Advanced water stopping dewatering well plugging system and construction method thereof

Abstract

The invention discloses an advanced water-stopping dewatering well plugging system which comprises a sand-free filter pipe shaft, a sand-free filter pipe shaft, a sand-free filter pipe shaft, a water-stopping device, a water-stopping device and a water-stopping device. The pisolite layer is filled on the outer side of the sand-free filter pipe shaft; the sand-free filter pipe shaft is filled with the sand; the steel pipe shaft is arranged at the upper part of the sand-free filter pipe shaft, and the inner diameter of the steel pipe shaft is consistent with that of the sand-free filter pipe shaft; the multiple steel plate water stop rings are arranged on the outer side of the steel pipe shaft; the underground waterproof layer is laid between the foundation cushion layer and the foundation raft; the well sealing steel plate is welded to the upper portion of the steel pipe shaft and used for completely sealing the steel pipe shaft, and a downcast pipe and a vent pipe are arranged in the middle of the well sealing steel plate in a penetrating mode. Before the plugging object is filled in the well, advanced water stopping can be achieved by welding the plugging steel plate and the steel pipe shaft, secondary water stopping is achieved by grouting in the well, double guarantees are provided for the plugging quality of the dewatering well, and the leakage risk of the dewatering well is reduced to a great extent.

Description

Technical Field

[0001] This invention relates to the field of dewatering well sealing technology, specifically to a dewatering well sealing system with advanced water-stopping capability and its construction method. Background Technology

[0002] With the acceleration of urbanization and the continuous increase in urban population density, traditional above-ground building models are no longer sufficient to meet the demand. Underground space development has become an important way to alleviate land resource pressure, leading to increasingly deeper underground engineering projects. Consequently, these projects are increasingly affected by groundwater, making dewatering before construction an essential measure to ensure normal construction. Well dewatering technology is simple in equipment, has a large drainage capacity, and provides good dewatering effects. It is particularly suitable for aquifers with strong water-rich potential and is currently widely used in dewatering projects. Traditional well sealing methods for dewatering mainly include dry material filling, micro-expansion concrete filling, and polyurethane foam methods.

[0003] Currently, there are various methods for sealing dewatering wells, but the quality of sealing remains difficult to guarantee. For example, the dry material filling method is not suitable for situations with high groundwater levels and large water volumes. The micro-expansion concrete filling method is complex to construct, costly, and has significant irreversibility issues. Furthermore, frequent underwater concrete pouring operations make it difficult to ensure the compactness of the concrete, resulting in poor seepage prevention. Another example is the polyurethane foam method, which is highly temperature sensitive, has high construction costs, poor durability, and is prone to cracking, leading to repeated leaks.

[0004] Therefore, how to achieve simple operation, avoid working with water, and minimize the risk of leakage in the sealing of dewatering wells is a problem that construction workers have been exploring and solving. Summary of the Invention

[0005] The purpose of this invention is to provide a pre-emptive water-stopping well sealing system and its construction method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a pre-sealing dewatering well sealing system, comprising: a sand-free filter pipe well casing, which is located below the foundation cushion layer as a dewatering well casing below the foundation cushion layer; a pebbles layer, which fills the outside of the sand-free filter pipe well casing; sand and gravel, which fills the inside of the sand-free filter pipe well casing, with the upper end face of the sand and gravel located below the top of the sand-free filter pipe well casing; a steel pipe well casing, which is located above the sand-free filter pipe well casing as a dewatering well casing above the foundation cushion layer, and the inner diameter of the steel pipe well casing is the same as the inner diameter of the sand-free filter pipe well casing; steel plate water-stop rings, which are arranged on the outside of the steel pipe well casing; an underground waterproof layer, which is laid between the foundation cushion layer and the foundation raft slab, and simultaneously turns upward to completely wrap the steel pipe well casing; and a sealing steel plate, which is welded to the upper part of the steel pipe well casing to completely seal the steel pipe well casing, with a dewatering pipe and a vent pipe passing through the middle of the sealing steel plate.

[0007] In a preferred embodiment, sand and gravel are filled to 400mm below the top of the sandless filter pipe well, and the bottom of the dewatering pipe is inserted into the sand and gravel to 200mm. This is used to first pump the groundwater in the drainage well to the bottom of the pipe, and then serve as a grouting pipe to fill the sandless filter pipe well and the steel pipe well with micro-expansion quick-setting cement grout.

[0008] In a preferred embodiment, the bottom of the vent pipe is suspended in the middle of the steel pipe well. During grouting, the vent pipe acts as an overflow pipe to determine whether the well is filled with micro-expansion quick-setting cement grout.

[0009] In a preferred embodiment, valves are provided at the top of both the rainwater pipe and the vent pipe.

[0010] In a preferred embodiment, the system includes a drainage pipe, a water pump, a grout delivery pipe, and a grouting pump. One end of the drainage pipe is connected to a valve, and the other end is connected to a water pump for draining groundwater. The water pump is used to pump out groundwater. One end of the grout delivery pipe is connected to a valve, and the other end is connected to a grouting pump for delivering micro-expansion rapid-setting cement grout into the well. The grouting pump is used to inject micro-expansion rapid-setting cement grout into the well.

[0011] In a preferred embodiment, three steel plate waterstop rings are provided, and the three steel plate waterstop rings are welded evenly and at intervals on the outside of the steel pipe well shaft, with a spacing of 200mm between two adjacent steel plate waterstop rings.

[0012] In a preferred embodiment, the diameter of the sealing steel plate is the same as the outer diameter of the steel pipe well, both being 300mm.

[0013] In a preferred embodiment, both the rainwater pipe and the vent pipe are made of galvanized steel pipe with an outer diameter of 30mm, and both the drainage pipe and the slurry conveying pipe are made of PVC flexible hose with an outer diameter of 30mm.

[0014] This invention also discloses a construction method for the above-mentioned advanced water-stopping dewatering well sealing system, comprising the following steps: S1. Before the foundation raft slab construction, two round holes are made in the middle of the well sealing steel plate for the dewatering pipe and the vent pipe to pass through. Then the dewatering pipe and the vent pipe are welded tightly to the well sealing steel plate. S2. Install valves and connect drain pipes and water pumps to drain water normally; S3. Weld the sealing steel plate to the upper part of the steel pipe well, completely sealing the steel pipe well and playing the role of pre-stopping water. At this time, the valves connected to the dewatering pipe and the vent pipe are all in the open state. S4. Turn the underground waterproof layer up to completely wrap the steel pipe well, and seal the top of the waterproof layer wrapped around the outside of the steel pipe well with sealant. S5. Carry out the foundation raft slab construction and superstructure construction. During the process, the water pump will continue to run to carry out dewatering construction. S6. When the well sealing conditions are met, well sealing construction shall commence in accordance with design requirements. S7. Mix micro-expansion quick-setting cement slurry; S8. Quickly shut off the water pump, disconnect the drain pipe from the valve, and at the same time connect the grouting pump and grout delivery pipe to the valve; S9. Start grouting until cement slurry overflows from the valve at the overflow pipe end, and the well is filled with cement slurry; S10. Simultaneously close both valves completely; S11. Remove the grout delivery pipe.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention uses a sand-free filter pipe well as the dewatering well below the foundation cushion layer, and a steel pipe well above it as the dewatering well above the foundation cushion layer. A sealing steel plate is welded to the upper part of the steel pipe well, completely sealing the steel pipe well and providing pre-sealing. The dewatering pipe and vent pipe pass through the middle of the sealing steel plate. Before filling the well with sealing material, pre-sealing is achieved by welding the sealing steel plate to the steel pipe well, and secondary sealing is achieved by grouting inside the well, providing double protection for the sealing quality of the dewatering well and greatly reducing the risk of leakage. This invention is simple to operate, avoids working with water, significantly improves construction efficiency, and is easy to maintain and operate. It is particularly suitable for dewatering well sealing projects with high groundwater levels and high water pressure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the pre-stopping and dewatering stage dewatering well sealing system of the present invention; Figure 2 This is a schematic diagram of the dewatering well sealing system during the grouting and sealing stage of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1- Sand-free filter pipe well shaft; 2- Pebble layer; 3- Sand and gravel; 4- Steel pipe well shaft; 5- Steel plate water-stop ring; 6- Underground waterproof layer; 7- Foundation cushion layer; 8- Well sealing steel plate; 9- Dewatering pipe; 10- Groundwater; 11- Vent pipe; 12- Drainage pipe; 13- Valve; 14- Water pump; 15- Grouting pipe; 16- Grouting pump; 17- Micro-expansion quick-setting cement grout; 18- Foundation raft slab; 19- Sealant. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0019] Example 1: like Figures 1 to 2As shown, the preferred embodiment of the pre-sealing dewatering well sealing system of the present invention includes: a sand-free filter pipe well casing 1, a gravel layer 2, sand and gravel 3, a steel pipe well casing 4, steel plate water-stop rings 5, an underground waterproof layer 6, a well-sealing steel plate 8, a dewatering pipe 9, and a venting pipe 11. The sand-free filter pipe well casing 1 is located below the foundation cushion layer 7, serving as the dewatering well casing below the foundation cushion layer 7. The gravel layer 2 fills the outside of the sand-free filter pipe well casing 1, serving as a filter layer to ensure smooth groundwater flow while preventing the loss of fine particles from the soil. The sand and gravel 3 fills the interior of the sand-free filter pipe well casing 1, with the upper end face of the sand and gravel 3 located below the top of the sand-free filter pipe well casing 1. The steel pipe well casing 4 is located above the sand-free filter pipe well casing 1, serving as the dewatering well casing above the foundation cushion layer 7, and the inner diameter of the steel pipe well casing 4 is the same as the inner diameter of the sand-free filter pipe well casing 1. Multiple steel plate water-stop rings 5 ​​are located on the outside of the steel pipe well casing 4, increasing the seepage path and reducing the risk of leakage. The underground waterproof layer 6 is laid between the foundation pad 7 and the foundation raft slab 18, and simultaneously turns upwards to completely enclose the steel pipe well 4. The top of the waterproof layer 6, which is wrapped around the outside of the steel pipe well 4, is sealed with sealant 19. The well sealing steel plate 8 is welded to the upper part of the steel pipe well 4 to completely seal the steel pipe well 4. A dewatering pipe 9 and a vent pipe 11 are inserted through the middle of the well sealing steel plate 8. The dewatering pipe 9 and the vent pipe 11 pass through the well sealing steel plate 8 and are welded tightly to the well sealing steel plate 8 to prevent water leakage.

[0020] Furthermore, the sand and gravel 3 is filled to 400mm below the top of the sandless filter pipe well 1, and the bottom of the dewatering pipe 9 is inserted into the sand and gravel 3 to a depth of 200mm. This is used to first pump the groundwater 10 in the drainage well to the bottom of the pipe, and then, as a grouting pipe, to fill the sandless filter pipe well 1 and the steel pipe well 4 with micro-expansion quick-setting cement grout 17.

[0021] Furthermore, the bottom of the vent pipe 11 is suspended in the middle of the steel pipe well 4. When pumping out groundwater in the well, it serves as a vent pipe. During grouting, the vent pipe 11 serves as an overflow pipe to determine whether the micro-expansion quick-setting cement grout 17 in the well is full.

[0022] Furthermore, valves 13 are threaded to the top of both the downpipe 9 and the vent pipe 11 to prevent backflow.

[0023] Furthermore, the system includes a drainage pipe 12, a water pump 14, a grout delivery pipe 15, and a grouting pump 16. One end of the drainage pipe 12 is connected to a valve 13, and the other end is connected to the water pump 14 for draining groundwater 10. The water pump 14 is used to pump out groundwater 10. One end of the grout delivery pipe 15 is connected to the valve 13, and the other end is connected to the grouting pump 16 for delivering micro-expansion quick-setting cement grout 17 into the well. The grouting pump 16 is used to inject micro-expansion quick-setting cement grout 17 into the well.

[0024] Furthermore, the steel plate waterstop ring 5 is provided in three layers. The three steel plate waterstop rings 5 ​​are evenly spaced and welded to the outside of the steel pipe well. The distance between two adjacent steel plate waterstop rings 5 ​​is 200mm, and the thickness is 5mm.

[0025] Furthermore, the diameter of the sealing steel plate 8 is the same as the outer diameter of the steel pipe well barrel 4, both being 300mm.

[0026] Furthermore, the materials of the downwater pipe 9 and the vent pipe 11 are both galvanized steel pipes with an outer diameter of 30mm. The materials of the drainage pipe 12 and the grout conveying pipe 15 are both PVC flexible hoses with an outer diameter of 30mm. The valves are made of stainless steel and are matched with the downwater pipes, vent pipes, etc. The water pump is a vacuum pump, and the cement grout is micro-expansion quick-setting with a strength grade of C35 or higher.

[0027] Example 2: This invention also discloses a construction method for the above-mentioned advanced water-stopping dewatering well sealing system, comprising the following steps: S1. Before the foundation raft slab construction, two round holes are made in the middle of the well sealing steel plate for the dewatering pipe and the vent pipe to pass through. Then the dewatering pipe and the vent pipe are welded tightly to the well sealing steel plate. S2. Install valves and connect drain pipes and water pumps to drain water normally; S3. Weld the sealing steel plate to the upper part of the steel pipe well, completely sealing the steel pipe well and playing the role of pre-stopping water. At this time, the valves connected to the dewatering pipe and the vent pipe are all in the open state. S4. Turn the underground waterproof layer up to completely wrap the steel pipe well, and seal the top of the waterproof layer wrapped around the outside of the steel pipe well with sealant. S5. Carry out the foundation raft slab construction and superstructure construction. During the process, the water pump will continue to run to carry out dewatering construction. S6. When the well sealing conditions are met, well sealing construction shall commence in accordance with design requirements. S7. Mix micro-expansion quick-setting cement slurry; S8. Quickly shut off the water pump, disconnect the drain pipe from the valve, and at the same time connect the grouting pump and grout delivery pipe to the valve; S9. Start grouting until cement slurry overflows from the valve at the overflow pipe end, indicating that the well is full of cement slurry; S10. Simultaneously close both valves.

[0028] S11. Remove the grout delivery pipe and weld the ends of the two valves to prevent water leakage due to future malfunctions.

[0029] 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 pre-emptive water-stopping well sealing system, characterized in that: include: Sandless filter pipe well (1), the sandless filter pipe well (1) is set below the foundation cushion layer (7) to serve as a dewatering well below the foundation cushion layer (7); Pebble layer (2), which fills the outside of sandless filter tube wellbore (1); Sand and gravel (3) are filled inside the sandless filter pipe well cylinder (1), and the upper end face of the sand and gravel (3) is located below the top of the sandless filter pipe well cylinder (1); Steel pipe well (4) is set on the upper part of sand-free filter pipe well (1) as a dewatering well above the foundation cushion layer (7), and the inner diameter of the steel pipe well (4) is consistent with the inner diameter of the sand-free filter pipe well (1). Steel plate water-stop ring (5), multiple steel plate water-stop rings (5) are set on the outside of the steel pipe well shaft (4); The underground waterproof layer (6) is laid between the foundation pad layer (7) and the foundation raft slab (18), and at the same time, it is turned up to completely wrap the steel pipe well cylinder (4); Well sealing steel plate (8) is welded to the upper part of the steel pipe well (4) to completely seal the steel pipe well (4). A dewatering pipe (9) and a venting pipe (11) are inserted through the middle of the well sealing steel plate (8).

2. The pre-emptive water-stopping dewatering well sealing system according to claim 1, characterized in that: The sand and gravel (3) is filled to 400mm below the top of the sandless filter pipe well (1). The bottom of the dewatering pipe (9) is inserted into the sand and gravel (3) 200mm away. It is used to first pump the groundwater (10) in the drainage well to the bottom of the pipe, and then act as a grouting pipe to fill the sandless filter pipe well (1) and the steel pipe well (4) with micro-expansion quick-setting cement grout (17).

3. The pre-emptive water-stopping dewatering well sealing system according to claim 2, characterized in that: The bottom of the vent pipe (11) is suspended in the middle of the steel pipe well (4). During grouting, the vent pipe (11) serves as an overflow pipe to determine whether the micro-expansion quick-setting cement grout (17) in the well is full.

4. The pre-stopping dewatering well sealing system according to claim 3, characterized in that: Valves (13) are provided at the top of both the rainwater pipe (9) and the vent pipe (11).

5. The pre-stopping dewatering well sealing system according to claim 4, characterized in that: Also includes: The system includes a drainage pipe (12), a water pump (14), a grout delivery pipe (15), and a grouting pump (16). One end of the drainage pipe (12) is connected to a valve (13), and the other end is connected to the water pump (14) for draining groundwater (10). The water pump (14) is used to pump out groundwater (10). One end of the grout delivery pipe (15) is connected to a valve (13), and the other end is connected to the grouting pump (16) for delivering micro-expansion quick-setting cement grout (17) into the well. The grouting pump (16) is used to inject micro-expansion quick-setting cement grout (17) into the well.

6. The pre-emptive water-stopping dewatering well sealing system according to claim 1, characterized in that: The steel plate waterstop ring (5) is provided in three layers. The three steel plate waterstop rings (5) are evenly spaced and welded to the outside of the steel pipe well. The distance between two adjacent steel plate waterstop rings (5) is 200mm.

7. The pre-emptive water-stopping dewatering well sealing system according to claim 1, characterized in that: The diameter of the sealing steel plate (8) is the same as the outer diameter of the steel pipe well barrel (4), both being 300mm.

8. The pre-stopping dewatering well sealing system according to claim 5, characterized in that: The rainwater pipe (9) and the vent pipe (11) are both made of galvanized steel pipe with an outer diameter of 30mm. The drainage pipe (12) and the slurry conveying pipe (15) are both made of PVC flexible hose with an outer diameter of 30mm.

9. A construction method for a pre-stopping dewatering well sealing system as described in any one of claims 5-9, characterized in that, Includes the following steps: S1. Before the foundation raft slab construction, two round holes are made in the middle of the well sealing steel plate for the dewatering pipe and the vent pipe to pass through. Then the dewatering pipe and the vent pipe are welded tightly to the well sealing steel plate. S2. Install valves and connect drain pipes and water pumps to drain water normally; S3. Weld the sealing steel plate to the upper part of the steel pipe well, completely sealing the steel pipe well and playing the role of pre-stopping water. At this time, the valves connected to the dewatering pipe and the vent pipe are all in the open state. S4. Turn the underground waterproof layer up to completely wrap the steel pipe well, and seal the top of the waterproof layer wrapped around the outside of the steel pipe well with sealant. S5. Carry out the foundation raft slab construction and superstructure construction. During the process, the water pump will continue to run to carry out dewatering construction. S6. When the well sealing conditions are met, well sealing construction shall commence in accordance with design requirements. S7. Mix micro-expansion quick-setting cement slurry; S8. Quickly shut off the water pump, disconnect the drain pipe from the valve, and at the same time connect the grouting pump and grout delivery pipe to the valve; S9. Start grouting until cement slurry overflows from the valve at the overflow pipe end, and the well is filled with cement slurry; S10. Simultaneously close both valves completely; S11. Remove the grout delivery pipe.

Images