A well sealing device for a construction engineering dewatering well

Abstract

This invention relates to the field of building construction technology, specifically to a well sealing device for a building engineering drainage well. It includes a graded sand and gravel layer and a steel casing. A cement well pipe is installed around the outer ring of the graded sand and gravel layer. A quick-setting concrete layer is laid on top of the graded sand and gravel layer. A cushion layer is installed at the bottom of the outer ring of the cement well pipe. A basement floor slab is laid on top of the cushion layer. A micro-expansion concrete sealing layer is laid on top of the quick-setting concrete layer. A water-stop steel plate is fixedly connected to the top of the inner ring of the steel casing, and a water-stop ring is fixedly connected to the outer ring of the steel casing. A support component is installed on top of the micro-expansion concrete sealing layer, and a waterproof component is installed at the bottom of the water-stop ring. Through full welding connection of the steel casing, water-stop ring, and water-stop steel plate, combined with a micro-expansion concrete sealing layer of equal strength to the base slab, a robust and rigid pressure-resistant framework is constructed. This effectively solves the problem of easy cracking and leakage in traditional sealing methods under high-pressure underwater conditions.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a well sealing device for a building engineering drainage well. Background Technology

[0002] With the acceleration of urbanization, the scale of deep underground projects such as super high-rise buildings, underground utility tunnels, and subways has surged, with excavation depths typically reaching 10–20 meters. These projects often face complex geological conditions such as high groundwater levels, highly confined water, and water-rich sand layers. Dewatering wells (drainage wells), as the core facility for dewatering foundation pits, need to continuously lower the groundwater level during the construction phase to ensure the stability of the foundation pit and a dry working environment. After the main structure (raft slab / base slab) is completed, the dewatering wells must be permanently sealed. The quality of the sealing directly determines the success or failure of waterproofing in underground projects and the long-term safety of the structure. Especially in recent years, influenced by factors such as abundant rainfall, ecological water replenishment, and water-saving measures, groundwater levels in many areas have continued to rise, making the need for well sealing and seepage prevention under high water pressure conditions increasingly urgent.

[0003] Currently, existing well sealing techniques for drainage wells mainly involve precast steel casing with welded water-stop steel plates, dry material filling, micro-expansion concrete grouting, and polyurethane plugging. However, these traditional techniques have significant limitations in actual construction: firstly, under high-pressure water of 0.3–0.8 MPa, the welded sealing surface of the steel plate and the joint between the concrete and the well wall are prone to cracking and seepage; secondly, water-rich formations often have large single-well inflows, and traditional plugging methods often require concrete pouring while the water is still running, making underwater welding impossible and leading to problems such as well blowouts, material backflow, and poor compaction; furthermore, staged well sealing can cause a sudden increase in water head pressure, further exacerbating the risk of leakage.

[0004] Existing well sealing technologies generally suffer from several drawbacks: high-pressure underwater structures are prone to cracking, and settlement leads to leakage. Traditional rigid plugs are easily punctured under high water pressure and cannot adapt to subsequent well casing settlement, resulting in cracks and water seepage at the joints, seriously threatening the durability of the project. Structural deformation and cracking, irregular gaps, and difficulties in sealing underwater structures further complicate matters. Purely rigid plugs cannot adapt to the micro-deformation of underground engineering and are easily cracked, making it difficult to effectively seal gaps. Therefore, it is necessary to develop a "rigid-flexible" well sealing device that can withstand high pressure and prevent cracking, adapt to deformation, and is waterproof. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a well sealing device for drainage wells in construction engineering. It solves the problems of easy cracking and leakage caused by settlement in high-pressure underwater structures, the easy puncture of traditional rigid plugs under high water pressure, and the inability to adapt to subsequent well pipe settlement, which leads to cracking and water leakage at the connection and seriously threatens the durability of the project.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a well sealing device for a building engineering drainage well, comprising a graded sand and gravel layer and a steel casing, wherein a cement well pipe is provided on the outer ring of the graded sand and gravel layer, a quick-setting concrete layer is laid on top of the graded sand and gravel layer, a cushion layer is provided at the bottom of the outer ring of the cement well pipe, a basement floor slab is laid on top of the cushion layer, a micro-expansion concrete sealing layer is laid on top of the quick-setting concrete layer, a water-stop steel plate is fixedly connected to the top of the inner ring of the steel casing, a water-stop ring is fixedly connected to the outer ring of the steel casing, a support component is provided on top of the micro-expansion concrete sealing layer, and a waterproof component is provided at the bottom of the water-stop ring.

[0007] Preferably, the support assembly includes a flange plate, the bottom center of which is in contact with the micro-expansion concrete sealing layer, and the top of the flange plate is threaded with evenly distributed bolts.

[0008] Preferably, a second layer of fine aggregate concrete is laid on the top of the waterstop steel plate, and a first layer of fine aggregate concrete is provided at the bottom of the waterstop steel plate.

[0009] Preferably, the waterproof component includes a waterproof membrane, the top of which is fixedly connected to a water-stop ring, and a rubber pad is connected to the bottom wall of the steel sleeve.

[0010] Preferably, a layer of hemp fiber grease is provided between the cement well pipe and the steel casing.

[0011] Preferably, a polyurethane waterproof coating layer is provided in the middle of the top of the flange pressure plate.

[0012] Preferably, a non-curing asphalt waterproof coating layer is provided on top of the polyurethane waterproof coating layer.

[0013] Preferably, the construction process is as follows: S1: Construction Preparation Clean up the construction site and prepare materials such as steel sleeves and water-stop rings, flange plates, water-stop steel plates, rubber gaskets, waterproof membranes, waterproof coatings, micro-expansion concrete, hemp fibers, and grease. S2 sleeve installation The steel casing with outwardly extending water-stopping ring is hoisted into place on the outside of the cement well pipe, and the gap between the cement well pipe and the steel casing is filled with hemp fiber and oil paste. S3: Leveling Construction The existing drainage wells should be properly protected, a bedding layer should be poured, and the wells should be cured until they reach the required strength. S4: Waterproofing Construction Waterproof membrane is applied to the subbase and base layer, extending the membrane to the bottom of the waterstop ring. The membrane is then fixed to the joint between the membrane and the waterstop ring using hot-melt or cold-bonding methods. S5: Structural Construction Structural construction was carried out while ensuring that the drainage wells were in normal dewatering operation mode. S6 drainage well lower part plugging After the precipitation reaches the standard and the conditions for sealing and draining wells are met, the bottom is compacted in layers, graded sand and gravel is laid, and quick-setting concrete is poured up to the elevation of the waterproof protective layer. Then, micro-expansion concrete with the same strength as the bottom slab is poured into the gap between the steel casing and the bottom slab. The pouring height is slightly less than half the height of the bottom slab, and it is vibrated to make it dense. S7: Flange Installation A flange pressure plate is installed on the upper part of the steel sleeve, and a rubber gasket is placed between the flange pressure plate and the steel sleeve, and then fastened with bolts. S8: Upper waterproofing construction The following layers are applied sequentially from bottom to top on the upper part of the steel casing: polyurethane waterproof coating layer, non-curing asphalt waterproof coating layer, fine stone concrete layer, full welding of the water-stop steel plate to the steel casing, polyurethane waterproof coating layer, and fine stone concrete protective layer. After each layer is completed, it is cured to the required standard to complete the construction.

[0014] Working Principle: For rigid compressive strength and sealing, a 10mm thick, 450mm inner diameter seamless steel pipe casing is fully welded to a 150mm outward-extending water-stop ring and a 10mm thick water-stop steel plate. This, combined with a micro-expansion concrete sealing layer with strength equal to the basement floor slab and a pouring height equal to half the floor slab height, constructs a robust rigid compressive strength framework. This framework can withstand high-pressure water loads of 0.3-0.8MPa, while the micro-expansion concrete compensates for its own shrinkage and adapts to subsequent well pipe settlement, preventing leakage caused by foundation deformation and cracking, thus ensuring the long-term durability of the sealing structure. The bottom graded sand and gravel layer and quick-setting concrete layer provide initial filtration and rapid sealing support.

[0015] In terms of flexible seepage prevention and deformation adaptation, a 30mm thick layer of hemp fiber grease between the cement well pipe and the steel casing effectively fills irregular gaps and absorbs structural deformation; a 3mm thick rubber gasket between the flange pressure plate and the top of the steel casing, secured with uniform M16 bolts, achieves flexible sealing and seepage prevention, preventing rigid cracking; a 3mm thick waterproof membrane extends and is fully welded to the bottom of the water-stop ring, increasing the seepage path of groundwater and ensuring reliable anchoring and seepage prevention between the casing and the base concrete; a 2mm thick polyurethane waterproof coating layer seals the top gaps, forming a flexible waterproof barrier, while a 3mm thick non-curing asphalt waterproof coating layer forms a creep-self-healing waterproof layer to adapt to structural micro-deformation. The synergistic effect of these flexible structures completely blocks micro-leakage paths.

[0016] In terms of structural stress and protection, the 10mm thick flange pressure plate and steel sleeve are concentrically set, and the micro-expansion concrete sealing layer is pressed downward by evenly distributed M16 bolts to support the overall sealing load. This uniform stress design ensures the full compaction of the rubber gasket. At the same time, the 50mm thick fine stone concrete layer at the bottom of the waterstop steel plate provides bottom rigid support, and the 75mm thick fine stone concrete layer at the top provides top compressive protection, ensuring that the core waterstop components are not damaged under long-term high water pressure conditions and maintaining the overall sealing stability.

[0017] This invention provides a sealing device for drainage wells in construction engineering. It has the following beneficial effects: 1. This invention constructs a robust, rigid, and pressure-resistant framework by fully welding a steel casing, a water-stop ring, and a water-stop steel plate together, in conjunction with a micro-expansion concrete sealing layer of equal strength to the base plate. This effectively solves the problem of easy cracking and leakage in traditional sealing methods under high-pressure underwater conditions. Simultaneously, the micro-expansion concrete can compensate for its own shrinkage and adapt to well casing settlement, avoiding leakage caused by foundation deformation and cracking, thus ensuring the long-term durability of the well sealing structure.

[0018] 2. This invention utilizes hemp fiber grease and rubber gaskets to effectively fill irregular gaps between the well casing, sleeve, and flange, absorbing structural deformation. Combined with waterproof membrane, polyurethane waterproof coating, and non-curing asphalt waterproof coating, it forms a "rigid-flexible, layered" waterproof system. This design effectively solves the problem of rigid tensile cracking and water seepage caused by structural deformation, completely blocking micro-leakage paths. Attached Figure Description

[0019] Figure 1 This is a schematic cross-sectional view of the overall structure of the well sealing system of the present invention. Figure 2 This is a schematic plan view of the flange water-stop ring structure of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the steel sleeve and water-stop ring of the present invention; Figure 4 This is a schematic diagram of the steel sleeve structure of the present invention; Figure 5 This is a schematic diagram of the flange pressure plate planar structure of the present invention; Figure 6 This is a schematic diagram of the planar structure of the water-stop steel plate of the present invention.

[0020] The components are as follows: 1. Graded sand and gravel layer; 2. Quick-setting concrete layer; 3. Cement well pipe; 4. Subbase layer; 5. Basement floor slab; 6. Micro-expansion concrete sealing layer; 7. Steel sleeve; 8. Water-stop ring; 9. Waterproof membrane; 10. Water-stop steel plate; 11. Flange pressure plate; 12. Rubber gasket; 13. Bolt; 14. Hemp fiber oil paste layer; 15. Polyurethane waterproof coating layer; 16. Non-curing asphalt waterproof coating layer; 17. Fine stone concrete layer one; 18. Fine stone concrete layer two. Detailed Implementation

[0021] 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0022] like Figure 1-6 As shown, this embodiment of the invention provides a well sealing device for a building engineering drainage well, including a graded sand and gravel layer 1 and a steel casing 7. A cement well pipe 3 is provided on the outer ring of the graded sand and gravel layer 1. A quick-setting concrete layer 2 is laid on top of the graded sand and gravel layer 1. A pad layer 4 is provided at the bottom of the outer ring of the cement well pipe 3. A basement floor slab 5 is laid on top of the pad layer 4. A micro-expansion concrete sealing layer 6 is laid on top of the quick-setting concrete layer 2. A water-stop steel plate 10 is fixedly connected to the top of the inner ring of the steel casing 7. A water-stop ring 8 is fixedly connected to the outer ring of the steel casing 7. A support component is provided on top of the micro-expansion concrete sealing layer 6. A waterproof component is provided at the bottom of the water-stop ring 8.

[0023] Specifically, the steel casing 7 is made of 10mm thick seamless steel pipe with an inner diameter of 450mm to resist the pressure load of high-pressure water. The micro-expansion concrete sealing layer 6 serves as the core rigid sealing structure, with its strength quantified to be equal to that of the basement floor slab, and its pouring height quantified to be 1 / 2 of the floor slab height, to withstand a high water pressure load of 0.3-0.8MPa. A water-stop ring 8 is welded to the outer wall of the steel casing 7, extending outwards by 150mm. This extension design increases the seepage path of groundwater and ensures reliable anchorage between the steel casing and the floor slab concrete. A 10mm thick water-stop steel plate 10 is fully welded to the top of the inner ring of the steel casing 7. This full-welding design completely blocks the vertical seepage path of groundwater along the pipe wall and ensures the overall sealing of the rigid pressure-resistant skeleton. The support assembly includes a flange plate 11, the bottom center of which is in contact with the micro-expansion concrete sealing layer 6, and the top of the flange plate 11 is threaded with evenly distributed bolts 13.

[0024] Specifically, the support assembly includes a 10mm thick steel plate flange 11, which is concentrically positioned with the steel sleeve 7. Its bottom center contacts the micro-expansion concrete sealing layer 6, pressing downwards and supporting the overall sealing load. The flange 11 has evenly distributed M16 bolts 13 threaded around its top circumference. This even distribution design ensures both uniform stress on the flange 11 and complete compaction of the rubber gasket 12 to prevent rigid cracking and water seepage. The top of the waterstop steel plate 10 is covered with a fine stone concrete layer 2 18, and the bottom of the waterstop steel plate 10 is provided with a fine stone concrete layer 17.

[0025] Specifically, a 50mm thick fine stone concrete layer 17 is laid at the bottom of the waterstop steel plate 10 to provide rigid support at the bottom, and a 75mm thick fine stone concrete layer 18 is laid at the top of the waterstop steel plate 10 to provide pressure protection at the top.

[0026] The waterproofing component includes a waterproof membrane 9, the top of which is fixedly connected to a water-stop ring 8, and a rubber pad 12 is connected to the bottom wall of a steel sleeve 7.

[0027] Specifically, the waterproofing components include a 3mm thick waterproof membrane 9, the top of which is fully welded to the bottom wall of the waterstop ring 8, and a 3mm thick rubber gasket 12 is sandwiched between the flange pressure plate 11 and the top of the steel sleeve 7. The rubber gasket 12 is designed to fill the gap between the flange and the sleeve, and also ensure a flexible seal and prevent leakage when the bolts 13 are tightened. A layer of hemp fiber grease 14 is provided between the cement well pipe 3 and the steel casing 7.

[0028] Specifically, hemp fiber and oil paste are filled between the cement well pipe 3 and the steel casing 7 for waterproofing.

[0029] A polyurethane waterproof coating layer 15 is provided in the middle of the top of the flange plate 11.

[0030] Specifically, a 2mm thick polyurethane waterproof coating layer 15 is applied to the top center of the flange plate 11 to seal the top gaps and form a flexible waterproof barrier.

[0031] A non-curing bitumen waterproof coating layer 16 is provided on top of the polyurethane waterproof coating layer 15.

[0032] Specifically, the non-curing asphalt waterproof coating layer 16 is 3mm thick and is used to form a creep self-healing waterproof layer to adapt to structural deformation. Example 2

[0033] The construction process is as follows: S1: Construction Preparation Clean up the construction site and prepare materials such as 10mm thick seamless steel pipe steel sleeve 7, water-stop ring 8, flange pressure plate 11, water-stop steel plate 10, rubber gasket 12, waterproof membrane 9, waterproof coating, micro-expansion concrete, hemp fiber, and grease. S2: Sleeve Installation The steel casing 7 with the water-stop ring 8 extending outward by 150mm is hoisted into place on the outside of the cement well pipe 3, and the gap between the cement well pipe 3 and the steel casing 7 with an inner diameter of 450mm is filled with hemp fiber oil paste. S3: Leveling Construction Protect the existing drainage wells, pour the foundation layer 4, and cure until the strength meets the standard. S4: Waterproofing Construction Apply a 3mm thick waterproof membrane 9 to the cushion layer 4 and the base layer of the bottom plate, extend the waterproof membrane 9 to the bottom of the waterstop ring 8, and fix the joint between the waterproof membrane 9 and the waterstop ring 8 by hot melting or cold bonding. S5: Structural Construction Carry out the construction of the basement floor slab structure, while ensuring that the drainage well is in normal dewatering operation condition; S6: Lower part of the drainage well is sealed After the precipitation reaches the standard and the conditions for sealing and draining wells are met, the bottom is compacted in layers, graded sand and gravel is laid, and quick-setting concrete is poured up to the elevation of the waterproof protective layer. Then, a micro-expansion concrete sealing layer 6 with the same strength as the bottom slab is poured into the gap between the steel casing 7 and the bottom slab. The pouring height is quantified to half the height of the bottom slab, and it is vibrated to make it dense. S7: Flange Installation A 10mm thick flange plate 11 is installed on the upper part of the steel sleeve 7. A 5mm thick rubber gasket 12 is placed between the flange plate 11 and the steel sleeve 7, and the flange is fastened with evenly distributed M16 bolts 13. S8: Upper waterproofing construction Apply a 2mm thick polyurethane waterproof coating layer 15, a 3mm thick non-curing asphalt waterproof coating layer 16, and a 50mm thick fine stone concrete layer 17 to the upper part of the steel sleeve 7 from bottom to top. Fully weld the 10mm thick water-stop steel plate 10 to the steel sleeve 7, apply a 2mm thick polyurethane waterproof coating layer 15, and pour a 75mm thick fine stone concrete layer 18. After each layer is completed, cure it to the required level to complete the construction.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A well sealing device for a drainage well in a construction project, comprising a graded sand and gravel layer (1) and a steel casing (7), characterized in that, The graded sand and gravel layer (1) is provided with a cement well pipe (3) on the outer ring, the graded sand and gravel layer (1) is provided with a quick-setting concrete layer (2) on top, the cement well pipe (3) is provided with a pad layer (4) at the bottom of the outer ring, the pad layer (4) is provided with a basement floor slab (5) on top, the quick-setting concrete layer (2) is provided with a micro-expansion concrete sealing layer (6) on top, the inner ring of the steel sleeve (7) is fixedly connected with a water-stop steel plate (10), the outer ring of the steel sleeve (7) is fixedly connected with a water-stop ring (8), the micro-expansion concrete sealing layer (6) is provided with a support component on top, and the water-stop ring (8) is provided with a waterproof component at the bottom.

2. The well sealing device for a drainage well in a building construction project according to claim 1, characterized in that, The support assembly includes a flange plate (11), the bottom center of which is in contact with the micro-expansion concrete sealing layer (6), and the top of the flange plate (11) is threaded with evenly distributed bolts (13).

3. The well sealing device for a drainage well in a building construction project according to claim 1, characterized in that, The top of the waterstop steel plate (10) is covered with a second layer of fine stone concrete (18), and the bottom of the waterstop steel plate (10) is covered with a first layer of fine stone concrete (17).

4. The well sealing device for a drainage well in a building construction project according to claim 1, characterized in that, The waterproof component includes a waterproof membrane (9), the top of which is fixedly connected to a water-stop ring (8), and a rubber pad (12) is connected to the bottom wall of the steel sleeve (7).

5. A well-sealing device for a drainage well in a building construction project according to claim 1, characterized in that, A layer of hemp fiber grease (14) is provided between the cement well pipe (3) and the steel casing (7).

6. A well-sealing device for a drainage well in a building construction project according to claim 2, characterized in that, A polyurethane waterproof coating layer (15) is provided in the middle of the top of the flange plate (11).

7. A well-sealing device for a drainage well in a building construction project according to claim 6, characterized in that, A non-curing bitumen waterproof coating layer (16) is provided on top of the polyurethane waterproof coating layer (15).

8. A well-sealing device for a drainage well in a building construction project according to any one of claims 1-7, characterized in that, The construction process is as follows: S1: Construction Preparation Clean up the construction site and prepare materials such as steel sleeve (7) + water-stop ring (8), flange pressure plate (11), water-stop steel plate (10), rubber gasket (12), waterproof membrane (9), waterproof coating, micro-expansion concrete, hemp fiber, and grease. S2 sleeve installation The steel casing (7) with the outwardly extending water-stop ring (8) is hoisted into place on the outside of the cement well pipe (3), and the gap between the cement well pipe (3) and the steel casing (7) is filled with hemp fiber oil paste. S3: Leveling Construction The existing drainage wells were properly protected, and a bedding layer (4) was poured and cured until the strength met the standard. S4: Waterproofing Construction Waterproof membrane (9) is applied to the base layer (4) and the bottom slab base layer. The membrane is extended to the bottom of the waterstop ring (8). The joint between the membrane and the waterstop ring (8) is fixed by hot melting or cold bonding. S5: Structural Construction Structural construction was carried out while ensuring that the drainage wells were in normal dewatering operation mode. S6 drainage well lower part plugging After the precipitation reaches the standard and the conditions for sealing and draining wells are met, the bottom is compacted in layers, graded sand and gravel is laid, and quick-setting concrete is poured to the elevation of the waterproof protective layer. Then, micro-expansion concrete with the same strength as the bottom plate is poured in the gap between the steel casing (7) and the bottom plate. The pouring height is slightly less than half the height of the bottom plate, and it is vibrated to compact. S7: Flange Installation A flange pressure plate (11) is installed on the upper part of the steel sleeve (7), and a rubber gasket (12) is placed between the flange pressure plate (11) and the steel sleeve (7), and fastened by bolts (13); S8: Upper waterproofing construction On the upper part of the steel sleeve (7), from bottom to top, a polyurethane waterproof coating layer (15), a non-curing asphalt waterproof coating layer (16), a fine stone concrete layer, a water-stop steel plate (10) fully welded to the steel sleeve (7), a polyurethane waterproof coating layer (15), and a fine stone concrete protective layer are constructed. After each layer is constructed, it is cured to the required standard to complete the construction.

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