A rapid sealing device for dewatering wells in foundation pits

Abstract

This utility model relates to the field of dewatering well sealing technology, and discloses a rapid sealing device for dewatering wells in foundation pits, including a dewatering well sealing component, a flange sealing component, and a leakage monitoring component. Water-stop rings are respectively installed on the outer and inner sides of the main body. The outer water-stop ring combines with the foundation concrete to form a rigid waterproof barrier, while the inner water-stop ring, in conjunction with an expansion filler material, blocks the leakage path within the well. The top flange component achieves dynamic sealing compensation through a flexible sealing gasket. The monitoring system includes an annular groove and a flow monitoring pipe, which can collect leakage fluid in a timely manner and provide early warning through a liquid level sensor. The device, through a multi-layered waterproofing system of rigid blocking, flexible compensation, and intelligent monitoring, significantly improves the seepage resistance after sealing the dewatering well, effectively copes with groundwater pressure and foundation settlement, avoids the cracking risk of traditional rigid sealing, and the integrated monitoring system enables real-time detection and rapid response to leakage, making it suitable for waterproofing deep foundation pit projects under complex geological conditions.

Description

Technical Field

[0001] This utility model relates to the field of dewatering well sealing technology, and in particular to a rapid sealing device for dewatering wells in foundation pits. Background Technology

[0002] With the construction of high-rise, super high-rise, and large-span buildings in urban development, the development of underground space has entered a new stage, facing the dual challenges of groundwater level control and waterproofing system construction in terms of construction technology. Among these challenges, the backfilling and sealing of manholes after completing their drainage function has become a key aspect of waterproofing quality control.

[0003] In current construction projects, most well sealing is achieved using concrete pouring. However, due to the shrinkage characteristics of concrete, it is difficult to achieve a dense filling within the well. This results in a leakage channel forming between the poured concrete and the sealing structure of the dewatering well. Later, under the pressure of groundwater, this can easily lead to leakage accidents in the foundation slab, which in turn can cause leakage problems in the underground structure. In addition, existing backfilling and sealing technologies lack early warning capabilities. By the time leakage is detected, economic losses or safety issues have often already occurred, making it difficult to recover. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a rapid sealing device for dewatering wells in foundation pits, which aims to improve the problem that concrete materials are difficult to fill densely in the well, resulting in leakage in underground structures, and the lack of early warning in existing backfilling and sealing technologies.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a rapid sealing device for dewatering wells in foundation pits, comprising a sand-free well pipe, a dewatering pipe, a foundation trench, a dewatering well sealing assembly, and a monitoring assembly. The sand-free well pipe is installed inside the foundation trench, and the dewatering pipe is vertically installed inside the sand-free well pipe. The dewatering well sealing assembly comprises a main body, an outer water-stop ring, and an inner water-stop ring. The outer water-stop ring is arranged around the outer side wall of the main body, and the inner water-stop ring is arranged around the inner side wall of the main body. The main body is fitted over the outer layer of the sand-free well pipe, and a flange assembly for sealing is provided at the upper end of the main body. The monitoring assembly comprises an inner annular groove, an inner monitoring pipe, an outer annular groove, and an outer monitoring pipe. The inner annular groove is opened on the inner side wall of the dewatering well sealing assembly, located directly below the inner water-stop ring and communicating with the inner monitoring pipe. The outer annular groove is opened on the outer side wall of the main body, located directly below the outer water-stop ring and communicating with the outer monitoring pipe.

[0006] Preferably, the inner annular groove is inclined inward to facilitate the flow of groundwater into the inner monitoring pipe, and the outer annular groove is inclined outward to facilitate the flow of groundwater into the outer monitoring pipe.

[0007] Preferably, both the inner and outer monitoring tubes are PVC pipes, and extend from the inner and outer annular grooves to a ground-level observable location.

[0008] Preferably, both the inner and outer monitoring tubes are equipped with liquid level sensors at observable locations on the ground, and the liquid level sensors are electrically connected to the alarm.

[0009] Preferably, the sand-free well pipe is filled with graded sand and gravel, and the outer side of the sand-free well pipe and the top of the foundation trench are filled with a concrete cushion layer. The main body and the sand-free well pipe are fixedly connected by the concrete cushion layer.

[0010] Preferably, the upper surface of the concrete cushion layer is flush with the top of the sand-free well pipe.

[0011] Preferably, the upper surface of the concrete cushion layer is provided with a waterproof layer, which extends up to the root of the water-stop ring outside the dewatering well sealing device, and the concrete cushion layer is filled with foundation reinforced concrete.

[0012] Preferably, the flange assembly is filled with micro-expansion reinforced concrete, which is connected to the foundation reinforced concrete.

[0013] Preferably, the graded sand and gravel are filled from bottom to top with micro-expansion concrete, leak-stopping waterproof material, and micro-expansion concrete, and the rainwater pipe passes through the leak-stopping waterproof material and extends into the upper layer of micro-expansion concrete.

[0014] Preferably, the flange assembly includes a rubber gasket, a flange cover plate, a flange ring, and fastening bolts. The flange ring is fixed to the top of the main body, the flange cover plate is connected to the flange ring by the fastening bolts, and the rubber gasket is disposed between the flange cover plate and the flange ring.

[0015] This utility model has the following beneficial effects:

[0016] 1. This utility model employs a multi-layered waterproofing system combining a rigid water-stop structure, flexible sealing components, and expanding filling material, significantly enhancing the seepage resistance of the sealed dewatering well. The tight integration of the rigid water-stop structure with the foundation structure, combined with the adaptability of the flexible seal to minor deformations, effectively resists groundwater pressure and copes with stress changes caused by foundation settlement, avoiding the cracking and leakage problems that are prone to occur in traditional sealing methods. The expanding filling material can fully fill various gaps and micropores, forming an all-round seal and fundamentally reducing the risk of leakage. At the same time, the stable connection between the entire device and the foundation structure, combined with the reasonable layout of the filter support material, improves the structural stability under complex geological conditions.

[0017] 2. In this invention, the leakage monitoring system enables real-time sensing and proactive early warning of potential leaks. Leaking water is preferentially intercepted and guided to the monitoring area. Combined with automated monitoring components, it can quickly detect leaks and issue alarms, significantly shortening the leak response time and providing an opportunity for timely intervention. Simultaneously, the integrated monitoring system avoids structural damage during subsequent secondary construction, reducing construction costs while further ensuring overall sealing performance. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of a rapid sealing device for dewatering wells in a foundation pit proposed in this utility model;

[0019] Figure 2 This is a schematic diagram of the annular groove of a rapid sealing device for dewatering wells in a foundation pit proposed in this utility model.

[0020] Legend:

[0021] 1. Sand-free well casing; 2. Dewatering pipe; 3. Graded sand and gravel; 4. Foundation trench; 5. Concrete cushion layer; 6. Waterproof layer; 7. Main body; 8. Outer water-stop ring; 9. Inner water-stop ring; 10. Inner annular groove; 11. Inner monitoring pipe; 12. Outer annular groove; 13. Outer monitoring pipe; 14. Rubber gasket; 15. Flange cover plate; 16. Flange ring; 17. Fastening bolts; 18. Micro-expansion concrete; 19. Leak-stopping waterproof material; 20. Foundation reinforced concrete; 21. Micro-expansion reinforced concrete; 22. Liquid level sensor. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Reference Figures 1-2This utility model provides an embodiment of a rapid sealing device for dewatering wells in a foundation pit, comprising a sand-free well pipe 1, a dewatering pipe 2, a foundation trench 4, a dewatering well sealing assembly, and a monitoring assembly. The sand-free well pipe 1 is installed inside the foundation trench 4, and the dewatering pipe 2 is vertically installed inside the sand-free well pipe 1. The dewatering well sealing assembly includes a main body 7, an outer water-stop ring 8, and an inner water-stop ring 9. The outer water-stop ring 8 is arranged around the outer side wall of the main body 7, and the inner water-stop ring 9 is arranged around the inner side wall of the main body 7. The main body 7 is fitted onto... The outer layer of the sand-free well casing 1 has a flange assembly for sealing at the upper end of the main body 7. The monitoring assembly includes an inner annular groove 10, an inner monitoring pipe 11, an outer annular groove 12, and an outer monitoring pipe 13. The inner annular groove 10 is located on the inner sidewall of the dewatering well sealing assembly, directly below the inner water-stop ring 9 and connected to the inner monitoring pipe 11. The outer annular groove 12 is located on the outer sidewall of the main body 7, directly below the outer water-stop ring 8 and connected to the outer monitoring pipe 13. The inner annular groove 10 slopes inward to facilitate the flow of groundwater into the inner monitoring pipe 11, and the outer annular groove 12 slopes outward to facilitate the flow of groundwater into the outer monitoring pipe 13. Both the inner monitoring pipe 11 and the outer monitoring pipe 13 are PVC pipes and extend from the inner annular groove 10 and the outer annular groove 12 to a ground-observable position. A liquid level sensor 22 is installed at the ground-observable position of both the inner monitoring pipe 11 and the outer monitoring pipe 13, and the liquid level sensor 22 is electrically connected to an alarm. The sand-free well pipe 1 is filled with graded sand and gravel 3. A concrete pad 5 is filled on the outside of the sand-free well pipe 1 and above the foundation trench 4. The main body 7 is fixedly connected to the sand-free well pipe 1 through the concrete pad 5. The upper surface of the concrete pad 5 is flush with the top of the sand-free well pipe 1. A waterproof layer 6 is provided on the upper surface of the concrete pad 5, extending upwards to the root of the outer water-stop ring 8 of the dewatering well sealing device. Foundation reinforced concrete 20 is filled above the concrete pad 5. Micro-expansion reinforced concrete 21 is filled on the outside of the flange assembly, connecting with the foundation reinforced concrete 20. From bottom to top, micro-expansion concrete 18, leak-stopping waterproof material 19, and micro-expansion concrete 18 are sequentially filled above the graded sand and gravel 3. The dewatering pipe 2 passes through the leak-stopping waterproof material 19 and extends into the upper layer of micro-expansion concrete 18. The flange assembly includes a rubber gasket 14, a flange cover plate 15, a flange ring 16, and fastening bolts 17. The flange ring 16 is fixed to the top of the main body 7. The flange cover plate 15 is connected to the flange ring 16 through the fastening bolts 17. The rubber gasket 14 is disposed between the flange cover plate 15 and the flange ring 16.

[0024] The specific implementation method is as follows: First, according to the drawings and actual site conditions, the dewatering wells in the foundation pit are measured and positioned. Gray lines are sprinkled on the base layer to clarify the installation axis and elevation of the sand-free well pipe 1, the foundation trench 4, and the main body 7, ensuring that the design elevation of the outer water-stop ring 8 and the inner water-stop ring 9 meets the waterproofing requirements. Holes are drilled according to the positioning dimensions, and the sand-free well pipe 1 is lowered, ensuring its verticality. Graded sand and gravel 3 are filled on the outside of the sand-free well pipe 1 to the design elevation. After washing the well, the dewatering pipe 2 is lowered, and the water pump is started to continuously dewater to below the bottom of the foundation trench 4. Before leaving the factory, the outer water-stop ring 8 is welded to the outer wall and the inner water-stop ring 9 is welded to the inner wall. An inner annular groove 10 is opened below the inner water-stop ring 9, and an outer annular groove 12 is opened below the outer water-stop ring 8. Debris in the foundation trench 4 is cleaned, and the trench is inspected and approved. Then, the prefabricated main body 7 is inserted into the outer layer of the sand-free well pipe 1, ensuring that the main body 7 is vertical and that the outer water-stop ring 8 and the inner water-stop ring 9 are located at the preset positions of the concrete pad 5 and the foundation reinforced concrete 20, respectively. Before pouring the concrete pad 5, polyethylene foam strips matching the groove size are embedded into the inner annular groove 10 and the outer annular groove 12. The surface of the foam strips is coated with a release agent and temporarily fixed along the groove opening with high-temperature resistant tape to prevent them from falling off during pouring. An annular plastic baffle is fitted on the outside of the outer annular groove 12 and fixed to the outer wall of the main body 7 with tape to form a temporary barrier against concrete intrusion. The concrete pad 5 is poured so that it covers the lower part of the sand-free well pipe 1 and the lower part of the main body 7, ensuring that the main body 7 and the sand-free well pipe 1 are tightly fixed by the pad, and the top surface of the pad is flush with the bottom surface of the main body 7. The top of the sand-free well pipe 1 is flush with the concrete pad 5; a waterproof layer 6 is constructed on the concrete pad 5, extending up to the root of the outer water-stop ring 8 and sealed and bonded; the annular plastic baffle is removed; the inner monitoring pipe 11 and the outer monitoring pipe 13 are welded to the inner annular groove 10 and the outer annular groove 12, respectively; the monitoring pipes first extend laterally along the side wall of the main body 7, covering the area of ​​the water-stop ring, and then extend longitudinally to the ground through the pre-embedded sleeve in the foundation reinforced concrete 20; the foundation reinforced concrete 20 is poured, surrounding the main body 7 and connecting with the concrete pad 5; the outer water-stop ring 8 is embedded in the foundation reinforced concrete 20 to form a rigid seal; when the water level stabilizes below the designed stop water level, the original dewatering equipment is removed, and a self-priming pump is installed to continue dewatering and maintain a dry environment in the well; graded filler is poured into the sand-free well pipe 1. Sand and gravel 3, fill to the level of the bottom of concrete cushion 5. During filling, keep the self-priming pump continuously dewatering. After dewatering stops, pour micro-expansion concrete 18, construction leak-stopping waterproof material 19, and pour micro-expansion concrete 18 again from bottom to top. The top surface of the uppermost micro-expansion concrete is lower than the top of the main body 7. After the concrete cushion 5 and the foundation reinforced concrete 20 have initially set, remove the polyethylene foam strips in the inner annular groove 10 and the outer annular groove 12 (they can be completely peeled off because of the release agent). Inject clean water into the annular groove to verify whether the water flows smoothly into the monitoring pipe. Seal the ends of the dewatering pipe 2 to ensure a seal. Place a rubber gasket 14 on the flange ring 16 at the top of the main body 7, cover the flange cover plate 15, and tighten the fastening bolts 17 evenly to form a seal.Liquid level sensors 22 are installed below the outlets of the inner monitoring pipe (11) and the outer monitoring pipe (13) on the ground. The power and signal lines of the sensors are connected to the alarm through conduits, and the line interfaces are waterproofed. The water level threshold for the liquid level sensor 22 to transmit the seepage signal to the alarm is set to simulate a seepage scenario. The water flow in the monitoring pipe is observed to see if it triggers the liquid level sensor 22. After confirming that there is no seepage around the main body, micro-expansion reinforced concrete 21 is poured on the outside of the flange assembly to connect it with the foundation reinforced concrete 20. The micro-expansion reinforced concrete 21 is cured according to the specifications.

[0025] Working principle: The outer and inner sides of the main body 7 are respectively equipped with an outer water-stop ring 8 and an inner water-stop ring 9. The outer water-stop ring 8 is tightly integrated with the foundation reinforced concrete 20, blocking the leakage path of external groundwater along the outer wall of the main body 7; the inner water-stop ring 9 forms a barrier on the inner side of the main body 7 to prevent seepage water in the well from spreading upward. The flange assembly at the top of the main body 7 forms a flexible seal through rubber gaskets 14 and fastening bolts 17, which can adapt to slight structural deformation and avoid cracks that may occur in rigid connections. At the same time, the graded sand and gravel 3 and multi-layer micro-expansion concrete 18 filled in the sandless well pipe 1 fill the gaps through their expansion properties, and the sealing is further strengthened by the surface waterproofing material 19, ensuring that the fine pores are effectively sealed. During drainage, the drainage pipe 2 continuously drains the groundwater in the sandless well pipe 1, maintaining a dry construction environment in the foundation trench 4, while the concrete cushion layer 5 provides stable support for the main body 7 and the sandless well pipe 1. After drainage is stopped, graded sand and gravel 3 is first filled into the sandless well pipe 1 as support, and then a sealed structure is formed by pouring multiple layers of micro-expansion concrete 18. The waterproof layer 6 on the upper surface of the concrete pad 5 is turned up to the root of the outer water-stop ring 8 to enhance waterproofing. Finally, the top of the main body 7 is sealed with flange cover plate 15, flange ring 16 and fastening bolts 17 to complete the conversion from active drainage to permanent sealing.

[0026] To achieve real-time leakage monitoring, an inner annular groove 10 and an outer annular groove 12 are respectively provided on the inner and outer sides of the main body 7. The annular grooves are located directly below the corresponding water-stop rings, with the inner annular groove 10 below the inner water-stop ring 9 and the outer annular groove 12 below the outer water-stop ring 8. When leakage occurs, whether it is seepage from the inner side of the gap between the sand-free manhole pipe 1 and the main body 7, or seepage from the outer side between the main body 7 and the foundation reinforced concrete 20, it will be intercepted by the corresponding annular grooves. The inner annular groove 10 guides the leakage water to the connected inner monitoring pipe 11, and the outer annular groove 12 guides the leakage water to the outer monitoring pipe 13. With the assistance of the natural pressure of the groundwater level and the slope of the pipes, the water flows smoothly along the inner monitoring pipe 11 and the outer monitoring pipe 13 to the inspection well on the ground. The liquid level sensor 22 in the ground inspection well monitors the water flow at all times. Once the water level reaches the warning condition, it will trigger the alarm to send a signal, realizing leakage warning.

[0027] The micro-expansion reinforced concrete 21 poured on the outside of the flange assembly connects with the foundation reinforced concrete 20, further reinforcing the closed structure. Even in the event of abnormal situations such as sudden rise in water level due to heavy rain or slight settlement of the foundation, the flexible sealing design of the device, including the outer water-stop ring 8, inner water-stop ring 9, and rubber gasket 14, can adapt to changes and ensure overall sealing. Meanwhile, the logic interlocking mechanism of the dual liquid level sensors 22 corresponding to the inner monitoring pipe 11 and the outer monitoring pipe 13 reduces false alarms caused by environmental interference and ensures the reliability of monitoring.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A rapid closure device for a dewatering well in a foundation pit, comprising a sandless well pipe (1), a dewatering pipe (2), a foundation trench (4), a dewatering well closure assembly and a monitoring assembly, characterized in that: The sand-free well pipe (1) is installed in the foundation trench (4), and the dewatering pipe (2) is installed vertically in the sand-free well pipe (1); The dewatering well sealing assembly includes a main body (7), an outer water-stop ring (8) and an inner water-stop ring (9). The outer water-stop ring (8) is arranged around the outer side wall of the main body (7), and the inner water-stop ring (9) is arranged around the inner side wall of the main body (7). The main body (7) is fitted on the outer layer of the sand-free well pipe (1). A flange assembly for sealing is provided at the upper end of the main body (7). The monitoring component includes an inner annular groove (10), an inner monitoring pipe (11), an outer annular groove (12), and an outer monitoring pipe (13). The inner annular groove (10) is located on the inner side wall of the dewatering well sealing component. The inner annular groove (10) is located directly below the inner water-stop ring (9) and is connected to the inner monitoring pipe (11). The outer annular groove (12) is located on the outer side wall of the main body (7). The outer annular groove (12) is located directly below the outer water-stop ring (8) and is connected to the outer monitoring pipe (13).

2. The quick sealing device for a dewatering well in a foundation pit according to claim 1, characterized in that: The inner annular groove (10) is inclined inward to facilitate the flow of groundwater into the inner monitoring pipe (11), and the outer annular groove (12) is inclined outward to facilitate the flow of groundwater into the outer monitoring pipe (13).

3. The quick sealing device for a dewatering well in a foundation pit according to claim 2, characterized in that: Both the inner monitoring tube (11) and the outer monitoring tube (13) are PVC pipes, and extend from the inner annular groove (10) and the outer annular groove (12) to the ground observation position.

4. The quick sealing device for a dewatering well in a foundation pit according to claim 3, characterized in that: Both the inner monitoring tube (11) and the outer monitoring tube (13) are equipped with liquid level sensors (22) at observable locations on the ground, and the liquid level sensors (22) are electrically connected to the alarm.

5. The rapid sealing device for dewatering wells in foundation pits according to claim 1, characterized in that: The sand-free well pipe (1) is filled with graded sand and gravel (3), and the outside of the sand-free well pipe (1) and the top of the foundation trench (4) are filled with concrete cushion layer (5). The main body (7) and the sand-free well pipe (1) are fixedly connected by the pouring of the concrete cushion layer (5).

6. A rapid sealing device for dewatering wells in foundation pits according to claim 5, characterized in that: The upper surface of the concrete cushion layer (5) is flush with the top of the sand-free well pipe (1).

7. A rapid sealing device for dewatering wells in foundation pits according to claim 6, characterized in that: The concrete cushion layer (5) is provided with a waterproof layer (6) on its upper surface. The waterproof layer (6) is turned up to the root of the outer water-stop ring (8) of the dewatering well sealing device. The concrete cushion layer (5) is filled with foundation reinforced concrete (20).

8. The rapid sealing device for dewatering wells in foundation pits according to claim 7, characterized in that: The flange assembly is filled with micro-expansion reinforced concrete (21) on the outside, which is connected to the foundation reinforced concrete (20).

9. A rapid sealing device for dewatering wells in foundation pits according to claim 5, characterized in that: The graded sand and gravel (3) is filled with micro-expansion concrete (18), leak-stopping waterproof material (19) and micro-expansion concrete (18) from bottom to top. The rainwater pipe (2) passes through the leak-stopping waterproof material (19) and extends into the upper micro-expansion concrete (18).

10. A rapid sealing device for dewatering wells in foundation pits according to claim 1, characterized in that: The flange assembly includes a rubber gasket (14), a flange cover plate (15), a flange ring (16), and fastening bolts (17). The flange ring (16) is fixed to the top of the main body (7). The flange cover plate (15) is connected to the flange ring (16) by the fastening bolts (17). The rubber gasket (14) is disposed between the flange cover plate (15) and the flange ring (16).

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