Post-grouting screw pile of post-planting device

Abstract

The utility model relates to the field of screw piles, in particular to a post-grouting screw pile of a post-planting device, which comprises a pile body, a grouting pipe and a reinforcement cage which are fixedly connected into a whole, the grouting pipe and the reinforcement cage are fixedly connected into a whole in advance and then are inserted into the pile body before the pile body is poured and initially set, a grouting valve is mounted at the bottom of the grouting pipe, and the grouting valve is connected with the reinforcement cage. The grouting valve is located at the bottom of the pile body, and the grouting pipe is used for implementing post-grouting operation through the grouting pump after the strength of the pile body is stable. According to the embodiment of the utility model, the technologies of post-implantation of the grouting pipe and post-grouting are adopted in the construction of the screw pile, so that the loose soil and mud cake at the bottom of the pile are effectively solidified, the compactness and the bearing capacity of the bottom of the pile are improved, the settlement of the pile foundation is reduced, and the long-term reliability and durability of the pile foundation are improved; and the integrity and the construction quality of the pile body structure are ensured.

Description

Technical Field

[0001] The utility model relates to the field of screw piles, in particular to a screw pile with a post-planting device and post-grouting. Background Art

[0002] Screw piles are a type of pile foundation widely used in foundation engineering, particularly suitable for supporting foundations in soft soil, clay, and other adverse geological conditions. Screw piles are drilled into the soil through rotation. Their helical design allows the pile to effectively compact the surrounding soil during construction, thereby enhancing the stability and bearing capacity of the pile foundation.

[0003] However, during actual construction, screw piles often encounter problems with loose soil and mud skin at the bottom of the pile. Loose soil refers to the loose and unevenly compacted soil at the bottom of the pile caused by disturbance during the screw drilling process. Mud skin is a layer of mud formed on the surface of the pile bottom due to the action of groundwater or mud during construction. These loose soil and mud skin can lead to insufficient bearing capacity of the soil at the bottom of the pile, increase the risk of pile settlement, and potentially affect the overall stability of the pile foundation. Utility Model Content

[0004] The purpose of the utility model is to provide a screw pile with post-grouted post-planting device to solve the problem of insufficient bearing capacity of the soil at the bottom of the screw pile due to loose and uneven compaction of the soil caused by disturbance during spiral drilling during the construction of the screw pile.

[0005] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0006] A screw pile with a post-planting device and post-grouting comprises a pile body, a grouting pipe and a steel cage fixedly connected as one body. The grouting pipe and the steel cage are pre-fixedly connected as one body and then inserted into the interior of the pile body before the pile body is poured and initially set. A grouting valve is installed at the bottom of the grouting pipe, and the grouting valve is located at the bottom of the pile body. The grouting pipe is used to implement post-grouting operations through a grouting pump after the strength of the pile body is stabilized.

[0007] Furthermore, part of the main bars or all of the main bars of the steel cage are replaced by the grouting pipe.

[0008] Furthermore, the grouting valve opens when the grouting pressure in the grouting pipe is greater than the external concrete pressure.

[0009] Furthermore, a grouting hole is provided on the side wall of the bottom of the grouting pipe, and the grouting valve includes a rubber sleeve wrapped around the outside of the grouting pipe and closing the grouting hole, and the rubber sleeve breaks when the grouting pressure in the grouting pipe is greater than the external concrete pressure.

[0010] Furthermore, a braided sleeve is sheathed on the outer side of the rubber sleeve.

[0011] Furthermore, a plug is installed at the bottom of the grouting pipe. The plug is in the shape of a cone with the tip facing downward, and the diameter of the bottom wall of the plug is larger than the diameter of the braided sleeve.

[0012] Furthermore, after the grouting operation is completed, the bottom of the grouting pipe is closed.

[0013] Furthermore, a puncture needle is provided inside the grouting pipe and above the grouting valve. The main agent and curing agent of the epoxy resin are pre-placed into the two cavities of the double-cavity capsule. The double-cavity capsule moves to the bottom of the grouting pipe together with the slurry during the grouting operation. When the double-cavity capsule is punctured, the main agent and curing agent mix to produce a curing reaction to form a second sealing layer.

[0014] Furthermore, an annular support frame is provided inside the grouting pipe, and the annular support frame is located at the same height as the puncture needle. The inner ring of the annular support frame is rolled up to form a flange. When the double-cavity capsule is punctured, the double-cavity capsule naturally shrinks and is fitted on the outside of the flange to form a first sealing layer.

[0015] Compared with the prior art, this application has the following beneficial effects:

[0016] Provided is a screw pile with a post-planting device and post-grouting. The post-implantation grouting pipe and post-grouting technology are adopted in the screw pile construction to effectively solidify the loose soil and mud skin at the pile bottom, thereby improving the density and bearing capacity of the pile bottom, reducing the settlement of the pile foundation, and improving the long-term reliability and durability of the pile foundation. In addition, the non-destructive grouting operation in the post-grouting process ensures the integrity of the pile structure and the construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely illustrative, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0018] Figure 1 This is a schematic structural diagram of an embodiment of the present utility model;

[0019] Figure 2 This is a structural diagram of a grouting valve according to an embodiment of the present utility model;

[0020] Figure 3 This is a schematic diagram of the process of placing a double-cavity capsule into the bottom of a grouting pipe according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the process of forming the first sealing layer and the second sealing layer after the double-chamber capsule according to the embodiment of the utility model is punctured;

[0022] The numbers in the figure represent the following:

[0023] 1-pile body; 2-grouting pipe; 21-grouting hole; 22-plug; 3-rebar cage; 4-grouting valve; 41-rubber sleeve; 42-braided sleeve; 6-sleeve; 61-annular support frame; 62-flange; 63-puncture needle; 7-double-cavity capsule; 71-cavity. DETAILED DESCRIPTION

[0024] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0025] Post-grouting is an auxiliary method for bored piles. This technology aims to solidify the loose soil and mud skin by post-grouting at the pile bottom, and to reinforce the soil at the pile bottom and a certain range around the pile, so as to improve the bearing capacity of the foundation pile, enhance the quality stability of the pile, and reduce the settlement of the pile foundation. For pile types such as drilled and bored bored piles, practice has shown that good results have been achieved.

[0026] Therefore, people want to transfer the post-grouting technology to screw piles, so that the loose soil and mud skin at the bottom of the screw piles can be solidified, thereby improving the bearing capacity and quality stability of the screw piles.

[0027] Combine Figure 1 、 Figure 2 The following provides a method for constructing screw piles with post-grouted post-planting devices, comprising the following steps:

[0028] Step 1: Prefabricate the grouting pipe 2 and the steel cage 3. A grouting valve 4 is installed at the bottom of the grouting pipe 2, and a wire plug is installed at the top of the grouting pipe 2. The grouting pipe 2 is tied or welded to the steel cage 3. The grouting pipe 2 can also be used to replace part or all of the main bars of the steel cage 3.

[0029] Step 2: Cast the pile body 1 of the screw pile underground. After the pile body 1 is cast and before initial setting, place the steel cage 3 and the grouting pipe 2 together into the interior of the pile body 1. First, use its own weight to insert the steel cage 3 into the concrete. When the steel cage 3 can no longer fall, connect the vibrator to the top of the steel cage 3 and use the exciting force of the vibrator to sink the steel cage 3 to the designed depth. At this time, the grouting valve 4 is located at the bottom of the pile body 1.

[0030] Step 3: After the strength of the pile body 1 is stable (generally 2 days after the pile is cast), unscrew the screw plug installed on the top of the grouting pipe 2, connect the output end of the grouting pump to the top of the grouting pipe 2, and implement the post-grouting operation. The grouting valve 4 is opened under the high-strength grouting pressure from the inside to the outside, and the slurry is injected into the rock and soil at the pile end to achieve non-destructive grouting.

[0031] Among them, the grouting valve 4 is a device that opens under specific pressure conditions. Its design purpose is to ensure that it can be opened under the action of pressure from the inside to the outside when slurry is injected into the grouting pipe 2, and will not be opened by the pressure of the external concrete during the insertion of the screw pile. Specifically, when the slurry pressure in the grouting pipe 2 is greater than the external concrete pressure, the grouting valve 4 will open or be destroyed, thereby allowing the slurry to flow out for grouting. It can be expressed as a traditional valve form or a plug form with similar functions. The core of the grouting valve 4 lies in its pressure response characteristics, ensuring that it only works during grouting operations and remains closed under other circumstances.

[0032] The grouting valve 4 in this embodiment is in the form of a plug that is destroyed under high-intensity grouting pressure. A grouting hole 21 is formed on the side wall of the grouting pipe 2. The grouting valve 4 includes a rubber sleeve 41 wrapped around the outside of the grouting pipe 2 and closing the grouting hole 21. The rubber sleeve 41 is double-layered, and a braided sleeve 42 is provided on the outside of the rubber sleeve 41. The braided sleeve 42 applies radial inward pressure to the rubber sleeve 41, so that the rubber sleeve 41 is firmly fixed on the outside of the grouting pipe 2.

[0033] During the process of inserting the grouting pipe 2 into the screw pile, the braided sleeve 42 provides protection for the rubber sleeve 41 to prevent the rubber sleeve 41 from being damaged due to friction with the concrete.

[0034] When the grouting pump performs the grouting operation, the rubber sleeve 41 and the braided sleeve 42 rupture under the high-intensity grouting pressure, and the slurry flows out evenly toward the surroundings of the grouting pipe 2 through the grouting hole 21 .

[0035] The rubber sleeve 41 may be made of natural rubber, chloroprene rubber, EPDM rubber, etc., and the braided sleeve 42 may be made of glass fiber, aramid fiber, polyester fiber, nylon fiber, etc.

[0036] Furthermore, a plug 22 is installed at the bottom of the grouting pipe 2. The plug 22 is in the shape of a cone with the tip facing downward. The diameter of the bottom wall of the plug 22 is larger than the diameter of the braided sleeve 42. During the process of inserting the grouting pipe 2 into the screw pile, the plug 22 provides protection for the braided sleeve 42 to prevent the braided sleeve 42 from shifting due to friction with the concrete.

[0037] The plug 22 may be made of steel, and the plug 22 is welded to the grouting pipe 2 .

[0038] The grouting pipe 2 is preferably a galvanized steel pipe with a diameter of 32 mm. When the length of the grouting pipe 2 is insufficient, two grouting pipes 2 can be connected by welding. Before welding, a sleeve 6 needs to be installed at the connection between the two galvanized steel pipes, and then the two ends of the sleeve 6 are welded to the two galvanized steel pipes respectively.

[0039] Furthermore, in order to prevent the slurry from flowing back into the grouting pipe 2 after the grouting is completed, the bottom of the grouting pipe 2 should be sealed before the grouting pump is removed. Since the rubber sleeve 41 and the braided sleeve 42 have been broken in the high-intensity grouting pressure, they cannot play the role of sealing the bottom of the grouting pipe 2. Moreover, due to the poor fluidity of the concrete slurry, even if the rubber sleeve 41 and the braided sleeve 42 of this embodiment are replaced with other types of one-way valves, it is difficult to achieve the purpose of closing the one-way valve to seal the grouting pipe 2.

[0040] In order to solve this problem, combined with Figure 3 and Figure 4 In this embodiment, epoxy resin is inserted into the bottom of the grouting pipe 2 to perform the sealing operation.

[0041] An annular support frame 61 is pre-installed at the bottom of the grouting pipe 2. The annular support frame 61 is located above the grouting valve 4. The inner ring of the annular support frame 61 is rolled up to form a flange 62. A puncture needle 63 is fixed just below the center of the annular support frame 61. The annular support frame 61 and the puncture needle 63 are both fixed to a sleeve 6 connected to the grouting pipe 2 by welding. The annular support frame 61 and the puncture needle 63 are basically at the same height.

[0042] The epoxy resin is contained in a double-cavity capsule 7, which is made of a high-strength elastic material, such as polyurethane elastomer, nitrile rubber, silicone rubber, etc. Two independent cavities 71 are provided inside the double-cavity capsule 7. The two cavities 71 are respectively filled with the main agent and curing agent of the epoxy resin. When the cavity 71 is filled, the double-cavity capsule 7 expands outward and remains taut.

[0043] When performing the operation of closing the bottom of the grouting pipe 2, the construction workers throw the double-cavity capsule 7 from the top of the grouting pipe 2, then install a pressure gauge between the grouting pipe 2 and the grouting pump, and then continue the grouting operation.

[0044] When the double-cavity capsule 7 descends to the position of the annular support frame 61, the double-cavity capsule 7 is blocked by the annular support frame 61. At this time, the central part of the double-cavity capsule 7 sags under the dual effects of gravity and grouting pressure, and is eventually punctured by the puncture needle 63 under the support frame.

[0045] After being punctured, the double-chamber capsule 7 loses the support of the internal liquid and will naturally shrink and tightly clamp the edge of the flange 62 of the annular support frame 61 to form a first sealing layer. The construction personnel judge the progress of the sealing operation by observing the grouting pressure displayed on the pressure gauge. When the grouting pressure displayed on the pressure gauge exceeds the predetermined threshold, it means that the first sealing layer has been formed and the construction personnel stop grouting.

[0046] At this time, at the bottom of the grouting pipe 2, the main agent and curing agent filled in the double-cavity capsule 7 flow out and mix, the mixed epoxy resin begins to solidify, and forms a second sealing layer below the first sealing layer in a short time.

[0047] This double sealing structure ensures that the bottom of the grouting pipe 2 can be permanently sealed, effectively preventing the slurry from flowing back into the grouting pipe 2. There is no need to wait for the slurry inside the grouting pipe 2 to completely solidify. After the epoxy resin reaches the curing time, the grouting pump and pressure gauge can be removed.

[0048] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and scope of protection of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present invention.

Claims

1. A screw pile with post-grouting device, characterized in that: The invention comprises a pile body (1), a grouting pipe (2) and a steel cage (3) which are fixedly connected as one body. The grouting pipe (2) and the steel cage (3) are fixedly connected as one body in advance and then inserted into the interior of the pile body (1) after the grouting of the pile body (1) is completed and before initial setting. A grouting valve (4) is installed at the bottom of the grouting pipe (2). The grouting valve (4) is located at the bottom of the pile body (1). The grouting pipe (2) is used to implement post-grouting operations through a grouting pump after the strength of the pile body (1) is stabilized.

2. The screw pile with post-grouting device according to claim 1, characterized in that: Part or all of the main reinforcements of the reinforcement cage (3) are replaced by the grouting pipe (2).

3. The screw pile with post-grouting device according to claim 1, characterized in that: The grouting valve (4) opens when the grouting pressure in the grouting pipe (2) is greater than the external concrete pressure.

4. The screw pile with post-grouting device according to claim 3, characterized in that: A grouting hole (21) is provided on the side wall of the bottom of the grouting pipe (2), and the grouting valve (4) comprises a rubber sleeve (41) wrapped around the outside of the grouting pipe (2) and closing the grouting hole (21), and the rubber sleeve (41) ruptures when the grouting pressure in the grouting pipe (2) is greater than the external concrete pressure.

5. The screw pile with post-grouting device according to claim 4, characterized in that: A braided sleeve (42) is sleeved on the outer side of the rubber sleeve (41).

6. The screw pile with post-grouting device according to claim 5, characterized in that: A plug (22) is installed at the bottom of the grouting pipe (2). The plug (22) is in a conical shape with the tip facing downward, and the diameter of the bottom wall of the plug (22) is larger than the diameter of the braided sleeve (42).

7. A screw pile with post-grouting device according to any one of claims 1 to 6, characterized in that: After the grouting operation is completed, the bottom of the grouting pipe (2) is closed.

8. The screw pile with post-grouting device according to claim 7, characterized in that: A puncture needle (63) is provided inside the grouting pipe (2) and above the grouting valve (4). The main agent and curing agent of the epoxy resin are pre-placed into the two cavities (71) of the double-cavity capsule (7). The double-cavity capsule (7) moves to the bottom of the grouting pipe (2) together with the slurry during the grouting operation. When the double-cavity capsule (7) is punctured, the main agent and curing agent mix and produce a curing reaction to form a second sealing layer.

9. The screw pile with post-grouting device according to claim 8, characterized in that: An annular support frame (61) is provided inside the grouting pipe (2), and the annular support frame (61) is located at the same height as the puncture needle (63). The inner ring of the annular support frame (61) is rolled up to form a flange (62). When the double-cavity capsule (7) is punctured, the double-cavity capsule (7) naturally shrinks and is fitted on the outside of the flange (62) to form a first sealing layer.

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