Deep countersunk small-diameter steel latticed column cast-in-place pile structure

Abstract

The utility model relates to the technical field of steel latticed column cast-in-place piles, and provides a deep-countersunk small-diameter steel latticed column cast-in-place pile structure which comprises a steel reinforcement cage arranged in a pouring hole, a latticed column embedded in the steel reinforcement cage and concrete poured in the pouring hole. A plurality of first square frames are arranged in the length direction of the reinforcement cage at intervals, the cross section of the reinforcement cage is circular, the cross section of the latticed column is square, the side length of each first square frame is larger than the side length of the latticed column located on the cross section, and guide wheels are rotationally connected to the four sides of each first square frame. And the axes of the four guide wheels are respectively parallel to the length directions of the four sides of the first square frame. The mounting method has the beneficial effect that the mounting precision of the latticed column is improved under the invisible condition.

Description

Technical Field

[0001] The present application relates to the technical field of steel lattice column cast-in-place piles, and in particular to a deep-buried small-diameter steel lattice column cast-in-place pile structure. Background Art

[0002] Steel lattice columns are often used in deep foundation pit support for subways and building construction, and the construction technology is relatively mature. For dock projects, since their structure is different from common structures such as subways and building construction, the cast-in-place piles and lattice columns are buried deeper. During the pile foundation construction phase, when the pile foundation is not visible, the lattice columns rely entirely on their own weight to maintain verticality during the lowering process. However, this does not allow for precise control of the verticality and pile center coordinates, and the verticality deviation is too large, which may lead to tilting, thereby affecting the subsequent construction quality. Therefore, further improvement is needed. Utility Model Content

[0003] In order to improve the installation accuracy of lattice columns in invisible conditions, the present application provides a deep-buried small-diameter steel lattice column cast-in-place pile structure.

[0004] This application provides a deep-buried small-diameter steel lattice column cast-in-place pile structure, which adopts the following technical solutions:

[0005] A deep-buried small-diameter steel lattice column cast-in-place pile structure comprises a steel cage arranged in a casting hole, a lattice column embedded in the steel cage, and concrete cast in the casting hole. A first square frame is coaxially arranged on the inner peripheral wall of the steel cage. A plurality of first frames are arranged at intervals along the length direction of the steel cage. The cross-section of the steel cage is circular, and the cross-section of the lattice column is square. The side length of the first square frame is greater than the side length of the lattice column in the cross-section. The four sides of the first frame are rotatably connected to guide wheels, and the axes of the four guide wheels are respectively parallel to the length directions of the four sides of the first frame.

[0006] By adopting the above technical solution, in the process of lowering the lattice column into the steel cage, several first square frames are set to form an installation channel for the lattice column. By providing a guide wheel, since its own cross-section is circular, it can move relatively smoothly while guiding the lattice column, reducing damage to the surface of the lattice column, and making the lattice column relatively centered in the steel cage. Moreover, since several first square frames are provided, the verticality of the lattice column and the accuracy of controlling the pile center coordinates are relatively improved, that is, the installation accuracy of the lattice column is improved in an invisible situation, so as to improve the consistency of the force between the lattice column and the cast-in-place pile.

[0007] Preferably, the inner peripheral wall of the steel cage is protruded with reinforcing ribs connected to the first square frame, the reinforcing ribs are arranged to avoid the guide wheels, and a plurality of the reinforcing ribs are arranged at intervals along the length direction of the side length of the first square frame.

[0008] By adopting the above technical solution, reinforcing ribs are provided to support and strengthen the first frame. Since the lattice column will exert a certain collision force on the guide wheel during the lowering process, the first frame may be deformed. In this regard, reinforcing ribs are provided to support the first steel bar and provide relative load capacity, thereby reducing the impact on the verticality of the lattice column when it is below.

[0009] Preferably, the steel cage is provided with a guide plate above the first square frame, and two guide plates are provided and symmetrically arranged along the axis of the steel cage. The length directions of the two guide plates are parallel to the length of the side length of the first square frame, and the spacing between the two guide plates is greater than the spacing between the two parallel guide wheels, and an elastic pad is provided on the upper surface of the guide plate.

[0010] By adopting the above technical solution, by providing a guide plate and an elastic pad on the guide plate, a guiding and positioning effect can be first played when the lattice column is under, and the elastic pad is provided to have a certain buffering effect, reducing the impact force when directly colliding with the first frame, so as to prevent the first frame from being deformed.

[0011] Preferably, the lattice column comprises four angle steels equidistantly distributed in a circular shape and a tie plate fixedly connected between adjacent angle steels, wherein a plurality of the tie plates are spaced apart along the length direction of the angle steels.

[0012] Preferably, a second square frame is provided below the first square frame located at the bottom of the steel cage, and the side length of the second square frame is smaller than the side length of the lattice column.

[0013] By adopting the above technical solution and providing a second frame, after the lattice column passes through multiple first frames above, the second frame stops the lattice column from continuing to move downward, thereby ensuring that the lattice column elevation meets the design requirements, thereby further improving the installation accuracy of the lattice column in an invisible situation.

[0014] Preferably, a positioning rod is provided on the upper end surface of the lattice column, the length direction of the positioning rod is parallel to the length direction of the lattice column, and the upper end of the positioning rod is exposed at the casting hole.

[0015] By adopting the above technical solution, after the lattice column passes through the first frame and the second frame for positioning, the lattice column and the steel cage are fixed. At this time, when the whole is placed in the reserved hole, it becomes invisible, which may cause deviations in the overall verticality of the lattice column and the steel cage. For this, a mounting rod is provided. Since the upper end of the mounting rod is exposed at the casting hole, if an offset occurs, the offset angle can be calculated and adjusted. That is, the center coordinates, verticality and deflection angle of the lattice column can be accurately controlled when the lattice column is invisible, so as to further improve the installation accuracy of the lattice column when it is invisible, so that the construction of the lattice column can fully meet the design and specification requirements, provide convenience for subsequent construction, and at the same time, in the deep buried state, the positioning installation rod can also be used for positioning and installation during the lowering of the guide tube.

[0016] Preferably, there are several positioning rods.

[0017] By adopting the above technical solution and providing a plurality of positioning rods, any offset or deflection between the line connecting every two adjacent positioning rods and the axial direction can be adjusted in a timely manner until the offset is correctly positioned, so as to accurately calculate the offset amount that needs to be adjusted for the lattice column, thereby improving the adjustment accuracy of the lattice column.

[0018] Preferably, at least three positioning rods are provided, and the three positioning rods are respectively provided at three top corners of the lattice column.

[0019] By adopting the above technical solution, since at least three positioning rods are provided, at least three planes can be formed for calculation.

[0020] In summary, the present invention has the following beneficial effects:

[0021] 1. By providing a plurality of first square frames, an installation channel for the lattice column is formed. By providing a guide wheel, due to its circular cross-section, it can guide the lattice column while moving relatively smoothly, reducing damage to the surface of the lattice column, and making the lattice column relatively centered in the steel cage. In addition, since a plurality of first square frames are provided, the verticality of the lattice column and the accuracy of controlling the pile center coordinates are relatively improved, that is, the installation accuracy of the lattice column is improved in an invisible situation, so as to improve the consistency of the force between the lattice column and the cast-in-place pile.

[0022] 2. By providing a second frame, after the lattice column passes through the multiple first frames above, the second frame stops the lattice column from continuing to move downward, which can ensure that the lattice column elevation meets the design requirements and further improve the installation accuracy of the lattice column in the invisible case.

[0023] 3. By providing a mounting rod, if there is an offset, the offset angle can be calculated and adjusted, that is, the center coordinates, verticality and deflection angle of the lattice column can be accurately controlled when the lattice column is not visible, so as to further improve the installation accuracy of the lattice column when it is not visible. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of Example 1 of the present application;

[0025] Figure 2 This is a schematic structural diagram of the first block in Example 1 of the present application;

[0026] Figure 3 This is a schematic diagram of the structure of the second block in Example 1 of the present application;

[0027] Figure 4 Schematic diagram of the structure of the positioning rod in Example 1 of the present application;

[0028] Figure 5 This is a schematic diagram of the connection structure between the positioning rod and the lattice column in Example 1 of the present application;

[0029] Figure 6 is a schematic structural diagram of the catheter in Example 1 of the present application;

[0030] Figure 7 It is a structural schematic diagram of the reinforcing ribs and guide plates in Example 2 of the present application.

[0031] Explanation of the accompanying reference numerals: 1. Casting hole; 2. Steel cage; 21. Main reinforcement; 22. Spiral reinforcement; 3. Lattice column; 31. Angle steel; 32. Tie plate; 4. First box; 41. Guide wheel; 42. Reinforcement rib; 5. Second box; 6. Positioning rod; 7. Conduit; 71. First pipe; 72. Second pipe; 73. Hopper; 8. Guide plate; 81. Elastic pad. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1-7 , further details of this application are given.

[0033] The embodiment of the present application discloses a deep-buried small-diameter steel lattice column cast-in-place pile structure.

[0034] Example 1:

[0035] A deep buried small diameter steel lattice column cast-in-place pile structure, referring to Figure 1, comprising a steel cage 2 disposed within a casting hole 1, a lattice column 3 embedded within the steel cage 2, and concrete poured within the casting hole 1 (not shown). In this embodiment, the steel cage 2 includes a plurality of main bars 21 equidistantly distributed in a circular pattern, and spiral bars 22 wound around the main bars 21, resulting in a circular cross-section of the steel cage 2. The lattice column 3 comprises four angle steels 31 equidistantly distributed in a circular pattern, and tie plates 32 fixedly connected between adjacent angle steels 31. Several tie plates 32 are spaced apart along the length of the angle steels 31, resulting in a square cross-section of the lattice column 3.

[0036] It should be noted that, for the sake of convenience, in this embodiment, the specifications of the lattice column 3 are shown as 450 mm*450 mm, but other specifications are also possible.

[0037] Reference Figure 1 、 Figure 2 A first square frame 4 is coaxially arranged on the inner peripheral wall of the steel cage 2. Several first square frames 4 are spaced apart along the length of the steel cage 2, specifically two, and are positioned near the upper portion of the steel cage 2. In this embodiment, the side length of the first square frame 4 is greater than the side length of the lattice column 3 in the cross section. Therefore, the first square frame 4 is sized at 500mm*500mm. Guide wheels 41 are rotatably connected to the four sides of the first frame 4, with the axes of the four guide wheels 41 being parallel to the length directions of the four sides of the first frame 4. The outer peripheral walls of the guide wheels 41 can abut against the side walls of the lattice column 3, i.e., the outer side walls of the gusset plate 32, to serve as a channel for installing the steel lattice columns, ensuring that the center coordinates and verticality of the lattice column 3 meet the requirements. A certain gap can also be left, depending on the specific requirements.

[0038] Reference Figure 3 The second frame 5 is located below the first frame 4 at the bottom of the steel cage 2. The side length of the second frame 5 is smaller than the side length of the lattice column 3. It can be a square steel frame of 430mm*430mm. After the lattice column 3 passes through the two steel frames above, it stops the column from continuing to move downward.

[0039] Reference Figure 4 、 Figure 5 Since the lattice column 3 is located below the steel cage 2 and is not visible, a positioning rod 6 is provided on the upper end surface of the lattice column 3. The length direction of the positioning rod 6 is parallel to the length direction of the lattice column 3, and the upper end of the positioning rod 6 is exposed outside the casting hole 1. There are several positioning rods 6. In this embodiment, there are at least three positioning rods 6. The three positioning rods 6 are respectively provided at three top corners of the lattice column 3 and are specifically welded to the angle steel 31. It should be noted that after the lattice column 3 and the steel cage 2 are welded, the positioning rod 6 is welded to the inner wall of the angle steel 31.

[0040] In this embodiment, the length of the positioning rod 6 can be a DN50 seamless steel pipe with a length of 5m and a wall thickness of 6mm. When the lattice column 3 is lowered and installed below the working surface, the operator can still make multiple adjustments through the deflection deformation δ of these three steel pipes to improve the precision control and accurately determine the column position and deflection angle.

[0041] Assuming the force point is 2.5m from the center of the steel pipe during adjustment, the maximum elastic deformation deflection δ of the steel pipe at this time is calculated as shown below. Furthermore, when the pipe is deeply buried, the positioning rod can be used for positioning during the lowering process.

[0042] in,

[0043] Deflection calculation formula δ=(wl^3) / 48EI

[0044] Elastic modulus E = 2.1 × 105 N / mm2

[0045] I Section moment of inertia I = π (D^4-d^4) / 64 = 482671.84 mm4

[0046] δ=(1000×5000^3) / (48×2.1×10^5×482671.84)=40.45mm.

[0047] It should be noted that when pouring concrete, it is usually poured through the conduit 7. If the concrete cannot be poured smoothly, the pouring end height will be raised to affect the pouring of the concrete. In this embodiment, Figure 6 As shown, the conduit 7 may include a first tube 71, a second tube 72 detachably connected to the first tube 71, and a hopper 73 detachably connected to the second tube 72. Specifically, flange connections are used to achieve detachable connections between the second tube 72 and the first tube 71, and between the hopper 73 and the second tube 72. Therefore, by removing the second tube 72, the buried depth of the conduit 7 is reduced, ensuring smooth construction and reducing the pouring length of the concrete, that is, accelerating the concrete pouring speed.

[0048] The implementation principle of a deep-buried small-diameter steel lattice column cast-in-place pile structure in the embodiment of the present application is as follows: before the lattice column 3 is installed, the steel cage 2 is first lowered into the casting hole 1, and the steel cage 2 is stably fixed on the leveled wood blocks set on both sides of the casting hole 1. After the steel cage 2 is fixed, the lattice column 3 is lifted, and the lattice column 3 is slowly lowered from the first frame 4 preset on the upper part of the steel cage 2 to the second frame 5. The verticality of the lattice column 3 is adjusted manually, and after further adjustment, the lattice column 3 and the steel cage 2 are fixed by welding. After the welding of the steel cage 2 and the lattice column 3 is completed, the steel cage 2 is further lifted, the fixed crossbar is removed, and the lattice column 3 and the steel cage 2 are sunk. The positioning rod 6 preset at the top of the lattice column 3 is used to control the sinking depth until the top elevation of the lattice column 3 reaches the design elevation.

[0049] After the steel cage 2 and lattice column 3 are lowered to the designed elevation, the three pre-welded positioning rods 6 on the upper portion of the lattice column 3 are measured. Any deviation or deflection between the line connecting two adjacent positioning rods 6 and the axial direction requires prompt adjustment until the lattice column 3 is correctly positioned. The lattice column 3 is then re-secured to the fixed crossbar using pre-set hangers. Once the lattice column 3 is precisely positioned, a seamless long conduit 7 is placed against the pre-reserved positioning rods 6 at the top of the lattice column 3. Short connectors are then connected to the hopper 73 for underwater concrete pouring. After the first batch of concrete is poured, the short conduit 7 is removed based on the depth of the conduit 7 until all concrete pours are complete.

[0050] Example 2:

[0051] Reference Figure 7 The difference from Example 1 is that the inner circumferential wall of the steel cage 2 is provided with protruding reinforcing ribs 42 connected to the first frame 4. The reinforcing ribs 42 are arranged away from the guide wheels 41. Several reinforcing ribs 42 are spaced apart along the length of the side of the first frame 4 to provide greater support for the first frame 4. Furthermore, the steel cage 2 is provided with guide plates 8 above the first frame 4. Two guide plates 8 are provided and symmetrically arranged along the axis of the steel cage 2. The lengths of the two guide plates 8 are parallel to the length of the side of the first frame 4. The spacing between the two guide plates 8 is greater than the spacing between the two parallel guide wheels 41. Elastic pads 81 are provided on the upper surfaces of the guide plates 8 to provide a certain buffering effect, reducing the impact force caused by direct collision with the first frame 4, thereby preventing deformation of the first frame 4.

[0052] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A deep-buried small-diameter steel lattice column cast-in-place pile structure, characterized by: The invention comprises a steel cage (2) arranged in a casting hole (1), a lattice column (3) embedded in the steel cage (2), and concrete cast in the casting hole (1); the inner peripheral wall of the steel cage (2) is coaxially provided with a first square frame (4); a plurality of the first square frames (4) are arranged at intervals along the length direction of the steel cage (2); the cross section of the steel cage (2) is circular; the cross section of the lattice column (3) is square; the side length of the first square frame (4) is greater than the side length of the lattice column (3) at the cross section; the four sides of the first frame (4) are rotatably connected to guide wheels (41); the axes of the four guide wheels (41) are respectively parallel to the length directions of the four sides of the first square frame (4).

2. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 1, characterized in that: The inner peripheral wall of the steel cage (2) is provided with reinforcing ribs (42) connected to the first frame (4), the reinforcing ribs (42) being arranged away from the guide wheel (41), and a plurality of the reinforcing ribs (42) being arranged at intervals along the length direction of the side length of the first frame (4).

3. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 1, characterized in that: The steel cage (2) is provided with a guide plate (8) above the first frame (4), two guide plates (8) are provided and are symmetrically arranged along the axis of the steel cage (2), the length directions of the two guide plates (8) are parallel to the length of the side of the first frame (4), the spacing between the two guide plates (8) is greater than the spacing between the two parallel guide wheels (41), and an elastic pad (81) is provided on the upper surface of the guide plate (8).

4. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 1, characterized in that: The lattice column (3) comprises four angle steels (31) distributed equidistantly in a ring shape and a gusset plate (32) fixedly connected between adjacent angle steels (31), wherein a plurality of gusset plates (32) are arranged at intervals along the length direction of the angle steel (31).

5. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 1, characterized in that: A second square frame (5) is provided below the first square frame (4) located at the bottom of the steel cage (2), and the side length of the second square frame (5) is smaller than the side length of the lattice column (3).

6. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 1, characterized in that: A positioning rod (6) is provided on the upper end surface of the lattice column (3), the length direction of the positioning rod (6) is parallel to the length direction of the lattice column (3), and the upper end of the positioning rod (6) is exposed outside the casting hole (1).

7. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 6, characterized in that: A plurality of positioning rods (6) are provided.

8. The deep-buried small-diameter steel lattice column cast-in-place pile structure according to claim 7, characterized in that: At least three positioning rods (6) are provided, and the three positioning rods (6) are respectively provided at three top corners of the lattice column (3).

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