A cast-in-place pile steel cage anti-floating structure

Abstract

A cast-in-place pile steel cage anti-floating structure comprises a cast-in-place platform, a conduit, a steel cage and an anti-floating device, wherein the cast-in-place platform is connected to the conduit, the conduit penetrates into the steel cage, the anti-floating device comprises an upper clamp, a lower clamp, an oblique support rod, a transverse support rod and a slot, the upper clamp is connected to the slot through the oblique support rod, and at the same time, the lower clamp is connected to the slot through the transverse support rod, a triangular structure is formed between the upper clamp, the lower clamp and the slot, the upper clamp and the lower clamp are respectively installed on the conduit, and the slot is sleeved on the top of the main reinforcement of the steel cage. The present invention is suitable for pile foundation construction with different hole depths, has strong applicability, and solves the problems of high precision requirements for docking the anti-floating device with the steel cage, and the problem that the long vertical pole is easy to deform and affects the anti-floating effect, and can be repeatedly assembled and disassembled for use, with low cost and high recycling rate.

Description

Technical Field

[0001] The invention relates to the field of pile foundation construction, and in particular to an anti-floating structure for preventing a steel cage from floating up. Background Art

[0002] When pouring concrete in reinforced concrete bored piles, the concrete starts to rise from the bottom of the pile hole along the four sides of the hole through the long guide tube. When the steel cage is subjected to the impact force or buoyancy of the rising concrete, the steel cage will float up, causing the main reinforcement of the steel cage to exceed the designed pile top elevation and causing a series of quality problems. Especially in the construction of pile foundations with deeper empty piles, the floating of the steel cage is more obvious, causing the steel cage to shift, the exposed steel bars to be too long, and even the pile to be abandoned in severe cases. It is particularly important to stabilize the steel cage before removing the guide tube for the first time and then continue with the subsequent concrete pouring.

[0003] In the application of pile foundation steel cage anti-floating structure, two or more steel bars or hard materials are generally used as vertical poles. The upper end of the vertical pole is fixed and locked on the inner wall of the steel casing or stuck in the grille on both sides of the flange frame of the filling platform. Then the other end of the vertical pole is locked with the top hoop of the steel cage through a fork rod or a buckle, or even the main reinforcement of the steel cage is covered by welding a steel pipe with a closed top. In this way, the upper end of the vertical pole is fixed to the outside world, and the lower end is fixed to the steel cage to prevent the steel cage from floating.

[0004] The current steel cage anti-floating structure has the following shortcomings, especially in the use of deep hole super-long piles, these problems are more prominent: First, in the construction of pile foundations at different depths, the current steel cage anti-floating method is not very applicable and has a low recycling rate; Second, in the construction of pile foundations with long empty piles, longer vertical poles are required, and the material is steel bars, which are used in large quantities and are cumbersome to use. When subjected to large buoyancy, they are easily deformed, thus failing to achieve the anti-floating effect; Third, the lower end of the vertical pole is used to cover the main reinforcement of the steel cage through a buckle or a steel pipe. In the construction of bored piles with mud wall protection, the required precision is high, and it is difficult to ensure that it can be quickly matched and connected with the main reinforcement of the steel cage. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a cast-in-place pile steel cage anti-floating structure, which is suitable for pile foundation construction with different hole depths and has strong applicability. At the same time, it solves the problems of high precision requirement for docking the anti-floating device with the steel cage and easy deformation of long vertical poles affecting the anti-floating effect. The structure can be repeatedly assembled and disassembled for use, has low cost and high recycling rate.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted is:

[0007] Provided is a cast-in-place pile steel cage anti-floating structure, comprising a cast-in-place platform, a conduit, a steel cage and an anti-floating device, wherein the cast-in-place platform is connected to the conduit, the conduit penetrates into the steel cage, the anti-floating device comprises an upper clamp, a lower clamp, an oblique support rod, a transverse support rod and a slot, the upper clamp is connected to the slot via the oblique support rod, and at the same time, the lower clamp is connected to the slot via the transverse support rod, a triangular structure is formed between the upper clamp, the lower clamp and the slot, the upper clamp and the lower clamp are respectively mounted on the conduit, and the slot is sleeved on the top of the main reinforcement of the steel cage.

[0008] As a further improvement of the present invention, a right triangle structure is formed between the upper clamp, the lower clamp and the slot.

[0009] As a further improvement of the present invention, the main bars of the steel cage are arranged in a circle, the slot as a whole is an arc-shaped structure adapted to at least two adjacent main bars, and the length of the slot can cover the tops of at least two main bars.

[0010] As a further improvement of the present invention, at least two of the clamping grooves are provided, and the clamping grooves are arranged at equal intervals along the circumference of the main reinforcement of the steel cage.

[0011] As a further improvement of the present invention, the cross section of the slot is an arc-shaped, triangular or inverted concave structure.

[0012] As a further improvement of the present invention, it also includes an inter-slot support rod, and the slots are connected by the inter-slot support rod.

[0013] As a further improvement of the present invention, the upper clamp and the lower clamp are both composed of two symmetrical half rings, and the two half rings are fixed by bolts.

[0014] As a further improvement of the present invention, the pouring platform includes a hopper and a flange frame, the hopper is fixed on the flange frame, and the bottom of the hopper is connected to the conduit.

[0015] As a further improvement of the present invention, a counterweight is placed on the flange frame.

[0016] As a further improvement of the present invention, it further comprises a steel casing, wherein the steel cage is located in the steel casing, and the pouring platform is fixed on the top of the steel casing.

[0017] The beneficial effects of the present invention are:

[0018] 1. Strong applicability. In the present invention, the upper and lower clamps of the anti-floating device are installed on the conduit, which is not affected by the hole depth. It is not necessary to select vertical poles of different lengths for anti-floating according to the hole depth, and it can be applicable to pile foundation construction with different hole depths.

[0019] 2. Ensure construction quality. The anti-floating device can effectively prevent the steel cage from floating up through the conduit, the pouring platform and the deadweight of the concrete during pouring, giving full play to the force of the anti-floating device and the conduit. A triangular structure is formed between the upper clamp, the lower clamp and the slot of the anti-floating device, which has the characteristics of stable structure and not easy to deform. Since the anti-floating device is installed on the conduit, the oblique support rods and transverse support rods used to connect the internal components of the anti-floating device are much shorter than the vertical rods in the prior art. In the present invention, there is no need to use long vertical rods to press down the steel cage, so as to avoid deformation of the long vertical rods when subjected to large buoyancy, which affects the quality of pile foundation construction.

[0020] 3. Low docking precision requirements, efficient and convenient. The anti-floating device is docked with the main reinforcement of the steel cage through the slot. Compared with the existing technology, the docking precision requirements are low, which can effectively reduce the docking time. The anti-floating device is connected and adjusted through the conduit, and the on-site operation efficiency is high, avoiding delays in the construction period due to the installation and disassembly of the anti-floating device.

[0021] 4. High economic effect. The anti-floating device can be made with local materials at the construction site. It is simple to make and easy to use. It does not require a large amount of steel and can be disassembled and recycled, saving a lot of material costs for the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 The structure of the anti-floating device of the present invention is shown in FIG. Figure 1 ;

[0024] Figure 3 The structure of the anti-floating device of the present invention is shown in FIG. Figure 2 ;

[0025] Marking description: 1-steel casing, 2-pouring platform, 21-hopper, 22-flange frame, 23-counterweight, 3-conduit, 4-rebar cage, 41-main reinforcement, 5-anti-floating device, 51-upper hoop, 52-lower hoop, 53-oblique support rod, 54-lateral support rod, 55-slot, 56-inter-slot support rod. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0027] In a subway station project in Guangzhou, a large number of pull-out piles were designed below the station structure floor, with a designed pile length of 12m. Due to the construction period, the pull-out piles needed to be constructed on the ground, that is, the designed hole depth was 32m, and the empty pile part was 20m deep. Since the steel cage of the pull-out pile was light, the empty pile length was deep, and the hollow section was not subject to any resistance, the steel cage floated up easily during concrete pouring. The use of the steel cage anti-floating device can effectively solve the problem of steel cage floating, ensure the construction quality of the pile foundation, and at the same time improve the on-site operation efficiency and reduce construction costs.

[0028] like Figure 1-3 As shown, a cast-in-place pile reinforcement cage 4 anti-floating structure,

[0029] A cast-in-place pile steel cage 4 anti-floating structure comprises a steel casing 1, a casting platform 2, a guide tube 3, a steel cage 4 and an anti-floating device 5, wherein the anti-floating device 5 comprises an upper clamp 51, a lower clamp 52, an oblique support rod 53, a transverse support rod 54 and a slot 55.

[0030] The steel cage 4 is located in the steel casing 1. The pouring platform 2 includes a hopper 21 and a flange frame 22. The hopper 21 is fixed on the flange frame 22. The flange frame 22 is fixed on the top of the steel casing 1. The bottom of the hopper 21 is connected to the conduit 3, and the conduit 3 penetrates into the steel cage 4. The main bars 41 of the steel cage 4 are arranged in a circle. There are four slots 55 made of thin steel plates. The slots 55 are generally in an arc structure that matches the three adjacent main bars 41. The length of the slots 55 can cover the tops of the three main bars 41. The cross section of the slots 55 is an arc, triangular or inverted concave structure. In this embodiment, the cross section of the slots 55 is preferably an inverted concave structure. The four slots 55 are arranged at equal intervals along the main bars 41 of the steel cage 4. The upper hoop 51 is connected to the slot 55 through an oblique support rod 53, and the lower hoop 52 is connected to the slot 55 through a transverse support rod 54. A firm and stable right triangle structure is formed between the upper hoop 51, the lower hoop 52 and the slot 55. The upper hoop 51 and the lower hoop 52 are composed of two symmetrical semi-rings, which are fixed by bolts. Two slots 55 are connected to each semi-ring, and an inter-slot support rod 56 is connected between the two slots 55. The inter-slot support rod 56 is used to further improve the structural strength. The anti-floating device 5 can be installed on the conduit 3 by splitting and closing the semi-rings and loosening and tightening the bolts, and can slide on the conduit 3 to adjust the depth. Through the depth adjustment, the slot 55 can be sleeved on the top of the main reinforcement 41 of the steel cage 4.

[0031] When using the anti-floating device 5 for construction, first calculate the total length of the conduit 3 to be lowered and the node depth to which the anti-floating device 5 needs to be lowered according to the actual hole depth, the elevation of the steel casing 1, the design pile top elevation and other data. According to the actual depth from the hole to the top of the steel cage 4, calculate the depth position where the anti-floating device 5 needs to be installed, combine the conduits 3 with different segment lengths, gradually lower the conduits 3, and when the conduits 3 are lowered to the node depth of the anti-floating device 5, install the anti-floating device 5 on the conduit 3 through the upper hoop 51 and the lower hoop 52, and then continue to lower the remaining conduits 3 until the slot 55 is sleeved on the top of the main reinforcement 41 of the steel cage 4. When pouring concrete, it is necessary to control the pouring speed. The anti-floating device 5 uses the hopper 21, the conduit 3, the flange frame 22 and the self-weight of the concrete in the hopper 21 to prevent the steel cage 4 from floating up. If necessary, according to the actual buoyancy, install an appropriate amount of counterweights 23 on the flange frame 22 to meet the anti-floating requirements. Before removing the conduit 3 for the first time, it is necessary to ensure that the height of the poured concrete (generally 3 to 5 meters) is sufficient to stabilize the steel cage 4 and prevent it from floating. Each time the conduit 3 is removed, attention must be paid to the buried depth of the conduit 3 and the concrete to avoid pile foundation quality problems. As the concrete pouring height increases, the conduit 3 is continuously removed section by section until the anti-floating device 5 is removed. The anti-floating device 5 can be separated and removed in advance by loosening the bolts. Finally, the remaining conduits 3 are removed as the pouring is completed.

[0032] In summary, the present invention has been made into actual samples and tested for multiple times as described in the specification and the illustrations. From the results of the test, it can be proved that the present invention can achieve its intended purpose, and its practical value is beyond doubt. The above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention in any form. Any person with ordinary knowledge in the technical field, if it does not depart from the scope of the technical features of the present invention, uses the equivalent embodiments of the technical content disclosed by the present invention to make partial changes or modifications, and does not depart from the technical features of the present invention, all still fall within the scope of the technical features of the present invention.

Claims

1. A cast-in-place pile steel cage anti-floating structure, comprising a cast-in-place platform, a conduit, a steel cage and an anti-floating device, wherein the cast-in-place platform is connected to the conduit, and the conduit penetrates into the steel cage, and is characterized in that: The anti-floating device includes an upper hoop, a lower hoop, an oblique support rod, a transverse support rod and a slot. The upper hoop is connected to the slot through the oblique support rod. At the same time, the lower hoop is connected to the slot through the transverse support rod. A triangular structure is formed between the upper hoop, the lower hoop and the slot. The upper hoop and the lower hoop are respectively installed on the conduit, and the slot is mounted on the top of the main reinforcement of the steel cage.

2. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1 is characterized in that: A right triangle structure is formed between the upper clamp, the lower clamp and the slot.

3. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1 is characterized in that: The main bars of the steel cage are arranged in a circle, and the clamping groove as a whole is an arc-shaped structure adapted to at least two adjacent main bars, and the length of the clamping groove can cover the tops of at least two main bars.

4. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 3 is characterized in that: There are at least two clamping grooves, and the clamping grooves are arranged at equal intervals along the circumference of the main reinforcement of the steel cage.

5. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1 is characterized in that: The cross section of the slot is an arc-shaped, triangular or concave structure.

6. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1, characterized in that: It also includes an inter-slot support rod, and the card slots are connected by the inter-slot support rod.

7. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1 is characterized by: The upper clamp and the lower clamp are both composed of two symmetrical half rings, and the two half rings are fixed by bolts.

8. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1, characterized in that: The pouring platform comprises a hopper and a flange frame, the hopper is fixed on the flange frame, and the bottom of the hopper is connected to a conduit.

9. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 8, characterized in that: A counterweight is placed on the flange frame.

10. The anti-floating structure of a cast-in-place pile reinforcement cage according to claim 1, characterized in that: It also includes a steel casing, in which the steel cage is located, and the pouring platform is fixed on the top of the steel casing.

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