A pile tip structure for pile end post-grouting and use method thereof

Abstract

The present invention discloses a pile tip structure for post-grouting at the pile end and a method of using the same, and belongs to the technical field of building construction. It comprises a welded end plate, a through hole is provided in the middle of the welded end plate, a threaded sleeve is provided in the middle of one end of the welded end plate, a protective tube is provided in the middle of the other end of the welded end plate, one end of the protective tube is fixed to the welded end plate, a closing plate is provided at the other end of the protective tube, the closing plate is fixed to the protective tube, four circumferentially arranged arc plates are provided inside the protective tube, at least one mounting shaft is provided on two arc plates arranged opposite to each other, the two ends of the mounting shaft are respectively fixed on the inner wall of the protective tube, and the four arc plates are slidably connected to the mounting shaft. This technical solution is used for the setting method of the grouting pile tip in the prior art. During the pile sinking process, the grouting holes provided thereon are easily blocked, resulting in the problem that the grouting effect is affected.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a pile tip structure for pile end post-grouting and a use method thereof. Background Art

[0002] PHC piles are cylindrical prefabricated piles with the advantages of high bearing capacity, fast construction speed, good construction quality and low engineering cost, so they are widely used in engineering construction. However, due to the bearing capacity of the foundation, the strength of the PHC pile body is often not fully utilized, resulting in a waste of resources.

[0003] Post-grouting is a very effective method to improve the bearing capacity of the foundation. Therefore, many engineering and technical personnel have borrowed the post-grouting technology of bored pile ends to improve the bearing performance of PHC piles. The research on the post-grouting technology of PHC pile ends is mainly carried out around the development of grouting pile tips. The grouting pile tips in the existing technology usually achieve the grouting operation of PHC piles by opening grouting holes on ordinary pile tips. However, in actual use, the grouting holes opened on the pile tips are easily blocked by the soil in the pile foundation hole when the PHC piles are sinking, which affects the grouting effect in the later stage. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a pile tip structure for post-grouting at the pile end and a method of using the same, in order to solve the problem that in the prior art, the grouting holes arranged thereon are easily blocked during the pile sinking process, thus affecting the grouting effect.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention discloses a pile tip structure for post-grouting at the pile end, comprising a welded end plate, a through hole is provided in the middle of the welded end plate, a threaded sleeve is provided in the middle of one end of the welded end plate, a protective tube is provided in the middle of the other end of the welded end plate, one end of the protective tube is fixed to the welded end plate, a closing plate is provided at the other end of the protective tube, the closing plate is fixed to the protective tube, four circumferentially arranged arc plates are provided inside the protective tube, at least one mounting shaft is provided on two arc plates arranged opposite to each other, the two ends of the mounting shaft are respectively fixed to the inner wall of the protective tube, the four arc plates are slidably connected to the mounting shaft, and the arc plates face A plurality of vertically evenly distributed blocking rods are arranged on one side surface of the inner wall of the protection tube, a plurality of grouting holes corresponding to the positions of the blocking rods are arranged on the protection tube, a spring is sleeved on the installation shaft, the two ends of the spring are respectively fixed on the inner side surfaces of two relatively arranged arc-shaped plates, a first wedge block is arranged on the side surface of the arc-shaped plate facing the inner wall of the protection tube, a slip ring is arranged inside the threaded sleeve, the slip ring is slidably connected to the inside of the threaded sleeve, a plurality of connecting rods corresponding to the positions of the first wedge blocks are arranged on the slip ring, a second wedge block is arranged on the connecting rod, and the inclined surfaces of the first wedge block and the second wedge block are in sliding contact with each other.

[0007] Furthermore, under the action of the spring, one end of the blocking rod is located outside the grouting hole.

[0008] Furthermore, the number of the installation shafts arranged on the arc-shaped plates arranged opposite to each other is two, and the two installation shafts are symmetrically arranged along the middle section of the arc-shaped plates.

[0009] Furthermore, the first wedge block is arranged in the middle of the arc plate.

[0010] Furthermore, the outer ring diameter of the slip ring is equal to the inner ring diameter of the protection tube.

[0011] Furthermore, a plurality of circumferentially evenly distributed supporting steel plates are provided on one end surface of the protection tube of the welded end plate, and the grouting holes are provided between adjacent supporting steel plates.

[0012] Furthermore, a grouting pipe is provided in the threaded sleeve, and one end of the grouting pipe is threadedly connected to the threaded sleeve.

[0013] Furthermore, the welded end plate is fixedly connected to one end of the precast pile located deep underground, and an annular support block is provided on the other end of the precast pile, the outer wall of the annular support block is in close contact with the inner wall of the other end of the precast pile, and the inner wall of the annular support block is slidably connected to the outer wall of the grouting pipe.

[0014] A method for using a pile tip structure for pile end post-grouting comprises the following steps:

[0015] S1, welding and fixing the welded end plate of the pile tip structure to one end of the prefabricated pile located deep underground;

[0016] S2, placing a grouting pipe inside the precast pile, and then threading one end of the grouting pipe onto the threaded sleeve, at which point the end of the plugging rod is located in the grouting hole;

[0017] S3, after the grouting pipe is installed, the prefabricated piles are sunk;

[0018] S4, after the pile is sunk to the designated position, the grouting pipe is rotated to make the end of the grouting pipe move downward to squeeze the slip ring, thereby driving the second wedge block to squeeze the first wedge block, thereby driving the arc plate to slide inward, so that the blocking rod is separated from the grouting hole, and then high-pressure grout is injected into the pile tip structure through the grouting pipe;

[0019] S5. After grouting is completed, the grouting pipe is rotated to disengage the grouting pipe from the threaded sleeve, and then the grouting pipe is taken out. At this time, the spring loses its squeezing force and will automatically reset, thereby driving the arc block to move outward, so that the blocking rod moves into the grouting hole and blocks the grouting hole again to prevent the slurry from flowing back after the grouting is completed.

[0020] The beneficial effects of the present invention are:

[0021] The grouting pile tip in the present technical solution can close the grouting hole during the early stage of pile sinking to prevent soil from entering the interior of the grouting pile tip and clogging the grouting hole. At the same time, during grouting, the grouting hole will automatically open under the squeezing action of the grouting pipe to facilitate the grouting operation. After the grouting is completed and the grouting pipe is taken out, the grouting hole can also be automatically closed to prevent the slurry from flowing back. Therefore, the grouting device in the present technical solution can greatly improve the grouting effect on the bottom of the precast pile.

[0022] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0024] Figure 1 It is a schematic diagram of an exploded view of the pile tip structure in the present invention;

[0025] Figure 2 It is a schematic diagram of a front view and a cross-sectional view of the pile tip structure in the present invention;

[0026] Figure 3It is a schematic diagram of the protection pipe and the welded end plate in the pile tip structure of the present invention;

[0027] Figure 4 It is a three-dimensional schematic diagram of the arc plate and the blocking rod in the pile tip structure of the present invention;

[0028] Figure 5 A three-dimensional schematic diagram of the arrangement of the slip ring and the second wedge block in the pile tip structure of the present invention;

[0029] Figure 6 It is a schematic diagram of the pile tip structure of the present invention being applied to a prefabricated pile for grouting;

[0030] Figure 7 It is a schematic diagram of an explosion when the pile tip structure of the present invention is applied to a prefabricated pile for grouting.

[0031] The following are marked in the accompanying drawings:

[0032] 1. Precast pile; 2. Grouting pipe; 3. Annular support block; 4. Welded end plate; 5. Threaded sleeve; 6. Support steel plate; 7. Closing plate; 8. Grouting hole; 9. Arc plate; 10. Blocking rod; 11. Mounting shaft; 12. First wedge block; 13. Spring; 14. Slip ring; 15. Connecting rod; 16. Second wedge block. DETAILED DESCRIPTION

[0033] like Figure 1 to Figure 7As shown, a pile tip structure for post-grouting of pile ends of the present invention comprises a welded end plate 4, a through hole is provided in the middle of the welded end plate 4, a threaded sleeve 5 is provided in the middle of one end of the welded end plate 4, a protective tube is provided in the middle of the other end of the welded end plate 4, one end of the protective tube is fixed to the welded end plate 4, a closing plate 7 is provided at the other end of the protective tube, the closing plate 7 is welded and fixed to the protective tube, four circumferentially arranged arc plates 9 are provided inside the protective tube, at least one mounting shaft 11 is provided on two oppositely arranged arc plates 9, in the present specific embodiment, two mounting shafts 11 are provided on one arc plate 9, two ends of the mounting shaft 11 are respectively fixed on the inner wall of the protective tube, the four arc plates 9 are slidably connected to the mounting shafts 11, and the arc plates 9 face the inner wall of the protective tube. A plurality of vertically evenly distributed blocking rods 10 are provided on one side surface. Specifically, three blocking rods 10 are provided on one arc plate 9. Of course, they can be arranged according to actual conditions. A plurality of grouting holes 8 corresponding to the blocking positions are provided on the protection tube. A spring 13 is sleeved on the mounting shaft 11. The two ends of the spring 13 are respectively welded and fixed on the inner side surfaces of the two oppositely arranged arc plates 9. A first wedge block 12 is provided on the side surface of the arc plate 9 facing the inner wall of the protection tube. A slip ring 14 is provided inside the threaded sleeve 5. The slip ring 14 is slidably connected to the inside of the threaded sleeve 5. A plurality of connecting rods 15 corresponding to the position of the first wedge block 12 are provided on the slip ring 14. A second wedge block 16 is provided on the connecting rod 15. The inclined surfaces of the first wedge block 12 and the second wedge block 16 are in sliding contact with each other.

[0034] At the same time, it is not difficult to understand that in order to realize the grouting operation, a grouting pipe 2 is required to be provided in the threaded sleeve 5, one end of the grouting pipe 2 is threadedly connected to the threaded sleeve 5, the end of the precast pile 1 located deep underground is fixedly connected to the welded end plate 4, and the other end of the grouting pipe 2 is provided with an annular support block 3, the outer wall of the annular support block 3 is in close contact with the inner wall of the other end of the precast pile 1, and the inner wall of the annular support block 3 is slidably connected to the outer wall of the grouting pipe 2. At the same time, the grouting pipe 2 at the upper end should also be connected to the grouting equipment, and the grouting equipment is a prior art and will not be described in detail here.

[0035] In summary, the working principle of grouting achieved by the above technical solution is:

[0036] When the prefabricated pile 1 is being driven, although the grouting pipe 2 is connected to the threaded sleeve 5, it is not tightly pressed against the slip ring 14. Therefore, under the action of the spring 13, the arc plates 9 at both ends of the spring 13 are pushed outward, so that the blocking rod 10 on the arc plate 9 moves toward the grouting hole 8, and then enters the grouting hole 8 to block the grouting hole 8, so as to prevent the soil on the inner wall of the pile foundation hole from entering the grouting hole 8 or causing the grouting hole 8 to be blocked during the pile driving process;

[0037] After the prefabricated pile 1 is installed in place, when grouting is required, it is only necessary to rotate the grouting pipe 2 to make it move downward in the threaded sleeve 5, that is, the end of the grouting pipe 2 moving downward will push the slip ring 14 to move downward, thereby driving the connecting rod 15 to move downward, and then the second wedge block 16 will push the first wedge block 12 to move, that is, the first wedge block 12 will move toward the middle of the protection pipe, thereby separating the blocking rod 10 from the grouting hole 8, and then the high-pressure slurry in the grouting pipe 2 can seep out from the grouting hole 8, thereby realizing the grouting operation of the pile foundation hole;

[0038] When grouting is completed, it is only necessary to rotate the grouting pipe 2 and take it out. At this time, the slip ring 14 loses its force, and under the reset torque of the spring 13, the arc plate 9 will be pushed to move to the outside of the protective tube, and then the first wedge block 12 will push the second wedge block 16 to move and reset, and at the same time, the sealing rod 10 will re-seal the grouting hole 8 to avoid slurry backflow after grouting is completed.

[0039] In the above scheme, the blocking rod 10 blocks from the inside to the outside, and moves from the outside to the inside to release the blockage of the grouting hole 8. The advantage of this is that even if there is mud outside the grouting hole 8, the blocking rod 10 is blocked from moving outward, but because the blocking rod 10 moves in the protection tube, the blocking and contact blocking effect of the blocking rod 10 on the grouting hole 8 will not be affected by the accumulation of mud outside the grouting hole 8. At the same time, the setting of the protection tube can protect the end of the grouting pipe 2, avoiding the problem of the end of the grouting pipe 2 being blocked and damaged by contact collision due to direct grouting.

[0040] In one feasible manner, under the action of the spring 13, one end of the sealing rod 10 is located outside the grouting hole 8. The advantage of the end being located outside is that even if soil is accumulated outside the grouting hole 8, a cavity can be formed on the soil after the end of the sealing rod 10 is inserted into the soil, that is, after the sealing rod 10 releases the blockage of the grouting hole 8, there is also a cavity on the soil outside the grouting hole 8, that is, the grouting hole 8 will not be blocked, which makes it easier for high-pressure slurry to penetrate outward in the later stage.

[0041] In one feasible manner, there are two mounting shafts 11 arranged on the relatively arranged arc plates 9, and the two mounting shafts 11 are symmetrically arranged along the middle section of the arc plate 9. The two symmetrical arrangements can enhance the translation effect of the arc plate 9 and avoid the rotation of the arc plate 9.

[0042] In one feasible manner, the first wedge block 12 is arranged in the middle of the arc plate 9, that is, the second wedge block 16 applies a torque from the middle of the arc plate 9 to push the arc plate 9, which can enhance the pushing effect on the arc plate 9.

[0043] In one feasible manner, the outer diameter of the slip ring 14 is equal to the inner diameter of the protective tube. It is not difficult to understand that this manner is for the slip ring 14 to slide in the protective tube. Of course, preferably, the outer diameter of the slip ring 14 is slightly smaller than the outer diameter of the grouting tube 2, such as 5 mm smaller. The advantage of this is that the end of the grouting tube 2 can be squeezed and pushed on the slip ring 14, and the threads set on the inner wall of the threaded sleeve 5 can be prevented from blocking and interfering with the movement of the slip ring 14.

[0044] In one feasible manner, a plurality of circumferentially evenly distributed supporting steel plates 6 are provided on one end face of the protective tube provided on the welded end plate 4, and grouting holes 8 are provided between adjacent supporting steel plates 6. The provision of the supporting steel plates 6 can avoid the problem of the protective tube being inserted into the soil due to the small contact area between the protective tube and the ground of the pile foundation hole, and can also improve the bearing capacity of the bottom end of the precast pile 1.

[0045] A method for using a pile tip structure for pile end post-grouting comprises the following steps:

[0046] S1, welding and fixing the welded end plate 4 of the pile tip structure to one end of the prefabricated pile 1 located deep underground;

[0047] S2, placing the grouting pipe 2 inside the precast pile 1, and then threading one end of the grouting pipe 2 onto the threaded sleeve 5, at which time the end of the blocking rod 10 is located in the grouting hole 8;

[0048] S3, after the grouting pipe 2 is installed, the prefabricated pile 1 is sunk;

[0049] S4, after the pile is sunk to the designated position, the grouting pipe 2 is rotated to make the end of the grouting pipe 2 move downward, to squeeze the slip ring 14, thereby driving the second wedge block 16 to squeeze the first wedge block 12, thereby driving the arc plate 9 to slide inward, so that the blocking rod 10 is separated from the grouting hole 8, and then the high-pressure grout is injected into the pile tip structure through the grouting pipe 2;

[0050] S5, after grouting is completed, the grouting pipe 2 is rotated to disengage the grouting pipe 2 from the threaded sleeve 5, and then the grouting pipe 2 is taken out. At this time, the spring 13 loses the squeezing force and will automatically reset, thereby driving the arc block to move outward, so that the blocking rod 10 moves into the grouting hole 8, and the grouting hole 8 is blocked again to prevent the slurry from flowing back after the grouting is completed.

[0051] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A pile tip structure for post-grouting of pile ends, characterized in that: The invention comprises a welding end plate (4), wherein a through hole is provided in the middle of the welding end plate (4), a threaded sleeve (5) is provided in the middle of one end of the welding end plate (4), a protection tube is provided in the middle of the other end of the welding end plate (4), one end of the protection tube is fixed to the welding end plate (4), a closing plate (7) is provided at the other end of the protection tube, the closing plate (7) is fixed to the protection tube, four circumferentially arranged arc plates (9) are provided inside the protection tube, two arc plates (9) arranged opposite to each other are each provided with at least one mounting shaft (11), the two ends of the mounting shaft (11) are respectively fixed to the inner wall of the protection tube, the four arc plates (9) are slidably connected to the mounting shaft (11), and a plurality of vertically evenly distributed arc plates (9) are provided on one side of the arc plate (9) facing the inner wall of the protection tube A sealing rod (10) is provided on the protective tube, a plurality of grouting holes (8) corresponding to the positions of the sealing rods are provided on the mounting shaft (11), springs (13) are sleeved on the mounting shaft (11), the two ends of the springs (13) are respectively fixed on the inner side surfaces of two arc-shaped plates (9) arranged opposite to each other, a first wedge block (12) is provided on one side of the arc-shaped plate (9) facing the inner wall of the protective tube, a slip ring (14) is provided inside the threaded sleeve (5), the slip ring (14) is slidably connected to the inside of the threaded sleeve (5), a plurality of connecting rods (15) corresponding to the positions of the first wedge blocks (12) are provided on the slip ring (14), and a second wedge block (16) is provided on the connecting rod (15), and the inclined surfaces of the first wedge block (12) and the second wedge block (16) are in sliding contact with each other.

2. A pile tip structure for post-grouting of pile end according to claim 1, characterized in that: Under the action of the spring (13), one end of the blocking rod (10) is located outside the grouting hole (8).

3. A pile tip structure for post-grouting of pile end according to claim 1, characterized in that: The number of mounting shafts (11) arranged on the arc-shaped plates (9) arranged opposite to each other is two, and the two mounting shafts (11) are symmetrically arranged along the middle cross section of the arc-shaped plate (9).

4. The pile tip structure for post-grouting of pile end according to claim 1, characterized in that: The first wedge-shaped block (12) is arranged in the middle of the arc-shaped plate (9).

5. The pile tip structure for post-grouting of pile end according to claim 1, characterized in that: The outer ring diameter of the slip ring (14) is equal to the inner ring diameter of the protection tube.

6. The pile tip structure for post-grouting of pile end according to claim 1, characterized in that: A plurality of support steel plates (6) evenly distributed around the circumference are provided on one end surface of the welding end plate (4) on which the protection tube is provided, and the grouting holes (8) are provided between adjacent support steel plates (6).

7. The pile tip structure for post-grouting of pile end according to claim 1, characterized in that: A grouting pipe (2) is arranged inside the threaded sleeve (5), and one end of the grouting pipe (2) is threadedly connected to the threaded sleeve (5).

8. The pile tip structure for post-grouting of pile end according to claim 1, characterized in that: The welded end plate (4) is fixedly connected to one end of the precast pile (1) located deep underground, and an annular support block (3) is provided on the other end of the precast pile, the outer wall of the annular support block (3) is in close contact with the inner wall of the other end of the precast pile (1), and the inner wall of the annular support block (3) is slidably connected to the outer wall of the grouting pipe (2).

9. A method for using a pile tip structure for post-grouting of pile end according to any one of claims 1 to 8, characterized in that: The steps include: S1, welding and fixing a welded end plate (4) of a pile tip structure to one end of a prefabricated pile (1) located deep underground; S2, placing a grouting pipe (2) inside the prefabricated pile (1), and then threading one end of the grouting pipe (2) onto the threaded sleeve (5), at which point the end of the blocking rod (10) is located inside the grouting hole (8); S3, after the grouting pipe (2) is installed, the prefabricated pile (1) is sunk; S4, after the pile is sunk to the designated position, the grouting pipe (2) is rotated to move the end of the grouting pipe (2) downward, thereby squeezing the slip ring (14), thereby driving the second wedge block (16) to squeeze the first wedge block (12), thereby driving the arc plate (9) to slide inward, causing the blocking rod (10) to separate from the grouting hole (8), and then injecting high-pressure grout into the pile tip structure through the grouting pipe (2); S5, after grouting is completed, the grouting pipe (2) is rotated to disengage the grouting pipe (2) from the threaded sleeve (5), and then the grouting pipe (2) is taken out. At this time, the spring (13) loses its squeezing force and automatically resets, thereby driving the arc block to move outward, so that the blocking rod (10) moves into the grouting hole (8), and the grouting hole (8) is blocked again to prevent the slurry from flowing back after the grouting is completed.

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