Construction method of water-rich stratum precipitation well plugging structure

Abstract

The invention discloses a water-rich stratum dewatering well plugging structure and a construction method, and belongs to the technical field of dewatering well plugging. A water-rich stratum dewatering well plugging structure comprises a dewatering well pipe vertically arranged on the ground and a cushion layer laid on the ground, and a waterproof coiled material is arranged between the cushion layer and the ground in advance; the external expansion cavity is formed in the periphery of the top of the dewatering well casing, and a plug steel pipe with the diameter larger than that of the dewatering well casing is placed at the bottom in the external expansion cavity; the waterproof coiled material is additionally arranged at the joint of the plug steel pipe and the cushion layer to form an integral waterproof layer, the top plugging steel plate is connected with the plug steel pipe in a welded mode, the plugging assembly is arranged at the joint of the dewatering well pipe and the plug steel pipe, and weak points which may leak in well plugging construction are reinforced through the three measures, so that the construction efficiency is improved. The anti-seepage reliability of the water-rich stratum dewatering well after dewatering is stopped is improved, and the operation and maintenance cost in the subsequent building use stage is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of plugging of dewatering wells, and in particular to a plugging structure and a construction method for a dewatering well in a water-rich stratum. Background Art

[0002] With the rapid development of my country's economic construction, underground engineering is in a stage of rapid development in my country, and underground engineering has been further popularized. During the construction of underground engineering, groundwater needs to be dewatered to ensure the smooth and safe construction of the main structure; after the construction of the main structure is completed, the dewatering well needs to be sealed.

[0003] At present, the drainage wells in the basement of construction projects are usually backfilled with concrete and sand and gravel to the wellhead, and the waterproof casing plugs are embedded when pouring the bottom plate. After the drainage is completed, the steel plate and the plug flange are fixed with bolts, and a waterproof sealing rubber ring is placed in the middle. However, this method has a poor sealing effect when sealing the drainage wells in water-rich formations, and there is a risk of leakage.

[0004] Therefore, the present application proposes a precipitation well sealing structure and construction method, mainly to improve the reliability of precipitation well sealing in water-rich formations and reduce the quality risk of basement ground leakage after precipitation is stopped. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to propose a water-rich stratum dewatering well plugging structure and a construction method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A plugging structure for a water-rich formation dewatering well, comprising: A drainage well pipe vertically arranged on the ground and a cushion layer laid on the ground, with a waterproof roll material preset between the cushion layer and the ground; An outer expansion cavity is provided around the top of the well pipe of the precipitation well, and a plugging steel pipe having a diameter larger than that of the well pipe of the precipitation well is placed at the bottom of the outer expansion cavity; A sealing structure for sealing the well pipe and the plugging steel pipe of the precipitation well.

[0007] In some embodiments, the diameter of the plugging steel pipe is larger than the diameter of the drainage well pipe, two first water-stop rings are fixed on the surface of the plugging steel pipe, and a sealing steel plate is welded on the top of the plugging steel pipe.

[0008] In some embodiments, the blocking structure comprises: The sand and gravel backfill layer filled in the well pipe of the precipitation well; Concrete filled above the sand and gravel backfill layer and in the gap between the well pipe of the precipitation well and the plugging steel pipe; A plugging assembly arranged inside the plugging steel pipe is used to plug the connection between the well pipe of the precipitation well and the plugging steel pipe; The concrete is filled above the plugging assembly.

[0009] In some embodiments, the sealing assembly includes a mounting frame and a rotating shaft rotatably connected to the surface of the mounting frame, and the surface of the rotating shaft is provided with a first thread, a second thread and a third thread in sequence from top to bottom, and the spiral direction of the third thread is opposite to the spiral direction of the first thread and the second thread.

[0010] In some embodiments, the blocking component further comprises: A first pressing ring threadedly connected to the first threaded surface and a first air bag fixed between the first pressing ring and the upper surface of the mounting frame; A second pressure ring threadedly connected to the second threaded surface and a second air bag disposed inside a cavity, wherein the cavity is opened inside the mounting frame; A third pressing ring is threadedly connected to the third threaded surface and a third air bag is fixed between the third pressing ring and the lower surface of the mounting frame.

[0011] In some embodiments, a groove is provided on the lower surface of the mounting frame for mounting the mounting frame on the top of the precipitation well pipe, two positioning blocks are fixed inside the groove, and two positioning grooves matching with the positioning blocks are provided on the top of the precipitation well pipe.

[0012] The present invention also provides a construction method for a water-rich stratum dewatering well plugging structure, based on the above-mentioned water-rich stratum dewatering well plugging structure, comprising the following steps: S1. Open an external expansion cavity around the top of the precipitation well pipe, place a plugging steel pipe at the bottom of the external expansion cavity, and backfill the external expansion cavity with concrete; S2. Completely lay the preset waterproof membrane on the concrete surface in the outer expansion cavity and turn it up to below the first water stop ring located at a high place; S3, filling the well pipe of the precipitation well with a gravel backfill layer, and filling concrete on the gravel backfill layer, and at the same time filling the concrete into the gap between the well pipe of the precipitation well and the plugging steel pipe; S4, placing the plugging assembly inside the plugging steel pipe, placing it so that the groove corresponds to the well pipe of the precipitation well, and the positioning block is clamped in the positioning groove, and then operating the plugging assembly to respectively block multiple connection points of the connection position between the well pipe of the precipitation well and the plugging steel pipe; S5. Fill the plugging steel pipe with concrete to the top of the plugging steel pipe, finally weld the sealing steel plate to the top of the plugging steel pipe, and fill the depression with concrete until it is flush with the cushion layer.

[0013] In some embodiments, the filling depth of the sand and gravel backfill layer in S3 is 3 m below the ground, and the sand and gravel backfill layer adopts 1:1 sand and gravel backfill.

[0014] In some embodiments, the outer expansion diameter of the outer expansion cavity in S1 is greater than 50 cm, and the outer expansion depth is greater than 50 cm.

[0015] In some embodiments, the method for operating the sealing component in S4 to separately seal multiple connection points of the connection positions of the drainage well pipe and the plugging steel pipe is to drive the first thread to drive the first pressure ring to squeeze the first airbag, deform the first airbag, and fill the gap between the sealing component and the plugging steel pipe; the second thread drives the second pressure ring to squeeze and deform the second airbag, so that the second airbag is squeezed out from the opening to fill the gap between the drainage well pipe and the plugging steel pipe; the third thread drives the third pressure ring to squeeze and deform the third airbag, so that it fills the gap between the mounting frame and the drainage well pipe.

[0016] Compared with the prior art, the present invention provides a plugging structure and construction method for a water-rich formation dewatering well, which has the following beneficial effects.

[0017] 1. The present invention forms an overall waterproof layer by adding a waterproof coil at the junction of the plugging steel pipe and the cushion layer, connects the top plugging steel plate and the plugging steel pipe by welding, and arranges a plugging component at the junction of the precipitation well pipe and the plugging steel pipe. The above three measures strengthen the weak points where leakage may occur during the sealing construction, improve the anti-seepage reliability of the precipitation well in the water-rich formation after the precipitation is stopped, and reduce the operation and maintenance costs in the subsequent building use stage.

[0018] 2. The present invention uses multiple air bags to respectively seal multiple connection points of the connection positions of the precipitation well pipe and the plugging steel pipe, and uses the waterproof property of the rubber air bags to reduce the risk of water seepage, thereby avoiding the incomplete filling of the gap between the connection positions of the precipitation well pipe and the plugging steel pipe by concrete, resulting in gaps and causing water seepage.

[0019] Other advantages, objectives and features of the present invention will be described in part in the following description; and in part, will be apparent to those skilled in the art based on an examination of the following; or, may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the explosion structure of the present invention.

[0022] Figure 3 For the present invention Figure 1 Schematic diagram of the structure enlarged at point A in the middle.

[0023] Figure 4 It is a schematic diagram of the cross-sectional structure of the plugging component in the present invention.

[0024] Figure 5 It is a schematic diagram of the explosion structure of the plugging component in the present invention.

[0025] Figure 6 It is a schematic diagram of the structure of the well pipe of the precipitation well in the present invention.

[0026] In the figure: 1. Well pipe of precipitation well; 2. Cushion layer; 3. Plug steel pipe; 301. First water stop ring; 302. Sealing steel plate; 4. Outward expansion cavity; 5. Waterproof membrane; 6. Sand and gravel backfill layer; 7. Concrete; 8. Second water stop ring; 9. Sealing assembly; 901. Mounting frame; 902. Rotating shaft; 903. First pressure ring; 9031. First air bag; 9032. First limiting rod; 9033. First thread; 904. Second pressure ring; 9041. Cavity; 9042. Second thread; 9043. Second air bag; 9044. Opening; 905. Third pressure ring; 9051. Third thread; 9052. Third air bag; 9053. Second limiting rod; 10. Rubber ring; 11. Positioning groove; 12. Positioning block. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Reference Figure 1-6 A water-rich formation precipitation well plugging structure comprises a precipitation well pipe 1 vertically arranged on the ground and a cushion layer 2 laid on the upper surface of the ground, the height of the cushion layer 2 is higher than the upper end of the precipitation well pipe 1, a depression for avoiding the precipitation well pipe 1 is arranged on the surface of the cushion layer 2, a waterproof coiled material 5 is preset between the cushion layer 2 and the ground, an outer expansion cavity 4 is opened around the top of the precipitation well pipe 1, the outer expansion diameter is greater than 50cm, the outer expansion depth is greater than 50cm, a plugging steel pipe 3 with a diameter greater than the diameter of the precipitation well pipe 1 is placed at the bottom of the outer expansion cavity 4, and the plugging steel pipe 3 and the precipitation well pipe 1 are connected. The well pipe 1 is concentrically arranged, so that a large gap is generated between the well pipe 1 and the plugging steel pipe 3, which is convenient for filling with concrete 7, and the height of the top of the plugging steel pipe 3 is lower than the height of the upper surface of the cushion layer 2. Two first water stop rings 301 are fixed on the surface of the plugging steel pipe 3, and the heights of the two first water stop rings 301 are respectively located in the middle of the depression and the middle of the outer expansion cavity 4. The outer expansion cavity 4 is backfilled with concrete 7, and the preset waterproof membrane 5 is completely laid on the surface of the concrete 7 in the outer expansion cavity 4, and turned up to below the first water stop ring 301 located at a high position; A gravel backfill layer 6 is filled in the precipitation well pipe 1, and the filling depth is 3m below the ground. The gravel backfill layer 6 is filled with 1:1 gravel backfill. Concrete 7 is filled above the gravel backfill layer 6, and the filling height is lower than the top of the precipitation well pipe 1. At the same time, the concrete 7 is filled into the gap between the precipitation well pipe 1 and the plugging steel pipe 3, and the filling height is also lower than the top of the precipitation well pipe 1. The gap between the precipitation well pipe 1 and the plugging steel pipe 3 is filled, and a plugging component 9 is placed inside the plugging steel pipe 3 to further block the connection between the precipitation well pipe 1 and the plugging steel pipe 3; Continue to fill the plugging steel pipe 3 with concrete 7 to the top of the plugging steel pipe 3, and finally weld the sealing steel plate 302 on the top of the plugging steel pipe 3, and fill the depression with concrete 7 until it is flush with the upper surface of the cushion layer 2, and steel bars are arranged in the cushion layer 2 and the concrete 7 in the depression, and the steel bars are welded to the plugging steel pipe 3 to make the plugging steel pipe 3 more stable, and a second water stop ring 8 is preset at the junction of the depression and the cushion layer 2, and the concrete 7 uses C35 micro-expansion, low-shrinkage, quick-setting concrete 7.

[0029] It can be understood that an overall waterproof layer is formed by adding a waterproof membrane 5 at the junction of the plugging steel pipe 3 and the cushion layer 2, the top sealing steel plate 302 is welded to the plugging steel pipe 3, and a sealing component 9 is arranged at the junction of the precipitation well pipe 1 and the plugging steel pipe 3. The above three measures strengthen the weak points where leakage may occur during the sealing construction, improve the anti-seepage reliability of the precipitation well in the water-rich formation after the precipitation is stopped, and reduce the operation and maintenance costs of the subsequent building use stage. The two first water stop rings 301 and the second water stop rings 8 further reduce the risk of leakage.

[0030] Specifically, the plugging assembly 9 includes a mounting frame 901, a groove for mounting the mounting frame 901 on the top of the precipitation well pipe 1 is provided on the lower surface of the mounting frame 901, two positioning blocks 12 are fixed inside the groove, and two positioning grooves 11 matching with the positioning blocks 12 are provided on the top of the precipitation well pipe 1; It can be understood that by setting the groove, the position of the mounting bracket 901 is positioned so that it is placed at the center of the plug steel pipe 3. By setting the positioning groove 11 and the positioning block 12, when the mounting bracket 901 is placed, the positioning block 12 is clamped in the positioning groove 11, thereby limiting the mounting bracket 901 and preventing the mounting bracket 901 from rotating at will.

[0031] Specifically, the plugging assembly 9 also includes a rotating shaft 902 rotatably connected to the surface of the mounting frame 901, and the surface of the rotating shaft 902 is provided with a first thread 9033, a second thread 9042 and a third thread 9051 from top to bottom, and the spiral direction of the third thread 9051 is opposite to the spiral direction of the first thread 9033 and the second thread 9042, and a hexagonal head is fixed on the upper end of the rotating shaft 902; The surface of the first thread 9033 is threadedly connected with a first pressure ring 903, and the first pressure ring 903 is arranged above the mounting frame 901. The first pressure ring 903 includes a sliding shaft and an upper pressure plate fixed at the upper end of the first sliding shaft. The diameter of the upper pressure plate is larger than the diameter of the first sliding shaft. A first limiting rod 9032 is fixed on the surface of the first sliding shaft. The first sliding shaft and the first limiting rod 9032 slide vertically on the top of the mounting frame 901, and the first sliding shaft is threadedly connected to the surface of the first thread 9033. A first airbag 9031 is fixed between the upper pressure plate and the upper surface of the mounting frame 901. The diameter of the upper pressure plate is the same as the diameter of the side of the mounting frame 901 and is smaller than the inner diameter of the plugging steel pipe 3, so that the first airbag 9031 can enter the gap between the upper pressure plate and the plugging steel pipe 3 for sealing.

[0032] A second pressure ring 904 is threadedly connected to the surface of the second thread 9042, and an annular cavity 9041 is opened inside the mounting frame 901 around the second thread 9042. The second pressure ring 904 includes an outer pressure plate and an inner moving block, which are concentrically arranged and fixedly connected by a plurality of connecting rods. The inner moving block is threadedly connected to the surface of the second thread 9042, and the outer pressure ring slides vertically inside the cavity 9041. A plurality of through grooves for moving the connecting rods are opened on the inner wall of the cavity 9041 close to the second thread 9042. A second airbag 9043 is arranged inside the cavity 9041, and the second airbag 9043 is located below the second pressure ring 904. An annular opening 9044 is opened at the bottom of the cavity 9041, and the annular opening 9044 is placed in the gap between the precipitation well pipe 1 and the plugging steel pipe 3; A third pressure ring 905 is threadedly connected to the surface of the third thread 9051, and the third pressure ring 905 is arranged below the mounting frame 901. The third pressure ring 905 includes a second sliding shaft threadedly connected to the surface of the third thread 9051 and a lower pressure plate fixed to the lower end of the second sliding shaft. A second limiting rod 9053 is fixed to the surface of the second sliding shaft. The second sliding shaft and the second limiting rod 9053 slide at the bottom of the mounting frame 901. A third airbag 9052 is fixed between the lower pressure plate and the lower surface of the mounting frame 901. The diameter of the lower pressure plate is the same as the diameter of the lower end of the mounting frame 901 and is smaller than the inner diameter of the precipitation well pipe 1. The lower pressure plate and the lower end of the mounting frame 901 are both placed inside the precipitation well pipe 1. It can be understood that by rotating the rotating shaft 902, the first thread 9033 drives the first pressure ring 903 to slide downward on the top of the mounting bracket 901, thereby squeezing the first airbag 9031, causing the first airbag 9031 to deform and fill the gap between the plugging component 9 and the plugging steel pipe 3. At the same time, the second thread 9042 drives the second pressure ring 904 to slide downward in the cavity 9041, squeezing and deforming the second airbag 9043, so that the second airbag 9043 is squeezed out from the opening 9044 to fill the gap between the precipitation well pipe 1 and the plugging steel pipe 3. The third thread 9051 drives the third pressure ring 905 to slide upward at the bottom of the mounting frame 901, thereby squeezing and deforming the third airbag 9052 to fill the gap between the mounting frame 901 and the precipitation well pipe 1. The multiple connection points of the connection position of the precipitation well pipe 1 and the plugging steel pipe 3 are respectively sealed by multiple airbags, and the waterproof property of the rubber airbag is used to reduce the risk of water seepage, so as to avoid the incomplete filling of the gap between the connection position of the precipitation well pipe 1 and the plugging steel pipe 3 by concrete 7, resulting in gaps and water seepage.

[0033] A plurality of rubber rings 10 are fixed to the lower surface of the upper pressing plate, the upper surface of the mounting frame 901 , the upper surface of the lower pressing plate and the lower surface of the mounting frame 901 , respectively.

[0034] It is understandable that by providing the rubber ring 10 , the first airbag 9031 and the third airbag 9052 generate curved surfaces when squeezed, and with the cooperation of the multiple rubber rings 10 , groundwater is further prevented from penetrating into the mounting frame 901 .

[0035] The present invention also provides a construction method for a water-rich stratum dewatering well plugging structure, based on the above-mentioned water-rich stratum dewatering well plugging structure, comprising the following steps: S1. Open an external expansion cavity 4 around the top of the precipitation well pipe 1. The external expansion diameter of the external expansion cavity 4 is greater than 50 cm, and the external expansion depth is greater than 50 cm. Place the plugging steel pipe 3 at the bottom of the external expansion cavity 4, and backfill the external expansion cavity 4 with concrete 7; S2, completely laying the preset waterproof membrane 5 on the surface of the concrete 7 in the outer expansion cavity 4, and turning it up to below the first water stop ring 301 located at a high place; S3, fill the well pipe 1 of the precipitation well with a gravel backfill layer 6, and fill the gravel backfill layer 6 with concrete 7, the filling depth of the gravel backfill layer 6 is 3m below the ground, the gravel backfill layer 6 is filled with 1:1 gravel backfill, and at the same time, fill the concrete 7 into the gap between the well pipe 1 of the precipitation well and the plugging steel pipe 3; S4. Put the plugging component 9 into the plugging steel pipe 3. When placing it, make the groove correspond to the drainage well pipe 1, and make the positioning block 12 clamped in the positioning groove 11. Then operate the plugging component 9 to respectively block multiple connection points of the connection position between the drainage well pipe 1 and the plugging steel pipe 3. The blocking method is to make the first thread 9033 drive the first pressure ring 903 to squeeze the first air bag 9031, so that the first air bag 9031 is deformed to fill the gap between the plugging component 9 and the plugging steel pipe 3. The second thread 9042 drives the second pressure ring 904 to squeeze and deform the second air bag 9043, so that the second air bag 9043 is squeezed out from the opening 9044 to fill the gap between the drainage well pipe 1 and the plugging steel pipe 3. The third thread 9051 drives the third pressure ring 905 to squeeze and deform the third air bag 9052, so that it fills the gap between the mounting frame 901 and the drainage well pipe 1. S5. Fill the plugging steel pipe 3 with concrete 7 to the top of the plugging steel pipe 3. Finally, weld the sealing steel plate 302 to the top of the plugging steel pipe 3, and fill the depression with concrete 7 to be flush with the cushion layer 2.

[0036] In the present invention, an outer expansion cavity 4 is opened around the top of the precipitation well pipe 1, and a plugging steel pipe 3 is placed at the bottom of the outer expansion cavity 4, and concrete 7 is backfilled in the outer expansion cavity 4, and a preset waterproof membrane 5 is completely laid on the surface of the concrete 7 in the outer expansion cavity 4, and turned up to below the first water stop ring 301 located at a high place, and a sand and gravel backfill layer 6 is filled in the precipitation well pipe 1, and the filling depth is 3m below the ground, and concrete 7 is filled above the sand and gravel backfill layer 6, and the filling height is lower than the top of the precipitation well pipe 1, and at the same time, the concrete 7 is filled to the precipitation well pipe 1 and the plugging steel pipe 3. The gap between the plugging assembly 9 and the plugging steel pipe 3 is filled with a filling height lower than the top of the well pipe 1 of the precipitation well. The plugging assembly 9 is placed inside the plugging steel pipe 3. When placing it, the groove corresponds to the well pipe 1 of the precipitation well, and the positioning block 12 is clamped in the positioning groove 11. Then, a tool is used to rotate the rotating shaft 902 through the hexagonal head, so that the first thread 9033 drives the first pressure ring 903 to squeeze the first airbag 9031, so that the first airbag 9031 is deformed, and the gap between the plugging assembly 9 and the plugging steel pipe 3 is filled. The second thread 9042 drives the second pressure ring 904 to squeeze the second airbag 9043 to deform. The shape is formed so that the second airbag 9043 is squeezed out from the opening 9044 to fill the gap between the precipitation well pipe 1 and the plugging steel pipe 3. The third thread 9051 drives the third pressure ring 905 to extrude and deform the third airbag 9052 to fill the gap between the mounting frame 901 and the precipitation well pipe 1. The multiple connection points of the connection position between the precipitation well pipe 1 and the plugging steel pipe 3 are respectively blocked by multiple airbags. Then, concrete 7 is filled in the plugging steel pipe 3 to the top of the plugging steel pipe 3. Finally, the plugging steel plate 302 is welded to the top of the plugging steel pipe 3, and The depression is filled with concrete 7 until it is flush with the cushion layer 2, and steel bars are arranged in both the cushion layer 2 and the concrete 7 in the depression to complete the construction. An overall waterproof layer is formed by adding a waterproof membrane 5 at the junction of the plugging steel pipe 3 and the cushion layer 2. The top sealing steel plate 302 is welded to the plugging steel pipe 3, and a sealing component 9 is arranged at the junction of the precipitation well pipe 1 and the plugging steel pipe 3. The above three measures strengthen the weak points that may cause leakage during the sealing construction, improve the anti-seepage reliability of the precipitation well in the water-rich formation after the precipitation is stopped, and reduce the operation and maintenance costs of the subsequent building use stage.

[0037] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0039] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A plugging structure for a water-rich formation dewatering well, characterized in that: include: A drainage well pipe (1) vertically arranged on the ground and a cushion layer (2) laid on the ground, wherein a waterproof coiled material (5) is preset between the cushion layer (2) and the ground; An outer expansion cavity (4) is provided around the top of the precipitation well pipe (1), and a plugging steel pipe (3) having a diameter greater than that of the precipitation well pipe (1) is placed at the bottom of the outer expansion cavity (4); A plugging structure for plugging a precipitation well pipe (1) and a plugging steel pipe (3).

2. A water-rich formation dewatering well plugging structure according to claim 1, characterized in that: The diameter of the plugging steel pipe (3) is greater than the diameter of the drainage well pipe (1); two first water stop rings (301) are fixed on the surface of the plugging steel pipe (3); and a sealing steel plate (302) is welded to the top of the plugging steel pipe (3).

3. The plugging structure for a water-rich formation dewatering well according to claim 1, characterized in that: The blocking structure comprises: A sand and gravel backfill layer (6) filled in the well pipe (1) of the precipitation well; Concrete (7) filled above the sand and gravel backfill layer (6) and in the gap between the drainage well pipe (1) and the plugging steel pipe (3); A plugging assembly (9) disposed inside the plugging steel pipe (3) and used to plug the connection between the drainage well pipe (1) and the plugging steel pipe (3); Concrete (7) is filled above the plugging component (9).

4. A water-rich formation dewatering well plugging structure according to claim 3, characterized in that: The plugging assembly (9) comprises a mounting frame (901) and a rotating shaft (902) rotatably connected to the surface of the mounting frame (901); the surface of the rotating shaft (902) is provided with a first thread (9033), a second thread (9042) and a third thread (9051) in sequence from top to bottom; the spiral direction of the third thread (9051) is opposite to the spiral direction of the first thread (9033) and the second thread (9042).

5. A water-rich formation dewatering well plugging structure according to claim 4, characterized in that: The blocking component (9) further comprises: A first pressing ring (903) threadedly connected to the surface of the first thread (9033), and a first air bag (9031) fixed between the first pressing ring (903) and the upper surface of the mounting frame (901); A second pressure ring (904) threadedly connected to the surface of the second thread (9042) and a second air bag (9043) arranged inside a cavity (9041), wherein the cavity (9041) is opened inside the mounting frame (901); A third pressing ring (905) threadedly connected to the surface of the third thread (9051) and a third air bag (9052) fixed between the third pressing ring (905) and the lower surface of the mounting frame (901).

6. A water-rich formation dewatering well plugging structure according to claim 4, characterized in that: The lower surface of the mounting frame (901) is provided with a groove for mounting the mounting frame (901) on the top of the precipitation well pipe (1), two positioning blocks (12) are fixed inside the groove, and the top of the precipitation well pipe (1) is provided with two positioning grooves (11) that match the positioning blocks (12).

7. The method for constructing a plugging structure for a water-rich formation dewatering well according to any one of claims 1 to 6, comprising the following steps: S1. Opening an outer expansion cavity (4) around the top of the drainage well pipe (1), placing a plugging steel pipe (3) at the bottom of the outer expansion cavity (4), and backfilling the outer expansion cavity (4) with concrete (7); S2, completely laying the preset waterproofing membrane (5) on the surface of the concrete (7) in the outer expansion cavity (4), and turning it up to below the first water stop ring (301) located at a high position; S3, filling the well pipe (1) with a gravel backfill layer (6), and filling the top of the gravel backfill layer (6) with concrete (7), and at the same time filling the concrete (7) into the gap between the well pipe (1) and the plugging steel pipe (3); S4, placing a plugging assembly (9) inside the plugging steel pipe (3), placing the plugging assembly (9) so that the groove corresponds to the well pipe (1) of the drainage well, and the positioning block (12) is engaged in the positioning groove (11), and then operating the plugging assembly (9) to respectively plug the multiple connection points of the connection position between the well pipe (1) of the drainage well and the plugging steel pipe (3); S5. Fill the plugging steel pipe (3) with concrete (7) until the top of the plugging steel pipe (3). Finally, weld a sealing steel plate (302) to the top of the plugging steel pipe (3), and fill the recess with concrete (7) until it is flush with the cushion layer (2).

8. The method for constructing a plugging structure for a water-rich formation dewatering well according to claim 7, characterized in that: The filling depth of the sand and gravel backfill layer (6) in S3 is 3 m below the ground, and the sand and gravel backfill layer (6) is filled with 1:1 sand and gravel.

9. The method for constructing a plugging structure for a water-rich formation dewatering well according to claim 7, characterized in that: The outer expansion cavity (4) in S1 has an outer expansion diameter greater than 50 cm and an outer expansion depth greater than 50 cm.

10. The method for constructing a plugging structure for a water-rich formation dewatering well according to claim 7, characterized in that: The method for operating the plugging component (9) in S4 to respectively plug the multiple connection points of the connection position between the drainage well pipe (1) and the plugging steel pipe (3) is to drive the first thread (9033) to drive the first pressure ring (903) to squeeze the first airbag (9031), so that the first airbag (9031) is deformed and fills the gap between the plugging component (9) and the plugging steel pipe (3); the second thread (9042) drives the second pressure ring (904) to squeeze and deform the second airbag (9043), so that the second airbag (9043) is squeezed out from the opening (9044) to fill the gap between the drainage well pipe (1) and the plugging steel pipe (3); and the third thread (9051) drives the third pressure ring (905) to squeeze and deform the third airbag (9052), so that it fills the gap between the mounting frame (901) and the drainage well pipe (1).

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