Foundation pile construction method

Abstract

The invention discloses a foundation pile construction method which comprises the following steps: a pile pressing step: a prefabricated special-shaped pile with a built-in embedded pipe is pressed and constructed to a preset depth of a foundation, and the prefabricated special-shaped pile is provided with a pile body formed by alternately connecting thick pile sections and thin pile sections; the embedded pipe is provided with a slurry outlet which can be communicated to the outer wall of the pile body at the shaft shoulder of the thick pile section or the thin pile section; a grouting pipe with a grouting opening formed in the side wall of the bottom extends into a preset position in the embedded pipe so that the grouting opening can be communicated with a grout outlet corresponding to the preset position, and the periphery of the thin pile section is filled with grout so that a radial gap between the thin pile section and the surrounding soil body can be eliminated. According to the foundation pile construction method provided by the invention, the periphery of the thin pile section can be filled with the slurry to eliminate the radial gap between the thin pile section and the surrounding soil body, so that the pulling resistance and the bearing capacity of the prefabricated special-shaped pile in a short period after construction are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pile construction methods, specifically to the construction method of foundation piles. Background Art

[0002] The precast special-shaped pile is a kind of precast pile, which refers to a pile with a cross-section changing along the axial direction (pile length direction). The precast special-shaped pile includes a thick pile section and a thin pile section. During the process of inserting it into the soil with relatively hard texture, a pile hole will be formed in the shape and size of the cross-section of the thick pile section. Therefore, after being inserted into the soil layer, the thick pile section can be in close contact with the surrounding soil layer. However, since the cross-section of the thin pile section is smaller than that of the thick pile section, there are radial and circumferential gaps between the thin pile section and the surrounding soil layer. It takes a very long period in the natural state for the soil around the thin pile section to recover (that is, the soil around the thin pile section fills the above gaps). Therefore, the skin friction on the front side of the soil cannot be exerted after the precast special-shaped pile is inserted into the soil with relatively hard texture, and its short-term uplift resistance and bearing capacity are relatively weak, seriously affecting the construction progress and test results. Summary of the Invention

[0003] The purpose of the present invention is to provide a construction method for foundation piles to solve the problem that the short-term uplift resistance and bearing capacity of precast special-shaped piles are relatively weak after pile pressing construction.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] The construction method of foundation piles includes the following steps:

[0006] Pile pressing step: Press the precast special-shaped pile with an embedded pre-pipe into the predetermined depth of the foundation. The precast special-shaped pile has a pile body formed by alternating connection of thick pile sections and thin pile sections, and slurry outlets that can communicate with the outer wall of the pile body are arranged at the shoulder of the thick pile section and / or at the thin pile section of the pre-pipe;

[0007] Grouting step: Vertically insert a grouting pipe with a grouting port on the bottom side wall into the predetermined position in the pre-pipe so that the grouting port communicates with the corresponding slurry outlet at the predetermined position, and fill the outer periphery of the thin pile section with slurry to eliminate the radial gap between the thin pile section and the surrounding soil.

[0008] Compared with the prior art, the beneficial effect of the present invention is that slurry can be filled into the outer periphery of the thin pile section to eliminate the radial gap between the thin pile section and the surrounding soil, thereby improving the short-term uplift resistance and bearing capacity performance after the construction of the precast special-shaped pile.

[0009] On the basis of the above solution, the grouting step includes:

[0010] Insert the grouting pipe into the embedded pipe and lower it to a position corresponding to a predetermined slurry outlet, and seal the two sides of the grouting port at a predetermined height in the vertical direction so that the grouting port is only connected to the corresponding slurry outlet, and then start grouting.

[0011] On the basis of the above solution, the volume of the slurry filled in the outer periphery of the thin pile section is less than the volume of the gap between the thin pile section and the soil around the pile.

[0012] On the basis of the above solution, sealing members are respectively arranged on the two sides of the grouting port in the vertical direction, and a clamping member is arranged on the outer wall of the grouting pipe. The sealing member includes at least one of an air bag and a sealing ring. Among them, the air bag is connected to an air pipe;

[0013] And / or, the slurry includes at least one of water, mud, and gel material.

[0014] On the basis of the above solution, the pile pressing step includes:

[0015] Initial pile pressing sub-step: First, expose the slurry outlet of the precast special-shaped pile, and press the first precast special-shaped pile into the soil at the predetermined pile position so that its top end is higher than the predetermined height above the ground surface;

[0016] Pile splicing and pile pressing sub-step; Vertically splice the second precast special-shaped pile to the first precast special-shaped pile at the same pile position, and make the embedded pipes of the two communicate longitudinally, and press the second precast special-shaped pile into the soil;

[0017] Repeat the pile splicing and pile pressing sub-step until the preset number of precast special-shaped piles are pressed to the predetermined depth at the same pile position.

[0018] On the basis of the above solution, it further includes:

[0019] Anticorrosion step before the pile pressing step: Apply anticorrosion material to the outer peripheral wall of the precast special-shaped pile and the connection end face of adjacent precast special-shaped piles.

[0020] On the basis of the above solution, the grouting step includes:

[0021] Initial grouting sub-step: Lower the grouting pipe to the position corresponding to the lowest slurry outlet, and start grouting under the sealed state of the two sides of the grouting port at a predetermined height in the vertical direction, so that the slurry flows out from this slurry outlet until the grouting of this thin pile section is completed;

[0022] Lifting grouting sub-step: Release the sealed state of the two sides of the grouting port at a predetermined height in the vertical direction, lift the height of the grouting pipe to the position of another slurry outlet above, and then enter the sealed state again, and start grouting so that the slurry flows out from this slurry outlet;

[0023] Repeat the lifting grouting sub-step until the grouting of the thin pile section at the uppermost end is completed.

[0024] On the basis of the above solution, it further includes: connecting a pile tip to the lower end of the first precast special-shaped pile before the pile pressing step;

[0025] and / or, using the static pressure method or the hammering method for pile pressing;

[0026] and / or, the grouting pressure is 1 Mpa to 60 MPa.

[0027] On the basis of the above solution, it further includes:

[0028] The hole leading step before the pile pressing step: leading a hole to a predetermined depth at a predetermined pile site;

[0029] The calibration step: aligning and placing the precast special-shaped pile at the hole position of the hole leading.

[0030] On the basis of the above solution, a temporary protective cover, a one-way valve or a tape is provided at the slurry outlet;

[0031] and / or, a limiting platform adapted to a sealing member is provided on the inner wall of the embedded pipe. Description of the Drawings

[0032] Figure 1 It is a flow chart of the foundation pile construction method in the embodiment of the present invention;

[0033] Figure 2 It is a sub-flow chart of the pile pressing step;

[0034] Figure 3 It is a sub-flow chart of the grouting step;

[0035] Figure 4 It is a structural schematic diagram of the precast special-shaped pile;

[0036] Figure 5 It is Figure 4 The enlarged view of part A in;

[0037] Figure 6 It is a cross-sectional view of the precast special-shaped pile;

[0038] Figure 7 It is Figure 6 The enlarged view of part B in;

[0039] Figure 8 It is a structural schematic diagram of another precast special-shaped pile;

[0040] Figure 9 It is a cross-sectional view of another precast special-shaped pile;

[0041] Figure 10 It is Figure 9 The enlarged view of part C in;

[0042] Figure 11 It is Figure 10 The enlarged view of part D in;

[0043] Figure 12 Schematic diagram of the cooperation between the limit clamping platform and the seal

[0044] Figure 13 Schematic diagram of the structure of the grouting pipe

[0045] Figure 14 is Figure 13 Enlarged view of part E in

[0046] Figure 15 Schematic diagram of the structure of another grouting pipe

[0047] Figure 16 is Figure 15 Enlarged view of part F in

[0048] Figure 17 Schematic diagram of the structure of another precast special-shaped pile

[0049] Figure 18 Cross-sectional view of another precast special-shaped pile

[0050] Figure 19 is Figure 18 Enlarged view of part H in

[0051] Figure 20 is Figure 18 Enlarged view of part I in

[0052] Figure 21 Exploded structure schematic diagram of the connection component

[0053] Figure 22 Cross-sectional view of the connection component

[0054] In the figure: 100, precast special-shaped pile; 1, thick pile section; 11, at the shoulder; 12, connection component hole; 2, thin pile section; 3, embedded pipe; 31, slurry outlet; 311, hole-sealing member; 32, main pipe; 33, branch pipe; 34, limit clamping platform; 4, main reinforcement; 41, stirrup; 42, upset head; 5, grouting pipe; 51, grouting port; 52, seal; 53, clamping member; 54, air pipe; 6, connection component; 61, small screw sleeve; 62, large screw sleeve; 621, socket cavity; 63, elastic locking component; 631, elastic member; 632, locking member; 64, anti-loosening nut; 65, inserting rod; 651, inserting end Specific implementation method

[0055] In this text, terms such as "upper, lower, inner, outer" are established based on the positional relationships shown in the drawings. Depending on the different drawings, the corresponding positional relationships may also change accordingly. Therefore, they should not be understood as absolute limitations on the scope of protection. Moreover, relational terms such as "first" and "second" are only used to distinguish one component with the same name from another, and do not necessarily require or imply any such actual relationship or order between these components.

[0056] In the embodiment, the vertical direction refers to the height direction, which is also the direction where the length of the pile is located, the direction where the axis of the pile is located, the direction where the length of the main reinforcement 4 is located, the direction where the axis of the main reinforcement 4 is located, the direction where the length of the grouting pipe 5 is located, and the vertical direction of the grouting pipe 5.

[0057] See Figure 1 , this embodiment provides a method for constructing a foundation pile, including the following steps:

[0058] Piling step: Press the precast special-shaped pile 100 with the built-in embedded pipe 3 into the predetermined depth of the foundation. The precast special-shaped pile 100 has a pile body formed by alternately connecting a thick pile section 1 and a thin pile section 2. The embedded pipe 3 is provided with slurry outlets 31 that can communicate with the outer wall of the pile body at the shoulder 11 of the thick pile section 1 and / or at the thin pile section 2.

[0059] Grouting step: Vertically insert the grouting pipe 5 with a grouting port 51 opened on the bottom side wall into the predetermined position inside the embedded pipe 3 so that the grouting port 51 communicates with the corresponding slurry outlet 31 at the predetermined position, and fill the slurry around the outer periphery of the thin pile section 2 to eliminate the radial gap between the thin pile section 2 and the surrounding soil.

[0060] Compared with the prior art, the beneficial effects are: The slurry can be filled around the outer periphery of the thin pile section 2 to eliminate the radial gap between the thin pile section 2 and the surrounding soil, thereby improving the uplift resistance performance and bearing capacity performance of the precast special-shaped pile 100 in the short term after construction.

[0061] Specifically, for the precast special-shaped pile 100, its thick pile section 1 and thin pile section 2 can be regular or irregular, and the pile type can be a pipe pile, a square pile, or a pile type with an irregular shape, which is not limited herein. See Figure 6 、 7 、9、10、18 - 20, the precast special-shaped pile 100 is provided with main reinforcements 4 and stirrups 41 to ensure that the pile body has good bearing capacity.

[0062] See Figure 6 - 7, 9 - 10, 18 - 20, the embedded pipe 3 includes a main pipe 32 and a branch pipe 33. The main pipe 32 is arranged along the length direction of the pile body. One end of the branch pipe 33 is connected to the main pipe 32, and the other end is a slurry outlet 31. The slurry outlet 31 is located on the outer wall of the pile body at the shoulder 11 of the thick pile section 1 and / or on the outer wall of the pile body at the thin pile section 2. Preferably, a plurality of slurry outlets 31 are circumferentially distributed along the shoulder of the thin pile section 2 and / or the thick pile section 1. The slurry can flow out from each slurry outlet 31 successively or simultaneously, quickly filling the gap between the thin pile section 2 and the surrounding soil. See Figure 19 , the slurry outlet 31 is located at the shoulder 11 of the thick pile section 1 and the opening faces downward for easy grouting. See Figure 7 , the slurry outlet 31 is located at the thin pile section 2 and is horizontally arranged, making the slurry discharge easier. See Figure 20 , the slurry outlet 31 is located at the shoulder 11 of the thick pile section 1 and the opening faces upward.

[0063] In this embodiment, the "shoulder" should be understood as the entire end face from the outer edge of the axial end face of the thick pile section 1 to the end face of the pile body of the thin pile section 2. Therefore, when there is no transition surface between the thick pile section 1 and the thin pile section 2, the "shoulder" should be understood as the axial end face of the thick pile section 1 at this time; when there is a transition section between the two, see Figures 19 to 20 , at this time, the "shoulder" should be understood as including the axial end face of the thick pile section 1 and the end face of the transition section.

[0064] See Figures 13 to 16 , a grouting port 51 is opened on the bottom side wall of the grouting pipe 5. In the grouting step, after the grouting pipe 5 is inserted into the embedded pipe 3 to a predetermined position, the grouting port 51 is made to communicate with the corresponding slurry outlet 31 at the predetermined position, and the slurry is filled into the outer periphery of the thin pile section 2 corresponding to the slurry outlet 31 to eliminate the radial gap between the thin pile section 2 and the surrounding soil.

[0065] On the basis of the above scheme, the grouting step includes: inserting the grouting pipe 5 into the embedded pipe 3 and lowering it to a position corresponding to a predetermined slurry outlet 31, and sealing at predetermined height positions on both vertical sides of the grouting port 51, so that the grouting port 51 is only connected to the corresponding slurry outlet 31, and then starting the grouting. In this embodiment, see Figures 11 to 13 , the embedded pipe 3 and the grouting pipe 5 jointly form a vertical sealed space. The grouting pipe 5 communicates with a specific slurry outlet 31 in the sealed space, so as to realize precise grouting for a specific thin pile section 2, so that the slurry flows out from the specific slurry outlet 31, avoiding the phenomenon of waste slurry caused by the slurry shooting out from the upper opening of the embedded pipe 3 or shooting towards the lower end of the embedded pipe 3 or shooting towards the inner wall of the embedded pipe 3.

[0066] On the basis of the above scheme, the volume of slurry filled at the periphery of the thin pile segment 2 is smaller than the volume of the gap between the thin pile segment 2 and the soil around the pile, that is, the slurry fills part of the gap between the thin pile segment 2 and the surrounding soil, and the remaining gap is filled with the subsequently restored soil. The restored soil and the slurry located at the periphery of the thin pile segment 2 bite to improve the holding force, greatly improve the side friction resistance of the pile body, thereby improving the pull-out resistance and bearing capacity of the prefabricated special-shaped pile 100.

[0067] Based on the above scheme, see Figures 8 to 12 , sealing members 52 are respectively arranged on both sides of the vertical grouting port 51, and a clamping member 53 is arranged on the outer wall of the grouting pipe 5. Two clamping members 53 are distributed on both sides of the vertical grouting port 51 to ensure that the sealing member 52 is firmly clamped to avoid the sealing failure caused by the vertical displacement of the sealing member 52. The sealing member 52 includes at least one of an air bag and a sealing ring. The air bag and the sealing ring can not only ensure the sealing effect, but also have a certain flexibility, and can also ensure that in the subsequent lifting grouting sub-step, it is convenient to contact and release the seal. Preferably, the air bag is connected to the air pipe 54 to ensure that the sealing member 52 is inflated at a predetermined position in the embedded pipe 3 to form a sealed space and grouting is performed through the grouting pipe 5. After the grouting is completed, the gas in the sealing member 52 is released through the air pipe 54 so that the grouting pipe 5 is vertically displaced to another predetermined position to be inflated again and grouting is performed on the other predetermined position.

[0068] On the basis of the above scheme, the slurry in this embodiment includes at least one of water, mud, and gel material. When water / mud is used for grouting, water / mud can wash the soil around the thin pile segment 2, thereby softening the soil. The softened soil collapses and fills the gap between the thin pile segment 2 and the soil around it. Water / mud is the most common slurry with almost no cost, which saves cost. When gel material is used for grouting, the gel material can directly fill the gap between the thin pile segment 2 and the soil around it, and the subsequent prefabricated special-shaped pile 100 has better pull-out resistance and bearing capacity. Preferably, for the same slurry outlet channel, water / mud grouting is performed first, and then gel material is performed. A part of the gap is caused by soil collapse caused by water / mud washing the soil, and the collapsed soil fills this part of the gap. Another part of the gap between the thin pile segment 2 and the soil around it is filled with gel material. On the one hand, the pull-out resistance and bearing capacity of the prefabricated special-shaped pile 100 are guaranteed. On the other hand, compared with the single use of gel material to fill the gap, the grouting cost is reduced.

[0069] On the basis of the above scheme, if two or more prefabricated special-shaped piles 100 are required to be pressed into the same pile position, the piles need to be connected. Figure 2, the pile pressing steps of the foundation pile construction method include: the initial pile pressing sub-step: first expose the slurry outlet 31 of the precast special-shaped pile 100, and press the first precast special-shaped pile 100 into the soil at the predetermined pile position, so that its top end is higher than the predetermined height above the ground surface, so as to facilitate subsequent pile connection; the pile connection and pile pressing sub-step; vertically connect the second precast special-shaped pile 100 to the first precast special-shaped pile 100 at the same pile position, and make the embedded pipes 3 of the two communicate longitudinally, and press the second precast special-shaped pile 100 into the soil, so that its top end is higher than the predetermined height above the ground surface; repeat the pile connection and pile pressing sub-step until the preset number of precast special-shaped piles 100 are pressed to the predetermined depth at the same pile position.

[0070] In this embodiment, when connecting the piles, the upper end of the previous precast special-shaped pile 100 and the lower end of the next precast special-shaped pile 100 can be connected through end plates or other connecting parts. The specific connection method is not strictly limited and can be selected according to actual needs. Preferably, the two precast special-shaped piles are connected by a connecting component 6, see Figure 5 , the pile body end face has a connecting component hole 12 formed by the small screw sleeve 61 and the large screw sleeve 62 in the embedded connecting component 6, see Figures 21 to 22 , the connecting component 6 includes a small screw sleeve 61 and a large screw sleeve 62 respectively arranged on the two end faces of the pile body and connecting the upset heads 42 of the main reinforcement bars 4, and also includes an elastic locking component 63 and a locking nut 64. Among them, the small screw sleeve 61 is threadedly connected with an inserting rod 65, the inserting rod has an inserting end 651, and the large screw sleeve 62 is provided with a socket cavity 621; the elastic locking component 63 is arranged in the socket cavity 621 and forms an inserting channel, and is encapsulated in the socket cavity 621 by the locking nut 64; the elastic locking component 63 reversely locks the inserting end 651 inserted into the inserting channel. The inserting end 651 has a circumferential recessed groove, the elastic locking component 63 is circumferentially distributed in the socket cavity 621 of the large screw sleeve 62, the elastic locking component 63 includes an elastic member 631 and a locking member 632 arranged on the elastic member 631. During the process of the inserting rod 65 being inserted into the socket cavity 621, the elastic locking component 63 is compressed until the inserting rod 65 is inserted in place, and the elastic locking component 63 rebounds, one side of the locking member 632 abuts against the inserting end 651, and the other side abuts against the locking nut 64 to achieve reverse locking. In this embodiment, the two ends of the precast special-shaped pile 100 can be respectively connected to the ends of another precast special-shaped pile 100. The connection by the connecting component 6 of this embodiment makes the precast special-shaped piles 100 have good anti-pulling and anti-tensile properties.

[0071] On the basis of the above solution, the foundation pile construction method further includes an anti-corrosion step before the pile pressing step: applying an anti-corrosion material to the outer peripheral wall of the precast special-shaped pile 100 and the connecting end face of adjacent precast special-shaped piles 100 to increase its durability.

[0072] On the basis of the above solution, see Figure 3, the grouting step of the foundation pile construction method includes: Initial grouting sub-step: Lower the grouting pipe 5 to the position corresponding to the slurry outlet 31 at the lowest point, and start grouting under the sealed state at the predetermined height positions on both vertical sides of the grouting port 51, so that the slurry flows out from the slurry outlet 31 until the grouting of the thin pile section 2 is completed; Lifting grouting sub-step: Release the sealed state at the predetermined height positions on both vertical sides of the grouting port 51, lift the height of the grouting pipe 5 to the position of another slurry outlet 31 above, and then enter the sealed state again, and start grouting so that the slurry flows out from the slurry outlet 31; Repeat the lifting grouting sub-step until the grouting of the uppermost thin pile section 2 is completed.

[0073] On the basis of the above scheme, the foundation pile construction method further includes: Connecting a pile tip to the lower end of the first precast special-shaped pile 100 before the pile pressing step, so as to facilitate the first precast special-shaped pile 100 to be quickly pressed into the soil body, and also facilitate the subsequent pile pressing after pile connection, reducing the resistance from the soil body during the pile pressing process.

[0074] On the basis of the above scheme, the foundation pile construction method further includes: Using the static pressure method or the hammering method for pile pressing to ensure that the pile can be smoothly pressed into the soil body.

[0075] On the basis of the above scheme, the foundation pile construction method further includes: The grouting pressure is 1 Mpa to 60 Mpa, so as to ensure that the slurry can reach the slurry outlet 31 from the embedded pipe 3 and has a certain impact force at the slurry outlet 31 to impact the thin pile section 2 and the soil body around it, ensuring that the soil body and the slurry can be fully mixed into one body, ensuring the improvement of the side friction of the precast special-shaped pile 100, and further improving the anti-pulling performance and bearing capacity of the precast special-shaped pile 100.

[0076] On the basis of the above scheme, to ensure the accuracy of the pile inserted into the predetermined pile position, the foundation pile construction method provided in this embodiment further includes: Pilot hole step before the pile pressing step: Drilling a pilot hole to a predetermined depth at the predetermined pile position point; Calibration step: Align and place the precast special-shaped pile 100 at the pilot hole position.

[0077] On the basis of the above scheme, the slurry outlet 31 is provided with a temporary protective cover, a one-way valve or a tape, and the protective cover, the one-way valve or the tape can be washed open by the slurry during the high-pressure grouting process to prevent the slurry outlet 31 from being blocked during the process of the precast special-shaped pile 100 being pressed into the soil body.

[0078] On the basis of the above scheme, see Figure 12 The inner wall of the embedded pipe 3 is provided with an indented limit platform 34 adapted to the seal 52 to limit the seal 52 to a specific position, ensuring the sealing effect and preventing the seal from moving vertically.

[0079] On the basis of the above scheme, see Figure 7 Figure 10, to avoid the phenomenon that the soil easily enters the slurry outlet 31 and causes blockage of the slurry outlet 31 after the precast special-shaped pile 100 is inserted into the foundation during construction, a detachable hole-sealing member 311 is provided at the slurry outlet 31, and the hole-sealing member 311 can be easily washed out by the slurry when the slurry outlet 31 discharges slurry. The hole-sealing member 311 can be foam, a protective cover, a one-way valve or a tape, etc., and is not strictly limited here, as long as it can meet the plugging function and can be washed open by the slurry subsequently.

[0080] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

Claims

1. Method for constructing foundation piles, Characterized in that, It includes the following steps: Piling step: Driving a precast special-shaped pile with an embedded pipe into the foundation to a predetermined depth. The precast special-shaped pile has a pile body formed by alternating thick pile segments and thin pile segments, and slurry outlets that can communicate with the outer wall of the pile body are provided at the shoulder of the thick pile segment and / or at the thin pile segment of the embedded pipe; Grouting step: Vertically inserting a grouting pipe with a grouting port on its bottom side wall into the embedded pipe to a predetermined position so that the grouting port communicates with the corresponding slurry outlet, and filling the slurry around the outer periphery of the thin pile segment to eliminate the radial gap between the thin pile segment and the surrounding soil.

2. The method for constructing foundation piles according to claim 1, Characterized in that, The grouting step includes: Inserting the grouting pipe into the embedded pipe and lowering it to a position corresponding to a predetermined slurry outlet, and sealing the grouting pipe at two predetermined height positions on both vertical sides of the grouting port so that the grouting port only communicates with the corresponding slurry outlet, and then starting grouting.

3. The method for constructing foundation piles according to claim 1, Characterized in that, The volume of the slurry filled around the outer periphery of the thin pile segment is less than the volume of the gap between the thin pile segment and the soil around the pile.

4. The method for constructing foundation piles according to claim 1, Characterized in that, Sealing members are respectively arranged on both vertical sides of the grouting port, and a clamping member is arranged on the outer wall of the grouting pipe. The sealing member includes at least one of an airbag and a sealing ring, wherein the airbag is connected to an air pipe; And / or, the slurry includes at least one of water, mud, and gel material.

5. The method for constructing foundation piles according to claim 2, Characterized in that, The piling step includes: Initial piling sub-step: First expose the slurry outlet of the precast special-shaped pile, and drive the first precast special-shaped pile into the soil at a predetermined pile position so that its top end is higher than the ground surface by a predetermined height; Pile connection and piling sub-step; Vertically connect the second precast special-shaped pile to the first precast special-shaped pile at the same pile position, and make the embedded pipes of the two communicate longitudinally, and drive the second precast special-shaped pile into the soil; Repeat the pile connection and piling sub-step until a preset number of precast special-shaped piles are driven into the soil at the same pile position to a predetermined depth.

6. The method for constructing special-shaped piles according to claim 6, Characterized in that, It further includes: Anticorrosion step before the piling step: Applying an anticorrosion material to the outer peripheral wall of the precast special-shaped pile and the connection end surface of adjacent precast special-shaped piles.

7. The method for constructing foundation piles according to claim 1, Characterized in that, The grouting step includes: Initial grouting sub-step: Lower the grouting pipe to the position corresponding to the lowest slurry outlet, and start grouting under the sealed state at two predetermined height positions on both vertical sides of the grouting port, so that the slurry flows out from this slurry outlet until the grouting of this thin pile segment is completed; Lifting grouting sub-step: Release the sealed state at two predetermined height positions on both vertical sides of the grouting port, lift the height of the grouting pipe to the position of another slurry outlet above, and then enter the sealed state again, and start grouting so that the slurry flows out from this slurry outlet; Repeat the above-mentioned lifting grouting sub-step until the grouting of the uppermost fine pile section is completed.

8. The foundation pile construction method according to claim 1, characterized in that it further comprises: connecting a pile tip to the lower end of the first precast special-shaped pile before the pile pressing step; and / or, using the static pressure method or the hammering method for pile pressing; and / or, the grouting pressure is 1 Mpa to 60 MPa.

9. The foundation pile construction method according to claim 1, characterized in that it further comprises: a hole leading step before the pile pressing step: leading a hole to a predetermined depth at a predetermined pile site; a calibration step: aligning and placing the precast special-shaped pile at the hole position of the hole leading.

10. The foundation pile construction method according to claim 4, characterized in that a temporary protective cover, a check valve or a tape is arranged at the slurry outlet; and / or, a limiting clamping platform adapted to the seal is arranged on the inner wall of the embedded pipe.

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