A dewatering well plugging construction method and a dewatering well plugging structure

Abstract

The application discloses a kind of precipitation well plugging construction methods, comprising: inserting precipitation pipe into precipitation well, filling sealing element between precipitation pipe and precipitation well;Steel casing bottom end is sleeved on the top of precipitation pipe, and steel casing and precipitation pipe are blocked with waterproof mortar, precipitation;Laying a layer of cushion on the outer periphery stratum of steel casing, laying concrete layer on the cushion, and reserving to be plugged groove on the outer steel casing of concrete layer;Precipitation pump is extracted, and sand and stone aggregate is filled into precipitation pipe;After checking no backwater, draining the accumulated water in steel casing, and filling into impermeable concrete again;Covering concave steel plate on the top of steel casing;If leakage backwater, carry out hole operation to precipitation pipe through valve body, and inject cement double liquid slurry into hole;Impermeable concrete is used to fill the to-be-plugged groove.This precipitation well plugging construction method and precipitation well plugging structure can effectively solve the problem of well plugging water gushing without quality hidden danger and easy operation.

Description

Technical Field

[0001] This invention relates to the field of dewatering well plugging technology, and in particular to a dewatering well plugging construction method and dewatering well plugging structure. Background Technology

[0002] In recent years, with the development of urban modernization, groundwater issues are frequently encountered in deep foundation construction, especially in riverside areas and areas rich in groundwater. When the groundwater level is high and the foundation is deep, the presence of standing water in the pit makes construction impossible, necessitating the use of wellpoint dewatering. According to design requirements, the groundwater level must be lowered to 1 meter below the excavation surface to prevent the foundation slab from floating. Dewatering wells need to continue pumping water after the completion of the underground structure construction but before the top slab backfilling and the sealing of the capping beam. This necessitates the retention of some dewatering wells, leading to the issue of well sealing. Traditional well sealing methods vary, such as full concrete pouring and clay ball sealing, but there are no unified standards or operating instructions. This can easily lead to confusion and unexpected situations during well sealing, frequently resulting in well sealing failure.

[0003] Therefore, for deep foundation pits with abundant groundwater, it is necessary to provide a dewatering well sealing structure that leaves no quality risks during the well sealing process, is easy to construct, and can effectively solve the problem of well water inrush. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a dewatering well sealing construction method and dewatering well sealing structure that does not leave any quality hidden dangers in the well sealing process, is easy to operate, and can effectively solve the problem of well water inrush.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for sealing dewatering wells includes the following steps:

[0007] S1. Insert the dewatering pipe into the dewatering well, so that the top of the dewatering pipe extends beyond the dewatering well by a predetermined length, and fill the gap between the dewatering pipe and the dewatering well with a sealing element to seal it.

[0008] S2. Place the bottom end of the steel casing over the top of the dewatering pipe and insert the bottom end of the steel casing into the stratum. Seal the joint between the steel casing and the dewatering pipe with waterproof mortar. Lower the dewatering pump through the steel casing into the dewatering pipe to carry out dewatering.

[0009] S3. Lay a cushion layer on the stratum around the steel casing, and lay a concrete layer on the cushion layer. Reserve a groove to be sealed outside the steel casing in the concrete layer so that the top surface of the steel casing is lower than the groove opening of the groove to be sealed, and weld the steel casing to the steel reinforcement in the concrete layer.

[0010] S4. After cleaning the loose soil on the steel casing wall, remove the dewatering pump and fill the prepared sand and gravel aggregate into the dewatering pipe. For every 3m of sand and gravel, pour in a bag of dry cement. When the filling reaches 1m from the bottom of the cushion layer, fill in a 100mm thick layer of quick-drying cement.

[0011] S5. After checking for backflow, use a self-priming pump to drain the water from the steel casing, and then fill it with impermeable concrete up to the top of the downpipe. After that, cover the top of the steel casing with a concave steel plate that is recessed in the middle and has a valve body on the bottom wall. The top of the concave steel plate is fixedly connected to the steel casing, and the bottom surface is against the top surface of the downpipe. During the installation of the concave steel plate, the valve body is in the open state.

[0012] S6. If leakage and backflow occur, use a diamond drill to open a hole in the downpipe through the space inside the valve body. After drilling, inject cement slurry into the hole until there is no leakage.

[0013] S7. Weld the steel sleeve to the concave steel plate to seal it. After confirming that the concave steel plate is tightly sealed and passes the acceptance test, roughen the construction joint thoroughly, apply cement-based penetrating crystalline waterproof material, clean the surface and side wall of the steel sleeve, close the valve body at the same time, and then fill the groove to be sealed with impermeable concrete.

[0014] As a further improvement to the above technical solution:

[0015] The steel casing has a wall thickness greater than or equal to 5 mm and a diameter 60 mm to 100 mm larger than the inner diameter of the dewatering well.

[0016] The steel sleeve is embedded 100mm into the bottom of the cushion layer, and its installation height is 150mm below the top surface of the concrete layer.

[0017] The groove to be sealed has dimensions of 800×800mm and a depth of 250mm.

[0018] The concrete layer contains reinforcing bars, and when the reinforcing bars are tied, the longitudinal reinforcing bars pass around the side of the steel sleeve.

[0019] In step S4, materials are added and compacted simultaneously. During the filling process, the bottom of the dewatering pipe is compacted using a lifting heavy object, and the top is tamped down using wooden sticks.

[0020] In S5, the top of the concave steel plate is fixedly connected to the steel sleeve by bolts, and a rubber sealing ring is provided between the top of the concave steel plate and the top surface of the steel sleeve.

[0021] When installing the concave steel panel, first connect the four bolts in a cross shape and tighten them symmetrically, then tighten the other bolts symmetrically and alternately.

[0022] In S6, the outer diameter of the drilling bit is 32mm, and the drilling depth penetrates the concrete backfill layer inside the dewatering pipe.

[0023] A dewatering well sealing structure includes a cushion layer, a concrete layer, a dewatering pipe, a dewatering well, a sealing element, a steel casing, a water-stop wing ring, and a concave steel plate. The dewatering pipe is inserted into the dewatering well and extends beyond the well by a predetermined length. The bottom end of the steel casing is fitted over the top of the dewatering pipe and inserted into the stratum. The cushion layer is laid on the stratum around the outer perimeter of the steel casing. The concrete layer is laid on the cushion layer and a pre-reserved sealing groove is provided outside the steel casing. The top surface of the steel casing is lower than the opening of the sealing groove. The middle part of the concave steel plate is recessed downward and a valve body is provided on the bottom wall. The top of the concave steel plate is fixedly connected to the steel casing, and the bottom surface abuts against the top surface of the dewatering pipe. A water-stop wing ring is provided on the outer wall of the steel casing.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] The dewatering well sealing construction method of this invention involves pre-embedding a steel casing before the concrete layer is constructed, leaving a sealing groove outside the steel casing. After the structure is completed and dewatering stops, the dewatering pump is immediately removed, and sand and gravel aggregate is backfilled. Impermeable concrete is then poured inside the dewatering pipe to prevent groundwater seepage. Subsequently, a concave steel plate with a downward-sloping center and a valve body on the bottom wall is added to the top of the steel casing. An opening is made through the valve body, and cement grout is injected into the opening until there is no leakage, effectively solving the problem of water inrush. Finally, impermeable concrete is used to fill the sealing groove to ensure water inrush prevention during well sealing. This dewatering well sealing construction method leaves no quality risks during the sealing process, is easy to operate, and effectively solves the problem of water inrush during well sealing.

[0026] The dewatering well sealing structure of this invention involves opening a valve body on a concave steel plate. The valve body transforms the groundwater pressure from blockage to drainage, ensuring a tight fit between the concave steel plate and the steel casing flange. A self-priming pump is used, connected to the valve body pre-installed on the concave steel plate, to pump water through the steel casing. If leakage is significant, a galvanized steel pipe can be used as a grouting conduit. A piston-type grouting pump injects cement (water glass) double-liquid grout into the sand and gravel aggregate in the dewatering pipe under a certain pressure. This reduces the risk of water and sand inrush during dewatering well sealing, improves the success rate and safety of well sealing, provides working conditions for subsequent station structure construction, and achieves good economic benefits. Compared with other methods, the sealing process is simple, easy to operate, fast, risk-free, low-cost, and highly effective. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the construction method for sealing dewatering wells according to the present invention.

[0028] Figure 2This is a schematic diagram of the well sealing structure of the present invention.

[0029] The labels in the diagram represent:

[0030] 1. Subbase; 2. Concrete layer; 3. Groove to be sealed; 4. Dewatering pipe; 5. Dewatering well; 6. Sealing element; 7. Steel sleeve; 8. Water-stop wing ring; 9. Concave steel plate; 10. Rubber sealing ring; 11. Bolt; 12. Impermeable concrete; 13. Valve body. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "assembly," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] Example 1:

[0036] Figure 1 This invention illustrates an embodiment of the dewatering well plugging construction method, which includes the following steps:

[0037] S1. Insert the downwater pipe 4 into the downwater well 5, so that the top of the downwater pipe 4 extends out of the downwater well 5 by a predetermined length, and fill the gap between the downwater pipe 4 and the downwater well 5 with a sealing element 6 to seal it.

[0038] S2. Place the bottom end of the steel casing 7 onto the top of the dewatering pipe 4, and insert the bottom end of the steel casing 7 into the stratum. Seal the joint between the steel casing 7 and the dewatering pipe 4 with waterproof mortar. Lower the dewatering pump through the steel casing 7 into the dewatering pipe 4 to carry out dewatering.

[0039] S3. Lay a cushion layer 1 on the stratum around the steel sleeve 7, and lay a concrete layer 2 on the cushion layer 1. Reserve a groove 3 to be sealed on the outside of the steel sleeve 7 in the concrete layer 2, so that the top surface of the steel sleeve 7 is lower than the groove opening of the groove 3 to be sealed, and weld the steel sleeve 7 to the steel reinforcement in the concrete layer 2.

[0040] S4. After cleaning the loose soil on the wall of the steel casing 7, remove the dewatering pump and fill the prepared sand and gravel aggregate into the dewatering pipe 4. For every 3m of sand and gravel filled, pour in a bag of dry cement. When the filling reaches 1m from the bottom of the cushion layer 1, fill in a 100mm thick layer of quick-drying cement.

[0041] S5. After checking that there is no backflow, use a self-priming pump to drain the water in the steel sleeve 7, and then fill it with impermeable concrete up to the top surface of the downpipe 4. After that, cover the top of the steel sleeve 7 with a concave steel plate 9 that is recessed in the middle and has a valve body 13 on the bottom wall, so that the top of the concave steel plate 9 is fixedly connected to the steel sleeve 7 and the bottom surface is against the top surface of the downpipe 4. During the installation of the concave steel plate 9, the valve body 13 is in the open state.

[0042] S6. If leakage occurs, use a diamond drill to drill a hole into the downpipe 4 through the space inside the valve body 13. After drilling, inject cement slurry into the hole until there is no leakage.

[0043] S7. Weld the steel sleeve 7 to the concave steel plate 9 to seal it. After confirming that the concave steel plate 9 is tightly sealed and passes the acceptance test, roughen the construction joint thoroughly, apply cement-based penetrating crystalline waterproof material, clean the surface and side wall of the steel sleeve 7, close the valve body 13 at the same time, and then fill the groove 3 to be sealed with impermeable concrete 12.

[0044] This dewatering well sealing method involves pre-embedding a steel casing 7 before constructing the concrete layer 2, leaving a sealing groove 3 outside the steel casing 7. After the structure is completed and dewatering in the dewatering well 5 stops, the dewatering pump is immediately removed, and sand and gravel aggregate is backfilled. Impermeable concrete is then poured inside the dewatering pipe 4 to prevent groundwater seepage. Subsequently, a concave steel plate 9 with a downward-sloping center and a valve body 13 on its bottom wall is added to the top of the steel casing 7. An opening is made through the valve body 13, and cement grout is injected into the opening until there is no leakage, effectively solving the water inrush problem. Finally, impermeable concrete 12 is used to fill the sealing groove 3 to ensure water inrush prevention during well sealing. This dewatering well sealing method eliminates quality risks during the sealing process, is easy to operate, and effectively solves the water inrush problem during well sealing. The valve body 13 is a ball valve.

[0045] In this embodiment, the wall thickness of the steel casing 7 is greater than or equal to 5mm, and its diameter is 60mm to 100mm larger than the inner diameter of the dewatering well 5.

[0046] In this embodiment, the steel sleeve 7 is embedded 100mm into the bottom of the pad layer 1, and the installation height is 150mm lower than the top surface of the concrete layer 2.

[0047] In this embodiment, the groove 3 to be sealed has dimensions of 800×800mm and a depth of 250mm.

[0048] In this embodiment, the concrete layer 2 is reinforced with steel bars. When the steel bars are tied, the longitudinal reinforcing bars pass around the side of the steel sleeve 7.

[0049] In this embodiment, during step S4, materials are added and compacted simultaneously. During the filling process, the bottom of the drainage pipe 4 is compacted using a lifting weight, and the top is tamped using a wooden stick.

[0050] In this embodiment, in S5, the top of the concave steel plate 9 is fixedly connected to the steel sleeve 7 by means of bolts 11, and a rubber sealing ring 10 is provided between the top of the concave steel plate 9 and the top surface of the steel sleeve 7.

[0051] The concave steel plate 9 with the ball valve is secured with bolt 11, and then sealed again by compaction grouting. After sealing the ball valve, it is left to stand for 24 hours. If no leakage is found, the groove 3 to be sealed is backfilled to ensure the quality of the dewatering well sealing. This dewatering well sealing construction method adopts the method of pre-embedding and then sealing, and sealing and then guiding water, so that there are no quality problems in the well sealing process and the construction is easy to operate, effectively solving the problem of water inrush during well sealing.

[0052] In this embodiment, when installing the concave steel panel 9, first connect the four bolts 11 in a cross shape and tighten them symmetrically, then tighten the other bolts 11 symmetrically and alternately.

[0053] In this embodiment, in step S6, the outer diameter of the drilling bit is 32mm, and the drilling depth penetrates the concrete backfill layer inside the dewatering pipe 4.

[0054] The ball valve flange steel casing plate is secured with bolt 11, and then sealed again by compaction grouting. After sealing the ball valve, it is left to stand for 24 hours. If no leakage is found, the bottom plate sealing groove is backfilled to ensure the quality of the dewatering well sealing. An innovative method of pre-embedding and then sealing, and sealing and then guiding water, is adopted, which eliminates quality problems in the well sealing process and is easy to operate, effectively solving the problem of water inrush during well sealing. After installing the concave steel casing plate 9, the valve body 13 is closed for an appropriate time to judge the leakage and backflow situation. If leakage and backflow are found, the groundwater is changed from blockage to drainage pressure by opening the valve body 13, which can ensure that the concave steel casing plate 9 and the steel sleeve 7 fit tightly.

[0055] In the above setup, after the anti-buoyancy requirements are met, when the last batch of anti-buoyancy dewatering wells are sealed off, the dewatering pump in the dewatering pipe 4 is immediately removed after the dewatering wells stop dewatering. Sand and gravel aggregate is then backfilled, and impermeable concrete is poured into the dewatering pipe 4 to prevent groundwater seepage from the dewatering wells 5. Simultaneously, bolts 11 are used to tighten the concave steel liner 9, and the valve body 13 on the concave steel liner 9 is opened. The valve body 13 changes the groundwater pressure from blockage to discharge, ensuring a tight fit between the concave steel liner 9 and the flange of the steel casing 7. A self-priming pump is then used to pump water through the valve body 13 pre-installed on the concave steel liner 9 through the steel casing 7. If leakage is significant, a galvanized steel pipe is used as a grouting conduit, and a piston-type grouting pump is used to inject cement (water glass) double-liquid grout into the sand and gravel aggregate in the dewatering pipe 4 under a certain pressure until there is no leakage.

[0056] Subbase 1, placed on the stratum; Concrete layer 2, placed on subbase 1; Groove 3 to be sealed, pre-reserved during the construction of concrete layer 2 and placed on concrete layer 2; Dewatering pipe 4, one end of dewatering pipe 4 is placed in the stratum below subbase 1, and the other end is placed in the groove to be sealed 3; Dewatering well 5, placed in the stratum below subbase 1; Sealing element 6, placed between dewatering well 5 and dewatering pipe 4, used to seal the gap between dewatering well 5 and dewatering pipe 4. The system includes: a steel sleeve 7, which is installed outside the dewatering pipe 4, with one end embedded in the bottom of the cushion layer 1 and the stratum, and the other end fitted with a flange; a water-stop wing ring 8, which is installed outside the steel sleeve 7; a concave steel liner 9, which is installed at the top of the steel sleeve 7 and the dewatering pipe 4; a rubber sealing ring 10, which is installed between the steel sleeve 7 and the concave steel liner 9; bolts 11, which are used to connect the steel sleeve 7 and the concave steel liner 9; and impermeable concrete 12, which is used to fill the groove 3 to be sealed. A valve body 13 is installed on the bottom wall of the concave steel liner 9.

[0057] The upper end face of the dewatering well 5 is attached to the lower end face of the cushion layer 1. The dewatering well 5 is cut before the cushion layer 1 is constructed and is attached to the bottom surface of the cushion layer 1.

[0058] The sealing element 6 is a sealant, which fills the annular gap between the dewatering well 5 and the dewatering pipe 4.

[0059] A valve body 13 is installed on the concave steel liner 9. If there is a large amount of water leakage, a galvanized steel pipe is used as a grouting conduit. A piston grouting pump is used to inject cement (water glass) double-liquid grout into the sand and gravel aggregate in the downwater pipe 4 under a certain pressure until there is no water leakage.

[0060] The rubber sealing ring 10 is preferably a water-swellable rubber sealing ring. The water-swellable rubber sealing ring will expand and deform by 2 to 3 times after encountering water, which can make the steel sleeve 7 more tightly sealed.

[0061] The outer edge of the water-stop ring 8 may be provided with a curved part with the bending direction of the curved part downward, thereby improving the water-blocking and sealing effect of the water-stop ring 8, while increasing its permeation path, and thus increasing its anti-permeation ability.

[0062] By fastening the concave steel liner plate 9 with bolts 11 and opening the valve body 13 on the concave steel liner plate 9, the groundwater pressure is changed from blockage to discharge through the valve body 13, ensuring a tight fit between the concave steel liner plate 9 and the flange of the steel casing 7. A self-priming pump is then used to pump water through the valve body 13 pre-installed on the concave steel liner plate 9 and through the steel casing 7. If the leakage is significant, a galvanized steel pipe can be used as a grouting conduit, and a piston-type grouting pump can be used to inject cement (water glass) double-liquid grout into the sand and gravel aggregate in the dewatering pipe 4 under a certain pressure. This reduces the risk of water and sand inrush during the sealing of the dewatering well 5, improves the success rate and safety of the sealing of the dewatering well 5, provides working conditions for the subsequent construction of the station structure, and achieves good economic benefits. Compared with other methods, the sealing process is simple, easy to operate, fast, risk-free, low-cost, and effective.

[0063] Example 2:

[0064] Figure 2This invention illustrates an embodiment of the dewatering well sealing structure. The dewatering well sealing structure of this embodiment includes a cushion layer 1, a concrete layer 2, a dewatering pipe 4, a dewatering well 5, a sealing element 6, a steel casing 7, a water-stopping ring 8, and a concave steel plate 9. The dewatering pipe 4 is inserted into the dewatering well 5 and extends a predetermined length beyond the well. The bottom end of the steel casing 7 is fitted over the top of the dewatering pipe 4 and inserted into the stratum. The cushion layer 1 is laid on the stratum surrounding the steel casing 7. The concrete layer 2 is laid on the cushion layer 1, and a pre-reserved sealing groove 3 is provided outside the steel casing 7. The top surface of the steel casing 7 is lower than the opening of the sealing groove 3. The middle part of the concave steel plate 9 is recessed downwards, and a valve body 13 is provided on the bottom wall. The top of the concave steel plate 9 is fixedly connected to the steel casing 7, and the bottom surface abuts against the top surface of the dewatering pipe 4. A water-stopping ring 8 is provided on the outer wall of the steel casing 7.

[0065] Opening the valve body 13 on the concave steel liner 9 changes the groundwater pressure from blockage to drainage, ensuring a tight fit between the concave steel liner 9 and the flange of the steel casing 7. A self-priming pump is then used to pump water through the valve body 13 pre-installed on the concave steel liner 9 and through the steel casing 7. If leakage is significant, a galvanized steel pipe can be used as a grouting conduit, and a piston-type grouting pump can inject cement (water glass) double-liquid grout into the sand and gravel aggregate in the dewatering pipe 4 under certain pressure. This reduces the risk of water and sand inrush during the sealing of the dewatering well 5, improves the success rate and safety of sealing the well, provides working conditions for subsequent construction of the station structure, and achieves good economic benefits. Compared with other methods, the sealing process is simple, easy to operate, fast, risk-free, low-cost, and effective.

[0066] Subbase 1 is provided on the ground layer;

[0067] Concrete layer 2 is provided on the foundation layer 1;

[0068] The groove 3 to be sealed is pre-reserved during the construction of concrete layer 2 and is set on concrete layer 2.

[0069] The rainwater pipe 4 has one end installed in the stratum, located at the lower end of the cushion layer 1, and the other end installed in the groove 3 to be sealed.

[0070] Dewatering well 5 is located within the stratum and below the cushion layer 1;

[0071] Seal 6 is provided between the dewatering well 5 and the dewatering pipe 4 to seal the gap between the dewatering well 5 and the dewatering pipe 4.

[0072] Steel sleeve 7 is installed outside the dewatering pipe 4, with one end buried in the bottom of the cushion layer 1 and the stratum, and the other end equipped with a flange.

[0073] Water-stop wing ring 8 is set on the outside of steel sleeve 7;

[0074] Concave steel liner 9 is installed at the top of the steel sleeve 7 and the downpipe 4;

[0075] Rubber sealing ring 10 is disposed between steel sleeve 7 and concave steel plate 9;

[0076] Bolt 11 is used to connect the steel sleeve 7 and the concave steel plate 9;

[0077] Impermeable concrete 12 is used to fill the groove 3 to be sealed.

[0078] Valve body 13 is mounted on the bottom wall of concave steel plate 9.

[0079] The upper end face of the dewatering well 5 is attached to the lower end face of the cushion layer 1. The dewatering well 5 is cut before the cushion layer 1 is constructed and is attached to the bottom surface of the cushion layer 1.

[0080] The sealing element 6 is a sealant, which fills the annular gap between the dewatering well 5 and the dewatering pipe 4.

[0081] A valve body 13 is installed on the concave steel liner 9. If there is a large amount of water leakage, a galvanized steel pipe is used as a grouting conduit. A piston grouting pump is used to inject cement (water glass) double-liquid grout into the sand and gravel aggregate in the downwater pipe 4 under a certain pressure until there is no water leakage.

[0082] The rubber sealing ring 10 is preferably a water-swellable rubber sealing ring. The water-swellable rubber sealing ring will expand and deform by 2 to 3 times after encountering water, which can make the steel sleeve 7 more tightly sealed.

[0083] The outer edge of the water-stop ring 8 may be provided with a curved part with the bending direction of the curved part downward, thereby improving the water-blocking and sealing effect of the water-stop ring 8, while increasing its permeation path, and thus increasing its anti-permeation ability.

[0084] By fastening the concave steel liner plate 9 with bolts 11 and opening the valve body 13 on the concave steel liner plate 9, the groundwater pressure is changed from blockage to discharge through the valve body 13, ensuring a tight fit between the concave steel liner plate 9 and the flange of the steel casing 7. A self-priming pump is then used to pump water through the valve body 13 pre-installed on the concave steel liner plate 9 and through the steel casing 7. If the leakage is significant, a galvanized steel pipe can be used as a grouting conduit, and a piston-type grouting pump can be used to inject cement (water glass) double-liquid grout into the sand and gravel aggregate in the dewatering pipe 4 under a certain pressure. This reduces the risk of water and sand inrush during the sealing of the dewatering well 5, improves the success rate and safety of the sealing of the dewatering well 5, provides working conditions for the subsequent construction of the station structure, and achieves good economic benefits. Compared with other methods, the sealing process is simple, easy to operate, fast, risk-free, low-cost, and effective.

[0085] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A method for sealing dewatering wells, characterized in that, Includes the following steps: S1. Insert the rainwater pipe (4) into the rainwater well (5) so that the top of the rainwater pipe (4) extends out of the rainwater well (5) by a predetermined length, and fill the gap between the rainwater pipe (4) and the rainwater well (5) with a sealing element (6) to seal it. S2. Place the bottom end of the steel casing (7) onto the top of the dewatering pipe (4) and insert the bottom end of the steel casing (7) into the stratum. Seal the joint between the steel casing (7) and the dewatering pipe (4) with waterproof mortar. Lower the dewatering pump through the steel casing (7) into the dewatering pipe (4) for dewatering. S3. Lay a cushion layer (1) on the stratum around the steel sleeve (7), and lay a concrete layer (2) on the cushion layer (1). Reserve a groove (3) to be sealed on the outside of the steel sleeve (7) in the concrete layer (2), so that the top surface of the steel sleeve (7) is lower than the groove opening of the groove (3) to be sealed, and weld the steel sleeve (7) to the steel reinforcement in the concrete layer (2). S4. After cleaning the loose soil on the wall of the steel casing (7), take out the dewatering pump and fill the prepared sand and gravel aggregate into the dewatering pipe (4). For every 3m of sand and gravel, pour in a bag of dry cement. When filling to 1m from the bottom of the cushion layer (1), fill with 100mm thick quick-drying cement. S5. After checking that there is no backflow, use a self-priming pump to drain the water in the steel sleeve (7) and then fill it with impermeable concrete up to the top surface of the downpipe (4). Then, cover the top of the steel sleeve (7) with a concave steel plate (9) that is recessed in the middle and has a valve body (13) on the bottom wall. The top of the concave steel plate (9) is fixedly connected to the steel sleeve (7) and the bottom surface is against the top surface of the downpipe (4). During the installation of the concave steel plate (9), the valve body (13) is in the open state. S6. If leakage occurs, use a diamond drill to open a hole in the downpipe (4) through the space inside the valve body (13). After drilling, inject cement slurry into the hole until there is no leakage. S7. Weld the steel sleeve (7) to the concave steel plate (9) and seal it. After confirming that the concave steel plate (9) is sealed tightly and passes the acceptance test, roughen the construction joint, apply cement-based penetrating crystalline waterproof material, clean the surface and side wall of the steel sleeve (7), close the valve body (13), and then fill the groove (3) to be sealed with impermeable concrete (12).

2. The method for sealing dewatering wells according to claim 1, characterized in that: The steel casing (7) has a wall thickness greater than or equal to 5 mm and a diameter 60 mm to 100 mm larger than the inner diameter of the dewatering well (5).

3. The method for sealing dewatering wells according to claim 1, characterized in that: The steel sleeve (7) is embedded 100mm into the bottom of the cushion layer (1), and its installation height is 150mm lower than the top surface of the concrete layer (2).

4. The method for sealing dewatering wells according to claim 1, characterized in that: The groove (3) to be sealed has a size of 800×800mm and a depth of 250mm.

5. The method for sealing dewatering wells according to claim 1, characterized in that: The concrete layer (2) contains reinforcing bars. When the reinforcing bars are tied, the longitudinal reinforcing bars pass around the side of the steel sleeve (7).

6. The method for sealing dewatering wells according to claim 1, characterized in that: In S4, materials are added and compacted at the same time. During the filling process, the bottom of the dewatering pipe (4) is compacted with a lifting weight and the top is compacted with a wooden stick.

7. The method for sealing dewatering wells according to claim 1, characterized in that, In S5, the top of the concave steel plate (9) is fixedly connected to the steel sleeve (7) by means of bolts (11) and rubber sealing ring (10) is provided between the top of the concave steel plate (9) and the top surface of the steel sleeve (7).

8. The method for sealing dewatering wells according to claim 7, characterized in that, When installing the concave steel panel (9), first connect the four bolts (11) in a cross shape and tighten them symmetrically, then tighten the other bolts (11) symmetrically and alternately.

9. The method for sealing dewatering wells according to claim 1, characterized in that: In S6, the outer diameter of the drilling bit is 32mm, and the drilling depth penetrates the concrete backfill layer inside the dewatering pipe (4).

10. A sealing structure for a dewatering well, characterized in that: The well sealing method described in any one of claims 1 to 9 is used to construct the well, which includes a cushion layer (1), a concrete layer (2), a dewatering pipe (4), a dewatering well (5), a sealing element (6), a steel casing (7), a water-stopping wing ring (8), and a concave steel plate (9). The dewatering pipe (4) is inserted into the dewatering well (5) and extends beyond the dewatering well (5) by a predetermined length. The bottom end of the steel casing (7) is fitted over the top of the dewatering pipe (4) and inserted into the stratum. The cushion layer (1) is laid on top of the steel casing. (7) On the outer stratum, the concrete layer (2) is laid on the cushion layer (1) and a groove (3) to be sealed is reserved outside the steel sleeve (7). The top surface of the steel sleeve (7) is lower than the groove opening of the groove (3) to be sealed. The middle part of the concave steel plate (9) is recessed downward and a valve body (13) is provided on the bottom wall. The top of the concave steel plate (9) is fixedly connected to the steel sleeve (7) and the bottom surface abuts against the top surface of the dewatering pipe (4). A water-stop wing ring (8) is provided on the outer wall of the steel sleeve (7).

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