Ultra-high water pressure dewatering well drainage plugging micro-permeation self-draining structure and construction method thereof

Abstract

The application discloses a kind of super-high water pressure dewatering well drainage plugging micro-permeation self-draining structure, it includes the steel pipe well being arranged at basement dewatering well mouth, steel pipe well upper end port sealing, steel pipe well upper is equipped with grouting pipe and drainage pipe, steel pipe well is filled with the gradation sandstone being fixed by hardening cement slurry, basement ground is laid from below to above with concrete cushion layer, waterproof layer and bottom slab reinforced concrete layer, bottom slab reinforced concrete layer is equipped with bottom slab post-cast concrete pit, steel pipe well upper end port, grouting pipe and drainage pipe are located in pit, pit is poured with reinforced concrete, pit above is laid with drainage plate extending to catch basin, the top of bottom slab reinforced concrete layer and drainage plate is laid with concrete surface layer.The application further discloses a kind of construction method of the above-mentioned super-high water pressure dewatering well drainage plugging micro-permeation self-draining structure.The purpose is to provide a kind of super-high water pressure dewatering well drainage plugging micro-permeation self-draining structure and its construction method, its well sealing speed is fast, well sealing effect is good, unnecessary maintenance is reduced in later period.

Description

Technical Field

[0001] This invention relates to the field of building construction, and in particular to a micro-seepage self-draining structure for sealing and plugging ultra-high water pressure dewatering wells and its construction method. Background Technology

[0002] When constructing a basement, due to its large area, a dewatering well needs to be installed in the middle of the basement. The dewatering well is sealed only when the foundation concrete strength reaches the design requirements or the basement foundation meets the anti-buoyancy requirements. However, in ultra-deep basements with a high permeability coefficient of the foundation soil, the dewatering well has a large inflow and high water pressure. As soon as the water pump stops pumping and the water is not removed, the water level rises back to the dewatering well opening. Sealing the dewatering well requires working under water pressure, which is not suitable for conventional construction methods. This makes sealing the well difficult, the quality is hard to guarantee, and sometimes the sealing fails. Even if the sealing is successfully completed, there is still a risk of basement leakage near the dewatering well in the later stages, and subsequent repairs are difficult. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a micro-seepage self-drainage structure for sealing and plugging ultra-high water pressure dewatering wells and its construction method, which has a fast sealing speed, good sealing effect, and reduces unnecessary maintenance in the later stage.

[0004] The ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure of this invention includes a steel pipe well installed vertically at the dewatering wellhead in the basement. The lower end of the steel pipe well is connected to the dewatering well, and the upper end of the steel pipe well is sealed by a sealing component. A grouting pipe and a drainage pipe are provided on the well wall near the upper end of the steel pipe well. The steel pipe well is filled with graded sand and gravel fixed together by hardened cement grout. A concrete cushion layer, a waterproof layer, and a reinforced concrete base slab are laid sequentially from bottom to top on the basement floor outside the steel pipe well. The concrete cushion layer, waterproof layer, and reinforced concrete base slab all contact the outer well wall of the steel pipe well along its circumference. The concrete cushion layer and waterproof layer... The contact point with the steel pipe well is located near the lower end of the steel pipe well. The upper surface of the reinforced concrete layer of the base slab is located above the upper end of the steel pipe well. A post-cast concrete pit for the base slab is opened on the upper surface of the reinforced concrete layer of the base slab, corresponding to the steel pipe well. The upper end of the steel pipe well, the grouting pipe, and the drain pipe are all located in the post-cast concrete pit of the base slab. Reinforced concrete is poured in the post-cast concrete pit of the base slab. The concrete strength in the post-cast concrete pit of the base slab is one grade higher than that in the reinforced concrete layer of the base slab. A drainage board extending to the sump is laid above the post-cast concrete pit of the base slab. A concrete surface layer is laid above the reinforced concrete layer of the base slab and the drainage board.

[0005] The present invention relates to a micro-seepage self-draining structure for ultra-high water pressure dewatering wells, wherein the steel pipe well comprises an upper part and a lower part of the steel pipe well arranged vertically. An annular support plate arranged circumferentially is fixed on the outer well wall of the lower port of the lower part of the steel pipe well. The annular support plate overlaps the edge of the dewatering well opening circumferentially. The lower port of the lower part of the steel pipe well is connected to the dewatering well. The upper port of the lower part of the steel pipe well is connected to the lower port of the upper part of the steel pipe well through a high-pressure flange. The upper port of the upper part of the steel pipe well is sealed by a sealing component. A grouting pipe and a drainage pipe are provided on the well wall of the upper part of the steel pipe well near the upper port. An annular waterstop plate arranged circumferentially is fixed on the outer well wall of the upper part of the steel pipe well.

[0006] The present invention discloses a micro-seepage self-draining structure for sealing and plugging ultra-high water pressure dewatering wells. The sealing components include a sealing flange, a sealing flange cover, and a locking component. The sealing flange is fixedly installed on the upper port of the steel pipe well. The sealing flange cover is rotatably installed on the sealing flange via a vertically arranged hinge shaft. The sealing flange cover and the sealing flange are fixedly connected by bolts. The locking component includes a handle fixedly installed on the sealing flange cover and a slot fixedly installed on the sealing flange. The handle is engaged in the slot. A rubber water-stop pad is provided between the sealing flange cover and the sealing flange.

[0007] The ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure of the present invention includes a base plate fixedly mounted on the well sealing flange, a vertical plate fixedly mounted on the base plate, a top plate fixedly mounted on the vertical plate opposite to the base plate, and a handle snapped between the base plate, the vertical plate and the top plate, which together form a slot.

[0008] The construction method of the above-mentioned ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure in this invention includes the following steps:

[0009] Step 1: Prepare the steel pipe well. Drill grouting holes and drainage holes on the well wall near the upper end. Weld grouting pipes to the grouting holes on the outer wall of the steel pipe well, and weld drainage pipes to the drainage holes on the outer wall of the steel pipe well. Install grouting valves on the grouting pipes and drainage valves on the drainage pipes. Connect drainage hoses to the drainage valves. Install a sealing device at the upper end of the steel pipe well.

[0010] The second step is to arrange the steel pipe wells vertically, placing the lower end of the well at the opening of the dewatering well. Then, on the basement floor surrounding the steel pipe wells, lay a concrete base layer and a waterproof layer sequentially from bottom to top, ensuring both layers are in circumferential contact with the outer wall of the well. The portion of the concrete base layer in contact with the well should be thickened, and the contact points of the concrete base layer and waterproof layer should be positioned close to the lower end of the well.

[0011] The third step involves installing the reinforcing steel bars on the waterproof layer and pre-reserving a concrete pit for the bottom slab at the upper end of the steel pipe well. This pit should contain the upper end of the steel pipe well, along with its sealing components, grouting pipes, grouting valves, drain pipes, drain valves, and drainage hoses. The bottom slab concrete is then poured, covering the reinforcing steel bars to form a reinforced concrete layer. This reinforced concrete layer should be in circumferential contact with the outer wall of the steel pipe well, and its upper surface should be higher than the upper end of the steel pipe well.

[0012] Step 4: Connect the drain hose to the sump, open the drain valve, remove the sealing piece from the top end of the steel pipe well, and fill the steel pipe well with graded sand and gravel from the top end until the top of the well. During this process, the water in the steel pipe well will flow through the drain pipe, drain valve, and drain hose into the sump. After the graded sand and gravel have settled and solidified, move the sealing piece back to the top end of the steel pipe well to seal it. Then close the drain valve and remove the drain hose.

[0013] Step 5: Open the grouting valve and inject a certain amount of quick-setting cement grout into the steel pipe well through the grouting pipe. Then close the grouting valve. Next, install reinforcing bars in the post-cast concrete pit of the base slab, and pour concrete with a strength one grade higher than that of the base slab concrete into the post-cast concrete pit.

[0014] Step 6: Lay a drainage board extending to the sump above the concrete pit after the base slab is poured, and then lay a concrete surface layer on top of the reinforced concrete layer of the base slab and the drainage board.

[0015] The construction method of this invention, wherein the specific steps of preparing the steel pipe well in the first step are as follows:

[0016] Prepare the upper and lower sections of the steel pipe well. Weld a circumferentially arranged annular waterstop plate to the outer wall of the upper section of the steel pipe well. Weld a circumferentially arranged annular support plate to the outer wall of the lower end of the lower section of the steel pipe well. Connect the lower end of the upper section of the steel pipe well to the upper end of the lower section of the steel pipe well through a connecting flange to form the steel pipe well. The upper end of the upper section of the steel pipe well is the upper end of the steel pipe well, and the lower end of the lower section of the steel pipe well is the lower end of the steel pipe well.

[0017] The construction method of this invention, wherein the first step of installing the sealing component at the upper end of the steel pipe well is as follows:

[0018] The sealing components consist of a well-sealing flange, a well-sealing flange cover, and locking components. The well-sealing flange is welded to the upper end of the steel pipe well. The well-sealing flange cover is rotatably installed on the well-sealing flange via a vertically arranged hinge shaft. A rubber water-stop gasket is bonded to the side of the well-sealing flange opposite to the well-sealing flange cover. The locking components consist of a handle and a locking groove. The handle is welded to the well-sealing flange cover, and the locking groove is fixed to the well-sealing flange. By rotating the well-sealing flange cover with the handle, when the handle is rotated into the locking groove and engages with the locking groove, the well-sealing flange cover is aligned with the well-sealing flange. Then, the well-sealing flange cover and the well-sealing flange are fixedly connected with bolts.

[0019] The construction method of this invention, wherein the first step of fixing the slot onto the well sealing flange is as follows:

[0020] A base plate is welded onto the well sealing flange, a vertical plate is welded onto the base plate, and a top plate, which is arranged opposite to the base plate, is welded onto the vertical plate, so that the base plate, vertical plate, and top plate together form a slot.

[0021] In the construction method of the present invention, the specific steps of placing the lower end of the steel pipe well at the wellhead of the dewatering well in the second step are as follows: align the lower end of the steel pipe well with the wellhead of the dewatering well, and overlap the annular support plate circumferentially on the edge of the dewatering wellhead.

[0022] The construction method of this invention, specifically the fourth step of removing the sealing component from the upper port of the steel pipe well, involves: removing the bolts between the sealing flange cover and the sealing flange; rotating the sealing flange cover using the handle to allow the handle to move out of the slot; continuing to rotate the sealing flange cover until it is removed from the upper port of the steel pipe well.

[0023] In the fourth step, the specific steps for moving the sealing component to the upper end of the steel pipe well to seal it are as follows: rotate the well sealing flange cover by the handle. When the handle is rotated into the slot and engages with the slot, the well sealing flange cover is aligned with the well sealing flange. Then, the well sealing flange cover is fixedly connected to the well sealing flange by bolts.

[0024] The difference between this invention and existing technologies lies in the addition of a drainage device to the steel pipe well. During well sealing, water is drained through this device, employing a pressure-reducing sealing method for rapid pressurized sealing. After sealing, the drainage device is then closed. The steel pipe well utilizes a pre-filling of graded sand and gravel followed by grouting instead of concrete, ensuring the compactness and quality of the filling material. A drainage board is placed within the concrete surface layer, leading to a nearby collection well, and a micro-seepage self-drainage process is implemented. Utilizing the self-healing function of the concrete's micro-seepage, unnecessary subsequent maintenance can be reduced. Therefore, this invention offers fast well sealing, excellent sealing effect, and reduced unnecessary subsequent maintenance.

[0025] The invention will now be further described with reference to the accompanying drawings. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the micro-seepage self-drainage structure for the ultra-high water pressure dewatering well drainage and sealing in this invention;

[0027] Figure 2 This is a top view of the locking component in this invention;

[0028] Figure 3 This is a side view of the locking component in this invention;

[0029] Figure 4 This is a flowchart illustrating the construction method of the micro-seepage self-drainage structure for the ultra-high water pressure dewatering well drainage and sealing in this invention.

[0030] In the picture:

[0031] 1. Concrete surface layer; 2. Drainage board; 3. Reinforced concrete base layer; 4. Waterproof layer; 5. Concrete cushion layer; 6. Dewatering well; 7. Annular support plate; 8. Lower part of steel pipe well; 9. Connection flange; 10. Annular waterstop plate; 11. Upper part of steel pipe well; 12. Grouting pipe; 13. Grouting valve; 14. Steel mesh; 15. Drainage pipe; 16. Drainage valve; 17. Drainage hose; 18. Sump well; 19. Well sealing flange; 20. Well sealing flange cover; 21. Hinge shaft; 22. Rubber waterstop pad; 23. Handle; 24. Base plate; 25. Vertical plate; 26. Post-cast concrete pit of base plate; 27. Top plate; 28. Steel pipe well; 29. ​​Slot. Detailed Implementation

[0032] like Figure 1 As shown, and in combination Figure 2 , 3As shown, the ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure of the present invention includes a steel pipe well 28 installed vertically at the basement dewatering well 6. The lower end of the steel pipe well 28 is connected to the dewatering well 6, and the upper end of the steel pipe well 28 is sealed by a sealing component. A grouting pipe 12 and a drainage pipe 15 are provided on the well wall of the steel pipe well 28 near the upper end. The steel pipe well 28 is filled with graded sand and gravel fixedly connected by hardened cement grout. On the basement floor outside the steel pipe well 28, a concrete cushion layer 5, a waterproof layer 4, and a reinforced concrete base slab layer 3 are laid sequentially from bottom to top. The concrete cushion layer 5, the waterproof layer 4, and the reinforced concrete base slab layer 3 all contact the outer well wall of the steel pipe well 28 along its circumference. The positions of the concrete cushion layer 5 and the waterproof layer 4 in contact with the steel pipe well 28 are arranged near the lower end of the steel pipe well 28. The reinforced concrete layer 3 is laid on top of the waterproof layer 4. Therefore, the lower surface of the bottom slab reinforced concrete layer 3 that contacts the steel pipe well 28 is also arranged close to the lower port of the steel pipe well 28. The upper surface of the bottom slab reinforced concrete layer 3 is located above the upper port of the steel pipe well 28. A bottom slab post-cast concrete pit 26 is opened on the upper surface of the bottom slab reinforced concrete layer 3, which is arranged corresponding to the steel pipe well 28. The upper port of the steel pipe well 28, the grouting pipe 12, and the drain pipe 15 are all located in the bottom slab post-cast concrete pit 26. Reinforced concrete is poured in the bottom slab post-cast concrete pit 26. The concrete strength in the bottom slab post-cast concrete pit 26 is one grade higher than the concrete strength of the bottom slab reinforced concrete layer 3. A drainage board 2 extending to the water collection well 18 is laid on top of the bottom slab post-cast concrete pit 26. A concrete surface layer 1 is laid on top of the bottom slab reinforced concrete layer 3 and the drainage board 2.

[0033] A grouting valve 13 is installed on the grouting pipe 12, and the grouting valve 13 is in the closed state; a drain valve 16 is installed on the drain pipe 15, and the drain valve 16 is in the closed state.

[0034] like Figure 1 As shown, the ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure of the present invention includes a steel pipe well 28 comprising an upper part 11 and a lower part 8 arranged vertically. An annular support plate 7 arranged circumferentially is fixed on the outer well wall of the lower port of the lower part 8. The annular support plate 7 overlaps the edge of the dewatering well 6 in the circumferential direction. The lower port of the lower part 8 is connected to the dewatering well 6. The upper port of the lower part 8 is connected to the lower port of the upper part 11 of the steel pipe well through a high-pressure flange 9. The upper port of the upper part 11 of the steel pipe well is sealed by a sealing component. A grouting pipe 12 and a drain pipe 15 are provided on the well wall of the upper part 11 near the upper port. An annular waterstop plate 10 arranged circumferentially is fixed on the outer well wall of the upper part 11 of the steel pipe well.

[0035] The annular support plate 7 is made of steel plate and is fixed to the lower part 8 of the steel pipe well by welding. The annular waterstop plate 10 is also made of steel plate and is fixed to the upper part 11 of the steel pipe well by welding. The annular waterstop plate 10 is existing technology. It waterproofs by increasing the water flow path on the outer wall of the upper part 11 of the steel pipe well. Its specific structure and working principle will not be described in detail.

[0036] The upper part 11 and the lower part 8 of the steel pipe well are coaxially connected by a connecting flange 9 to form a steel pipe well 28. The upper port of the upper part 11 is the upper port of the steel pipe well 28, and the lower port of the lower part 8 is the lower port of the steel pipe well 28. The concrete cushion layer 5 and the waterproof layer 4 are both in contact with the outer wall of the lower part 8 of the steel pipe well along its circumference. This arrangement ensures that the contact positions of the concrete cushion layer 5 and the waterproof layer 4 with the steel pipe well 28 are close to the lower port of the steel pipe well 28. Meanwhile, the bottom reinforced concrete layer 3 is in contact with the outer well walls of the upper part 11 and the lower part 8 of the steel pipe well along the circumference of both. The lower surface of the bottom reinforced concrete layer 3 is in contact with the outer well wall of the lower part 8 of the steel pipe well. This allows the lower surface of the bottom reinforced concrete layer 3 in contact with the steel pipe well 28 to be arranged close to the lower port of the steel pipe well 28, while the upper surface of the bottom reinforced concrete layer 3 is located above the upper port of the upper part 11 of the steel pipe well.

[0037] To enhance the sealing of the connection between the upper part 11 and the lower part 8 of the steel pipe well, a rubber waterproof gasket can be installed between the connecting flanges 9.

[0038] Combination Figure 2 , 3 As shown, the ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure of the present invention includes a sealing flange 19, a sealing flange cover 20, and a locking component. The sealing flange 19 is fixedly installed on the upper port of the upper part 11 of the steel pipe well. The sealing flange cover 20 is rotatably installed on the sealing flange 19 through a vertically arranged hinge shaft 21. The sealing flange cover 20 and the sealing flange 19 are fixedly connected by bolts. The locking component includes a handle 23 fixedly installed on the sealing flange cover 20 and a slot 29 fixedly installed on the sealing flange 19. The handle 23 is engaged in the slot 29. A rubber water-stop pad 22 is provided between the sealing flange cover 20 and the sealing flange 19.

[0039] The hinge shaft 21 can be bolted and is vertically welded to the well sealing flange 19. The well sealing flange cover 20 is rotatably mounted on the well sealing flange 19 via the hinge shaft 21, and is located above the well sealing flange 19. Since the hinge shaft 21 is arranged vertically, when the well sealing flange cover 20 rotates around the hinge shaft 21, the well sealing flange cover 20 rotates horizontally. The well sealing flange cover 20 can be rotated by holding the handle 23. When the handle 23 is rotated towards the slot 29, the well sealing flange cover 20 also rotates accordingly. When the handle 23 is rotated into the slot 29, the handle 23 engages with the slot 29, and at the same time, the well sealing flange cover 20 and the well sealing flange 19 are vertically aligned, and their bolt holes are also vertically aligned. Then, the two can be fixedly connected by bolts. In this way, the well sealing flange cover 20 seals the upper port of the upper part 11 of the steel pipe well, achieving a seal on the upper port. Conversely, by removing the bolts between the well sealing flange cover 20 and the well sealing flange 19, and turning the handle 23 out of the slot 29, until the handle 23, along with the well sealing flange cover 20, is turned to the outside of the upper part 11 of the steel pipe well, the upper end of the upper part 11 of the steel pipe well can be exposed again.

[0040] The rubber water-stop gasket 22 is bonded to the well sealing flange 19, specifically to the side of the well sealing flange 19 opposite to the well sealing flange cover 20, which can further enhance the sealing performance between the well sealing flange cover 20 and the well sealing flange 19.

[0041] Combination Figure 2 , 3 As shown, the ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure of the present invention includes a base plate 24 fixedly welded to the well sealing flange 19, a vertical plate 25 fixedly welded to the base plate 24, and a top plate 27 fixedly welded to the vertical plate 25 opposite to the base plate 24. A handle 23 is engaged between the base plate 24, the vertical plate 25, and the top plate 27. The base plate 24, the vertical plate 25, and the top plate 27 together form a groove 29. The base plate 24, the vertical plate 25, and the top plate 27 together form a U-shaped groove, which is the groove 29. When the handle 23 enters the groove 29, it engages with the groove 29.

[0042] like Figure 4 As shown, and in combination Figure 1-3 As shown, the construction method of the above-mentioned ultra-high water pressure dewatering well drainage and sealing micro-seepage self-drainage structure in this invention includes the following steps:

[0043] Step 1: Prepare the steel pipe well 28. Open grouting holes and drainage holes on the well wall near the upper end of the steel pipe well 28. Weld grouting pipes 12 to the grouting holes on the outer wall of the steel pipe well 28, and weld drainage pipes 15 to the drainage holes on the outer wall of the steel pipe well 28. Install grouting valves 13 on the grouting pipes 12 and drainage valves 16 on the drainage pipes 15. Connect drainage hoses 17 to the drainage valves 16. Install a sealing component at the upper end of the steel pipe well 28.

[0044] The second step is to arrange the steel pipe well 28 vertically, with its lower end positioned at the opening of the dewatering well 6. Then, on the basement floor surrounding the steel pipe well 28, a concrete pad 5 and a waterproof layer 4 are laid sequentially from bottom to top, ensuring both are in circumferential contact with the outer wall of the steel pipe well 28. The portion of the concrete pad 5 in contact with the steel pipe well 28 is thickened, and the contact points of the concrete pad 5 and waterproof layer 4 are positioned close to the lower end of the steel pipe well 28.

[0045] The third step involves installing the bottom slab reinforcement on the waterproof layer 4, and reserving a post-cast concrete pit 26 at the upper end of the steel pipe well 28. This ensures that the upper end of the steel pipe well 28, along with its sealing components, grouting pipe 12, grouting valve 13, drain pipe 15, drain valve 16, and drainage hose 17, are all located within the post-cast concrete pit 26. The bottom slab concrete is then poured, covering the bottom slab reinforcement to form a reinforced concrete layer 3. This reinforced concrete layer 3 is then in circumferential contact with the outer wall of the steel pipe well 28, and its upper surface is higher than the upper end of the steel pipe well 28.

[0046] Step 4: Connect the drain hose 17 to the collection well 18, open the drain valve 16, remove the sealing piece from the upper end of the steel pipe well 28, and fill the steel pipe well 28 with graded sand and gravel from the upper end until the top of the steel pipe well 28. During this process, the water in the steel pipe well 28 is discharged into the collection well 18 through the drain pipe 15, the drain valve 16, and the drain hose 17 in sequence. After the graded sand and gravel settle and solidify, move the sealing piece to the upper end of the steel pipe well 28 to seal it. Then close the drain valve 16 and remove the drain hose 17.

[0047] Step 5: Open the grouting valve 13 and inject a certain amount of quick-setting cement grout into the steel pipe well 28 through the grouting pipe 12. Then close the grouting valve 13. Next, install reinforcing bars in the post-cast concrete pit 26 of the base slab and pour concrete with a strength one grade higher than that of the base slab concrete into the post-cast concrete pit 26 of the base slab.

[0048] Step 6: Lay a drainage board 2 extending to the water collection well 18 above the concrete pit 26 after the base slab is poured, and then lay a concrete surface layer 1 above the reinforced concrete layer 3 of the base slab and the drainage board 2.

[0049] In the construction method of this invention, the specific steps for preparing the steel pipe well 28 in the first step are as follows:

[0050] Prepare an upper part 11 and a lower part 8 of a steel pipe well. Weld an annular waterstop plate 10 arranged circumferentially on the outer well wall of the upper part 11. Weld an annular support plate 7 arranged circumferentially on the outer well wall of the lower end of the lower part 8. Connect the lower end of the upper part 11 and the upper end of the lower part 8 through a connecting flange 9 to form a steel pipe well 28. The upper end of the upper part 11 is the upper end of the steel pipe well 28, and the lower end of the lower part 8 is the lower end of the steel pipe well 28.

[0051] Grouting holes and drainage holes are opened on the well wall near the upper end of the upper part 11 of the steel pipe well. The grouting pipe 12 and the drainage pipe 15 are both welded to the upper part 11 of the steel pipe well.

[0052] The construction method of this invention, wherein the first step of installing the sealing component at the upper end of the steel pipe well 28 is as follows:

[0053] The sealing components consist of a well-sealing flange 19, a well-sealing flange cover 20, and locking components. The well-sealing flange 19 is welded to the upper end of the upper part 11 of the steel pipe well. The well-sealing flange cover 20 is rotatably installed on the well-sealing flange 19 via a vertically arranged hinge shaft 21. A rubber water-stop gasket 22 is bonded to the side of the well-sealing flange 19 opposite to the well-sealing flange cover 20. The locking components consist of a handle 23 and a slot 29. The handle 23 is welded to the well-sealing flange cover 20, and the slot 29 is fixed to the well-sealing flange 19. The well-sealing flange cover 20 is rotated by the handle 23. When the handle 23 rotates into the slot 29 and engages with the slot 29, the well-sealing flange cover 20 is aligned with the well-sealing flange 19. Then, the well-sealing flange cover 20 and the well-sealing flange 19 are fixedly connected by bolts.

[0054] In the construction method of this invention, the specific steps of fixing the slot 29 onto the well sealing flange 19 in the first step are as follows:

[0055] A base plate 24 is welded onto the well sealing flange 19, a vertical plate 25 is welded onto the base plate 24, and a top plate 27, which is arranged opposite to the base plate 24, is welded onto the vertical plate 25, so that the base plate 24, the vertical plate 25 and the top plate 27 together form a slot 29.

[0056] In the construction method of the present invention, the specific steps of placing the lower end of the steel pipe well 28 at the wellhead of the dewatering well 6 in the second step are as follows: align the lower end of the lower part 8 of the steel pipe well with the wellhead of the dewatering well 6, and overlap the annular support plate 7 circumferentially on the edge of the wellhead of the dewatering well 6.

[0057] In the construction method of the present invention, in the second step, the steel pipe well 28 is arranged vertically, that is, the upper part 11 and the lower part 8 of the steel pipe well are both arranged vertically, with the upper part 11 of the steel pipe well located above the lower part 8 of the steel pipe well.

[0058] In the second step, when laying the concrete cushion layer 5 and the waterproof layer 4 sequentially from bottom to top on the basement floor around the steel pipe well 28, both the concrete cushion layer 5 and the waterproof layer 4 are in circumferential contact with the outer wall of the lower part 8 of the steel pipe well. The part of the concrete cushion layer 5 that is in contact with the lower part 8 of the steel pipe well is thickened. Since both the concrete cushion layer 5 and the waterproof layer 4 are in contact with the lower part 8 of the steel pipe well, it is possible to arrange the position of the concrete cushion layer 5 and the waterproof layer 4 in contact with the steel pipe well 28 close to the lower end of the steel pipe well 28.

[0059] In the construction method of the present invention, in the third step, a post-cast concrete pit 26 is reserved at the upper port of the upper part 11 of the steel pipe well, so that the upper port of the upper part 11 of the steel pipe well, as well as the sealing parts, grouting pipe 12, grouting valve 13, drain pipe 15, drain valve 16 and drainage hose 17 thereon are all located in the post-cast concrete pit 26 of the bottom plate.

[0060] In the third step, after the bottom reinforced concrete layer 3 is formed, since the bottom reinforced concrete layer 3 is laid on the waterproof layer 4, and the position of the waterproof layer 4 in contact with the steel pipe well 28 is close to the lower end of the steel pipe well 28, the position of the lower surface of the bottom reinforced concrete layer 3 in contact with the steel pipe well 28 is also close to the lower end of the steel pipe well 28. The bottom reinforced concrete layer 3 is in circumferential contact with the outer well wall of both the upper part 11 and the lower part 8 of the steel pipe well, and the lower surface of the bottom reinforced concrete layer 3 is in contact with the lower part 8 of the steel pipe well. Therefore, the position of the lower surface of the bottom reinforced concrete layer 3 in contact with the steel pipe well 28 can be arranged close to the lower end of the steel pipe well 28. The upper surface of the bottom reinforced concrete layer 3 is higher than the upper end of the upper part 11 of the steel pipe well.

[0061] In the construction method of the present invention, the specific steps of removing the sealing component from the upper port of the steel pipe well 28 in the fourth step are as follows: remove the bolts between the sealing flange cover 20 and the sealing flange 19, rotate the sealing flange cover 20 by the handle 23, so that the handle 23 is turned out of the slot 29, and continue to rotate the sealing flange cover 20 until the sealing flange cover 20 is removed from the upper port of the upper part 11 of the steel pipe well.

[0062] After removing the sealing flange cover 20, graded sand and gravel can be filled into the steel pipe well 28 from the upper port of the upper part 11 until the top of the steel pipe well 28.

[0063] In the fourth step, the specific steps for moving the sealing component to the upper end of the steel pipe well 28 to seal it are as follows: rotate the well sealing flange cover 20 by the handle 23. When the handle 23 is rotated into the slot 29 and engages with the slot 29, the well sealing flange cover 20 is aligned with the well sealing flange 19. Then, the well sealing flange cover 20 and the well sealing flange 19 are fixedly connected by bolts.

[0064] Sealing the upper end of the steel pipe well 28 means sealing the upper end of the upper part 11 of the steel pipe well.

[0065] In the fourth step, when filling the steel pipe well 28 with graded sand and gravel, since the lower end of the steel pipe well 28 is connected to the dewatering well 6, the graded sand and gravel first fills the dewatering well 6, and then fills the steel pipe well 28.

[0066] In the fifth step, injecting a certain amount of quick-setting cement grout into the steel pipe well 28 refers to injecting a volume of quick-setting cement grout equal to that of the steel pipe well 28. After the quick-setting cement grout hardens, it can fix the graded sand and gravel in the dewatering well 6 and the steel pipe well 28 into a single unit. At this point, it can be said that the steel pipe well 28 is filled with graded sand and gravel fixedly connected by the hardened cement grout.

[0067] Both the upper part 11 and the lower part 8 of the steel pipe well are steel pipes with a diameter of 300 mm. The connecting flange 9 includes a first connecting flange and a second connecting flange. The first connecting flange is fixed at the lower end of the upper part 11 of the steel pipe well, and the second connecting flange is fixed at the upper end of the lower part 8 of the steel pipe well. When connecting the upper part 11 and the lower part 8 of the steel pipe well through the connecting flange 9, the lower end of the upper part 11 of the steel pipe well is aligned with the upper end of the lower part 8 of the steel pipe well, and the bolt holes of the first connecting flange and the second connecting flange are also aligned. Then, the first connecting flange and the second connecting flange are connected by bolts to form the steel pipe well 28.

[0068] The specific structure of the upper part 11 of the steel pipe well is as follows: the bottom (i.e. the lower end) of the upper part 11 of the steel pipe well is welded with a first connecting flange, the middle part is welded with an annular water stop plate 10, the top is welded with a well sealing flange 19 and a grouting pipe 12 and a drain pipe 15 that are close to it.

[0069] The specific structure of the steel pipe well bottom part 8 is as follows: a ring support plate 7 is welded near the lower end of the steel pipe well bottom part 8, and a second connecting flange is welded at the top (i.e., at the upper end).

[0070] The sealing flange 19 is welded to the upper end of the upper part 11 of the steel pipe well. A vertically arranged hinge shaft 21 (which can be bolted) is welded to the sealing flange 19. The sealing flange cover 20 is rotatably mounted on the sealing flange 19 via the hinge shaft 21, that is, the sealing flange cover 20 is located above the sealing flange 19 and also above the upper end of the upper part 11 of the steel pipe well. Since the hinge shaft 21 is arranged vertically, when the sealing flange cover 20 is rotated by the handle 23, the sealing flange cover 20 rotates around the hinge shaft 21 and in the horizontal direction. Beforehand, ensure that when the handle 23 is rotated into the slot 29 and engages with it, the well sealing flange cover 20 is perfectly aligned vertically with the well sealing flange 19, and the bolt holes on both are also perfectly aligned vertically. At this point, the well sealing flange cover 20 and the well sealing flange 19 can be connected with bolts, thus sealing the upper port of the upper part 11 of the steel pipe well, i.e., the upper port of the steel pipe well 28. Of course, when it is necessary to remove the well sealing flange cover 20 from the upper port of the upper part 11 of the steel pipe well, remove the bolts, rotate the handle 23 to move the handle 23 out of the slot 29, and continue rotating the well sealing flange cover 20 until it is rotated to the outside of the upper part 11 of the steel pipe well, exposing the upper port of the upper part 11.

[0071] The base plate 24 is welded to the well sealing flange 19. The base plate 24, vertical plate 25, and top plate 27 are all made of 10mm thick steel plates. The base plate 24, vertical plate 25, and top plate 27 together form a U-shaped groove, which is the slot 29. When the handle 23 is rotated into the slot 29, it is considered that the handle 23 is engaged in the slot 29. At this time, due to the obstruction of the handle 23 by the slot 29, and since the handle 23 is welded to the well sealing flange cover 20, the obstruction of the handle 23 by the slot 29 is also the obstruction of the well sealing flange cover 20. Due to this obstruction, the water in the steel pipe well 28 cannot push the well sealing flange cover 20 open, which can achieve rapid sealing and facilitate the subsequent use of bolts to further fix the well sealing flange cover 20 and the well sealing flange 19.

[0072] In order to achieve better sealing of the upper port of the upper part 11 of the steel pipe well by the sealing flange cover 20, after the sealing flange cover 20 is rotatably installed on the sealing flange 19 by the vertically arranged hinge shaft 21, a rubber water-stop gasket 22 is bonded to the side of the sealing flange 19 opposite to the sealing flange cover 20, which can further enhance the sealing performance between the sealing flange cover 20 and the sealing flange 19.

[0073] The drain pipe 15, drain valve 16, and drain hose 17 constitute a drain device. One end of the drain pipe 15 is welded to the drain hole on the outer wall of the upper part 11 of the steel pipe well. The other end of the drain pipe 15 is threadedly connected to one end of the drain valve 16, and the other end of the drain valve 16 is connected to one end of the drain hose 17. The other end of the drain hose 17 extends into the collection well 18. To prevent graded sand and gravel from entering the drain pipe 15, a steel mesh 14 is welded to the drain hole on the inner side of the upper part 11 of the steel pipe well.

[0074] The grouting pipe 12 and the grouting valve 13 form a grouting device. One end of the grouting pipe 12 is welded to the grouting hole on the outer wall of the upper part 11 of the steel pipe well, and the other end of the grouting pipe 12 is threadedly connected to the grouting valve 13.

[0075] The drainage device and the grouting device are in a straight line, that is, the drainage device and the grouting device are respectively located on opposite sides of the upper part 11 of the steel pipe well. The hinge shaft 21 and the locking part are also in a straight line, that is, the hinge shaft 21 and the locking part are respectively located on opposite sides of the sealing flange cover 20. When the handle 23 is turned to make the sealing flange cover 20 rotate, in order to prevent the drainage device and the grouting device from obstructing the rotation of the handle 23, the above two straight lines can be made perpendicular to each other.

[0076] The concrete cushion layer 5 at the wellhead of dewatering well 6 is locally thickened to facilitate the fixing of the lower part 8 of the steel pipe well. The lower part 8 of the steel pipe well is placed on the wellhead of dewatering well 6, and the annular support plate 7 covers the wellhead of dewatering well 6 to prevent concrete from falling in. Then, the concrete cushion layer 5 is constructed. The waterproof layer 4 is constructed and effectively connected to the lower part 8 of the steel pipe well to prevent water leakage. At the same time as the bottom slab reinforcement is installed, the upper part 11 of the steel pipe well is installed through the extension flange 9 at an appropriate time and reinforced with the bottom slab reinforcement. This allows part of the bottom slab reinforcement to support the steel pipe well 28 and prevent displacement when pouring the bottom slab concrete.

[0077] To reserve a post-cast concrete pit 26 above the upper part 11 of the steel pipe well, after the bottom slab reinforcement is installed, the post-cast concrete pit 26 can be cut out from the bottom slab reinforcement using a cutting tool, and the cut reinforcement can be placed for later use. When pouring the bottom slab concrete, baffles can be fixed to the side walls and bottom walls of the post-cast concrete pit 26 to prevent the bottom slab concrete from flowing into the post-cast concrete pit 26. After the bottom slab concrete has solidified, the baffles can be removed, thus forming the post-cast concrete pit 26.

[0078] Once the foundation slab concrete reaches its design strength, the dewatering well 6 can be sealed to reduce dewatering costs. Extend the end of the drainage hose 17 furthest from the steel pipe well 28 to the collection well 18 and open the drain valve 16. Fill the steel pipe well 28 with graded sand and gravel until it reaches the top. During this process, water in the steel pipe well 28 is drained into the collection well 18 through the drain device. After the graded sand and gravel settle and solidify, rotate the sealing flange cover 20 using the handle 23, quickly turning the handle 23 into the slot 29 to engage with it, aligning the bolt holes on the sealing flange cover 20 and the sealing flange 19. Install the bolts and tighten them one by one. Water will still drain through the drain device. After checking that all bolts are tightened, close the drain valve 16. After checking that there is no leakage or air seepage between the sealing flange cover 20 and the sealing flange 19, remove the drainage hose 17.

[0079] If there are two or more dewatering wells 6 in the basement, after sealing all the wells 6 using the above method and waiting for the groundwater to stop flowing, pressure grouting should be performed on the steel pipe well 28 through the grouting pipe 12 under static water pressure to prevent the grout from being carried away by the groundwater. After checking that there is no leakage or air seepage from the well sealing flange cover 20 and well sealing flange 19, grouting should begin. The grout material is quick-setting cement grout, and the grouting pressure should be greater than 1.3 times the static groundwater pressure at this time. When the grouting pump pressure reaches the grouting pressure, the grouting valve 13 should be slowly opened. Grouting should be stopped and the grouting valve 13 closed when the grout volume reaches the volume of the steel pipe well 28. It is important to note that grouting should be carried out slowly. Clean the post-cast concrete pit 26 of the base slab, remove the rust from the steel bars cut off when reserving the post-cast concrete pit 26 of the base slab, also remove the rust from the steel pipe well 28 located in the post-cast concrete pit 26 of the base slab, weld the steel bars at the post-cast concrete pit 26 of the base slab, and pour the post-cast concrete pit 26 of the base slab with micro-expansion concrete with a strength one grade higher than that of the base slab concrete.

[0080] Check the area around the post-cast concrete pit 26 for any leakage, specifically checking for gaps between the reinforced concrete in the pit and the original reinforced concrete layer 3 of the base slab. If gaps exist, inject polyurethane foam into the gaps until there is no leakage. Place the drainage board 2 into the sump 18, ensuring that the drainage board 2 overlaps with the post-cast concrete pit 26 by at least 500 mm to ensure unobstructed drainage. Then, pour the concrete surface layer 1.

[0081] The difference between this invention and existing technologies lies in the addition of a drainage device to the steel pipe well 28. During well sealing, water is drained through this device, employing a pressure-reducing sealing method for rapid pressurized sealing. After sealing, the drainage device is then closed. The steel pipe well 28 utilizes a pre-filling of graded sand and gravel followed by grouting instead of concrete, ensuring the compactness and quality of the filling material. A drainage board 2 is placed within the concrete surface layer 1, leading to a nearby collection well 18. A micro-seepage self-drainage process is incorporated, utilizing the self-healing function of the concrete to reduce unnecessary subsequent maintenance. Therefore, this invention offers fast sealing speed, excellent sealing effect, and reduced unnecessary subsequent maintenance.

[0082] This invention adds a pressure-resistant locking element at the sealing flange 19 to accelerate the sealing speed and achieve rapid pressurized sealing. If there is a gap between the reinforced concrete in the pit 26 after the concrete is poured and the original reinforced concrete layer 3 of the base slab, polyurethane foam is injected into the gap to replace the water-stop steel plate. In small-space concrete construction, this can prevent air accumulation under the water-stop steel plate, which can lead to poor concrete compaction. This ensures the quality of concrete construction and reduces leakage. The drainage board 2 is made of plastic. Placing the plastic drainage board 2 above the pit 26, between the concrete surface layer 1 and the pit 26, allows minor leaks caused by rising groundwater levels or exceeding design groundwater levels to be automatically guided to the collection well 18 via the plastic drainage board 2. This adds a micro-seepage self-drainage process and utilizes the self-healing function of concrete micro-seepage to reduce unnecessary later maintenance.

[0083] This invention employs a drainage device (including a drainage pipe 15, a drainage valve 16, and a drainage hose 17) added to the steel pipe well 28. During well sealing, drainage is achieved through this device, using pressure reduction during sealing to significantly reduce water pressure, lower the difficulty of sealing, and ensure successful sealing on the first attempt. After sealing, the drainage device is then closed. To facilitate drainage, the dewatering well 6 is initially positioned as close as possible to the collection well 18. A pressure-resistant locking device is added to the well-sealing flange 19. The well-sealing flange cover 20 is located above the upper end of the steel pipe well 28, that is, above the well-sealing flange 19. During well sealing, the well-sealing flange cover 20 rotates around the hinge shaft 21. Since the hinge shaft 21 is arranged vertically, the well-sealing flange cover 20 rotates horizontally, allowing the handle 23 to quickly engage in the groove 29 formed by the base plate 24, vertical plate 25, and top plate 27. This aligns the well-sealing flange cover 20 and the well-sealing flange 19 vertically, and also aligns the bolt holes on the well-sealing flange cover 20 and the well-sealing flange 19, facilitating quick installation of flange bolts, accelerating the well-sealing speed, achieving rapid pressurized well sealing, and simplifying operation and construction. The rubber water-stop gasket 22 is pre-adheded to the well-sealing flange 19 to ensure that its position does not move, enabling rapid well sealing, ensuring flange sealing quality, and reducing the need for rework due to flange leakage. When sealing the well, graded sand and gravel are filled into the steel pipe well 28 until the top of the well is reached. During this process, the water in the steel pipe well 28 is discharged to the collection well 18 through the drain pipe 15, the drain valve 16 and the drain hose 17. After the graded sand and gravel settles and solidifies, the well is sealed by rotating the flange cover. If there are two or more dewatering wells 6, all dewatering wells 6 are sealed in the same way. After the groundwater stops flowing, quick-setting cement grout is injected into the graded sand and gravel in the steel pipe well 28 through the grouting pipe 12. This ensures that the filling material in the well is not lifted by water pressure, and ensures the compactness and quality of the filling material. The construction is simple and easy to operate. If, after the pouring of reinforced concrete, gaps exist between the reinforced concrete in the post-cast concrete pit 26 and the original reinforced concrete layer 3 of the base slab, polyurethane foam is injected into the gaps to replace the water-stop steel plate. This reduces the area of ​​the post-cast concrete pit 26 and, in small-space concrete construction, prevents air accumulation under the water-stop steel plate, thus ensuring concrete construction quality and reducing leakage. A plastic drainage board 2 is placed between the concrete surface layer 1 and the post-cast concrete pit 26 to form a drainage channel to the nearby collection well 18. A micro-seepage self-drainage process is added, allowing minor leaks caused by rising groundwater levels or exceeding design limits to be automatically guided to the collection well 18 via the plastic drainage board 2. The self-healing function of the concrete micro-seepage automatically seals the leaks later, reducing unnecessary subsequent maintenance. This invention is simple to construct and easy to operate, ensuring successful sealing of the ultra-high water pressure dewatering well 6 on the first attempt, reducing leakage.

[0084] It should be noted that the terms "center", "upper", "lower", "front", "rear", "left", "right", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0085] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0086] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A micro-seepage self-draining structure for sealing and plugging ultra-high water pressure dewatering wells, characterized in that: The system includes a steel pipe manhole vertically installed at the basement dewatering wellhead. The lower end of the manhole is connected to the dewatering well, and the upper end is sealed with a plug. A grouting pipe and a drain pipe are installed on the manhole wall near the upper end. The manhole is filled with graded sand and gravel fixed together by hardened cement grout. Outside the manhole, the basement floor is laid with a concrete cushion layer, a waterproof layer, and a reinforced concrete base slab layer, sequentially from bottom to top. All three layers contact the outer wall of the manhole circumferentially. The contact points between the concrete cushion layer and the waterproof layer and the manhole are close to... The bottom port of the steel pipe well is arranged near the bottom port. The upper surface of the reinforced concrete layer of the bottom slab is located above the upper port of the steel pipe well. A post-cast concrete pit corresponding to the steel pipe well is opened on the upper surface of the reinforced concrete layer of the bottom slab. The upper port of the steel pipe well, the grouting pipe and the drain pipe are all located in the post-cast concrete pit of the bottom slab. Reinforced concrete is poured in the post-cast concrete pit of the bottom slab. The concrete strength in the post-cast concrete pit of the bottom slab is one grade higher than the concrete strength of the reinforced concrete layer of the bottom slab. A drainage board extending to the sump is laid above the post-cast concrete pit of the bottom slab. A concrete surface layer is laid above the reinforced concrete layer of the bottom slab and the drainage board.

2. The micro-seepage self-draining structure for sealing and plugging ultra-high water pressure dewatering wells according to claim 1, characterized in that: The steel pipe well includes an upper part and a lower part of the steel pipe well, both arranged vertically. A ring-shaped support plate arranged circumferentially is fixed on the outer well wall of the lower port of the lower part of the steel pipe well. The ring-shaped support plate overlaps the edge of the dewatering well opening circumferentially. The lower port of the lower part of the steel pipe well is connected to the dewatering well. The upper port of the lower part of the steel pipe well is connected to the lower port of the upper part of the steel pipe well through a flange. The upper port of the upper part of the steel pipe well is sealed by a sealing component. A grouting pipe and a drain pipe are provided on the well wall of the upper part of the steel pipe well near the upper port. A ring-shaped waterstop plate arranged circumferentially is fixed on the outer well wall of the upper part of the steel pipe well.

3. The micro-seepage self-draining structure for ultra-high water pressure dewatering well drainage and sealing as described in claim 2, characterized in that: The sealing components include a well sealing flange, a well sealing flange cover, and a locking component. The well sealing flange is fixedly installed at the upper port of the steel pipe well. The well sealing flange cover is rotatably installed on the well sealing flange via a vertically arranged hinge shaft. The well sealing flange cover and the well sealing flange are fixedly connected by bolts. The locking component includes a handle fixedly installed on the well sealing flange cover and a slot fixedly installed on the well sealing flange. The handle is engaged in the slot. A rubber water-stop gasket is provided between the well sealing flange cover and the well sealing flange.

4. The micro-seepage self-draining structure for sealing and plugging ultra-high water pressure dewatering wells according to claim 3, characterized in that: A base plate is fixedly mounted on the well sealing flange, a vertical plate is fixedly mounted on the base plate, and a top plate is fixedly mounted on the vertical plate opposite to the base plate. The handle is engaged between the base plate, the vertical plate, and the top plate, which together form a slot.

5. A construction method for a micro-seepage self-drainage structure for sealing and plugging ultra-high water pressure dewatering wells as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Prepare the steel pipe well. Drill grouting holes and drainage holes on the well wall near the upper end. Weld grouting pipes to the grouting holes on the outer wall of the steel pipe well, and weld drainage pipes to the drainage holes on the outer wall of the steel pipe well. Install grouting valves on the grouting pipes and drainage valves on the drainage pipes. Connect drainage hoses to the drainage valves. Install a sealing device at the upper end of the steel pipe well. The second step is to arrange the steel pipe wells vertically, placing the lower end of the well at the opening of the dewatering well. Then, on the basement floor surrounding the steel pipe wells, lay a concrete base layer and a waterproof layer sequentially from bottom to top, ensuring both layers are in circumferential contact with the outer wall of the well. The portion of the concrete base layer in contact with the well should be thickened, and the contact points of the concrete base layer and waterproof layer should be positioned close to the lower end of the well. The third step involves installing the reinforcing steel bars on the waterproof layer and pre-reserving a concrete pit for the bottom slab at the upper end of the steel pipe well. This pit should contain the upper end of the steel pipe well, along with its sealing components, grouting pipes, grouting valves, drain pipes, drain valves, and drainage hoses. The bottom slab concrete is then poured, covering the reinforcing steel bars to form a reinforced concrete layer. This reinforced concrete layer should be in circumferential contact with the outer wall of the steel pipe well, and its upper surface should be higher than the upper end of the steel pipe well. Step 4: Connect the drain hose to the sump, open the drain valve, remove the sealing piece from the top end of the steel pipe well, and fill the steel pipe well with graded sand and gravel from the top end until the top of the well. During this process, the water in the steel pipe well will flow through the drain pipe, drain valve, and drain hose into the sump. After the graded sand and gravel have settled and solidified, move the sealing piece back to the top end of the steel pipe well to seal it. Then close the drain valve and remove the drain hose. Step 5: Open the grouting valve and inject a certain amount of quick-setting cement grout into the steel pipe well through the grouting pipe. Then close the grouting valve. Next, install reinforcing bars in the post-cast concrete pit of the base slab, and pour concrete with a strength one grade higher than that of the base slab concrete into the post-cast concrete pit. Step 6: Lay a drainage board extending to the sump above the concrete pit after the base slab is poured, and then lay a concrete surface layer on top of the reinforced concrete layer of the base slab and the drainage board.

6. The construction method according to claim 5, characterized in that, The specific steps for preparing the steel pipe well in the first step are as follows: Prepare the upper and lower sections of the steel pipe well. Weld a circumferentially arranged annular waterstop plate to the outer wall of the upper section of the steel pipe well. Weld a circumferentially arranged annular support plate to the outer wall of the lower end of the lower section of the steel pipe well. Connect the lower end of the upper section of the steel pipe well to the upper end of the lower section of the steel pipe well through a connecting flange to form the steel pipe well. The upper end of the upper section of the steel pipe well is the upper end of the steel pipe well, and the lower end of the lower section of the steel pipe well is the lower end of the steel pipe well.

7. The construction method according to claim 6, characterized in that, The specific steps for installing the sealing component at the upper end of the steel pipe well in the first step are as follows: The sealing components consist of a well-sealing flange, a well-sealing flange cover, and locking components. The well-sealing flange is welded to the upper end of the steel pipe well. The well-sealing flange cover is rotatably installed on the well-sealing flange via a vertically arranged hinge shaft. A rubber water-stop gasket is bonded to the side of the well-sealing flange opposite to the well-sealing flange cover. The locking components consist of a handle and a locking groove. The handle is welded to the well-sealing flange cover, and the locking groove is fixed to the well-sealing flange. By rotating the well-sealing flange cover with the handle, when the handle is rotated into the locking groove and engages with the locking groove, the well-sealing flange cover is aligned with the well-sealing flange. Then, the well-sealing flange cover and the well-sealing flange are fixedly connected with bolts.

8. The construction method according to claim 7, characterized in that, The specific steps for fixing the slot onto the well sealing flange in the first step are as follows: A base plate is welded onto the well sealing flange, a vertical plate is welded onto the base plate, and a top plate, which is arranged opposite to the base plate, is welded onto the vertical plate, so that the base plate, vertical plate, and top plate together form a slot.

9. The construction method according to claim 8, characterized in that, In the second step, the specific steps for placing the lower end of the steel pipe well at the wellhead of the dewatering well are as follows: align the lower end of the steel pipe well with the wellhead of the dewatering well, and overlap the annular support plate circumferentially on the edge of the dewatering wellhead.

10. The construction method according to claim 9, characterized in that, In the fourth step, the specific steps for removing the sealing component from the upper end of the steel pipe well are as follows: remove the bolts between the sealing flange cover and the sealing flange, rotate the sealing flange cover using the handle to allow the handle to turn out of the slot, and continue rotating the sealing flange cover until the sealing flange cover is removed from the upper end of the steel pipe well. In the fourth step, the specific steps for moving the sealing component to the upper end of the steel pipe well to seal it are as follows: rotate the well sealing flange cover by the handle. When the handle is rotated into the slot and engages with the slot, the well sealing flange cover is aligned with the well sealing flange. Then, the well sealing flange cover is fixedly connected to the well sealing flange by bolts.

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