Cast-in-place pile head structure and pile head green cutting construction method

Abstract

The invention relates to the technical field of cast-in-place pile construction, and provides a cast-in-place pile head structure and a green pile head cutting construction method.The cast-in-place pile head structure comprises a reinforcement cage, a sleeve and an annular isolation pipe, the sleeve and the reinforcement cage comprise a longitudinal bar set and a stirrup set, and the longitudinal bar set comprises a plurality of longitudinal bars arranged at intervals in the circumferential direction; the stirrup set comprises a plurality of stirrups arranged at intervals in the vertical direction, and the longitudinal rib set is sleeved with the stirrups. The sleeve sleeves one end of the longitudinal bar; the guide pipe is located on the inner side of the longitudinal rib set, the two ends of the guide pipe are located outside the longitudinal rib set, and a sealing piece is detachably arranged at a pipe opening of the guide pipe. The reinforcement cage is sleeved with the annular isolation pipe, and the annular isolation pipe is located at the bottom of the sleeve. The pile head cutting efficiency of the cast-in-place pile can be improved, and noise and pollution generated by the cast-in-place pile head cutting technology are reduced.

Description

Technical Field

[0001] This application relates to the technical field of cast-in-place pile construction, and particularly to the pile head structure of cast-in-place piles and the green cutting construction method of pile heads. Background Art

[0002] When pouring concrete, due to the upward return of cement slurry, the strength of the pile head part may be difficult to guarantee. Breaking the pile head can ensure that the concrete quality of the pile top part meets the design requirements. During the process of cutting off the cast-in-place pile head, conventional methods include manual chiseling, mechanical crushing, and hydraulic cutting. Manual chiseling relies on a large amount of labor, which is not only inefficient but also difficult to guarantee the construction quality; although mechanical crushing can improve the construction efficiency, it often causes greater damage to the pile body concrete and longitudinal bars; the hydraulic cutting technology reduces the construction noise and dust to a certain extent, but the cost is high and there is still a certain degree of pollution. These problems seriously restrict the development and application of the cast-in-place pile head cutting technology. Summary of the Invention

[0003] In order to improve the efficiency of cutting off the cast-in-place pile head and reduce the noise and pollution generated by the cast-in-place pile head cutting technology, on the one hand, this application provides a cast-in-place pile head structure, adopting the following technical solution: The cast-in-place pile head structure includes: A steel reinforcement cage, including a longitudinal bar group and a stirrup group. The longitudinal bar group includes multiple longitudinal bars arranged at intervals along the circumferential direction, and the stirrup group includes multiple stirrups arranged at intervals along the vertical direction, and each stirrup is sleeved outside the longitudinal bar group; A casing, sleeved at one end of the longitudinal bar; A conduit, which is located inside the longitudinal bar group, and both ends of the conduit are located outside the longitudinal bar group, and a seal is detachably arranged at the pipe orifice of the conduit; A circumferential isolation pipe, sleeved outside the steel reinforcement cage and located at the bottom of the casing.

[0004] By adopting the above technical solution, the circumferential isolation pipe is sleeved outside the steel reinforcement cage and located at the bottom of the casing. By arranging the casing and the circumferential isolation pipe outside the longitudinal bars, the over-poured concrete of the pile body is effectively isolated, avoiding the later concrete breaking work, preventing the damage to the pile body concrete, and protecting the integrity of the pile body. The seal in the conduit ensures the sealing effect during the pouring process. After the pouring is completed and the cast-in-place pile hardens, the seal is taken out, and the rope saw chain can be inserted into the cast-in-place pile through the conduit, and the pile head can be cut off from the inside of the cast-in-place pile, realizing green cutting without dust and less noise, significantly reducing the construction noise and dust pollution, and improving the construction environment. The casing is sleeved at one end of the longitudinal bar, making it not easy for the longitudinal bar to be wrapped by the concrete in the over-poured area of the pile body, facilitating the overall detachment of the later pile head and reducing the damage to the longitudinal bars at the same time.

[0005] Optionally, a plurality of partition plates are arranged in the conduit, and the plurality of partition plates are arranged at intervals along the length direction of the sleeve. The partition plates divide a plurality of processing channels in the conduit.

[0006] By adopting the above technical solution, a plurality of partition plates are arranged in the conduit, and the partition plates are arranged at intervals along the length direction of the sleeve, dividing a plurality of processing channels for accommodating the wire saw chain in the conduit. The wire saw channels can be placed in different processing channels, and the cutting position can be further adjusted through a plurality of processing channels; it is convenient to adjust the cutting position again according to the actual working conditions to improve the construction quality.

[0007] Optionally, it further includes an adjusting arc plate, and the adjusting arc plate is slidably arranged in the conduit in the vertical direction; a limiting member is arranged in the conduit, and the limiting member is used to limit the vertical position of the adjusting arc plate.

[0008] By adopting the above technical solution, the adjusting arc plate is slidably arranged in the conduit in the vertical direction, and the limiting member arranged in the conduit is used to limit the vertical position of the adjusting arc plate; before the cutting operation, the adjusting arc plate can be limited at different height positions through the limiting member, realizing the adjustment of the cutting position of the wire saw chain.

[0009] Optionally, a plurality of guide posts are arranged at intervals in the conduit, and the guide posts pass through the adjusting arc plate; the limiting member includes a limiting nut threadedly connected to the guide posts, and the limiting nut is located on the side of the adjusting arc plate away from the sleeve.

[0010] By adopting the above technical solution, guide posts are arranged at intervals in the conduit, the guide posts pass through the adjusting arc plate, and the vertical position of the adjusting arc plate is limited by the limiting nut threadedly connected to the guide posts, ensuring the stability and adjustability of the adjusting arc plate in the conduit, and improving the construction accuracy and reliability.

[0011] Optionally, the circumferential isolation pipe includes a first splicing pipe section and a second splicing pipe section, and the first splicing pipe section and the second splicing pipe section are detachably connected.

[0012] By adopting the above technical solution, the circumferential isolation pipe includes a first splicing pipe section and a second splicing pipe section, and the first splicing pipe section and the second splicing pipe section are detachably connected, which is convenient for the assembly and disassembly of the circumferential isolation pipe, improves the construction efficiency, and is also convenient for transportation and storage, reducing the construction cost.

[0013] Optionally, a connecting inner cylinder is arranged on the inner side wall of the second splicing pipe section, one end of the connecting inner cylinder extends outside the second splicing pipe section, and the connecting inner cylinder is made of an elastic material; connecting inner cylinders are arranged at both ends of the second splicing pipe section, and one end of the connecting inner cylinder can be inserted into the first splicing pipe section.

[0014] By adopting the above technical solution, the connecting inner cylinder provided on the inner side wall of the second splicing pipe section is made of an elastic material and extends to the outside of the second splicing pipe section at one end; connecting inner cylinders are provided at both ends of the second splicing pipe, and one end can be inserted into the first splicing pipe section, realizing the rapid connection and disassembly between the first splicing pipe section and the second splicing pipe section of the circumferential isolation pipe, improving the construction convenience, ensuring good sealing at the connection part, and preventing leakage during concrete pouring.

[0015] Optionally, multiple lifting pipes are further provided at one end of the steel reinforcement cage provided with the sleeve, and the multiple lifting pipes are arranged at intervals around the axis of the sleeve.

[0016] By adopting the above technical solution, multiple lifting pipes are further provided at one end of the steel reinforcement cage provided with the sleeve, and the multiple lifting pipes are arranged at intervals around the axis of the sleeve, providing lifting positions for subsequent pile head removal, realizing the rapid and efficient mechanical lifting after the pile head cutting is completed, simplifying the construction process, reducing the labor cost, and improving the construction efficiency.

[0017] On the other hand, the present application provides a method for green removal of pile heads, including the following steps: S1. Pretreatment before pouring, marking the removal position of the pile head on the longitudinal bars, sleeving the circumferential isolation pipe outside the longitudinal bar group, and making the circumferential isolation pipe located at the marked removal position; arranging the conduit inside the longitudinal bar group, making the conduit also at the removal position, and using a seal to seal both ends of the conduit; sleeving sleeves on the upper ends of each longitudinal bar in the longitudinal bar group, and determining the length of the sleeve according to the removal position; S2. Pouring treatment of the cast-in-place pile; S3. Removing the pile head, after the cast-in-place pile hardens, removing the seals at both ends of the conduit, threading a wire saw chain into the conduit, and cutting by a wire saw cutting machine; S4. Lifting the pile head away, after the pile head is removed, using a lifting device to lift the pile head away from the cast-in-place pile.

[0018] By adopting the above technical solution, by marking the removal position on the longitudinal bars and arranging the circumferential isolation pipe and the conduit, the over-poured concrete is effectively isolated, avoiding damage to the pile body concrete during the later breaking work. Threading a wire saw chain into the conduit for pile head cutting realizes green cutting with no dust and less noise. Finally, the pile head is efficiently lifted away by a lifting device, simplifying the construction process and improving the construction efficiency and environmental protection performance.

[0019] Optionally, in S1, after the sleeves are sleeved, multiple lifting pipes are connected to one end of the steel reinforcement cage provided with the sleeves, and the multiple lifting pipes are arranged at intervals around the axis of the circumferential isolation pipe; In S4, before lifting, first thread a lifting rope through the lifting pipe, and then use a lifting device to connect the lifting rope to realize the lifting of the pile head.

[0020] By adopting the above technical solution, after the casing is sleeved, a plurality of lifting pipes are connected to one end of the steel reinforcement cage where the casing is provided, and the plurality of lifting pipes are arranged at intervals around the axis of the circumferential isolation pipe, thereby improving the stability and safety of lifting; before lifting, first pass the lifting rope through the lifting pipe, and then use the lifting equipment to connect the lifting rope to realize the lifting of the pile head, which simplifies the construction process and improves the construction efficiency.

[0021] Optionally, in S1, it further includes: when sleeving the circumferential isolation pipe, applying a release agent to the inner wall of the circumferential isolation pipe.

[0022] By adopting the above technical solution, when sleeving the circumferential isolation pipe, applying a release agent to the inner wall of the circumferential isolation pipe effectively reduces the adhesion between the circumferential isolation pipe and the concrete, facilitates the overall detachment of the pile head in the later stage, and further improves the construction efficiency.

[0023] In summary, the present application includes at least one of the following beneficial effects: 1. By arranging the isolation pipe outside the longitudinal bars of the steel reinforcement cage of the cast-in-place pile, the excess cast-in concrete of the pile body is effectively isolated, thereby avoiding the later concrete breaking work, preventing the damage to the pile body concrete, and protecting the integrity of the pile body; 2. Using the wire saw chain inserted into the circumferential conduit to cut the concrete pile head inside the pile body realizes green cutting with no dust and less noise, significantly reduces the construction noise and dust pollution, and improves the construction environment; 3. By arranging the casing on the longitudinal bars of the pile head, the longitudinal bars in the excess casting area do not bond with the concrete, which facilitates the overall detachment of the pile head in the later stage, reduces the damage to the longitudinal bars, and improves the construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the overall structural schematic diagram of the steel reinforcement cage of the pile head of the cast-in-place pile in Embodiment 1 of the present application; Figure 2 is the top view structural schematic diagram of the steel reinforcement cage in Embodiment 1 of the present application; Figure 3 is Figure 2 the partial enlarged structural schematic diagram at A in Figure 4 is the structural schematic diagram when the pile head of the cast-in-place pile in Embodiment 1 of the present application is lifted off; Figure 5 is the structural schematic diagram of the conduit in Embodiment 2 of the present application; Figure 6 is the structural schematic diagram of the circumferential isolation pipe in Embodiment 2 of the present application; Figure 7 is the structural schematic diagram of the conduit in Embodiment 3 of the present application; Figure 8 Yes Figure 7 It is a schematic diagram of a partially enlarged structure at position B in the middle; Explanation of reference numerals: 1, steel reinforcement cage; 11, longitudinal bars; 12, stirrups; 2, casing; 3, conduit; 31, partition plate; 311, processing channel; 32, adjusting arc plate; 33, guiding column; 4, circumferential isolation pipe; 41, first splicing pipe section; 42, second splicing pipe section; 43, connecting inner cylinder; 5, limit nut; 6, hoisting pipe; 7, installation bracket; 8, hoisting rope; 9, seal. Specific implementation manners

[0025] The following will further elaborate on this application in conjunction with the attached Figures 1-8 drawings.

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings. The described embodiments are only possible technical implementations of the present invention, not all possible implementations. Those skilled in the art can completely combine the embodiments of the present invention to obtain other embodiments without creative labor, and these embodiments are also within the protection scope of the present invention.

[0027] Embodiment 1: Referring to Figure 1 , the pile head structure of the cast-in-place pile provided in the embodiment of this application includes a steel reinforcement cage 1, a casing 2, a conduit 3, and a circumferential isolation pipe 4. Among them, the cooperation relationship between the steel reinforcement cage 1, the casing 2, and the circumferential isolation pipe 4 makes the structure more stable, achieving the purpose of effectively protecting the pile body concrete and realizing efficient cutting.

[0028] Referring to Figure 1 , the steel reinforcement cage 1 includes a group of longitudinal bars 11 and a group of stirrups 12. The group of longitudinal bars 11 includes multiple longitudinal bars 11 arranged at equal intervals in the circumferential direction, and the group of stirrups 12 includes multiple stirrups 12 arranged at equal intervals in the vertical direction, and each stirrup 12 is sleeved outside the group of longitudinal bars 11. The cooperation between the group of longitudinal bars 11 and the group of stirrups 12 ensures the overall stability of the cast-in-place pile. A casing 2 is sleeved on the top end of each longitudinal bar 11, and one end of the casing 2 is closed. The casing 2 is made of PVC material with a specific thickness. When pouring concrete for the steel reinforcement cage 1, the casing 2 can withstand the pressure during concrete pouring and maintain its shape unchanged. In specific use, the casing 2 is firmly installed on the steel reinforcement cage 1 through tape and steel wire rope, and a release agent is applied to the outer side wall of the casing 2 to form a smooth interface between the casing 2 and the concrete, facilitating the subsequent smooth detachment of the pile head. In actual construction, the length of the casing 2 needs to be adjusted according to the height of the pile head cutting to meet different construction requirements.

[0029] Referring to Figure 1 and Figure 2, the conduit 3 is located inside the 11 groups of longitudinal bars, and both ends of the conduit 3 are located outside the 11 groups of longitudinal bars. Refer to Figure 3 , a seal 9 is detachably arranged at the pipe orifice of the conduit 3. The cross-section of the conduit 3 is circular. The seal 9 can be set as a columnar sealing plug, or can also be set as a threaded plug screwed to the pipe orifice. In this embodiment, the seal 9 is specifically set as a sealing plug made of an elastic material. After the cast-in-place pile to be poured hardens, the seal 9 can be removed, and the rope saw chain can be inserted into the cast-in-place pile through the conduit 3 to perform pile head cutting operations from the inside of the cast-in-place pile. Specifically in implementation, the conduit 3 can be made of hard plastic material to reduce costs, while maintaining sufficient stiffness and corrosion resistance to meet construction requirements. A lubricating layer is arranged inside the conduit 3 to reduce the frictional resistance of the rope saw chain during cutting and improve the cutting efficiency. The lubricating layer uses a special lubricating oil agent and is evenly covered on the inner wall of the conduit 3 by spraying or smearing.

[0030] Refer to Figure 1 and Figure 4 , at one end of the steel reinforcement cage 1 where the sleeve 2 is arranged, a plurality of lifting pipes 6 are also arranged; the plurality of lifting pipes 6 are arranged at equal intervals around the axis of the sleeve 2; one end of the lifting pipe 6 is located inside the steel reinforcement cage 1, and the other end is located outside the steel reinforcement cage 1. In this embodiment, specifically three lifting pipes 6 are arranged. An installation bracket 7 is fixed on the lifting pipe 6, and the installation bracket 7 is fixed to the adjacent sleeve 2 by wire rope binding to realize the installation of the lifting pipe 6 at one end of the steel reinforcement cage 1. Refer to Figure 4 , the arrangement of the lifting pipe 6 provides a lifting site for the use of lifting equipment. When the cast-in-place pile hardens, a lifting rope 8 can be inserted and connected in the lifting pipe 6, and the pile head can be quickly removed by mechanical lifting. The lifting pipe 6 is made of high-strength metal material to ensure its stability and safety during the lifting process. Specifically in implementation, the diameter of the lifting pipe 6 needs to be designed according to the size of the lifting rope 8, and generally it is selected to be slightly larger than the diameter of the lifting rope 8 by 2 - 3 millimeters. The number of lifting pipes 6 is configured according to the size of the pile head, and generally 4 are selected as the standard configuration. The lifting pipes 6 are evenly arranged along the circumferential direction of the steel reinforcement cage 1 to ensure uniform force on the pile head during the lifting process.

[0031] The implementation principle of this embodiment is as follows: The pile head structure of the cast-in-place pile provided in this embodiment realizes the green and efficient removal of the pile head by arranging the circumferential isolation pipe 4 outside the longitudinal bars 11 of the steel reinforcement cage 1, arranging the conduit 3 inside, arranging the sleeve 2 at the upper end of the longitudinal bars 11, and connecting a plurality of lifting pipes 6 at one end of the steel reinforcement cage 1 where the sleeve 2 is arranged. The circumferential isolation pipe 4 isolates the over-poured concrete, the rope saw chain is inserted into the conduit 3 for noiseless and less-dusty cutting, the sleeve 2 prevents the steel bars from being wrapped by the concrete, facilitating the overall detachment of the pile head. The lifting pipe 6 is used for mechanical lifting, simplifies the construction process, improves the construction efficiency, and reduces the labor cost. This structure comprehensively uses a variety of measures to achieve a double improvement in environmental protection and economic benefits, meeting the requirements of modern building construction.

[0032] Example 2: Referring to Figure 5 , the difference between this embodiment and the above Embodiment 1 is that: a plurality of arc-shaped partitions 31 are fixedly connected inside the conduit 3, and the plurality of partitions 31 are arranged at intervals along the length direction of the sleeve 2, and the partitions 31 divide a plurality of processing channels 311 inside the conduit 3.

[0033] Although, before the pouring construction, the positions of the conduit 3 and the annular isolation pipe are preliminarily determined according to the required cutting size; however, when pouring the cast-in-place pile, the cast-in-place pile obtained by pouring will settle to a certain extent under its own gravity, especially under the condition of soft soil foundation. This settlement will cause the height of the cast-in-place pile to slightly decrease, and it is necessary to make up for it by overpouring. The arrangement of a plurality of processing channels 311 inside the conduit 3 facilitates the re-adjustment and confirmation of the cutting position after the cast-in-place pile is hardened, and improves the applicability in different construction environments.

[0034] Among them, the partition 31 is made of a high-strength metal material (such as aluminum or stainless steel), and has good mechanical strength and wear resistance. The surface of the partition 31 is polished to reduce the friction with the wire saw chain.

[0035] Referring to Figure 6 , in this embodiment, the circumferential isolation pipe 4 includes a first splicing pipe section 41 and a second splicing pipe section 42. A connecting inner cylinder 43 is arranged on the inner side wall of the second splicing pipe section 42. One end of the connecting inner cylinder 43 extends outside the second splicing pipe section 42, and the connecting inner cylinder 43 is made of an elastic material. Both ends of the first splicing pipe section 41 are provided with connecting inner cylinders 43, and the connecting inner cylinders 43 can be inserted into the pipe orifices of the first splicing pipe section 41. The outer diameter of the connecting inner cylinder 43 is slightly larger than the inner diameter of the first splicing pipe section 41 to ensure a tight connection. The length design of the connecting inner cylinder 43 ensures that both ends thereof can be inserted into the first splicing pipe section 41 and the second splicing pipe section 42 by a certain distance respectively to increase the connection stability.

[0036] Example 3: Referring to Figure 7 and Figure 8, The difference between this embodiment and the above-mentioned Embodiment 2 is that: there is no partition plate arranged inside the conduit 3 in this embodiment. An adjusting arc plate 32 is arranged inside the conduit 3. The adjusting arc plate 32 is made of a lightweight and high-strength metal material (such as aluminum alloy) and has relatively high rigidity and toughness. Guide posts 33 are arranged at intervals inside the conduit 3, and the guide posts 33 pass through the adjusting arc plate 32. The limit nut 5 is located on the side of the adjusting arc plate 32 away from the sleeve 2. Multiple guide posts 33 are arranged at intervals inside the conduit 3, the guide posts 33 pass through the adjusting arc plate 32, and both ends of the guide posts 33 are fixedly connected to the inner side wall of the conduit 3. In this embodiment, the guide posts 33 are arranged near the ports of the conduit 3, and a pair of guide posts 33 are arranged at both ends of the conduit 3. The guide posts 33 are made of high-strength alloy steel material to ensure their stability and load-bearing capacity. A limiting member is arranged inside the conduit 3, and the limiting member is specifically set as a limit nut 5 threadedly connected to the guide post 33, and the limit nut 5 is located on the side of the adjusting arc plate 32 away from the sleeve 2. The vertical height of the adjusting arc plate 32 inside the conduit 3 can be adjusted through the limit nut 5, so as to further adjust the cutting position of the wire saw chain.

[0037] Embodiment 4: The embodiment of the present application provides a construction method for green removal of pile heads, including the following steps: S1. Pretreatment before pouring. Mark the removal position of the pile head on the longitudinal bars 11. After applying a release agent on the inner wall of the circumferential isolation pipe 4, sleeve the circumferential isolation pipe 4 outside the group of longitudinal bars 11, and make the circumferential isolation pipe 4 located at the marked removal position; arrange the conduit 3 inside the group of longitudinal bars 11, tie the conduit 3 to the removal position through a steel wire rope, and use a seal 9 to seal both ends of the conduit 3; sleeve sleeves 2 on the upper ends of each longitudinal bar 11 in the group of longitudinal bars 11, apply a release agent on the outer side wall of the sleeve 2, and determine the length of the sleeve 2 according to the removal position. After the sleeve 2 is sleeved, connect a plurality of lifting pipes 6 through an installation bracket 7 at one end of the steel reinforcement cage 1 where the sleeve 2 is provided, and make the plurality of lifting pipes 6 arranged at intervals around the axis of the circumferential isolation pipe 4; wherein, one end of the installation bracket 7 is fixed to the sleeve 2, and the other end is fixedly connected to the lifting pipe 6.

[0038] S2. Pouring treatment of the cast-in-place pile. Build a formwork around the steel reinforcement cage 1 and then carry out concrete pouring.

[0039] S3. Remove the pile head. After the cast-in-place pile hardens, take out the seals 9 at both ends of the conduit 3, thread a wire saw chain into the conduit 3, and perform cutting through a wire saw cutting machine until the pile head is completely removed.

[0040] S4. Lift off the pile head. After the pile head is removed, use a lifting device to lift the pile head off the cast-in-place pile. Before lifting, first thread a lifting rope 8 through the lifting pipe 6, and then use the lifting device to connect the lifting rope 8 to realize the lifting of the pile head, and then lift the pile head off the cast-in-place pile.

[0041] The implementation principle of this embodiment is as follows: In the construction method of this embodiment, by arranging a circumferential isolation pipe 4 outside the longitudinal bars 11 of the steel reinforcement cage 1, arranging a conduit 3 inside, arranging a sleeve 2 on the pile head longitudinal bars 11, and arranging a lifting pipe 6, the green and efficient removal of the pile head is realized. The circumferential isolation pipe 4 isolates the over-poured concrete. A wire saw chain is passed through the conduit 3 for noiseless and less dusty cutting. The sleeve 2 prevents the steel bars from being wrapped by the concrete, facilitating the overall detachment of the pile head. The lifting pipe 6 is used for mechanical lifting, simplifying the construction process, improving the construction efficiency, and reducing the labor cost. This method comprehensively uses a variety of measures to achieve a double improvement in environmental protection and economic benefits, meeting the requirements of modern building construction.

[0042] The above are all preferred embodiments of this application. The protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. The pile head structure of a cast-in-place pile, characterized in that, Comprising: A steel reinforcement cage (1), including a group of longitudinal bars (11) and a group of stirrups (12). The group of longitudinal bars (11) includes multiple longitudinal bars (11) arranged at intervals in the circumferential direction. The group of stirrups (12) includes multiple stirrups (12) arranged at intervals in the vertical direction. And each stirrup (12) is sleeved outside the group of longitudinal bars (11); A casing (2), sleeved at one end of the longitudinal bars (11); A conduit (3), the conduit (3) is located inside the group of longitudinal bars (11), and both ends of the conduit (3) are outside the group of longitudinal bars (11), and a seal (9) is detachably arranged at the pipe orifice of the conduit (3); A circumferential isolation pipe (4), sleeved outside the steel reinforcement cage (1) and located at the bottom of the casing (2).

2. The cast-in-place pile head structure according to claim 1, wherein A plurality of partition plates (31) are arranged in the conduit (3). The plurality of partition plates (31) are arranged at intervals along the length direction of the casing (2). The partition plates (31) partition a plurality of processing channels (311) in the conduit (3).

3. The cast-in-place pile head structure according to claim 1, characterized in that It further includes an adjusting arc plate (32), the adjusting arc plate (32) is slidably arranged in the conduit (3) in the vertical direction; a limiting member is arranged in the conduit (3), and the limiting member is used to limit the vertical position of the adjusting arc plate (32).

4. The cast-in-place pile head structure according to claim 3, characterized in that, A plurality of guiding columns (33) are arranged at intervals in the conduit (3), and the guiding columns (33) pass through the adjusting arc plate (32); the limiting member includes a limiting nut (5) threadedly connected to the guiding column (33), and the limiting nut (5) is located on the side of the adjusting arc plate (32) away from the casing (2).

5. The cast-in-place pile head structure according to claim 3, characterized in that The circumferential isolation pipe (4) includes a first splicing pipe section (41) and a second splicing pipe section (42), and the first splicing pipe section (41) is detachably connected to the second splicing pipe section (42).

6. The cast-in-place pile head structure according to claim 5, characterized in that, A connecting inner cylinder (43) is arranged on the inner side wall of the second splicing pipe section (42). One end of the connecting inner cylinder (43) extends outside the second splicing pipe section (42). The connecting inner cylinder (43) is made of an elastic material; both ends of the second splicing pipe section (42) are provided with connecting inner cylinders (43), and one end of the connecting inner cylinder (43) can be inserted into the first splicing pipe section (41).

7. The cast-in-place pile head structure according to claim 1, characterized in that, One end of the steel reinforcement cage (1) provided with the casing (2) is further provided with a plurality of lifting pipes (6), and the plurality of lifting pipes (6) are arranged at intervals around the axis of the casing (2).

8. A green cutting construction method for pile heads, characterized in that, Using the cast-in-place pile head structure according to claim 7 for pile head cutting construction, including the following steps: S1. Pretreatment before pouring. Mark the cutting position of the pile head on the longitudinal bars (11), and sleeve the circumferential isolation pipe (4) outside the group of longitudinal bars (11), so that the circumferential isolation pipe (4) is located at the marked cutting position; arrange the conduit (3) inside the group of longitudinal bars (11), so that the conduit (3) is also at the cutting position, and use the seal (9) to seal both ends of the conduit (3); sleeve the casing (2) on the upper ends of each longitudinal bar (11) in the group of longitudinal bars (11), and determine the length of the casing (2) according to the cutting position; S2. Cast-in-place pile pouring treatment; S3. Cut off the pile head. After the cast-in-place pile hardens, remove the seals (9) at both ends of the conduit (3), thread a wire saw chain into the conduit (3), and perform cutting with a wire saw cutting machine. S4. Lift off the pile head. After the pile head is cut off, use a hoisting device to lift the pile head off the cast-in-place pile.

9. The construction method for green removal of pile heads according to claim 8, characterized in that, What is further included in S1 is that after the casing (2) is sleeved, a plurality of the hoisting pipes (6) are connected to one end of the reinforcement cage (1) where the casing (2) is provided, and the plurality of the hoisting pipes (6) are arranged at intervals around the axis of the circumferential isolation pipe (4). What is further included in S4 is that before hoisting, first thread a hoisting rope (8) through the hoisting pipe (6), and then use a hoisting device to connect the hoisting rope (8) to realize the hoisting of the pile head.

10. The construction method for green removal of pile heads according to claim 9, characterized in that, What is further included in S1 is that when the circumferential isolation pipe (4) is sleeved, a release agent is applied to the inner wall of the circumferential isolation pipe (4).

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