Slip casting hollow pile and construction method

Abstract

The slip casting hollow pile comprises a plurality of standard parts, the space between every two adjacent standard parts is filled with concrete slurry, and concrete slurry rings are formed after the concrete slurry among all the standard parts is gathered and solidified; the concrete slurry ring and all the standard parts in the concrete slurry ring form an integrated slip casting hollow pile; the standard component comprises a hollow grouting anchor rod, a plurality of dowel bars are arranged on the hollow grouting anchor rod, and the dowel bars are distributed on the two sides of the hollow grouting anchor rod respectively. And a plurality of grouting holes are formed in the periphery of the hollow grouting anchor rod. Through interaction force generated by the standard parts, the stress rods arranged between the standard parts and the concrete arranged between the standard parts and the stress rods, the joint stress mode of the multiple standard parts is achieved, high theoretical value and practical value are achieved, construction is convenient, large excavation is avoided, the drilling construction speed is high, the construction efficiency is effectively improved, and the construction cost is reduced. The concrete consumption is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of pile foundations, and particularly relates to a grouting-formed hollow pile and a construction method, which can be used on soil where standard parts can be applied. Background Art

[0002] Pile foundations are widely used in important buildings and structures bearing large loads due to their high bearing capacity. Currently, in terms of construction forms, they are mainly divided into cast-in-place piles and precast piles. Cast-in-place piles have good compressive and anti-pulling performance, but in the construction process, they involve links such as drilling, mud wall protection, and concrete pouring, with a long construction period. Sometimes, a mud pit needs to be set up, and the excavated soil and the used mud have a certain impact on the environment. Precast piles are precast inside the factory and transported to the site for pile driving after curing. Their quality is relatively stable, and concrete is saved, but their horizontal bearing capacity is poor, and they have high requirements for the operation level of construction equipment and construction personnel. Moreover, a large precast pile diameter will lead to large soil layer resistance and difficult pile pressing, with construction quality risks. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: how to solve the problems of high construction cost, large amount of waste soil of the existing cast-in-place pile foundation, and difficult pile pressing of precast piles, and provide a grouting-formed hollow pile and a construction method.

[0004] To solve the above problems, the present invention is realized through the following technical solutions: A grouting-formed hollow pile includes multiple standard parts, and concrete slurry is filled between adjacent standard parts. After the concrete slurry between all standard parts aggregates and solidifies, a concrete slurry ring is formed; the concrete slurry ring and all the standard parts inside it form an integral grouting-formed hollow pile; the standard part includes a hollow grouting anchor rod, on which there are multiple load transfer rods, which are respectively distributed on both sides of the hollow grouting anchor rod; and several grouting holes are arranged around the hollow grouting anchor rod.

[0005] An anchor plate or a cutting edge is arranged at the bottom of the hollow grouting anchor rod.

[0006] The thickness of the anchor plate is d; during the process of rotary pressing and drilling of the standard part, the drilling depth of the standard part and the thickness d of the anchor plate maintain a linear relationship.

[0007] The grouting holes are uniformly arranged along the axial and radial directions of the hollow grouting anchor rod.

[0008] The number of load transfer rods on both sides is equal, and they are all perpendicular to the hollow grouting anchor rod. The spacing of the load transfer rods on one side is the same, and the vertical spacing is all N·d, where N is at least 2; the distance between the load transfer rods on one side of the hollow grouting anchor rod and the adjacent load transfer rods on the other side in the vertical direction is all N·d / 2.

[0009] The clear distance between two adjacent standard components is greater than the length of a single load transfer bar but less than twice the length of the load transfer bar.

[0010] The multiple standard components are arranged in a ring, and after the concrete slurry set between the standard components, they bear force together with the standard components.

[0011] A construction method for a grouting-formed hollow pile includes the following steps: Step 1: Locate and set out the position of the hole formation, and mark the contour line of the integral pile. Step 2: On the contour line, first use the construction machinery to drill the first standard component; when drilling to a depth where it only needs to rotate 90° to reach the specified depth, stop drilling. At this time, the axial directions of the load transfer bars on both sides of the hollow grouting anchor correspond to the center of the integral pile formed by multiple standard components. Step 3: Drill the remaining standard components according to the marked contour line, and the drilling depth meets the requirements of Step 2. Step 4: Use the standard component construction machinery to rotate each standard component by 90° in turn. Finally, the load transfer bars overlap with each other in space. Step 5: Conduct high-pressure grouting inside all standard components. The concrete slurry is injected into the soil through the grouting holes reserved in the hollow grouting anchor under the action of pressure; in this way, the concrete slurry will gather and solidify around the standard components. Since all standard components are located on the contour line, the concrete slurry will form a concrete slurry ring. Step 6: Take core samples at the middle position between adjacent standard components to check the grouting effect of the soil; after reaching the grouting effect, stop grouting and fill the drill holes with concrete slurry. Step 7: After the concrete slurry solidifies, complete the construction of the integral pile foundation.

[0012] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the anchor plate located at the bottom of the anchor can be replaced by a cutting edge. When a cutting edge is provided at the bottom of the anchor, the construction method changes from helically drilling into the soil to mechanically pressing into the soil. After pressing to the designed depth, rotate 90°, and conduct high-pressure grouting to form a whole. The remaining construction steps are the same. The cutting edge is located at the bottom and provides a soil-breaking effect during the downward pressing process.

[0013] The present invention realizes the co-loading form of multiple standard components through the interaction forces generated by the standard components, the load transfer bars arranged between the standard components, and the concrete arranged between the standard components and the load transfer bars. It has strong theoretical value and practical value, is convenient for construction, exempts from large-scale excavation, has a fast drilling construction speed, effectively improves the construction efficiency, saves the consumption of concrete, and effectively improves the bearing capacity of the pile foundation, which has a positive effect on realizing ecological environment protection. Description of the Drawings

[0014] Figure 1 Schematic plan view provided by the present invention; Figure 2 Schematic diagram of a single standard part; Figure 3 Schematic construction drawing; Figure 4 is Figure 1 sectional view 1-1 in Figure 5 Schematic diagram of an anchor rod with a blade foot. Specific implementation manner

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0016] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0017] As Figure 1 — Figure 5 As shown, a grouting-formed hollow pile includes a plurality of standard parts 1, and concrete slurry 2 is filled between adjacent standard parts 1. After the concrete slurry 2 between all the standard parts 1 aggregates and solidifies, a concrete slurry ring is formed; the concrete slurry ring and all the standard parts 1 inside it form an integral grouting-formed hollow pile. The standard part 1 includes a hollow grouting anchor rod 3, and a force transfer rod 5 is arranged on the hollow grouting anchor rod 3. There are a plurality of force transfer rods 5, which are respectively distributed on both sides of the hollow grouting anchor rod 3; and a plurality of grouting holes 6 are arranged around the hollow grouting anchor rod 3.

[0018] If the net distance between adjacent standard parts 1 is small and the concrete slurry 2 can be injected into the soil only by the high-pressure grouting of the hollow grouting anchor rod 3, the grouting holes 6 may not be arranged around the hollow grouting anchor rod 3.

[0019] Furthermore, an anchor plate 4 or a blade foot 4a is arranged at the bottom of the hollow grouting anchor rod 3.

[0020] Furthermore, the thickness of the anchor plate 4 is d; during the rotary pressing drilling process of the standard part 1, the drilling depth of the standard part 1 and the thickness d of the anchor plate 4 maintain a linear relationship.

[0021] Further, the grouting holes 6 are uniformly arranged along the axial and radial directions of the hollow grouting anchor rod 3.

[0022] Further, the number of the load transfer bars 5 on both sides is equal, and they are all perpendicular to the hollow grouting anchor rod 3. The spacing between the load transfer bars 5 on one side is the same, and the spacing in the vertical direction is all N·d, where N is at least 2; the distance between the load transfer bars 5 on one side of the hollow grouting anchor rod 3 and the adjacent load transfer bars 5 on the other side in the vertical direction is all N·d / 2.

[0023] Further, the clear distance between two adjacent standard parts 1 is greater than the length of a single load transfer bar 5, but less than twice the length of the load transfer bar 5.

[0024] The multiple standard parts 1 are arranged in a ring, and after the concrete slurry 2 set between the standard parts 1, it will bear force together with the standard parts 1.

[0025] As Figure 3 shown, a construction method for a grouting-formed hollow pile includes the following steps: Step 1: Position and loft the hole-forming position, and mark the contour line 7 of the integral pile; Step 2: On the contour line, first use the construction machinery to drill the first standard part 1, as Figure 3 (a) shown; when drilling to a depth where it only needs to rotate 90° to reach the specified depth, stop drilling. At this time, the axial directions of the load transfer bars 5 on both sides of the hollow grouting anchor rod 3 correspond to the center of the integral pile formed by multiple standard parts 1; Step 3: Drill the remaining standard parts 1 according to the marked contour line 7, and the drilling depth is the same as required in Step 2; the number of standard parts 1 is determined according to the size of the contour line. A total of 10 standard parts 1 are set in the figure, as Figure 3 (b)— Figure 3 (c) shown; Step 4: Use the construction machinery of the standard part 1 to rotate each standard part 1 by 90 degrees in turn. Finally, the load transfer bars 5 overlap with each other in space, as Figure 3 (d)— Figure 3 (e) shown; Step 5: Perform high-pressure grouting inside all the standard parts 1. The concrete slurry 2 is injected into the soil through the grouting holes 6 reserved in the hollow grouting anchor rod 3 under the action of pressure, as Figure 3 (f) shown; in this way, the concrete slurry 2 will gather and solidify around the standard parts 1. Since all the standard parts 1 are located on the contour line 7, the concrete slurry 2 will form a concrete slurry ring. The inside of the concrete slurry ring is the hollow area of the integral pile. The inner wall and outer wall of the concrete slurry ring are not smooth, Figure 3 only for illustration; Step 6: Core sampling is carried out at the middle position between adjacent standard parts 1 to check the grouting effect of the soil. After the grouting effect is achieved, stop grouting and fill the borehole with concrete slurry 2.

[0026] Step 7: After the concrete slurry 2 solidifies, the construction of the integral pile foundation is completed.

[0027] In the present invention, the anchor plate located at the bottom of the anchor rod can be replaced by a cutting edge 4a. When the cutting edge 4a is provided at the bottom of the anchor rod, the construction method is changed from helically drilling into the soil to mechanically pressing into the soil. After pressing to the designed depth, rotate 90°, and high-pressure grouting is carried out to form a whole. The remaining construction steps are the same. The cutting edge 4a is located at the bottom and provides a function of breaking soil during the pressing process.

[0028] The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the overall concept of the present invention, several changes and improvements can still be made, and these should also be regarded as the protection scope of the present invention.

Claims

1. A grouting hollow pile, characterized in that: The invention comprises a plurality of standard parts (1), wherein concrete slurry (2) is filled between adjacent standard parts (1), and the concrete slurry (2) between all the standard parts (1) is aggregated and solidified to form a concrete slurry ring; the concrete slurry ring and all the standard parts (1) inside it form an integrated grouting-molded hollow pile; the standard part (1) comprises a hollow grouting anchor rod (3), a force transmission rod (5) is arranged on the hollow grouting anchor rod (3), and a plurality of force transmission rods (5) are respectively distributed on both sides of the hollow grouting anchor rod (3); and a plurality of grouting holes (6) are arranged around the hollow grouting anchor rod (3).

2. A grouting hollow pile according to claim 1, characterized in that: An anchor plate (4) or a blade foot (4a) is provided at the bottom of the hollow grouting anchor rod (3).

3. A grouting hollow pile according to claim 2, characterized in that: The thickness of the anchor plate (4) is d; during the spinning drilling process of the standard component (1), the drilling depth of the standard component (1) and the thickness d of the anchor plate (4) maintain a linear relationship.

4. A grouting hollow pile according to claim 1, characterized in that: The grouting holes (6) are evenly arranged along the axial direction and radial direction of the hollow grouting anchor rod (3).

5. The grouting hollow pile according to claim 1, characterized in that: The number of force transfer rods (5) on both sides is equal and they are perpendicular to the hollow grouting anchor rod (3). The spacing between the force transfer rods (5) on one side is the same and the spacing in the vertical direction is N·d, where N is at least 2. The distance between the force transfer rod (5) on one side of the hollow grouting anchor rod (3) and the force transfer rod (5) on the other side adjacent to it in the vertical direction is N·d / 2.

6. A grouting hollow pile according to claim 1, characterized in that: The net distance between the two adjacent standard parts (1) is greater than a single length of the force transmission rod (5), but less than two times the length of the force transmission rod (5).

7. The grouting hollow pile according to claim 1, characterized in that: The plurality of standard parts (1) are arranged in a ring, and the concrete slurry (2) disposed between the standard parts (1) is subjected to force together with the standard parts (1) after solidification.

8. A construction method for grouting hollow piles according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: Locate and stake out the hole location and mark the contour line (7) of the integrated pile; Step 2: On the contour line, first use a construction machine to drill into the first standard part (1); when the drilling reaches the point where it still needs to rotate 90° to reach the specified depth, the drilling is stopped. At this time, the axial directions of the force transmission rods (5) on both sides of the hollow grouting anchor rod (3) correspond to the center of the integrated pile formed by the multiple standard parts (1); Step 3: Drill the remaining standard parts (1) according to the marked contour line (7), and the drilling depth is the same as that required in step 2; Step 4: Use the standard component (1) construction machinery to rotate each standard component (1) by 90 degrees in turn, so that the force transmission rods (5) are finally overlapped in space; Step 5: Perform high-pressure grouting inside all standard parts (1), and the concrete slurry (2) is injected into the soil through the grouting holes (6) reserved in the hollow grouting anchor rod (3) under pressure; thus, the concrete slurry (2) will gather and solidify around the standard parts (1), and since all the standard parts (1) are located on the contour line (7), the concrete slurry (2) will form a concrete slurry ring; Step 6: Drill core samples at the middle position of adjacent standard parts (1) to check the grouting effect of the soil; stop grouting after the grouting effect is achieved, and fill the drill hole with concrete slurry (2); Step 7: After the concrete slurry (2) solidifies, the construction of the integrated pile foundation is completed.

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