Soft and hard composite secant pile and construction method thereof

Abstract

The soft and hard combined type secant pile comprises a plurality of soft piles and a plurality of hard piles which are arranged in a staggered mode, the hard piles are prefabricated annular pipe piles, and the soft piles are plain concrete piles; parts of circumferences of the adjacent hard piles and soft piles are crossed and embedded, and an annular crushing area is formed at the joint face of the hard piles and the soft piles. A plurality of grouting holes are formed in the peripheral side of the hard pile at intervals and are arranged in the length direction of the hard pile in a full-length mode, and a curing agent is jetted in the annular crushing area through the grouting holes in a high-pressure mode. The formed secant pile is high in supporting strength and good in water seepage prevention effect.

Description

Technical Field

[0001] The invention belongs to the technical field of pile foundation construction, and in particular relates to a soft-hard composite interlocking pile and a construction method thereof. Background Art

[0002] Interlocking piles are a kind of foundation pit retaining structure in which piles are interlocked with each other. They are composed of an unreinforced super-slow concrete pile and a reinforced concrete pile, which are partially interlocked and arranged at intervals to achieve interlocking arrangement. Existing interlocking pile construction mostly uses all-plain C20 concrete piles and reinforced concrete piles to interlock, but the pile quality and anti-seepage and water-stopping effects are not ideal, and the construction efficiency is low and the construction cost is high.

[0003] The Chinese patent with the patent number CN115613567A discloses a construction method of a wind power foundation interlocking pile, including using a vibrating pipe sinking pile machine to vibrate and sink the casing into place, constructing the first plain concrete pile, taking soil with a rotary drilling rig, pouring concrete and removing the casing, constructing the second plain concrete pile and the third plain concrete pile, and constructing the first steel cage concrete pile and the second steel cage concrete pile, and repeating the steps in sequence until the interlocking pile construction is completed. This construction method has a fast construction speed, and the construction time of a single pile is about 6 hours, which improves the construction efficiency. In addition, by using vibration to press down and pull out the casing, the underwater poured concrete is vibrated, which can effectively control the floating of the steel cage, making the concrete more compact and the pile body higher in quality.

[0004] However, the use of vibration pipe sinking construction, on the one hand, causes great disturbance to the soil, which is not conducive to the stability of the stratum and causes large construction noise; on the other hand, the bonding effect between the outer reinforced cage concrete piles and the plain concrete piles is poor, resulting in poor water-blocking effect. Summary of the invention

[0005] The present invention provides a soft-hard composite interlocking pile and a construction method thereof, so as to solve the problem that the interlocking pile has insufficient anti-seepage and water-stopping and supporting effects.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: In a first aspect, the present application discloses a soft-hard composite bite pile, comprising a plurality of soft piles and a plurality of hard piles arranged alternately, wherein the hard piles are prefabricated annular pipe piles, and the soft piles are plain concrete piles; The adjacent hard piles and soft piles are partially intersected and embedded in the circumference, and an annular crushing area is formed at the intersection of the hard pile and the soft pile; A plurality of grouting holes are arranged at intervals around the hard pile, and the grouting holes are arranged along the length direction of the hard pile. Curing agent is injected into the annular crushing zone through the grouting holes at high pressure. Furthermore, a plurality of drill teeth are circumferentially welded to the bottom wall of the hard pile, the drill teeth are outwardly expanded and the tooth ends of the drill teeth extend out of the side wall of the hard pile.

[0007] Furthermore, the diameter of the hard pile is greater than the diameter of the soft pile.

[0008] Furthermore, a pile tip plate is fixed to the end of the bottom wall of the hard pile, the drill teeth are fixed to the pile tip plate or the side wall of the pile head, and a cutting edge is fixed on the surface of the pile tip plate.

[0009] Furthermore, if the pile diameter R≤R0 of the hard pile, the hard pile includes a grouting arc section for engaging with the soft piles on both sides, and a supporting arc section for contacting the surrounding soil, and the grouting hole is opened in the grouting arc section.

[0010] Furthermore, if the pile diameter R of the hard pile is greater than R0, the grouting holes are evenly arranged around the hard pile, and a first partition plate and a second partition plate are inserted into the hard pile; The plate surfaces of the first partition plate and the second partition plate are both parallel to the inner wall of the foundation pit, and the outer wall of the hard pile body between the first partition plate and the second partition plate is embedded in the soft pile.

[0011] Furthermore, a limiting structure is fixed to the area of ​​the inner ring wall of the hard pile near the end, and the first partition plate and the second partition plate are both inserted into the limiting structure.

[0012] Furthermore, the area enclosed by the first partition, the second partition and the inner ring wall of the hard pile is grouting to form a high-pressure grouting block, and the area between the first partition and the inner ring wall of the hard pile, and the area between the second partition and the inner ring wall of the hard pile are grouting to form a normal-pressure grouting block.

[0013] In a second aspect, the present application discloses a construction method of a soft-hard composite occlusal pile, comprising the following construction steps: S1: Clean and level the site, measure and stake out, and determine the location of soft piles and hard piles and the distance between the two piles according to the design documents; S2: After determining the stakeout point, the first soft pile is constructed using the spraying pile construction method; S3: Repeat step S2 to construct the next soft pile and reserve a hard pile position; S4: After the first and second soft piles have initially set and before the final setting, the self-drilling prefabricated annular pipe pile construction method is used to construct the first hard pile at the reserved hard pile position; S41: When the hard pile driving is completed, the final positioning of the hard pile is controlled by the drilling machine so that the area with the grouting hole on the surface of the hard pile is embedded in the soft pile; S42: inserting a high-pressure grouting pipe into the middle area of ​​the prefabricated annular pipe pile, and pulling the high-pressure grouting pipe upward while performing high-pressure grouting into the prefabricated annular pipe pile until the inner space of the prefabricated annular pipe pile is completely filled with grouting; S5: After the first hard pile is driven into the pile position between the soft piles, steps S2-S4 are repeated until the construction of the soft-hard composite piles is completed according to the design requirements.

[0014] In a third aspect, the present application discloses a construction method of a soft-hard composite occlusal pile, comprising the following construction steps: S1: Clean and level the site, measure and stake out, and determine the location of soft piles and hard piles and the distance between the two piles according to the design documents; S2: After determining the stakeout point, the first soft pile is constructed using the spraying pile construction method; S3: Repeat step S2 to construct the next soft pile and reserve a hard pile position; S4: After the first and second soft piles have initially set and before the final setting, the self-drilling prefabricated annular pipe pile construction method is used to construct the first hard pile at the reserved hard pile position; S41: inserting the first partition plate and the second partition plate into the inner hole of the hard pile, and guiding the insertion of the first partition plate and the second partition plate through the limiting structure; S42: Use a drilling rig to drill the hard pile down to the designed depth; S43: using a high-pressure grouting device to perform high-pressure grouting on the area between the first partition plate and the second partition plate until the space between the first partition plate and the second partition plate is completely filled with grouting; S44: using normal pressure grouting equipment to perform normal pressure grouting into the space between the first partition and the inner wall of the hard pile, and into the space between the second partition and the inner wall of the hard pile, until the grouting filling is completed; S5: After the first hard pile is driven into the pile position between the soft piles, steps S2-S4 are repeated until the construction of the soft-hard composite piles is completed according to the design requirements.

[0015] The present invention can achieve the following beneficial effects: The composite interlocking pile of the present invention adopts soft pile water stopping and hard pile support, and forms an annular crushing zone between the soft pile and the hard pile. After the hard pile is driven, the secondary grouting reinforcement of the annular crushing zone can be achieved through the grouting holes around the hard pile, thereby making the anti-seepage effect at the interface between the soft pile and the hard pile better and the connection strength stronger; at the same time, the prefabricated annular pipe pile is adopted, which can improve the construction efficiency on the one hand, and ensure the support strength of the interlocking pile on the other hand, so that the composite interlocking pile of the present application can be applied to various soft soil layers and hard soil layers, and has good adaptability. Drill teeth are welded on the end face of the hard pile, so that the hard pile can be driven into the stratum by self-rotation; at the same time, the drill teeth expand outward to the side wall of the hard pile, and an annular crushing zone is formed while drilling into the hard pile downward. At the same time, the annular crushing zone can also be used as a slag discharge channel during the drilling of the hard pile, thereby making the construction efficiency of the composite interlocking pile of the present application higher. The present application sets a first partition and a second partition in the hard pile, or opens grouting holes in partitions, so that during the later grouting, the high-pressure grouting slurry can be more accurately injected into the annular crushing zone, reducing the diffusion of the slurry to the surrounding soil layers, so as to achieve an efficient reinforcement effect and reduce construction costs. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 This is a rendering of the effect after the construction of the interlocking piles of the present invention is completed and the foundation pit is excavated; Figure 2 It is a vertical cross-sectional schematic diagram of the interlocking pile after the construction of the present invention is completed; Figure 3 It is a schematic diagram of the overall structure of the hard pile of the present invention, without showing the drill teeth; Figure 4 It is a horizontal section schematic diagram of the present invention after the construction of the occlusal pile is completed when R≤R0; Figure 5 It is a horizontal section schematic diagram of the present invention after the construction of the occlusal pile is completed when R>R0; Figure 6 It is the construction process diagram of the soft pile of the present invention; Figure 7 It is a construction process diagram of the hard pile of the present invention.

[0016] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Soft pile; 2. Hard pile; 21. Grouting hole; 22. Grouting arc section; 23. Support arc section; 24. Limiting structure; 3. Annular crushing area; 4. Drill teeth; 5. Pile tip plate; 51. Cutting edge; 6. First partition; 7. Second partition; 8. High-pressure grouting block; 9. Normal-pressure grouting block; 100. Interlocking piles; 200. Foundation pit. DETAILED DESCRIPTION

[0017] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0018] like Figures 1 to 5 As shown, a soft-hard composite interlocking pile comprises a plurality of soft piles 1 for waterproofing and water-stopping and a plurality of hard piles 2 for support, which are staggered around the circumference of a foundation pit 200. The soft piles 1 and the hard piles 2 are partially circumferentially inlaid and cross-arranged to form an interlocking structure. The soft piles 1 of the present application are plain concrete piles, and the hard piles 2 are prefabricated annular pipe piles.

[0019] During construction, the soft piles 1 are cast at intervals first, and the hard piles 2 are drilled between two adjacent soft piles 1 after the soft piles 1 are initially set and before the soft piles are finally set. A plurality of drill teeth 4 are welded circumferentially on the bottom wall of the hard pile 2, and the drill teeth 4 are arranged to expand outwards and the tooth ends of the drill teeth 4 extend out of the side wall of the hard pile 2. When drilling into the hard pile 2 downwards, the drilling movement of the drill teeth 4 can cause secondary damage to the soft pile 1 at the interface between the hard pile 2 and the soft pile 1, forming an annular crushing zone 3.

[0020] The side wall of each hard pile 2 is provided with a number of grouting holes 21 at intervals, and the grouting holes 21 are arranged along the length direction of the hard pile 2. When the hard pile 2 is driven into the designed position, the grouting holes 21 can be used to inject the curing agent into the annular crushing zone 3 under high pressure, thereby realizing the secondary reinforcement grouting of the annular crushing zone 3. If the hard pile 2 is directly driven between two adjacent soft piles 1, since the soft pile 1 has completed the initial setting, the bonding effect at the interface between the soft pile 1 and the hard pile 2 will be poor, and it is easy to leak water at the interface between the soft pile 1 and the hard pile 2; after the annular crushing zone 3 is formed and the annular crushing zone 3 is subjected to secondary reinforcement grouting, the water seepage prevention effect at the interface between the soft pile 1 and the hard pile 2 can be improved, and the connection strength between the soft pile 1 and the hard pile 2 can be improved, which also has a good effect on improving the support strength.

[0021] The hard pile 2 is driven to rotate by a drilling rig to realize the piling construction of the hard pile 2. The drill teeth 4 are provided to facilitate the self-drilling of the hard pile 2, thereby improving the convenience and construction efficiency of the piling of the hard pile 2. At the same time, the design of the drill teeth 4 can automatically form an annular crushing zone 3 during the drilling of the hard pile 2, and the formed annular crushing zone 3 can also become a slag discharge channel, so that the gravel soil generated during the driving of the hard pile 2 can be guided to the ground through the annular crushing zone 3. Such a design makes the occlusal pile 100 of the present application applicable to various strata. In a preferred embodiment, the pile diameter of the hard pile 2 is larger than the pile diameter of the soft pile 1, so that a larger area of ​​the annular crushing zone 3 can be formed at the interface between the hard pile 2 and the soft pile 1, thereby improving the occlusal bonding effect between the hard pile 2 and the soft pile 1. At the same time, the pile diameter of the hard pile 2 is larger, and the support strength will be stronger.

[0022] It should be noted that, refer to Figure 2 A pile tip plate 5 is fixed to the end of the bottom wall of the hard pile 2, and the drill teeth 4 are fixed to the pile tip plate 5 or the side wall of the pile head, and a cutting edge 51 is fixed on the surface of the pile tip plate 5. The pile tip plate 5 can prevent the soil layer from entering the inner area of ​​the hard pile 2 during the drilling of the hard pile 2, so as to reduce the impact on the subsequent high-pressure grouting construction to the annular crushing area 3; the cutting edge 51 can assist the drill teeth 4 in cutting the stratum, and the cutting edge 51 can push the crushed stone soil formed by cutting to move to the annular crushing area 3, and assist the crushed stone soil in the drilling process to be discharged from the ground along the annular crushing area 3.

[0023] In the process of high-pressure grouting into the annular crushing zone 3 through the grouting hole 21, the present application provides two construction embodiments when the pile diameter R of the hard pile 2 is ≤ R0, and when the pile diameter R of the hard pile 2 is greater than R0, wherein the pile diameter R refers to the outer diameter of the hard pile 2, and R0 is the dividing value of the pile diameter of the hard pile 2 for distinguishing the two construction methods. R0 can be selected according to the actual situation on site. Usually, the pile diameter R of the prefabricated annular pipe pile is 600mm-2000mm, and R0 can select 800mm or 1000mm as the limit value.

[0024] If the pile diameter R≤R0 of the hard pile 2, the hard pile 2 includes a grouting arc section 22 for engaging with the soft piles 1 on both sides, and a supporting arc section 23 for contacting the surrounding soil, and the grouting hole 21 is only provided in the grouting arc section 22. After the hard pile 2 is driven into the stratum, the drilling rig can be used to accurately control the hard pile 2 to rotate to a suitable angle until the grouting arc section 22 engages with the soft pile 1. When the hard pile 2 rotates to a suitable area, a high-pressure grouting pipe is used to perform grouting construction inside the hard pile 2.

[0025] If the pile diameter R of the hard pile 2 is greater than R0, the grouting holes 21 are evenly arranged around the hard pile 2, and the limiting structure 24 is fixed to the area near the end of the inner ring wall of the hard pile 2. The limiting structure 24 can be a block made of steel and welded to the inner wall of the hard pile 2. The first partition 6 and the second partition 7 are inserted into the limiting structure 24. The movement of the first partition 6 and the second partition 7 inserted into the hard pile 2 is guided by setting the limiting structure 24. The plate surfaces of the first partition 6 and the second partition 7 are parallel to the inner wall of the foundation pit, and the pile body of the hard pile 2 between the first partition 6 and the second partition 7 is embedded in the soft pile 1. During the specific construction, after the hard pile 2 is driven, the limiting structure 24 can be welded and fixed, and the first partition 6 and the second partition 7 can be further installed; under ideal conditions, the length of the first partition 6 and the second partition 7 is consistent with the pile length of the hard pile 2.

[0026] After the first partition 6 and the second partition 7 are installed, grouting construction is carried out into the hard pile 2 using a high-pressure grouting pipe; wherein, high-pressure grouting is carried out in the area enclosed by the first partition 6, the second partition 7 and the inner ring wall of the hard pile 2 to form a high-pressure grouting block 8; normal-pressure grouting is carried out between the first partition 6 and the inner ring wall of the hard pile 2, and between the second partition 7 and the inner ring wall of the hard pile 2 to form a normal-pressure grouting block 9.

[0027] When high-pressure grouting is used to fill the internal space of the hard pile 2 and the slurry fills the annular crushing zone 3, the grouting pipe is usually rotated 360 degrees to achieve grouting; the interlocking pile is set as a foundation pit support structure. If the slurry penetrates toward one side of the foundation pit excavation surface, or penetrates into the soil layer on the opposite side of the foundation pit excavation surface, on the one hand, the slurry is wasted, and on the other hand, the surrounding soil layer will harden, increasing the difficulty of foundation pit excavation. Therefore, it is necessary to accurately guide the slurry to be injected into the annular crushing zone 3 to reduce the spread of the slurry to other areas.

[0028] When the diameter of the hard pile 2 is small, it is difficult to install the first partition 6 and the second partition 7 in the hard pile 2, while it is relatively easy to use a drilling rig to rotate the hard pile 2 accurately. Therefore, grouting holes 21 are opened in the side partitions of the hard pile 2 to accurately introduce the high-pressure slurry into the annular crushing zone 3. When the diameter of the hard pile 2 is large, the first partition 6 and the second partition 7 are installed in the hard pile 2, so that three partitions are formed in the hard pile 2. When high-pressure grouting is performed toward the middle partition, the first partition 6 and the second partition 7 can prevent the slurry from diffusing toward the partitions on both sides, thereby accurately introducing the slurry into the annular crushing zone 3; the partitions on both sides are filled with normal pressure grouting, which reduces the amount of slurry that seeps into the surrounding soil layer through the grouting holes 21, and also enhances the overall strength of the hard pile 2.

[0029] This application provides a construction method for a soft-hard composite interlocking pile when the pile diameter R≤R0 of the hard pile 2, referring to Figure 6 and Figure 7 , including the following construction steps: S1: Clean and level the site, measure and stake out, make a good drainage system, and determine the pile positions and distance between soft piles 1 and hard piles 2 according to the design documents. Soft piles 1 and hard piles 2 are arranged crosswise, the distance between the pile centers of soft piles 1 and hard piles 2 is 400-1800mm, and the center lines of soft piles 1 and hard piles 2 are in the same plane.

[0030] S2: After determining the stakeout point, the first soft pile 1 is constructed by using the spraying pile construction method. The soft pile 1 is a mixing concrete pile with a pile diameter of 600-2000mm, and the pile materials are original soil and cement slurry.

[0031] S21: Install and debug the pile driver. Position the drill rig according to the soft pile 1 layout point, with the drill bit facing the center of the soft pile 1 position. Use the theodolite to make sure that the layer rail is perpendicular to the mixing shaft, and level the chassis to ensure that the inclination of the main shaft of the pile driver is no more than 1%.

[0032] S22: Prepare cement slurry with a cement content of 15%-30%. The slurry needs to be stirred continuously in the mixer until it is sent to the pump.

[0033] S23: Start the drilling rig, rotate it downward and break the soil, start the high-pressure grouting pump while breaking the soil layer, pump the prepared cement slurry into the broken soil, mix it thoroughly, and rotate the mixing blades in both directions to cut and mix the mixed slurry and broken soil until the designed depth is reached; the drilling speed of the drilling rig shall not exceed 1.0 m / min. S24: After the drilling rig sinks to the designed depth, the grouting pump is turned off, and the drilling rig is lifted while rotating. The blades cut and mix the soil from both directions. The lifting speed of the drilling rig is not more than 0.8m / min.

[0034] S25: Repeat steps S23 and S24 to mix the soil and cement mortar evenly.

[0035] S26: Lift the drilling rig out of the ground, clean the equipment, and move to the next soft pile 1 position.

[0036] S3: Repeat step S2 to construct the next soft pile 1 and reserve a position for the hard pile 2; S4: After the first and second soft piles 1 have initially set and before the final setting, the self-drilling pipe pile construction method is used to construct the first hard pile 2 at the reserved hard pile 2 position. The construction equipment uses a drilling rig dedicated to self-drilling pipe piles, including a bracket, a long spiral device, a power drill bit and a pipe pile connector, wherein the pipe pile connector is installed at the bottom of the power drill bit to connect the drill bit and the pipe pile. The hard pile 2 construction steps include: S41: the annular pipe pile is connected to the drilling rig via a pipe pile connector, and the annular pipe pile is driven in according to the determined position of the hard pile 2; S42: After the hard pile 2 is driven into the designed depth of the stratum, the final positioning of the hard pile 2 is finely adjusted by the drilling machine so that the area with the grouting hole 21 on the surface of the hard pile 2 is embedded in the soft pile 1; S43: inserting a high-pressure grouting pipe into the middle area of ​​the prefabricated annular pipe pile, and simultaneously pulling the high-pressure grouting pipe upward to perform high-pressure grouting into the prefabricated annular pipe pile until the inner space of the prefabricated annular pipe pile is completely filled with grouting; S44: Separate the pipe pile and the drilling rig, and move the drilling rig to the next hard pile 2 position.

[0037] S5: After the first hard pile 2 is driven into the pile position between the soft piles 1, steps S2-S4 are repeated until all the hard-soft composite piles are constructed according to the design requirements.

[0038] This application provides a construction method for a soft-hard composite interlocking pile with a pile diameter R>R0 for a hard pile 2. Figure 6 and Figure 7 , including the following construction steps: S1: Clean and level the site, measure and stake out, and determine the pile positions and distance between soft pile 1 and hard pile 2 according to the design documents; S2: After determining the stakeout point, the first soft pile 1 is constructed using the spraying pile construction method; S3: Repeat step S2 to construct the next soft pile 1 and reserve a position for the hard pile 2; S4: After the first and second soft piles 1 are initially set and before the final set, the first hard pile 2 is constructed at the reserved hard pile 2 position by using the self-drilling annular pipe pile construction method; S41: welding a limiting structure on the inner wall of the hard pile, and inserting the first partition plate 6 and the second partition plate 7 into the hard pile 2, and guiding the installation of the first partition plate 6 and the second partition plate 7 through the limiting structure 24; S42: Drilling the hard pile 2 downwards to a designed depth using a drilling rig; S43: using a high-pressure grouting device to perform high-pressure grouting on the area between the first partition plate 6 and the second partition plate 7 until the space between the first partition plate 6 and the second partition plate 7 is completely filled with grouting; S44: using normal pressure grouting equipment to perform normal pressure grouting into the space between the first partition plate 6 and the inner wall of the hard pile 2, and into the space between the second partition plate 7 and the inner wall of the hard pile 2, until the grouting filling is completed; S5: After the first hard pile 2 is driven into the pile position between the soft piles 1, steps S2-S4 are repeated until all the hard-soft composite piles are constructed according to the design requirements.

[0039] It should be noted that in the construction method of the soft-hard composite interlocking pile with the pile diameter R>R0 of the hard pile 2, the detailed construction method of steps S1-S5 is the same as the construction method of the soft-hard composite interlocking pile with the pile diameter R≤R0 of the hard pile 2. In order to reduce repeated descriptions, it is not described in detail in this embodiment.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A soft and hard composite occlusal pile, characterized in that: It comprises a plurality of soft piles (1) and a plurality of hard piles (2) arranged in a staggered manner, wherein the hard piles (2) are prefabricated annular pipe piles, and the soft piles (1) are plain concrete piles; The adjacent hard piles (2) and soft piles (1) are partially interlocked and interlocked, and an annular crushing area (3) is formed at the intersection of the hard pile (2) and the soft pile (1); A plurality of grouting holes (21) are provided at intervals around the hard pile (2), and the grouting holes (21) are arranged along the length direction of the hard pile (2). A curing agent is injected into the annular crushing zone (3) through the grouting holes (21) at high pressure.

2. The soft-hard composite occlusal pile according to claim 1, characterized in that: A plurality of drill teeth (4) are welded circumferentially to the bottom wall of the hard pile (2); the drill teeth (4) are arranged to expand outwards and the tooth ends of the drill teeth (4) extend out of the side wall of the hard pile (2).

3. The soft-hard composite occlusal pile according to claim 1, characterized in that: The pile diameter of the hard pile (2) is greater than the pile diameter of the soft pile (1).

4. The soft-hard composite occlusal pile according to claim 2, characterized in that: A pile tip plate (5) is fixed to the end of the bottom wall of the hard pile (2), the drill teeth (4) are fixed to the pile tip plate (5) or the side wall of the pile head, and a cutting edge (51) is fixed on the plate surface of the pile tip plate (5).

5. The soft-hard composite occlusal pile according to claim 1, characterized in that: If the pile diameter R of the hard pile (2) is less than or equal to R0, the hard pile (2) comprises a grouting arc section (22) for engaging with the soft piles (1) on both sides, and a supporting arc section (23) for contacting the surrounding soil, and the grouting hole (21) is opened in the grouting arc section (22).

6. The soft-hard composite occlusal pile according to claim 1, characterized in that: If the pile diameter R of the hard pile (2) is greater than R0, the grouting holes (21) are evenly arranged around the hard pile (2), and a first partition plate (6) and a second partition plate (7) are inserted into the hard pile (2); The plate surfaces of the first partition plate (6) and the second partition plate (7) are both parallel to the inner wall of the foundation pit, and the outer wall of the hard pile (2) between the first partition plate (6) and the second partition plate (7) is embedded in the soft pile (1).

7. The soft-hard composite occlusal pile according to claim 6, characterized in that: A limiting structure (24) is fixed to an area of ​​the inner ring wall of the hard pile (2) close to the end, and the first partition plate (6) and the second partition plate (7) are both inserted into the limiting structure (24).

8. The soft-hard composite occlusal pile according to claim 6, characterized in that: The area enclosed by the first partition plate (6), the second partition plate (7) and the inner ring wall of the hard pile (2) is grouting to form a high-pressure grouting block (8), and the area between the first partition plate (6) and the inner ring wall of the hard pile (2), and the area between the second partition plate (7) and the inner ring wall of the hard pile (2) are grouting to form a normal-pressure grouting block (9).

9. A construction method for a soft-hard composite occlusal pile, characterized in that: The construction steps include: S1: clean and level the site, measure and stake out, and determine the location of the soft piles (1) and the hard piles (2) and the distance between the two piles according to the design documents; S2: After the stakeout point is determined, the first soft pile (1) is constructed using the spraying pile construction method; S3: Repeat step S2 to construct the next soft pile (1) and reserve a position for the hard pile (2); S4: After the first and second soft piles (1) have initially set and before they have finally set, a self-drilling prefabricated annular pipe pile construction method is used to construct the first hard pile (2) at the reserved hard pile (2) position; S41: when the driving of the hard pile (2) is completed, the final positioning of the hard pile (2) is controlled by the drilling machine so that the area on the surface of the hard pile (2) where the grouting hole (21) is opened is embedded in the soft pile (1); S42: inserting a high-pressure grouting pipe into the middle area of ​​the prefabricated annular pipe pile, and pulling the high-pressure grouting pipe upward while performing high-pressure grouting into the prefabricated annular pipe pile until the inner space of the prefabricated annular pipe pile is completely filled with grouting; S5: After the first hard pile (2) is driven into the pile position between the soft piles (1), steps S2 to S4 are repeated until all the soft-hard composite piles are constructed in accordance with the design requirements.

10. A construction method for a soft-hard composite occlusal pile, characterized in that: The construction steps include: S1: clean and level the site, measure and stake out, and determine the location of the soft piles (1) and the hard piles (2) and the distance between the two piles according to the design documents; S2: After the stakeout point is determined, the first soft pile (1) is constructed using the spraying pile construction method; S3: Repeat step S2 to construct the next soft pile (1) and reserve a position for the hard pile (2); S4: After the first and second soft piles (1) have initially set and before they have finally set, a self-drilling prefabricated annular pipe pile construction method is used to construct the first hard pile (2) at the reserved hard pile (2) position; S41: inserting the first partition plate (6) and the second partition plate (7) into the inner hole of the hard pile (2), and guiding the insertion of the first partition plate (6) and the second partition plate (7) by means of the limiting structure (24); S42: Drilling the hard pile (2) downwards to a designed depth using a drilling rig; S43: using high-pressure grouting equipment to perform high-pressure grouting on the area between the first partition (6) and the second partition (7) until the space between the first partition (6) and the second partition (7) is completely filled with grouting; S44: using normal pressure grouting equipment to perform normal pressure grouting into the space between the first partition plate (6) and the inner wall of the hard pile (2), and into the space between the second partition plate (7) and the inner wall of the hard pile (2), until the grouting filling is completed; S5: After the first hard pile (2) is driven into the pile position between the soft piles (1), steps S2 to S4 are repeated until all the soft-hard composite piles are constructed in accordance with the design requirements.

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