one side of the sleeper, a jacking plate is slidably connected in the limiting groove, the top of the jacking plate is fixed to the bottom of the screw block, one side of the jacking plate is provided with an inclined surface, the inclined surface is inclined from the top of the jacking plate to the bottom, and the sleeper is provided with a hole connected with the limiting groove corresponding to the limiting groove;

[0021] The encircling member includes a top arm sliding on the inner wall of the hole, one end of the top arm located in the limiting groove is installed with a wheel seat, a pulley that abuts against the inclined surface of the jacking plate is rotatably installed in the wheel seat, and the other end of the top arm is rotatably connected to the encircling plate.

[0022] Further to this solution, the installation of the positioning plate in step 5 includes the following steps:

[0023] V1: Use a crane to suspend the positioning plate to the position directly above the steel cage;

[0024] V2: At least two people hold the positioning plate and use a crane to approach the steel cage. During the operation, the positioning plate is always lowered vertically from the top of the steel cage;

[0025] V3: Fix and adjust the positioning plate and the steel cage, and level the top of the positioning plate to a horizontal state.

[0026] Further to this solution, the positioning plate includes a plate body, with anchor feet fixed on the top of the plate body, a plurality of anchor feet are provided and arranged equidistantly in a circle on the top of the plate body, and screw columns are rotatably installed at positions on the bottom of the plate body corresponding to the anchor feet.

[0027] Furthermore, regarding this scheme, a connecting key is fixedly connected to the bottom of the disk body corresponding to the bottom foot of the anchor bolt, the cross-section of the connecting key is convex, the interior of the screw column is hollow, the top of the screw column rotates at the connecting key, the top of the steel bar of the steel cage is processed into a threaded shape by a tapping process, and the positioning disk is screwed to the top of the steel bar of the steel cage through the screw column.

[0028] Further to this solution, the shaped steel sheath template in step six includes:

[0029] Two sheath formworks are combined to form a columnar casting formwork, and the inner wall diameter of the casting formwork matches the diameter of the cast-in-place pile.

[0030] Further to this solution, the jacket formwork is provided with protrusion one and protrusion two at both ends close to the inner wall side, a notch is provided between the protrusion one and the protrusion two, and a grouting channel is formed at the notch when the two jacket formworks are combined.

[0031] Further to this solution, connecting plates are fixed on both sides of the sheath formwork, and after the sheath formworks are combined, adjacent connecting plates are connected by bolt rods, and nuts threaded onto the bolt rods are provided on both sides of the connecting plates of one of the sheath formworks.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] During the implementation of the high-capped cast-in-place pile one-time pile pre-embedded anchor bar construction method, the shock-absorbing pad can be installed without secondary grouting, and high-strength grouting materials can be saved to a large extent in large-scale projects. At the same time, during the implementation of the construction method, the height of the steel cage can be determined and the steel cage can be fixed by a height positioning device, and there is no need for frequent manual adjustment of the position of the steel cage, which reduces the position deviation of the steel cage in the cast-in-place pile, saves manpower, and simplifies the pouring steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the integrated construction steps of the high cap cast-in-place pile of the present invention;

[0035] Figure 2 It is a schematic diagram of the overall structure of the present invention;

[0036] Figure 3 It is a schematic diagram of the cross-sectional structure of the present invention;

[0037] Figure 4 It is a schematic diagram of the sheath formwork structure of the present invention;

[0038] Figure 5 It is a schematic diagram of the explosion structure of the positioning plate of the present invention.

[0039] In the figure: 1. sleeper; 2. screw rod; 3. screw block; 4. jacking plate; 5. hinged arm; 6. turnbuckle; 7. hook; 8. jacking arm; 801. rod one; 802. rod two; 9. wheel seat; 10. pulley; 11. hugging plate; 12. limit groove; 13. plate; 14. anchor foot; 15. screw column; 16. connecting key; 17. sheath formwork; 171. protrusion one; 172. protrusion two; 173. notch; 18. connecting plate; 19. bolt rod; 20. nut. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that, in the description of the present invention, the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0042] Furthermore, it should be understood that for the sake of ease of description, the sizes of the various components shown in the drawings are not drawn according to actual proportions. For example, the thickness or width of certain layers may be exaggerated relative to other layers.

[0043] It should be noted that like reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined or described in one drawing, it will not require further detailed discussion and description in the description of the subsequent drawings.

[0044] like Figure 1 As shown, the present invention provides a technical solution: a construction method for high cap cast-in-place piles with pre-buried anchor bars, comprising the following steps:

[0045] Step 1: Measure the pile position, determine and mark the position of the cast-in-place pile to provide basic conditions for subsequent construction and allow the steel cage to be arranged at the designated position according to design requirements;

[0046] Step 2: Use a drilling rig to drill to the designed depth, remove the sediment at the bottom of the hole, ensure that the bottom of the hole is clean, avoid debris affecting the tensile and compressive resistance of the pile bottom, and improve the bearing capacity of the pile bottom and the quality of the cast-in-place pile;

[0047] Step 3: Lower the steel cage, adjust the height of the steel cage through the height positioning device and fix the steel cage to the preset height at the top of the steel cage. The steel cage is used to enhance the tensile and compressive properties of the pile body;

[0048] Step 4: Pour the concrete into the piles. Continue pouring the concrete until it reaches the ground. The concrete pouring should be continued for no more than 3 hours. Use a vibrator to expel the concrete bubbles and make the cement, sand and steel frame closely connected to improve the density of the pile.

[0049] Step 5: Install the positioning plate on the top of the steel cage to determine the height of the upper concrete pouring (the height of the concrete pouring exposed to the ground). The traditional method of determining the height during the pouring process is to manually use auxiliary tools such as calipers to determine the height of the pile pouring. The elevation is not accurate and needs to be measured from time to time. The positioning plate is more intuitive and convenient for the installation of seismic isolation pads.

[0050] Step 6: Upper formwork: after removing the facilities on the ground, set the steel jacket formwork above the ground and continue to pour concrete until the preset height, providing a forming formwork for the concrete pouring of the high pedestal part to ensure that the shape and size meet the requirements;

[0051] Step 7: Install the bearings. After the concrete solidifies, remove the anchor bars on the positioning plate, blow and polish the top of the positioning plate, and then install the rubber bearings.

[0052] To ensure the smooth implementation of this embodiment, it should be understood that in step 3, the top height of the steel cage is determined by a preset height positioning device, and determining the top height of the steel cage includes the following steps:

[0053] S1: Determine the height of the steel cage exposed above the ground after it is placed into the drill hole;

[0054] S2: Use a crane to lower the steel cage and adjust the height of the steel cage to the preset height;

[0055] S3: Connect and install the adjusting member in the height positioning device to the steel cage, and then control the height of the steel cage exposed above the ground to a preset height through the adjusting member;

[0056] S4: Use the surrounding parts and adjusting parts in the height positioning device to fix the steel cage.

[0057] like Figure 1 and Figure 2 and Figure 3 As shown, in order to ensure the smooth implementation of this embodiment, it is necessary to understand that the height positioning device includes two sleepers 1, the adjusting member includes a screw rod 2 and a screw block 3, the screw rod 2 is rotatably installed on the sleeper 1, the screw block 3 is screwed on the surface of the screw rod 2, a hinged arm 5 is hinged on one side of the screw block 3, and a hook 7 is screwed on the other end of the hinged arm 5 through a basket screw 6, the adjusting member is connected to the transverse ribs of the steel cage through the hook 7, and a limiting groove 12 is provided on one side of the sleeper 1, and the limiting groove 12 slides inside It is connected with a jacking plate 4, the top of which is fixed to the bottom of the screw block 3, one side of the jacking plate 4 is arranged as an inclined surface, the inclined surface is inclined from the top of the jacking plate 4 to the bottom end, the sleeper 1 is provided with a hole connected with the limiting groove 12 corresponding to the limiting groove 12, the surrounding piece includes a top arm 8 sliding on the inner wall of the hole, one end of the top arm 8 located in the limiting groove 12 is installed with a wheel seat 9, a pulley 10 is rotatably installed in the wheel seat 9 and abuts against the inclined surface of the jacking plate 4, and the other end of the top arm 8 is rotatably connected with the surrounding plate 11.

[0058] The height positioning device is controlled by rotating the screw rod 2 during use. When the screw rod 2 rotates, the screw block 3 is limited left and right by the limiting groove 12. Therefore, when the screw rod 2 rotates, the screw block 3 can be adjusted in height. During use, the hook 7 is hung on the ribs of the steel cage. During the lifting and lowering of the screw block 3, the articulated arms 5 on both sides can pull and lift the steel cage through the hook 7 to control its height. At the same time, the screw block 3 also controls the height change of the jacking plate 4 during the lifting and lowering process. Since one side of the jacking plate 4 is an inclined surface, the jacking plate 4 will push the surrounding plate 11 towards the steel cage during the rising process. The steel cage is clamped together, but because the two are carried out synchronously, after the adjusting piece controls the steel cage to a predetermined height, the surrounding plate 11 may not just hold the steel cage. At this time, the rod 2 802 is manually rotated by a wrench or other tool. The rod 2 802 is screwed to the rod 1 801 to adjust the distance between the two. The distance of the extending surrounding plate 11 is controlled in the lateral direction to be adjusted to a state where the steel cage is just held together. The steel cage is kept in a vertical state under the dual limit of the surrounding plate 11 and the upper hook 7. The steel cage is kept in a vertical state during the first concrete pouring process. After the concrete solidifies, the steel cage is always kept vertical.

[0059] like Figure 1 As shown, to ensure the smooth implementation of this embodiment, it should be understood that the installation of the positioning plate in step five includes the following steps:

[0060] V1: Use the crane to suspend the positioning plate to the position just above the steel cage;

[0061] V2: At least two people hold the positioning plate and use the crane to slowly approach the steel cage. During the operation, the positioning plate is always lowered vertically from the top of the steel cage.

[0062] V3: Fix and fine-tune the positioning plate and the steel cage, and level the top of the positioning plate to a horizontal state.

[0063] like Figure 2 and Figure 4 As shown, in order to ensure the smooth implementation of this embodiment, it is necessary to understand that the positioning plate includes a plate body 13, an anchor foot 14 is fixed on the top of the plate body 13, a plurality of anchor feet 14 are provided and are arranged equidistantly in a circle on the top of the plate body 13, and screw columns 15 are rotatably installed at the positions of the anchor feet 14 at the bottom of the plate body 13. The anchor foot 14 is hollow inside and has a threaded inner wall. Anchor bars are screwed on its inner wall to prevent concrete from being poured into the anchor foot 14 during the concrete pouring process. After the concrete pouring is completed and the cast-in-place pile is formed, the anchor bars are removed, which can be conveniently connected and fixed to the shock-absorbing pad.

[0064] like Figure 5 As shown, in order to ensure the smooth implementation of this embodiment, it is necessary to understand that a connecting key 16 is fixedly connected to the bottom of the disk body 13 corresponding to the anchor foot 14, and the cross-section of the connecting key 16 is "convex" shaped, the screw column 15 is hollow inside, and the top of the screw column 15 is rotated at the connecting key 16. The top of the steel bar of the steel cage is processed into a threaded shape through a tapping process, and the positioning disk is screwed to the top of the steel bar of the steel cage through the screw column 15. The screw column 15 is connected to the steel cage by screwing, and the disk body 13 is controlled to be in a horizontal state by rotating each screw column 15 in turn, which is convenient for the subsequent installation of the seismic isolation pad.

[0065] like Figure 4As shown, in order to ensure the smooth implementation of this embodiment, it is necessary to understand that the shaped steel jacket formwork in step six includes two jacket formworks 17, and the two jacket formworks 17 are combined to form a columnar casting formwork. The inner wall diameter of the casting formwork matches the diameter of the cast-in-place pile. The jacket formwork 17 is respectively provided with a protrusion 171 and a protrusion 2 172 at both ends close to the inner wall side, and a notch 173 is provided between the protrusion 171 and the protrusion 2 172. After the two jacket formworks 17 are combined, a grouting channel is formed at the notch 173. Connecting plates 18 are fixed on both sides of the jacket formworks 17. After the jacket formworks 17 are combined, adjacent connecting plates 18 are connected by bolt rods 19. Nuts 20 screwed on the bolt rods 19 are provided on both sides of the connecting plate 18 of one of the jacket formworks 17. The jacket formwork 17 is used for pouring concrete of the high cap part. The two sheath formworks 17 are connected and fixed by bolt rods 19. After fixation, the notches 173 formed at the protrusions 171 and 172 on both sides are also used for pouring concrete. Since the notch 173 is close to the inner wall of the sheath formwork 17, concrete is first poured at the notch 173 when pouring the high pedestal, and the high pedestal is poured after the concrete solidifies. This can effectively avoid the gap generated after the sheath formworks 17 are connected, and can also increase the tightness between the two sheath formworks 17. Since the notch 173 is separated from the main part of the high pedestal, the solidified concrete at the notch 173 can automatically detach when the nut 20 is turned to separate the sheath formwork 17. It should be noted that during operation, the nut 20 that separates the two connecting plates 18 can be pushed away from one of the sheath formworks 17, making it convenient for the concrete at the notch 173 to detach.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for high cap cast-in-place piles with pre-embedded anchor bars in one pile formation, characterized in that: The following steps are involved: Step 1: Measure the pile position, determine and mark the location of the cast-in-place pile; Step 2: Drilling: Use a drilling rig to drill to the designed depth, remove the sediment at the bottom of the hole, and ensure that the bottom of the hole is clean; Step 3: lower the steel cage, adjust the height of the steel cage through the height positioning device and fix the steel cage to the preset height at the top of the steel cage; Step 4: Pile pouring, continue pouring concrete until it reaches the ground; Step 5: Install the positioning plate, install the positioning plate on the top of the steel cage, the positioning plate limits the upper concrete pouring height by its own height, the positioning plate is provided with an anchor foot (14) to realize the rapid positioning of the rubber bearing, the height of the positioning plate is adjusted by the screw connection column (15) on the positioning plate to determine the upper concrete pouring height, the positioning plate comprises a plate body (13), the anchor foot (14) is fixed to the top of the plate body (13), a plurality of anchor feet (14) are provided and are arranged in a circumferentially equidistant shape on the top of the plate body (13), and the screw connection column (15) is installed at the bottom of the plate body (13) and corresponds to the anchor foot (14); Step 6: Upper formwork, set the steel jacket formwork above the ground and continue pouring concrete until the proposed preset height; Step 7: Install the bearing. After the concrete solidifies, remove the anchor bars on the positioning plate, blow and polish the top of the positioning plate, and then install the rubber bearing. In step 3, the top height of the steel cage is determined by a preset height positioning device, and determining the top height of the steel cage includes the following steps: S1: Determine the height of the steel cage exposed above the ground after it is placed into the drill hole; S2: Use a crane to lower the steel cage and adjust the height of the steel cage to a predetermined height; S3: Connect and install the adjusting member in the height positioning device to the steel cage, and then control the height of the steel cage exposed above the ground to a predetermined height through the adjusting member; S4: Fix the steel cage by using the surrounding pieces in the height positioning device and the adjusting pieces; The height positioning device in step 3 comprises two sleepers (1), the adjusting member comprises a screw rod (2) and a screw block (3), the screw rod (2) is rotatably mounted on the sleeper (1), the screw block (3) is screwed on the surface of the screw rod (2), a hinged arm (5) is hinged on one side of the screw block (3), a hook (7) is screwed on the other end of the hinged arm (5) via a turnbuckle (6), and the adjusting member is connected to the transverse ribs of the steel cage via the hook (7); A limit groove (12) is provided on one side of the sleeper (1) used in step 3, and a jacking plate (4) is slidably connected in the limit groove (12). The top of the jacking plate (4) is fixed to the bottom of the screw block (3), and one side of the jacking plate (4) is provided with an inclined surface, which is inclined from the top end to the bottom end of the jacking plate (4). The sleeper (1) is provided with a hole corresponding to the limit groove (12) and connected to the limit groove (12).

2. The method for constructing high cap cast-in-place piles with pre-embedded anchor bars in one step according to claim 1, characterized in that: The encircling member comprises a top arm (8) which slides on the inner wall of the hole, one end of the top arm (8) located in the limiting groove (12) is mounted with a wheel seat (9), a pulley (10) which abuts against the inclined surface of the jacking plate (4) is rotatably mounted in the wheel seat (9), and the other end of the top arm (8) is rotatably connected to the encircling plate (11).

3. The one-time pile construction method for high cap cast-in-place piles with pre-embedded anchor bars according to claim 1 is characterized in that: Installing the positioning plate in step 5 includes the following steps: V1: Use a crane to suspend the positioning plate to the position directly above the steel cage; V2: At least two people hold the positioning plate and use a crane to approach the steel cage. During the operation, the positioning plate is always lowered vertically from the top of the steel cage; V3: Fix and adjust the positioning plate and the steel cage, and level the top of the positioning plate to a horizontal state.

4. The method for constructing high cap cast-in-place piles with pre-embedded anchor bars in one step according to claim 3, characterized in that: A connection key (16) is fixedly connected to the bottom of the plate body (13) at a position corresponding to the anchor bolt foot (14); the cross section of the connection key (16) is convex; the screw connection column (15) is hollow inside; the top end of the screw connection column (15) rotates at the connection key (16); the top end of the steel bar of the steel cage is processed into a threaded shape through a tapping process; and the positioning plate is screwed to the top end of the steel bar of the steel cage through the screw connection column (15).

5. The method for constructing high cap cast-in-place piles with pre-embedded anchor bars in one step according to claim 1, characterized in that: The steel jacket template in step 6 includes: Two sheath support formworks (17) are combined to form a columnar casting formwork, wherein the inner wall diameter of the casting formwork matches the diameter of the cast-in-place pile.

6. The method for constructing high cap cast-in-place piles with pre-embedded anchor bars in one step according to claim 5, characterized in that: The jacket formwork (17) in step six is ​​provided with a protrusion 1 (171) and a protrusion 2 (172) at both ends close to the inner wall, and a notch (173) is provided between the protrusion 1 (171) and the protrusion 2 (172). After the two jacket formworks (17) are combined, a grouting channel is formed at the notch (173).

7. The method for constructing high cap cast-in-place piles with pre-embedded anchor bars in one step according to claim 6, characterized in that: In step six, connecting plates (18) are fixed on both sides of the jacket formwork (17). After the jacket formworks (17) are combined, adjacent connecting plates (18) are connected by bolt rods (19), and nuts (20) screwed to the bolt rods (19) are arranged on both sides of the connecting plates (18) of one of the jacket formworks (17).

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