Concrete precast well pipe and construction process thereof

Abstract

This invention patent relates to the field of precast concrete components and geotechnical engineering well construction technology, specifically a precast concrete well pipe and its construction process. The pipe includes a pipe body with permeable holes on its surface and a locking structure inside. The process includes: S1. Well pipe arrival inspection; S2. Construction preparation and surveying; S3. Well construction; S4. Setting up a grid-shaped steel support frame at the wellhead; S5. Hoisting the first section of the well pipe into the well; S6. Well pipe positioning and fixing; S7. Backfilling with filter material on the outer wall; S8. Well washing and wellhead treatment. This precast concrete well pipe and its construction process, through the locking structure, allows for rapid positioning during use. After the locking structure is closed, two pipe bodies can be joined together. Depending on the needs, it can also be used in conjunction with a filter screen and installation groove to efficiently intercept sediment and prevent particle intrusion, further improving filtration accuracy and anti-clogging effect.

Description

Technical Field

[0001] This invention patent relates to the field of precast concrete components and geotechnical engineering well construction technology, specifically a precast concrete well pipe and its construction process. Background Technology

[0002] Traditional infiltration wells, collection wells, and dewatering wells mostly use cast-in-place reinforced concrete well pipes, plain concrete filter pipes, or plastic filter pipes. Traditional well pipe connections often use welding, flange connections, or cast-in-place concrete joints, resulting in complex construction procedures, long construction periods, and difficulties in quality control. Conventional caisson or direct pipe sinking processes are prone to well pipe displacement, affecting the quality of well completion. Therefore, there is an urgent need for a precast concrete well pipe and its construction process to improve the above problems.

[0003] Invention Patent Content

[0004] The purpose of this invention patent is to at least address one of the aforementioned technical defects.

[0005] Therefore, one objective of this invention is to propose a precast concrete well pipe and its construction process to solve the problems mentioned in the background art and overcome the shortcomings of the prior art.

[0006] To achieve the above objectives, one embodiment of the present invention provides a precast concrete well pipe and its construction process, including a pipe body, an installation groove on the surface of the pipe body, a stainless steel filter screen fixedly installed inside the installation groove, and a locking structure provided inside the pipe body.

[0007] The locking structure includes a threaded groove formed at the top of the tube body, a threaded cylinder is threadedly connected inside the threaded groove, a conical cylinder is fixedly installed at the top of the threaded cylinder, and a cone head is provided at the top of the conical cylinder.

[0008] The locking structure also includes an installation cavity at the bottom of the tube body, a limiting frame is fixedly installed inside the installation cavity, a limiting ring is engaged inside the limiting frame, a groove is provided on the outer side of the limiting ring, and a rubber ring is engaged inside the groove.

[0009] The present invention patent is further configured such that: the conical cylinder is adapted to the limiting ring, and the limiting ring is composed of two symmetrical semicircles.

[0010] By adopting the above technical solution, the conical cylinder is adapted to the limiting ring composed of two semicircles, which enables the cone head to smoothly enter and automatically lock during insertion, thus achieving the functions of quick centering, reliable connection, and preventing loosening.

[0011] The present invention patent is further configured such that: an adapter groove is provided on the outer side of the tube body, and an adapter hole is provided inside the adapter groove through the tube body, and a rivet is engaged inside the adapter hole.

[0012] By adopting the above technical solution, the adapter groove, adapter hole and rivet are used together to reinforce the tube connection after the plug is locked, which can enhance the connection strength and prevent the plug structure from loosening due to force or vibration.

[0013] This invention patent is further configured to include the following steps:

[0014] S1. Well casing arrival inspection: Check the appearance, dimensions, and concrete strength of the well casing;

[0015] S2. Construction preparation and surveying: The site is leveled and compacted, the well locations are measured and laid out, and the well location deviation is controlled;

[0016] S3. Hole-forming operation: After the hole is completed, clean the hole and change the slurry to remove sediment from the bottom of the hole;

[0017] S4. Install a grid-shaped steel support frame at the wellhead: use a level to level and correct the support surface to ensure it is horizontal and stable;

[0018] S5. Install a bottom cover at the bottom of the first section of the well pipe, and add a flexible elastic pad at the connection between the bottom cover and the well pipe; after hoisting the first section of the well pipe into the borehole, hoist the subsequent well pipes, ensuring that the male connector rod and the female connector sleeve are vertically and precisely aligned. A flexible elastic pad is also added to the well pipe connection interface, which not only filters sediment but also replaces the traditional construction process of laying permeable netting on the outside, effectively reducing on-site work intensity, simplifying construction procedures, and improving construction efficiency.

[0019] S6. Well casing positioning and fixing: The well casing is fixed in the center using a positioning device;

[0020] S7. Backfilling of external filter material: After the well pipe is in place, check the elevation of the top of the well pipe, measure the distance between the top of the well pipe and the bottom of the well, and calculate the volume of filter material backfilling.

[0021] S8. Well cleaning and wellhead treatment: Remove sediment and debris from inside the well casing.

[0022] This invention patent further specifies the following steps: S1 and S2: After the pipe body is qualified, a wooden pad is placed at the bottom to prevent rolling, with no more than two layers stacked; the site is leveled and compacted, and the well location is laid out to control deviation; the diameter of the pilot borehole is larger than the outer diameter of the well pipe, specifically determined by the design based on local hydrogeology; the depth is designed based on the aquifer depth, thickness, and water-bearing capacity; the borehole depth deviation is ≤±200mm; and mud slurry wall protection and other technical measures are used in easily collapsed strata. Verticality (apex angle deviation): ≤1° for ≤100m well section, >100m well section: ≤1.5° increase per 100m.

[0023] By adopting the above technical solution, the diameter of the pilot borehole is larger than the outer diameter of the well casing, and the specific diameter is determined by the design based on the local hydrogeology. The depth is designed according to the burial depth, thickness, and water-bearing capacity of the aquifer, with a borehole depth deviation of ≤±200mm. Combined with the stacking of wooden blocks and mud wall protection, it serves to provide uniform filling space for the filter material, prevent rolling damage to the well casing, ensure borehole stability, and reserve a margin for sediment adjustment.

[0024] The invention patent is further configured as follows: Steps S3 and S4: After the hole is completed, the hole is cleaned and the slurry is replaced to remove the sediment at the bottom of the hole and ensure the stability of the hole wall; a grid-shaped steel support frame is set at the wellhead, and a level is used to level and correct it. The well pipe clamp is in contact with the support surface for support, and point contact is strictly prohibited. After the acceptance is qualified, the hoisting, docking and lowering construction is carried out.

[0025] By adopting the above technical solutions, the borehole wall is stabilized by cleaning and replacing the slurry, the grid-shaped support is leveled and corrected with a level, and the well pipe clamps are in contact with the support surface for support, which plays a role in preventing the borehole wall from collapsing, ensuring the support surface is horizontal and stable, avoiding the well pipe from tilting or slipping, and improving the safety of hoisting and docking.

[0026] This invention patent is further configured as follows: Step S5: hoist the first section of well pipe into the hole, temporarily support and fix it to ensure vertical centering; hoist the next section of well pipe, align the male head insertion rod with the female head sleeve, slowly lower it to complete the insertion, and use locking components to mechanically lock it; for each section of pipe sinking, use a level to level the grid-shaped steel frame, and repeat the insertion, locking, and sinking process section by section to the designed well bottom elevation.

[0027] By adopting the above technical solution, the sections are inserted one by one, mechanically locked, and each section is leveled, which can ensure high coaxiality of multiple well pipe sections, firm connection, accurate verticality, prevent overall tilting, and ensure the quality of sinking.

[0028] The present invention patent is further configured as follows: Steps S6 and S7: The well pipe is fixed in the center using a positioning device to prevent it from shifting or floating during the backfilling of filter material; after the well pipe is in place, the top elevation is checked, the distance between the top of the well pipe and the bottom of the well is measured, and the volume of filter material backfilling is calculated; the bottom is backfilled first to provide a certain end support force for the subsequent secondary backfilling process, and to prevent the secondary backfilled filter material from generating sinking force with the pipe body, which would damage the pile body and the pipe body joint; then the secondary backfilling is carried out; small stone filter material is backfilled evenly, symmetrically and slowly along the annular gap around the well pipe.

[0029] By adopting the above technical solution, the positioning device is fixed in the center to prevent displacement and floating, and the backfilling is carried out in stages to avoid tensile damage to the well pipe, ensure that the filter material layer is uniform and dense, prevent well pipe displacement, and improve the reverse filtration effect and well completion stability.

[0030] The invention patent is further configured as follows: Step S8: Remove sediment and debris from the well pipe, wash the well until the water is clear, and ensure smooth water seepage; set a protective structure at the wellhead to complete the well construction.

[0031] By adopting the above technical solution, the well is washed until the water is clear and a wellhead protection structure is set up, which can remove debris from the pipe, unclog the seepage channel, ensure clear water, prevent damage to the wellhead and foreign objects from falling in, and complete the well construction.

[0032] In summary, the beneficial technical effects of this invention patent are as follows:

[0033] 1. The precast concrete well pipe and its construction process, through the setting of a locking structure, can be quickly positioned during use, and after the locking structure is closed, two pipe bodies can be spliced ​​together. Through the use of the installation groove and filter screen, it can effectively intercept mud and sand and block particle intrusion, further improving the filtration accuracy and anti-clogging effect. Through the use of the matching groove, matching hole and rivet, the flange and other structures can be eliminated and the strength of the pipe body connection can be improved. Through the above steps, the process and construction time can be reduced, and the quality is easy to control.

[0034] 2. The precast concrete well casing and its construction technology, through pilot large-diameter ultra-deep drilling, precise leveling with a grid-shaped support, plug-in mechanical locking connection, and section-by-section verticality control, ensure high verticality and stable centering of the well casing. By employing hole cleaning and slurry replacement, surface contact support, graded bottom backfilling, and uniform annular filter material filling, the collapse of the borehole wall, well casing displacement and floating, and axial damage are effectively prevented. Combined with well washing and wellhead protection, the well completion quality, seepage efficiency, and construction safety are significantly improved, achieving efficient, precise, and reliable well completion operations.

[0035] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this invention. Attached Figure Description

[0036] The above and / or additional aspects and advantages of this invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0037] Figure 1 This is a schematic diagram of the structure of this invention patent;

[0038] Figure 2 This is a schematic diagram of the structure of the top end of the tube body of this invention patent;

[0039] Figure 3 This is a schematic diagram of the structure of the bottom end of the tube body of this invention patent;

[0040] Figure 4 This is a schematic diagram of the structure of the rivet of this invention patent;

[0041] Figure 5 This is a schematic diagram of the construction process of this invention patent.

[0042] In the diagram: 1. Pipe body; 2. Mounting groove; 3. Filter screen; 4. Locking structure; 5. Threaded groove; 6. Threaded cylinder; 7. Conical cylinder; 8. Conical head; 9. Mounting cavity; 10. Limiting bracket; 11. Limiting ring; 12. Groove; 13. Rubber ring; 14. Adaptor groove; 15. Adaptor hole; 16. Rivet. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] Reference Figure 1 This invention discloses a precast concrete well pipe and its construction process, comprising a pipe body 1, an installation groove 2 on the surface of the pipe body 1, a stainless steel filter screen 3 fixedly installed inside the installation groove 2, and a locking structure 4 inside the pipe body 1. In this embodiment, the installation groove 2 provides a stable embedding space for the filter screen 3, which serves to fix and limit the filter screen 3. The stainless steel filter screen 3 serves to filter mud and impurities in groundwater and prevent clogging. The locking structure 4 serves to enable quick docking of the upper and lower sections of the pipe body 1 and maintain a firm connection.

[0046] Reference Figure 1 and Figure 2 The locking structure 4 includes a threaded groove 5 opened at the top of the tube body 1. A threaded cylinder 6 is threadedly connected inside the threaded groove 5. A tapered cylinder 7 is fixedly installed on the top of the threaded cylinder 6. A cone head 8 is provided on the top of the tapered cylinder 7. In this embodiment, the threaded groove 5 serves to provide a foundation for the threaded connection and enhance the stability of the connection. The threaded cylinder 6 serves to facilitate disassembly and assembly. The tapered cylinder 7 serves to guide the centering and realize the insertion guide. The cone head 8 serves to insert into the limiting ring 11 and trigger the locking action.

[0047] Reference Figure 1 and Figure 3The locking structure 4 also includes an installation cavity 9 at the bottom of the tube body 1. A limit frame 10 is fixedly installed inside the installation cavity 9. A limit ring 11 is engaged inside the limit frame 10. A groove 12 is provided on the outer side of the limit ring 11. A rubber ring is engaged inside the groove 12. In this embodiment, the installation cavity 9 serves to accommodate the locking components and provide installation space. The limit frame 10 serves to fix the position of the limit ring 11 and prevent it from shifting. The limit ring 11 serves to cooperate with the cone head 8 to achieve engagement and locking. The groove 12 serves to accommodate and fix the rubber ring. The rubber ring serves to provide elastic restoring force and enable the limit ring 11 to automatically reset and lock.

[0048] Reference Figure 2 and Figure 3 The conical cylinder 7 is adapted to the limiting ring 11, which is composed of two symmetrical semicircles. In this embodiment, the adaptation of the conical cylinder 7 and the limiting ring 11 ensures that the two are accurately matched and smoothly locked during insertion. The limiting ring 11, which is composed of two symmetrical semicircles, can open outwards and automatically return to its original position and tighten after the conical head 8 enters.

[0049] Reference Figure 4 The outer side of the tube body 1 is provided with an adapter groove 14. The adapter groove 14 is provided with an adapter hole 15 that penetrates the tube body 1. A rivet 16 is engaged inside the adapter hole 15. In this embodiment, the adapter groove 14 provides clearance space for the installation of the rivet 16 and prevents it from protruding. The adapter hole 15 penetrates the wall thickness of the tube body 1 and provides a fixing channel for the rivet 16. The rivet 16 provides secondary reinforcement connection and prevents the plug-in structure from loosening.

[0050] Example 2

[0051] This invention patent discloses a precast concrete well pipe and its construction process, comprising the following steps:

[0052] S1. Well casing arrival inspection: Check the appearance, dimensions, and concrete strength of the well casing;

[0053] S2. Construction preparation and surveying: The site is leveled and compacted, the well locations are measured and laid out, and the well location deviation is controlled;

[0054] S3. Hole-forming operation: After the hole is completed, clean the hole and change the slurry to remove sediment from the bottom of the hole;

[0055] S4. Install a grid-shaped steel support frame at the wellhead: use a level to level and correct the support surface to ensure it is horizontal and stable;

[0056] S5. Install a bottom cover at the bottom of the first section of the well pipe, and add a flexible elastic pad at the connection between the bottom cover and the well pipe; after hoisting the first section of the well pipe into the borehole, hoist the subsequent well pipes, ensuring that the male connector rod and the female connector sleeve are vertically and precisely aligned. A flexible elastic pad is also added to the well pipe connection interface, which not only filters sediment but also replaces the traditional construction process of laying permeable netting on the outside, effectively reducing on-site work intensity, simplifying construction procedures, and improving construction efficiency.

[0057] S6. Well casing positioning and fixing: The well casing is fixed in the center using a positioning device;

[0058] S7. Backfilling of external filter material: After the well pipe is in place, check the elevation of the top of the well pipe, measure the distance between the top of the well pipe and the bottom of the well, and calculate the volume of filter material backfilling.

[0059] S8. Well cleaning and wellhead treatment: Remove sediment and debris from inside the well casing.

[0060] Steps S1 and S2: After the pipe body is qualified, place wooden blocks at the bottom to prevent rolling, stacking no more than two layers; level and compact the site, and control deviations during well site layout; the diameter of the pilot borehole is larger than the outer diameter of the well pipe, specifically determined by the design based on local hydrogeology. The depth is designed based on the aquifer depth, thickness, and water-bearing capacity; borehole depth deviation ≤ ±200mm; for strata prone to collapse, use techniques such as mud wall protection. Verticality (apex angle deviation): ≤1° for ≤100m well sections, >100m well sections: ≤1.5° increase per 100m.

[0061] Steps S3 and S4: After the hole is completed, clean the hole and replace the slurry to remove sediment from the bottom of the hole and ensure the stability of the hole wall; set up a grid-shaped steel support frame at the wellhead, level and correct it with a level, and ensure that the well pipe clamps are in contact with the support surface, and point contact is strictly prohibited. After acceptance, hoisting, docking and lowering construction can be carried out.

[0062] Step S5: Hoist the first section of well pipe into the hole, temporarily support and fix it to ensure vertical centering; hoist the next section of well pipe, align the male plug rod with the female sleeve, slowly lower it to complete the insertion, and use locking components to mechanically lock it; after sinking each section of pipe, use a level to level the grid-shaped steel frame, and repeat the insertion, locking, and sinking process section by section to the designed bottom elevation of the well.

[0063] Steps S6 and S7: Use a positioning device to center and fix the well pipe to prevent it from shifting or floating during backfilling of filter material; after the well pipe is in place, check the top elevation, measure the distance between the top of the well pipe and the bottom of the well, and calculate the volume of filter material backfilling; first, backfill the bottom to provide a certain end support force for the secondary backfilling process, and prevent the secondary backfilled filter material from sinking with the pipe body, which could damage the pile body and the pipe body joint; then perform secondary backfilling; backfill small stone filter material evenly, symmetrically and slowly along the annular gap around the well pipe.

[0064] Step S8: Remove sediment and debris from the well casing, wash the well until the water is clear to ensure smooth water seepage; install a protective structure at the wellhead to complete the well construction.

[0065] The implementation principle of this embodiment is as follows:

[0066] During construction, the site is first leveled and compacted, and the well location is surveyed and marked out. A pilot borehole is then drilled using a drilling rig. The borehole diameter is larger than the well casing, with the specific diameter determined by the design based on local hydrogeology, to ensure a uniform annular filter material filling space on the outer wall of the well casing. The depth is designed based on the aquifer depth, thickness, and water-bearing capacity, with a borehole depth deviation of ≤±200mm. For strata prone to collapse, mud slurry wall protection and other technical measures are employed. Verticality (apex angle deviation): ≤1° for ≤100m well sections, >100m well sections: ≤1.5° per 100m increment. Mud slurry wall protection is used in strata prone to collapse. After the borehole wall stabilizes, the borehole is cleaned and the mud slurry is replaced to remove sediment from the bottom, ensuring the thickness meets design requirements. Subsequently, a grid-shaped steel support frame is installed at the wellhead, and a level is used for leveling and correction to ensure the support surface is horizontal, stable, and evenly stressed. The well casing clamp and the grid-shaped support must use surface contact support.

[0067] After the well pipe clamps and supports are arranged, the first section of well pipe is hoisted into the hole and temporarily supported and fixed to ensure that the well pipe is vertically centered. Then the next section of well pipe is hoisted, and the male head insertion rod is vertically aligned with the female head sleeve of the next section. It is slowly lowered to complete the insertion. During the insertion process, the cone 8 is inserted into the limiting ring 11 inside the installation cavity 9. The limiting ring 11 separates outward, and the rubber ring deforms. When the cone 8 enters the limiting ring 11, the rubber ring quickly returns to its original shape, driving the limiting ring 11 to re-assemble and complete the splicing of the pipe body 1. Then, the rivet 16 is used to pass through the matching hole 15 at the contact end of the two pipe bodies 1 and fix it to complete the connection of the pipe body 1. This process is repeated to complete the splicing of more pipe bodies 1.

[0068] After completing the above steps, a positioning device is used to center and fix the well pipe to prevent it from shifting or floating during backfilling of filter material. After the well pipe is in place and before backfilling the outer wall with filter material, the elevation of the top of the well pipe is checked with a depth gauge to ensure it meets the design requirements. At the same time, the distance between the top and bottom of the well pipe is measured, and the volume of filter material backfill is calculated. The bottom is backfilled first to provide a certain end support force for the secondary backfilling process, preventing the secondary backfilled filter material from sinking with the pipe body and causing damage to the pile body and the pipe body joint. Then, the secondary backfilling of filter material is carried out. Then, small stone filter material is backfilled evenly, symmetrically, and slowly along the annular gap around the well pipe. Finally, the sediment and debris inside the well pipe are removed, and the well is washed until the water is clear to ensure smooth water seepage from the opening. A protective structure is then set up at the wellhead to complete the well.

[0069] Compared with the prior art, this invention patent has the following advantages:

[0070] By setting the locking structure 4, quick positioning can be achieved during use. After the locking structure 4 is closed, the two pipe bodies 1 can be spliced ​​together. Through the cooperation of the installation groove 2 and the filter screen 3, mud and sand can be efficiently intercepted and particles can be blocked from entering, further improving the filtration accuracy and anti-clogging effect. Through the cooperation of the adapter groove 14, adapter hole 15, and rivet 16, structures such as flanges can be removed, and the connection strength of the pipe body 1 can be improved. Through the above steps, the process and construction time can be reduced, and the quality is easy to control. By using pilot large-diameter ultra-deep drilling, precise leveling with a grid-shaped support, plug-in mechanical locking connection, and section-by-section verticality control, the high verticality and stable centering of the well pipe are ensured. By using hole cleaning and slurry replacement, surface contact support, graded bottom backfilling, and uniform annular filter material filling, the collapse of the hole wall, the displacement and floating of the well pipe, and axial damage are effectively prevented. Combined with well washing and wellhead protection, the well completion quality, seepage efficiency, and construction safety are significantly improved, achieving efficient, accurate, and reliable well completion operations.

[0071] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made to the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A precast concrete well pipe, characterized in that: Includes a pipe body (1), the surface of which is provided with an installation groove (2), a stainless steel filter screen (3) is fixedly installed inside the installation groove (2), and a locking structure (4) is provided inside the pipe body (1). The locking structure (4) includes a threaded groove (5) opened at the top of the tube body (1), a threaded cylinder (6) is threadedly connected inside the threaded groove (5), a conical cylinder (7) is fixedly installed at the top of the threaded cylinder (6), and a cone head (8) is provided at the top of the conical cylinder (7). The locking structure (4) also includes an installation cavity (9) opened at the bottom of the tube body (1). A limit frame (10) is fixedly installed inside the installation cavity (9). A limit ring (11) is snapped into the inside of the limit frame (10). A groove (12) is opened on the outside of the limit ring (11). A rubber ring (13) is snapped into the inside of the groove (12).

2. A precast concrete well pipe according to claim 1, characterized in that: The conical cylinder (7) is adapted to the limiting ring (11), which is composed of two symmetrical semicircles.

3. A precast concrete well pipe according to claim 1, characterized in that: The outer side of the tube (1) is provided with an adapter groove (14), and the inside of the adapter groove (14) is provided with an adapter hole (15) through the tube (1). A rivet (16) is snapped into the inside of the adapter hole (15).

4. The construction process of a precast concrete well pipe according to claim 1, characterized in that: Includes the following steps: S1. Well casing arrival inspection: Check the appearance, dimensions, and concrete strength of the well casing; S2. Construction preparation and surveying: The site is leveled and compacted, the well locations are measured and laid out, and the well location deviation is controlled; S3. Hole-forming operation: After the hole is completed, clean the hole and change the slurry to remove sediment from the bottom of the hole; S4. Install a grid-shaped steel support frame at the wellhead: use a level to level and correct the support surface to ensure it is horizontal and stable; S5. Install a well bottom cover at the bottom of the first section of the well pipe, and add a flexible elastic pad at the connection between the well bottom cover and the well pipe; after hoisting the first section of the well pipe into the hole, hoist the subsequent well pipes, ensuring that the male connector rod and the female connector sleeve are vertically and precisely aligned. A flexible elastic pad is also added to the well pipe connection interface, which can both filter mud and sand, and replace the traditional construction process of laying permeable netting on the outside, effectively reducing on-site work intensity, simplifying construction procedures, and improving construction efficiency. S6. Well casing positioning and fixing: The well casing is fixed in the center using a positioning device; S7. Backfilling of external filter material: After the well pipe is in place, check the elevation of the top of the well pipe, measure the distance between the top of the well pipe and the bottom of the well, and calculate the volume of filter material backfilling. S8. Well cleaning and wellhead treatment: Remove sediment and debris from inside the well casing.

5. The construction process of a precast concrete well pipe according to claim 4, characterized in that: Steps S1 and S2: After the pipe body is qualified, place wooden blocks at the bottom to prevent rolling, with no more than two layers stacked; level and compact the site, and control the deviation of the well location layout; the diameter of the pilot borehole is larger than the outer diameter of the well pipe, and the specific diameter is determined by the design based on the local hydrogeology; the depth is designed based on the burial depth, thickness, and water-bearing capacity of the aquifer; the borehole depth deviation is ≤±200mm; for strata prone to borehole collapse, use technical measures such as mud wall protection; verticality (apex angle deviation): ≤1° for well sections ≤100m, >100m well sections: ≤1.5° per 100m.

6. The construction process of a precast concrete well pipe according to claim 4, characterized in that: Steps S3 and S4: After the hole is completed, clean the hole and replace the slurry to remove sediment from the bottom of the hole and ensure the stability of the hole wall; set up a grid-shaped steel support frame at the wellhead, level and correct it with a level, and ensure that the well pipe clamps are in contact with the support surface, and point contact is strictly prohibited. After acceptance, hoisting, docking and lowering construction can be carried out.

7. The construction process of a precast concrete well pipe according to claim 4, characterized in that: Step S5: Install the bottom cover at the bottom of the first section of the well pipe, and add a flexible elastic pad at the connection between the bottom cover and the well pipe; after hoisting the first section of the well pipe into the hole, hoist the subsequent well pipes, ensuring that the male insertion rod and the female sleeve are vertically and accurately aligned. A flexible elastic pad is also added to the well pipe joint, which can filter mud and sand, and replace the traditional construction process of laying permeable netting on the outside, effectively reducing on-site work intensity, simplifying construction procedures, and improving construction efficiency. Slowly lower the pipe to complete the insertion, and use a locking component for mechanical locking; after each section of pipe is sunk, use a level to level the grid-shaped steel frame, repeating the insertion, locking, and sinking process section by section until the designed bottom elevation of the well is reached.

8. The construction process of a precast concrete well pipe according to claim 4, characterized in that: Steps S6 and S7: Use a positioning device to center and fix the well pipe to prevent it from shifting or floating during backfilling of filter material; after the well pipe is in place, check the top elevation, measure the distance between the top and bottom of the well, and calculate the volume of filter material backfilling; first, backfill the bottom to provide a certain end support force for the secondary backfilling process, and prevent the secondary backfilled filter material from sinking with the pipe body, which could damage the pile body and the pipe body joint; then perform secondary backfilling; backfill small stone filter material evenly, symmetrically, and slowly along the annular gap around the well pipe.

9. The construction process of a precast concrete well pipe according to claim 4, characterized in that: Step S8: Remove sediment and debris from the well casing, and wash the well until the water is clear to ensure smooth water seepage; A protective structure was installed at the wellhead to complete the well completion.

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