Well shut-in structure and construction device and method for precipitation well

Abstract

The present application belongs to the technical field of sealing well of precipitation well, and discloses a sealing well method of precipitation well, which utilizes a sealing member to isolate the upper and lower well pipes, realizes feeding and filling in the lower well pipe of the sealing member, pressure cement slurry filling in the upper well pipe of the sealing member, and waterproof material is used to strengthen waterproof, and then fine stone concrete or grouting material is poured, and after the sealing plate is closed, a rigid water stop wing ring is arranged inside, and fine stone concrete is poured to form multiple waterproof measures; the sealing member is used to feed and fill the well pipe, which can weaken the effect of groundwater to the greatest extent, and avoids the problems of cement and fine material return caused by groundwater flushing in the prior art. The present application is suitable for sealing well of precipitation well under complex conditions of rich groundwater and high water pressure, and has the advantages of fast sealing well effect, small work load, short cycle, no influence on the surrounding environment, no influence on the safety of underground building structure, flexible and convenient operation, and saved construction period and cost.

Description

Technical Field

[0001] This invention belongs to the field of dewatering well sealing technology, specifically a dewatering well sealing structure, construction device and method. Background Technology

[0002] In the construction engineering field, underground space, as an extremely valuable natural resource, is receiving increasing attention for its large-scale development and utilization. Numerous underground facilities are being constructed, including urban underground utility tunnels, underground parking garages, underground shopping malls, civil defense projects, subways, and tunnels. Underground construction requires dewatering. After dewatering, the building structure will bear the pressure of groundwater. The sealing of dewatering wells is a crucial step in underground engineering construction, affecting underground waterproofing and the smooth progress of subsequent procedures. Improper sealing of dewatering wells can lead to groundwater intrusion or leakage, which is difficult to manage, causing delays and losses, and incurring substantial costs for waterproofing and sealing.

[0003] Currently, dewatering wells mainly consist of bridge-type steel pipes, sand-free pipes, and corrugated pipes. Bridge-type steel pipes have a bridge section within the permeable layer of the soil and rock mass; sand-free pipes are sand-free concrete well pipes containing only gravel and cement; corrugated pipes have perforated openings; all of these well pipes are sealed at the bottom with a sand-retaining section. The commonly used well-sealing methods are: after dewatering, backfilling with dry materials such as cement and gravel, or pouring concrete, sealing with a top cover and grouting, or using pure grouting for sealing. However, when groundwater is abundant, the groundwater level is high, the groundwater flow velocity is high, and the water pressure and inflow are large, backfilling with dry materials or concrete presents challenges such as difficulty in backfilling, easy washing away of cement and fine materials, and difficulty in sealing and waterproofing the well; simply grouting for sealing without backfilling results in a large amount of cement consumption. Summary of the Invention

[0004] This invention aims to address the problems of existing well sealing methods in situations with abundant groundwater, high groundwater levels, high groundwater flow velocity, high water pressure, and large inflow volumes. These problems include difficulties in backfilling with dry materials or concrete, and challenges in sealing and waterproofing the well. Furthermore, simply injecting cement grout for sealing without backfilling results in excessive cement consumption. Therefore, this invention provides a well sealing structure, construction device, and method for dewatering wells.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A method for sealing a dewatering well is provided, comprising the following steps:

[0007] S1. Excavate the foundation pit to the cushion layer, and transform the well pipes in the cushion layer and above into solid steel pipes. Waterproof the outside of the steel pipes, and then pour the bottom slab concrete.

[0008] S2. Before sealing the well, hoist and lower the sealing parts of the lower sealing plate to below the water level in the well pipe, and pump the water level in the well to a depth of not less than 0.5m below the concrete bottom slab.

[0009] S3. Weld a flange plate for installing the top sealing plate at a designated position inside the steel pipe;

[0010] S4. Lift the seal to below the flange plate, insert the steel conduit into the inlet of the seal and seal it, then connect the feeding hose to form a connector.

[0011] S5. Lower the connector to the bottom of the well casing and close the lower sealing plate;

[0012] S6. Feed the filler into the connecting body and lift the connecting body at a uniform speed according to the feeding speed. During the lifting process, the lower sealing plate is opened by the weight of the filler. After lifting the sealing element to a set distance from the flange plate, stop feeding.

[0013] S7. Continue to lift the connecting body so that the packing in the steel conduit is discharged through the opened lower sealing plate. After removing the steel conduit, close the lower sealing plate and loosen the seal.

[0014] S8. Install the grouting blind flange onto the flange plate and inject grout into the well under pressure through the grouting blind flange to seal it.

[0015] S9. Remove the grouting blind flange, perform waterproofing treatment in the cavity below the flange plate, and fill the grouting material to the upper opening of the flange plate, then install the sealing plate.

[0016] In a preferred embodiment, the method further includes step S10: cutting the steel pipe to a height not lower than the surface elevation of the concrete base slab, roughening and cleaning the concrete section of the well wall, welding at least one rigid waterproof wing ring at the designed position inside the well pipe, applying water-swellable sealing adhesive at the junction of the wing ring and the steel pipe, applying an interface agent to the inner wall of the well pipe and the roughened section, and pouring waterproof concrete to seal it.

[0017] Preferably, in step S10, the waterproof concrete is waterproof micro-expansion concrete, which can be poured and sealed separately or poured together with the concrete panel on the concrete base plate. The waterproof concrete has an impermeability grade of not less than P6.

[0018] In a preferred embodiment, in step S1, if the well casing is a bridge-type well casing, the bridge-type casing is cut off and a solid steel pipe is re-welded; if the well casing is a sand-free well casing or a corrugated pipe with perforated holes, the sand-free casing is chiseled off or the corrugated pipe is cut off and a solid steel pipe with welded reinforcing steel brackets is installed.

[0019] Preferably, in step S1, the waterproofing treatment is as follows: at least one rigid waterproof wing ring is welded at the designed position on the concrete base plate section outside the steel pipe; the contact point between the pad and the steel pipe is sealed and water-swellable sealant is applied; water-swellable sealant is applied at the weld point between the wing ring and the steel pipe; after the waterproof layer is applied on the pad, an interface agent is applied to the outer wall of the steel pipe.

[0020] In a preferred embodiment, in step S6, the filler is fine aggregate concrete material, and its feeding method is as follows:

[0021] Insert the grouting pipe from the feeding hose to the lower sealing plate, inject concentrated cement grout with a water-cement ratio of 0.45:1 to 0.55:1 until grout overflows from the feeding hose opening, then stop grouting and remove the grouting pipe.

[0022] The concrete pump pumps fine aggregate concrete into the feeding hose. The connection body is raised at a constant speed according to the feeding speed until the sealing part is a set distance from the flange plate, and then the feeding stops.

[0023] In another preferred embodiment, in step S6, the filler is sand and gravel or crushed concrete bricks, and the feeding method is as follows:

[0024] The filler is dropped into the well casing through a funnel set on a high-positioned feeding hose. The connector is lifted while filling. During the filling process, the filler is pushed down through the connector to fill the well casing using a rod. The filler can be delivered by air pressure using a jet pump or manually.

[0025] In a preferred embodiment, in step S8, pressure grouting is performed as follows:

[0026] After the grouting pipe with ball valve on the grouting blind flange is connected to the grouting pipe, the ball valve is closed after the cement grout is injected under pressure. The ball valve is opened the next day. If water gushes out of the well, grouting is carried out again. This cycle continues until the ball valve is opened the next day with no backflow or only a small amount of backflow.

[0027] Preferably, the cement slurry has a water-cement ratio of 0.6:1 to 1:1, and contains an early-strength high-performance water-reducing agent and a water glass additive. The water-reducing agent is added at a dosage of 2% to 4%, and the cement slurry is prepared by adding the water-reducing agent first, followed by the water glass additive. In specific implementation, a thick slurry is injected first, followed by a thin slurry.

[0028] In a preferred embodiment, in step S9, the filling material is waterproof micro-expansion fine stone concrete or grout.

[0029] A construction device for implementing the above-mentioned method for sealing dewatering wells is also provided, including a sealing element, a lifting device for lifting the sealing element, a lifting wire rope for connecting the sealing element and the lifting device, and a connecting pipe assembly connected to the sealing element and the feeding pipe of the feeding device; the sealing element includes a main body composed of an inner pipe, an outer pipe and an inner ring plate, a sealing assembly disposed on the outside of the outer pipe and a lower sealing plate disposed at the bottom of the main body for closing the inner pipe; one end of the lifting wire rope is fixedly connected to the inner ring plate.

[0030] Preferably, the sealing assembly includes an upper limit rubber plate and a lower limit rubber plate respectively disposed at the top and bottom of the outer tube, and an annular sealing plate disposed on the wall of the outer tube; the annular sealing plate is a ring-shaped body made of ultra-fine polyethylene fiber, and the upper outer wall of the annular sealing plate is wrapped with polyester fabric.

[0031] Preferably, one side of the lower sealing plate is connected to the inner tube wall via a hinge, and the hinge is provided with a waist-shaped groove, through which bolts are screwed to the inner tube.

[0032] Preferably, the lower sealing plate is provided with a first steel wire rope at the end away from the hinge, and a pulley is provided in the middle of the lower sealing plate. A second steel wire rope is provided on the pulley, and both the first and second steel wire ropes can be attached to the hanging ring inside the inner tube opening.

[0033] Preferably, both the lower sealing plate and the inner tube are provided with limiting steel bars, wherein the limiting steel bars on the inner tube are inclined towards the side closer to the lower sealing plate, and the bottom of the limiting steel bars on the lower sealing plate and the limiting steel bars on the inner tube are at the same elevation.

[0034] Preferably, the connecting pipe assembly includes a steel conduit that is sealed to the inner pipe socket, a feeding hose that is connected to the steel conduit and the feeding pipe at both ends respectively, and multiple tie rods that connect the steel conduit and the sealing element; the inner wall of the socket of the steel conduit is also provided with a hanging ring for attaching the first steel wire rope.

[0035] A dewatering well sealing structure constructed using the above-mentioned dewatering well sealing method is also provided.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] I. This invention utilizes a sealing element to isolate the well pipe from top to bottom, enabling material filling in the lower part of the well pipe and pressure injection of cement grout in the upper part of the well pipe. Waterproofing is reinforced with waterproof material, followed by the pouring of waterproof fine stone concrete or grout. After the upper sealing plate is closed, a rigid water-stop wing ring is installed inside. The pouring of fine stone concrete forms multiple waterproof measures, resulting in a good sealing and waterproofing effect.

[0038] Second, the sealing element designed in this invention can be opened to feed and fill material, or it can be closed to seal. As the sealing element rises, the material is fed and filled to the bottom well pipe, which minimizes the effect of groundwater and avoids the problem of groundwater washing away the filler and causing cement and fine materials to return, as is the case in the prior art.

[0039] Third, this invention is applicable to sealing dewatering wells under complex conditions of abundant groundwater and high water pressure. It achieves fast sealing, requires little work, has a short cycle, has no impact on the surrounding environment, and does not affect the safety of underground building structures. It solves the problem of dewatering wells under complex conditions of abundant groundwater and high water pressure, and is both flexible and convenient to operate, while saving construction time and costs. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0041] Figure 1 This is a diagram showing the state of the sealing element provided by this invention when it is lowered into the well.

[0042] Figure 2 yes Figure 1 Enlarged structural diagram of the provided seal;

[0043] Figure 3 This is a connection diagram of the sealing element and the connecting pipe assembly provided by the present invention;

[0044] Figure 4 This is a state diagram of pump feeding provided by the present invention;

[0045] Figure 5 This is a state diagram of pressure grouting provided by the present invention;

[0046] Figure 6 This is a schematic diagram of the structure of the dewatering well after sealing provided by the present invention.

[0047] The attached diagram lists the components represented by each number as follows:

[0048] 1-Sealing element, 1.1-Main body, 1.1.1-Inner pipe, 1.1.2-Outer pipe, 1.1.3-Inner ring plate, 1.2-Sealing assembly, 1.2.1-Upper limit rubber plate, 1.2.2-Lower limit rubber plate, 1.2.3-Annular sealing plate, 1.3-Lower sealing plate, 1.4-Hinge, 1.5-Limiting steel bar, 2-Lifting wire rope, 3-Connecting pipe assembly, 3.1-Steel guide pipe, 3.2-Feeding hose, 3.3-Tie rod, 4-First wire rope, 5-Second wire rope, 6-Flange plate, 7-Grouting blind flange, 8-Grouting pipe, 9-Upper sealing plate, 10-Bedding layer, 10.1-Waterproof layer, 20-Steel pipe, 20.1-Rigid waterproof wing ring, 30-Bottom slab concrete, 40-Waterproof concrete, 50-Cement slurry diffuser. Detailed Implementation

[0049] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0050] 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 a part of the embodiments of the present invention, and not all of them. 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.

[0051] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] Furthermore, the terms "first," "second," etc., used in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0053] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0054] This embodiment provides a sealing device for dewatering wells, used for sealing dewatering wells. It includes a sealing element 1, a lifting device (not shown in the figure) for lifting the sealing element, a lifting wire rope 2 for connecting the sealing element and the lifting device, and a connecting pipe assembly 3 that connects the sealing element and the feeding device (not shown in the figure) to the feeding pipe. The lifting device in this embodiment can be an electric hoist, forklift, or other auxiliary lifting device with a support frame.

[0055] Preferred options are listed below. Figure 2As shown, the sealing element 1 includes a main body 1.1 composed of an inner tube 1.1.1, an outer tube 1.1.2, and an inner ring plate 1.1.3; a sealing assembly 1.2 located outside the outer tube 1.1.2; and a lower sealing plate 1.3 located at the bottom of the main body 1.1 for closing the inner tube 1.1.1. Specifically, the sealing assembly 1.2 in this embodiment includes an upper limit rubber plate 1.2.1 and a lower limit rubber plate 1.2.2 located at the top and bottom of the outer tube 1.1.2, respectively, and an annular sealing plate 1.2.3 located on the wall of the outer tube 1.1.2. The sealing assembly achieves a seal between the main body and the well casing wall. Preferably, the annular sealing plate 1.2.3 is a ring-shaped body made of ultra-fine polyethylene fiber (commonly known as "air fiber"). The upper outer wall of the annular sealing plate is wrapped with polyester fabric (not shown in the figure).

[0056] Preferably, the connection between the lower sealing plate 1.3 and the main body 1.1 is as follows: one side of the lower sealing plate 1.3 is connected to the wall of the inner tube 1.1.1 via a hinge 1.4. The hinge 1.4 has a waist-shaped groove, and a bolt passes through the waist-shaped groove and is screwed into the inner tube, allowing the lower sealing plate to rotate relative to the inner tube while also having a certain vertical displacement. After the lower sealing plate rotates to engage with the inner tube, it can continue to move upward to close the inner tube. A sealing ring is provided on the outer side of the inner flange of the lower sealing plate to achieve a seal between the lower sealing plate and the inner tube.

[0057] Preferably, the switching structure for controlling the lower sealing plate 1.3 is as follows: a first steel wire rope 4 is provided at the end of the lower sealing plate 1.3 away from the hinge 1.4, and the lower sealing plate 1.3 can be closed by controlling the lower sealing plate 1.3 via the first steel wire rope 4; furthermore, a pulley is provided in the middle of the lower sealing plate 1.3, and a second steel wire rope 5 is provided on the pulley, and the lower sealing plate 1.3 can also be closed by controlling the lower sealing plate 1.3 via the second steel wire rope 5. Preferably, both the first steel wire rope 4 and the second steel wire rope 5 can be attached to the hanging ring inside the opening of the inner tube 1.1.1.

[0058] Preferably, the lifting method of the seal 1 is as follows: a lifting eye screw is set on the inner ring plate 1.1.3, one end of the lifting wire rope 2 is fixedly connected to the lifting eye screw on the inner ring plate 1.1.3, and the other end of the lifting wire rope 2 is connected to the lifting device.

[0059] Further details are attached. Figure 4 As shown, both the lower sealing plate 1.3 and the inner tube 1.1.1 are provided with limiting steel bars 1.5. The limiting steel bars 1.5 on the inner tube 1.1.1 are inclined towards the side closer to the lower sealing plate 1.3. This design can limit the opening angle of the lower sealing plate and prevent the lower sealing plate from being difficult to pull closed when opened vertically. The bottom of the limiting steel bar and the limiting steel bar on the lower sealing plate are at the same elevation. The limiting steel bar on the lower sealing plate can press the lower sealing plate tightly when it contacts the bottom of the well after it is closed. Together with the limiting steel bars on the inner tube, it can ensure that the sealing element is laid flat at the bottom of the well.

[0060] Preferred options are listed below. Figure 3 As shown, the connecting pipe assembly 3 includes a steel conduit 3.1 that is sealed to the inner pipe 1.1.1 with a socket, a feeding hose 3.2 whose two ends are respectively connected to the steel conduit 3.1 and the feeding pipe, and multiple tie rods 3.3 connecting the steel conduit 3.1 and the sealing element 1. Specifically, the steel conduit and the feeding hose are connected by a pipe clamp; a connecting flange is provided on the steel conduit, a connecting stud is provided on the inner ring plate of the sealing element, one end of the tie rod is screwed to the connecting stud, and the other end passes through the through hole of the connecting flange and is fixed by a nut; furthermore, the inner wall of the socket of the steel conduit 3.1 is also provided with a hanging ring for attaching the first steel wire rope 4.

[0061] A method for sealing a dewatering well is also provided, including the following steps:

[0062] S1. Excavate the foundation pit down to the foundation layer 10, and replace the well pipes in the area of ​​foundation layer 10 and above with solid steel pipes 20. Apply waterproofing treatment to the outside of the steel pipes 20, and then pour the bottom slab concrete 30 to form the structure shown in the attached figure. Figure 1 The well casing structure is shown. In specific implementation, when the well casing is a bridge-type casing, the bridge-type pipe is cut off and a solid steel pipe is re-welded; when the well casing is a sand-free casing, the sand-free pipe is chiseled off or the corrugated pipe is cut off and a solid steel pipe with welded reinforcing brackets is installed. The reinforcing brackets are inserted into the soil beside the sand-free pipe or corrugated pipe to stabilize the steel pipe. At least one rigid waterproof wing ring 20.1 is welded at the designed position on the concrete base slab section outside the steel pipe. The contact point between the padding layer 10 and the steel pipe 20 is sealed and water-swellable sealant is applied. Water-swellable sealant is also applied at the weld point between the wing ring 20.1 and the steel pipe 20. After the waterproof layer 10.1 is installed on the padding layer 10, an interface agent is applied to the outer wall of the steel pipe, and then the base slab concrete is poured. When the construction node meets the conditions for sealing the well and is ready to close the dewatering well casing, a flushing pipe is inserted into the bottom of the well to flush away the sediment. Then, the sediment is pumped away by a water pump, and the water pump and drainage pipe are removed.

[0063] S2. Before sealing the well, hoist and lower the sealing element 1 of the lower sealing plate 1.3 below the water level in the well pipe, and pump the water level in the well to a depth of not less than 0.5m below the concrete bottom slab. For specific implementation, see attached... Figure 1 As shown, the sealing element 1 of the lower sealing plate 1.3 is opened and pulled by the lifting steel wire rope 2. The sealing element 1 is lowered to below the water level (and the water level when the water pump is pumping water) using tools. Then, the water level is pumped to a depth of not less than 0.5m below the concrete base plate by the water pump, and then the water pump is lifted out.

[0064] S3. Weld the flange plate 6 for installing the upper sealing plate at a designated position inside the steel pipe 20. For specific implementation, see attached... Figure 1 As shown, the flange plate 6 is placed on the lifting wire rope 2, and then the flange plate 6 is moved to the set position inside the steel pipe 20 and welded firmly. After the weld has cooled naturally, the upper end of the lifting wire rope 2 is hung on the hook set at the bottom of the flange plate 6 for fixation.

[0065] S4. Raise the sealing element 1 to below the flange plate 6, insert the steel conduit 3.1 into the inlet of the sealing element 1 and seal it, then connect the feeding hose 3.2 to form a connecting body. For specific implementation, see attached... Figure 3 As shown, the steel wire rope 2 is used to lift the sealing element 1 to below the flange plate 6 at a uniform speed and balance. The first steel wire rope 4 is hung on the hanging ring inside the steel conduit 3.1. The second steel wire rope 5 is passed out from the steel conduit 3.1. The steel conduit 3.1 is inserted into the feed port (i.e., inner tube 1.1.1) of the sealing element 1. The socket of the steel conduit is inserted into the inner tube of the sealing element, which is fitted with a sealing ring or wrapped with water-stopping material, to achieve a seal. Multiple tie rods 3.3 are connected to the steel conduit 3.1 and the inner ring plate 1.1.3 for fixed connection, so that the steel conduit and the sealing element are tightly sealed and there is no water leakage at the connection between the two. Finally, the feeding hose is connected by a pipe clamp, so that the sealing element, the steel conduit and the feeding hose form a connected body.

[0066] S5. Lower the connector to the bottom of the well casing and close the lower sealing plate 1.3. For specific implementation, see attached... Figure 4 As shown, when the sealing element 1 of the lower sealing plate 1.3 is in the open state, it is lowered to the bottom of the well pipe by means of a tool. Then, the second steel wire rope 5 is pulled up to control the lower sealing plate 1.3 to close. Then, the sealing element 1 is lowered to the bottom of the well pipe and the lower sealing plate 1.3 is tightened by the limiting steel bar 1.5 at the bottom of the lower sealing plate 1.3 (at this time, the limiting steel bar at the bottom of the lower sealing plate and the limiting steel bar of the inner pipe are at the same elevation).

[0067] S6. Feed the filler into the connecting body and lift the connecting body at a uniform speed according to the feeding speed. During the lifting process, the lower sealing plate 1.3 is opened by the weight of the filler. After lifting the sealing element 1 to a set distance from the flange plate 6, stop feeding.

[0068] In practice, when the filler is fine aggregate concrete, the feeding method is as follows:

[0069] ① Insert the grouting pipe from the feeding hose to the lower sealing plate, and inject thick cement grout with a water-cement ratio of 0.45:1 to 0.55:1 until grout overflows from the feeding hose opening. Stop grouting and then remove the grouting pipe. Specifically, insert the grouting pipe into the feeding hose 3.2 and send it to the lower sealing plate 1.3 of the sealing element 1. Use a grouting machine to inject thick cement grout through the grouting pipe until thick cement grout overflows from the feeding hose opening. Stop grouting and then remove the grouting hose.

[0070] ② Connect the concrete pump to the feeding hose and pump fine aggregate concrete. Raise the connector at a uniform speed according to the feeding rate until the sealing element is at a set distance from the flange plate, then stop feeding. Specifically, after removing the grouting pipe, pull one end of the second steel wire rope 5 to remove it. Connect the feeding hose 3.2 to the conveying pump system, slightly raise the connector by a distance equal to the diameter of the lower sealing plate 1.3, and simultaneously start pumping. Under the action of pumping pressure and the gravity of the filling material inside the pipe, the lower sealing plate 1.3 at the bottom of the sealing element moves down and opens. Control the connector to rise synchronously and uniformly according to the feeding speed. Once the sealing element 1 is at a set distance from the flange plate 6, specifically until the sealing element is completely exposed above the filling material, stop pumping.

[0071] By first injecting concentrated cement slurry, water can be discharged from the steel conduit. At the same time, when the fine aggregate concrete is pumped, the concentrated cement slurry enters the well pipe below the seal and is located above the fine aggregate concrete. Under pressure, the concentrated cement slurry enters the annular sealing plate. The cement slurry forms a barrier at the polyester fabric of the annular sealing plate, thus achieving a sealing effect.

[0072] When the filler material is sand, gravel, or crushed concrete bricks, the feeding method is as follows:

[0073] The filler is dropped into the well casing through a funnel set on a high-positioned feeding hose. The connector is lifted while filling. During the filling process, the filler is pushed down through the connector to fill the well casing using a rod. The filler can be delivered by air pressure using a jet pump or manually.

[0074] S7. Continue to lift the connecting body so that the material in the steel conduit 3.1 is discharged from the opened lower sealing plate 1.3. After removing the steel conduit 3.1, close the lower sealing plate 1.3 and loosen the seal 1. In specific implementation, after stopping the pumping, quickly lift the connecting body by a distance not less than the diameter of the lower sealing plate so that the material in the steel conduit falls into the well. Remove the feeding hose 3.2 and the pull rod 3.3 in sequence, move the steel conduit 3.1 upward so that the lower sealing plate 1.3 is closed under the action of the first steel wire rope 4. Then remove the first steel wire rope 4, remove the steel conduit 3.1, lower the seal 1 to the feeding surface using a tool, and loosen the lifting end of the lifting steel wire rope 2 so that the lifting steel wire falls into the well.

[0075] S8. Install the grouting blind flange 7 onto the flange plate 6, and inject grout into the well under pressure through the grouting blind flange 7 for sealing. For specific implementation, see attached... Figure 5As shown, the grouting blind flange 7 is installed on the flange plate 6. The flange plate 6 is equipped with at least two grouting pipes 8 with ball valves. After connecting one of the grouting pipes 8 to the grouting pipe, pressure grout is injected, and the ball valve is closed. The ball valve is opened the next day. If water gushes out of the well, grouting is repeated, and this cycle continues until the ball valve is opened the next day with no backflow or only a small amount of backflow. Preferably, the cement grout is a cement grout with a water-cement ratio of 0.6:1 to 1:1, and the cement grout contains an early-strength high-performance water-reducing agent and a water glass additive. The water-reducing agent is added at a dosage of 2% to 4%, and the cement grout is prepared by adding the water-reducing agent first, followed by the water glass additive. Preferably, the cement grout is first injected in a thicker consistency and then in a thinner consistency.

[0076] S9. Remove the grouting blind flange 7, perform waterproofing treatment in the cavity below the flange plate 6, and fill the cavity with grout up to the upper inner opening of the flange plate 6. Then install the sealing plate 9. Specifically, after removing the grouting blind flange, the cement grout has solidified and settled. Apply a thick slurry of waterproofing material such as "Jintang Waterproof" or sprinkle dry waterproofing powder at the leakage point in the cavity below the flange plate 6. Then, grout up to the upper inner opening of the flange plate 6 and install the sealing plate 9. Preferably, waterproof micro-expansion fine aggregate concrete or grouting material is used for grouting.

[0077] S10. Cut the steel pipe 20 to a height not lower than the surface elevation of the concrete base slab, roughen the concrete section of the well wall and clean it. Weld at least one rigid waterproof wing ring 20.1 at the designed position inside the well pipe, and apply water-swellable sealing adhesive at the joint between the wing ring 20.1 and the steel pipe 20. Apply an interface agent to the inner wall of the well pipe and pour waterproof concrete 40 to seal it. Preferably, the waterproof concrete 40 is waterproof micro-expansion concrete, which can be poured and sealed separately or poured together with the concrete panel on the concrete base slab. The waterproof concrete has a permeability resistance grade of not less than P6.

[0078] Using the above-mentioned method for sealing dewatering wells, the following results are formed: Figure 6 The diagram shows the sealing structure for the dewatering well. In the section below the subbase and beneath the solid steel pipe, pressure grouting is used to create a cement grout diffuser 50 outside the well pipe, further enhancing the waterproofing effect.

[0079] It is worth noting that when applying an interface agent to the outer and inner walls of the well casing, epoxy resin adhesive, polyurethane adhesive, or acrylic adhesive is used, factors such as the adhesive's strength, drying time, weather resistance, and chemical resistance should be considered, and the selection should be made according to the actual situation.

[0080] When dewatering a group of wells, the well pipes must be sealed from the low-lying areas to the higher areas. It is advisable to seal the wells during the dry season to avoid the difficulty of dewatering due to the large amount of water flowing into the wells and the difficulty of sealing the wells.

[0081] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for sealing a dewatering well, characterized in that: Includes the following steps: S1. Excavate the foundation pit to the cushion layer, and transform the well pipes in the cushion layer and above into solid steel pipes. Waterproof the outside of the steel pipes, and then pour the bottom slab concrete. S2. Before sealing the well, hoist and lower the sealing parts of the lower sealing plate to below the water level in the well pipe, and pump the water level in the well to a depth of not less than 0.5m below the concrete bottom slab. S3. Weld a flange plate for installing the top sealing plate at a designated position inside the steel pipe; S4. Lift the seal to below the flange plate, insert the steel conduit into the inlet of the seal and seal it, then connect the feeding hose to form a connector. S5. Lower the connector to the bottom of the well casing and close the lower sealing plate; S6. Feed the filler into the connecting body and lift the connecting body at a uniform speed according to the feeding speed. During the lifting process, the lower sealing plate is opened by the weight of the filler. After lifting the sealing element to a set distance from the flange plate, stop feeding. S7. Continue to lift the connecting body so that the packing in the steel conduit is discharged through the opened lower sealing plate. After removing the steel conduit, close the lower sealing plate and loosen the seal. S8. Install the grouting blind flange onto the flange plate, and inject cement grout into the well under pressure through the grouting blind flange to seal it; S9. Remove the grouting blind flange, perform waterproofing treatment in the cavity below the flange plate, and fill the grouting material to the upper opening of the flange plate, then install the sealing plate.

2. The method for sealing a dewatering well according to claim 1, characterized in that: It also includes step S10: cutting the steel pipe to a height no lower than the concrete base plate, roughening the concrete section of the well wall and cleaning it, welding at least one rigid waterproof wing ring at the designed position inside the well pipe, applying water-swellable sealing adhesive at the joint between the wing ring and the steel pipe, applying an interface agent to the inner wall of the well pipe and the roughened section, and pouring waterproof concrete to seal it.

3. The method for sealing dewatering wells according to claim 2, characterized in that: In step S10, the waterproof concrete is made of waterproof micro-expansion concrete, which is poured and sealed separately or poured together with the concrete panel on the concrete base plate. The waterproof concrete has a permeability grade of not less than P6.

4. The method for sealing a dewatering well according to claim 1, characterized in that: In step S1, if the well casing is a bridge-type well casing, the bridge-type casing is cut off and a solid steel pipe is re-welded; if the well casing is a sand-free well casing or a corrugated pipe with perforated holes, the sand-free casing is chiseled off or the corrugated pipe is cut off and a solid steel pipe with welded reinforcing steel brackets is installed.

5. The method for sealing a dewatering well according to claim 1, characterized in that: In step S6, the filler is fine aggregate concrete material, and its feeding method is as follows: Insert the grouting pipe from the feeding hose to the lower sealing plate, inject concentrated cement grout with a water-cement ratio of 0.45:1 to 0.55:1 until grout overflows from the feeding hose opening, then stop grouting and remove the grouting pipe. The concrete pump pumps fine aggregate concrete into the feeding hose. The connection body is raised at a constant speed according to the feeding speed until the sealing part is a set distance from the flange plate, and then the feeding stops.

6. The method for sealing a dewatering well according to claim 1, characterized in that: In step S6, the filler material is sand and gravel or crushed concrete bricks, and its feeding method is as follows: The filler is dropped into the well casing through a funnel set on a high-positioned feeding hose. The connector is lifted while filling. During the filling process, the filler is pushed down through the connector to fill the well casing using a rod. The filler is delivered by air pressure using a jet pump or manually.

7. The method for sealing a dewatering well according to claim 1, characterized in that: In step S8, the cement slurry is a cement slurry with a water-cement ratio of 0.6:1 to 1:1, and the cement slurry contains an early-strength high-performance water-reducing agent and a water glass additive, wherein the dosage of the water-reducing agent is 2% to 4%.

8. The method for sealing a dewatering well according to claim 1, characterized in that: In step S9, the filling material is waterproof micro-expansion fine stone concrete or grout.

9. A well sealing device for dewatering wells, characterized in that: The well sealing method for dewatering wells according to any one of claims 1 to 8 includes a sealing element, a lifting device for lifting the sealing element, a lifting wire rope for connecting the sealing element and the lifting device, and a connecting pipe assembly connected to the sealing element and the feeding device. The sealing element includes a main body consisting of an inner tube, an outer tube, and an inner ring plate, a sealing assembly located on the outside of the outer tube, and a lower sealing plate located at the bottom of the main body for closing the inner tube; One end of the lifting wire rope is fixedly connected to the inner ring plate.

10. The well sealing device for dewatering wells according to claim 9, characterized in that: The sealing assembly includes an upper limit rubber plate and a lower limit rubber plate respectively disposed at the top and bottom of the outer tube, and an annular sealing plate disposed on the wall of the outer tube; the annular sealing plate is an annular body made of ultra-fine polyethylene fiber, and the upper outer wall of the annular sealing plate is wrapped with polyester fabric.

11. The well sealing device for dewatering wells according to claim 9, characterized in that: One side of the lower sealing plate is connected to the inner tube wall via a hinge. The hinge has a waist-shaped groove, and the bolt is screwed to the inner tube through the waist-shaped groove.

12. The well sealing construction device for dewatering wells according to claim 11, characterized in that: The lower sealing plate is provided with a first steel wire rope at the end away from the hinge, and a pulley is provided in the middle of the lower sealing plate. A second steel wire rope is provided on the pulley. Both the first steel wire rope and the second steel wire rope can be attached to the hanging ring inside the inner tube opening.

13. The well sealing device for dewatering wells according to claim 9, characterized in that: Both the lower sealing plate and the inner tube are equipped with limiting steel bars. The limiting steel bars on the inner tube are inclined towards the side closer to the lower sealing plate, and the bottom of the limiting steel bars on the lower sealing plate and the limiting steel bars on the inner tube are at the same elevation.

14. The well sealing device for dewatering wells according to claim 12, characterized in that: The connecting pipe assembly includes a steel conduit that is sealed to the inner pipe socket, a feeding hose that is connected to the steel conduit and the feeding pipe at both ends respectively, and multiple tie rods that connect the steel conduit and the sealing element. The inner wall of the socket of the steel conduit is also provided with a hanging ring for attaching the first steel wire rope.

15. A sealing structure for a dewatering well, characterized in that: It was constructed using the well sealing method for dewatering wells as described in any one of claims 1 to 8.

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