A plugging device for a subway construction decompression well

Abstract

The utility model relates to municipal works construction technical field discloses a kind of plugging device of subway construction depressurization well, and a complete composite plugging mechanism is filled with solidification in well pipe inside. The structure is successively dense stacking from bottom to top: fine gravel filling layer of covering filter tube, filling concrete, fixedly welded in the inner water-stop steel sheet of well pipe inner wall, and the concrete filling layer with built-in steel wire mesh. Preferably, outer water-stop steel sheet is also fixed on the outer wall of well pipe, which is in structure with the inner water-stop steel sheet inside echo. The utility model solves the problem of easy leakage and poor long-term stability caused by single plugging structure and lack of reliable waterproof structure in the prior art through the synergistic effect of the above multi-level, multi-material composite plugging mechanism and the double water-stop steel plates inside and outside. The formed plugging body has high integrity and dense structure, significantly improved permeability resistance and durability, and can form a safe and reliable permanent plugging.

Description

Technical Field

[0001] This utility model relates to the field of municipal engineering construction technology, and in particular to a sealing device for a pressure-reducing well in subway construction. Background Technology

[0002] During the construction of underground projects such as subways and tunnels, in order to ensure the dryness and safety of the foundation pit or cut-and-cover sections, it is usually necessary to install depressurization wells around the engineering structure to temporarily lower the surrounding groundwater level by extracting groundwater. These depressurization wells are key temporary facilities to ensure the smooth progress of construction.

[0003] Once the main structural work is completed and its weight and strength are sufficient to resist the buoyancy of groundwater, these pressure relief wells have fulfilled their historical mission and require permanent sealing. The quality of the sealing is crucial; if the sealing is not tight or reliable, the abandoned well pipes will become weak channels for groundwater to re-infiltrate. Over time, continuous leakage will not only cause soil erosion and uneven ground settlement, but will also threaten the long-term safety of the completed subway structure and surrounding buildings.

[0004] Existing sealing techniques often involve simply backfilling the well casing with materials such as concrete, cement mortar, or clay in one go or in stages. While this method seems simple, in practice, due to the depth and moisture inside the well casing, it is difficult to ensure the uniformity and compactness of the backfill material from top to bottom. Especially at the junction with the inner wall of the well casing, tiny gaps or leakage channels can easily occur due to material shrinkage or poor adhesion.

[0005] More importantly, this simple filling structure lacks specialized, highly reliable waterproofing features, and its seepage prevention performance relies entirely on the impermeability of the filling material itself and its bond strength with the well casing. In environments with complex geological conditions and high groundwater pressure, this single line of defense is particularly vulnerable. Once a local defect occurs, it can develop into a through-flow leakage, leading to sealing failure. Therefore, the sealing structure formed by existing technologies is too simple, lacking structural redundancy and reliable waterproofing guarantees, and cannot meet the stringent requirements of long-term stability and zero leakage for permanent projects such as subways.

[0006] Therefore, this utility model proposes a sealing device for pressure-reducing wells in subway construction to address the shortcomings of existing technologies. Utility Model Content

[0007] In view of the problems of existing sealing devices for subway construction pressure relief wells, such as simple sealing structure, lack of reliable waterproof construction, and poor long-term sealing stability, this utility model aims to provide a sealing device for subway construction pressure relief wells with an improved structure that can effectively solve the above problems.

[0008] This utility model provides a sealing device for a pressure-reducing well in subway construction, including a well pipe and a filter pipe connected to the bottom of the well pipe; the sealing device also includes a composite sealing mechanism that is filled and solidified inside the well pipe.

[0009] The composite sealing mechanism consists of, from bottom to top, a fine stone filling layer, a filling concrete layer, at least one inner water-stop steel plate, and a concrete sealing layer.

[0010] Furthermore, the fine stone filling layer covers the filter pipe, the filling concrete is poured on the fine stone filling layer, the inner water-stop steel plate is fixedly welded to the inner wall of the well pipe above the filling concrete, and the concrete sealing layer is sealed on the inner water-stop steel plate to seal the top of the well pipe to be flush with the ground.

[0011] Preferably, an outer water-stop steel plate is also fixed on the outer wall of the well pipe, and the outer water-stop steel plate and the inner water-stop steel plate together form a double water-stop structure.

[0012] Preferably, there are two inner water-stop steel plates, which are spaced apart along the axial direction of the well pipe.

[0013] Preferably, a wire mesh is also laid inside the concrete sealing layer.

[0014] Preferably, the sealing device further includes a sealing assembly, which includes a sealing body, an elastic memory sheet, and a sealing strip; the sealing body is slidably installed on the top of the well pipe and has a reserved hole for the grouting pipe to pass through, the elastic memory sheet is disposed in the reserved hole, and the sealing strip is arranged around the outer periphery of the sealing body.

[0015] Preferably, the sealing assembly further includes at least three triangular support plates, which are radially fixed to the upper surface of the sealing body with the reserved hole as the center.

[0016] Preferably, the sealing device further includes a grouting mechanism, which includes a mixing tank, a motor, a mixing rod, and a grouting pump; the mixing rod is driven by the motor and is located inside the mixing tank.

[0017] Preferably, an opening and closing baffle is rotatably connected between the outlet of the mixing tank and the inlet of the grouting pump.

[0018] This utility model has the following beneficial effects:

[0019] 1. This utility model solves the problems of simple sealing structure, poor integrity, and easy leakage channels in the existing depressurization well sealing structure by setting a multi-layer composite sealing mechanism consisting of a fine stone filling layer, filling concrete, inner water-stop steel plate and concrete sealing layer inside the well pipe. It achieves the technical effect of stable and reliable sealing structure, good sealing performance and long-term effective isolation of groundwater.

[0020] 2. This utility model solves the problem of easy failure and insufficient waterproofing reliability of the single-layer water-stop structure in the prior art by welding an inner water-stop steel plate to the inner wall of the well pipe and working in conjunction with the outer water-stop steel plate preset on the outer wall of the well pipe. It forms a double waterproof barrier inside and outside, which greatly improves the seepage resistance and safety of the sealing device.

[0021] 3. This utility model solves the problems of inaccurate positioning of grouting pipes, easy leakage of grout at the wellhead, and impact on construction quality in the existing technology by setting a sealing body with elastic memory sheet and sealing strip. It achieves stable fixation of grouting pipes and temporary sealing of wellhead, ensures the standardization of grouting operation, and effectively improves the forming quality of the final sealing body. Attached Figure Description

[0022] Figure 1 This is a three-dimensional schematic diagram of a sealing device for a pressure-reducing well in subway construction proposed in this utility model;

[0023] Figure 2 This is a schematic diagram of the inner water-stop steel plate of a sealing device for a pressure-reducing well in subway construction proposed in this utility model;

[0024] Figure 3 This is a schematic diagram of the structure of the elastic memory plate of the sealing device for a pressure-reducing well in subway construction proposed in this utility model;

[0025] Figure 4 This is a schematic diagram of the structure of the stirring rod of a sealing device for a pressure-reducing well in subway construction proposed in this utility model.

[0026] Legend:

[0027] 1. Ground surface; 2. Well casing; 3. Composite plugging mechanism; 31. Pluging body; 32. Grouting pipe; 33. Fine aggregate filling layer; 34. Filling concrete; 35. External waterstop steel plate; 36. Internal waterstop steel plate; 37. Concrete sealing layer; 38. Pluging component; 381. Elastic memory sheet; 382. Sealing strip; 383. Triangular support plate; 4. Filter pipe; 5. Grouting mechanism; 51. Mixing tank; 52. Motor; 53. Mixing rod; 54. Opening and closing baffle; 55. Grouting pump. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model 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 this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0029] Example:

[0030] Please refer to Figures 1 to 4 This utility model provides a sealing device for a pressure relief well in subway construction, which aims to solve the problems of insufficient sealing performance and poor long-term stability of the sealing structure of pressure relief wells in subway construction in the prior art.

[0031] like Figure 1 As shown, the sealing device for the pressure reduction well in subway construction includes a well pipe 2 and a composite sealing mechanism 3 filled and solidified inside the well pipe 2. The well pipe 2 serves as the main body of the pressure reduction well and provides a bearing space for the composite sealing mechanism 3. A filter pipe 4 is fixedly connected to the bottom of the well pipe 2.

[0032] The composite sealing mechanism 3 is the core for permanently sealing the well pipe 2. From bottom to top, it includes a fine gravel filling layer 33, a filling concrete 34, at least one inner water-stop steel plate 36, and a concrete sealing layer 37. Specifically, the fine gravel filling layer 33 fills the bottom of the well pipe 2, and its filling height is sufficient to completely cover and seal the filter pipe 4. The filling concrete 34 is poured on the top surface of the fine gravel filling layer 33, forming the main part of the sealing structure. The inner water-stop steel plate 36 is fixedly welded to the inner wall of the well pipe 2, and its installation position is above the filling concrete 34, which is used to form a radial waterproof barrier inside the well pipe 2. The concrete sealing layer 37 is filled on the top of the inner water-stop steel plate 36, and its top surface is finally flush with the ground 1 to complete the final sealing of the top of the well pipe 2.

[0033] To further improve the reliability of the sealing and standardize the construction process, the technical solution of this embodiment also includes structures for auxiliary positioning, sealing and enhanced waterproofing during the construction process.

[0034] Please refer to the following carefully. Figure 1 , Figure 2 and Figure 3An outer water-stop steel plate 35 is also fixed on the outer wall of the well pipe 2. The outer water-stop steel plate 35 and the aforementioned inner water-stop steel plate 36 correspond to each other in spatial position, forming a double water-stop barrier, which greatly improves the long-term waterproof reliability of the sealing device. In this embodiment, the number of inner water-stop steel plates 36 is preferably two, and they are spaced apart along the axial direction of the well pipe 2 to form multiple internal waterproof barriers.

[0035] Additionally, the sealing device also includes a sealing component 38 for auxiliary positioning and sealing during the filling of the composite sealing mechanism 3. Please refer to the following for details. Figure 3 The core structure is described in detail as follows: The sealing assembly 38 includes a sealing body 31, which is slidably installed on the top of the well pipe 2, and a reserved hole is provided on the sealing body 31 for the grouting pipe 32 to pass through. An elastic memory plate 381 and a sealing strip 382 are also provided inside and around the sealing body 31. The elastic memory plate 381 is disposed on the inner wall of the reserved hole to fix the grouting pipe 32 in an elastic clamping manner, while the sealing strip 382 is disposed around the outer periphery of the sealing body 31 to tightly fit with the inner wall of the well pipe 2 to form a reliable seal. To enhance the fixing effect on the grouting pipe 32, the sealing assembly 38 also includes at least three triangular support plates 383. These triangular support plates 383 are radially fixed to the upper surface of the sealing body 31 with the reserved hole as the center, and provide reinforced support for the elastic memory plate 381. This structural combination ensures the stable centering of the grouting pipe 32 and the effective sealing of the wellhead during construction.

[0036] Based on the above embodiments, the present invention may further include the following preferred technical solutions:

[0037] As a preferred embodiment, in order to further enhance the integrity and crack resistance of the top sealing structure, a wire mesh is also laid inside the concrete sealing layer 37. The wire mesh and the concrete sealing layer 37 are combined to form a reinforced concrete structure, which can effectively resist tensile stress caused by temperature changes or external loads.

[0038] As another preferred embodiment, in order to achieve efficient preparation and delivery of cement slurry and concrete, please refer to... Figure 1 and Figure 4The sealing device also includes a grouting mechanism 5 connected to the grouting pipe 32; the grouting mechanism 5 includes a mixing tank 51, a motor 52, a mixing rod 53, and a grouting pump 55; the mixing tank 51 is used to contain and mix the grout, the mixing rod 53 is disposed inside the mixing tank 51, the motor 52 is fixed to the outside or top of the mixing tank 51, and its output shaft is connected to the mixing rod 53 for driving the mixing rod 53 to rotate to fully mix the grout, the inlet of the grouting pump 55 is connected to the outlet of the mixing tank 51, and its outlet is connected to a conduit. Connected to the input end of the grouting pipe 32, it is used to pressurize and pump the mixed grout or concrete to a designated location. Based on the above-mentioned grouting mechanism 5, in order to accurately control the flow of grout from the mixing tank 51 to the grouting pump 55, an opening and closing baffle 54 is rotatably connected between the outlet of the mixing tank 51 and the inlet of the grouting pump 55. The opening and closing baffle 54 rotates around the limiting shaft at the bottom of the mixing tank 51. By manually turning or other driving methods, the outlet of the mixing tank 51 can be easily opened or closed, thereby realizing the start and stop control of the feeding process.

[0039] The working principle is as follows:

[0040] Before the plugging operation, the plugging body 31 is first slidably installed on the top of the well pipe 2, and the grouting pipe 32 is passed through the elastic memory plate 381 in the center and lowered to the bottom of the filter pipe 4. Through the combined action of the elastic memory plate 381 and the triangular support plate 383, the grouting pipe 32 is stably fixed in the center of the well pipe 2. At the same time, the sealing strip 382 is tightly attached to the inner wall of the well pipe 2 to perform preliminary sealing of the wellhead. The grouting mechanism 5 is started, and the motor 52 drives the stirring rod 53 to mix the cement slurry or concrete evenly in the mixing tank 51. Then the opening and closing baffle 54 is opened, and the material enters the grouting pump 55 and is pumped down into the well through the grouting pipe 32.

[0041] At the start of the sealing process, fine stones are first filled into the bottom of the well pipe 2 through the grouting pipe 32 to form a fine stone filling layer 33 covering the filter pipe 4. Cement slurry is then injected into this layer to solidify it. Next, filling concrete 34 is poured upward through the grouting pipe 32, which can be done in stages to ensure the quality of the pouring. After the filling concrete 34 has finally set, the temporary sealing components 38 and the grouting pipe 32 are removed, and two inner water-stop steel plates 36 are welded and fixed at a predetermined height on the inner wall of the well pipe 2. Finally, a concrete sealing layer 37 is poured on top of the inner water-stop steel plates 36, and a wire mesh is laid in it until the wellhead is flush with the ground 1. Through the setting of the inner water-stop steel plates 35 and the outer water-stop steel plates 36, and the synergistic effect of the multi-layered composite sealing mechanism 3 of different materials from bottom to top, this utility model effectively solves the problems of insufficient sealing performance and poor long-term stability of the sealing structure in the prior art, and achieves high-reliability permanent sealing of the depressurization well.

Claims

1. A sealing device for a pressure-reducing well in subway construction, comprising a well pipe (2), wherein a filter pipe (4) is connected to the bottom of the well pipe (2); characterized in that, The well casing (2) is internally filled with a composite sealing mechanism (3), which, from bottom to top, comprises: A fine pebble filling layer (33) is provided to cover and seal the filter tube (4); A filling concrete (34) is poured on top of the fine stone filling layer (33); At least one inner water-stop steel plate (36) is fixedly welded to the inner wall of the well pipe (2) and located above the filling concrete (34); And a concrete sealing layer (37) is filled on the inner waterstop steel plate (36) to seal the top of the well pipe (2) to be flush with the ground (1).

2. The sealing device for the pressure-reducing well in subway construction according to claim 1, characterized in that, An outer water-stop steel plate (35) is also fixed on the outer wall of the well pipe (2). The inner water-stop steel plate (36) and the outer water-stop steel plate (35) together form a double water-stop structure.

3. The sealing device for the pressure-reducing well in subway construction according to claim 1, characterized in that, The number of inner water-stop steel plates (36) is two, and they are spaced apart along the axial direction of the well pipe (2).

4. The sealing device for the pressure-reducing well in subway construction according to claim 1, characterized in that, The concrete sealing layer (37) is also covered with wire mesh.

5. The sealing device for the pressure-reducing well in subway construction according to claim 1, characterized in that, It also includes a plugging assembly (38) for auxiliary positioning and sealing during filling of the composite plugging mechanism (3), the plugging assembly (38) comprising: A sealing body (31) is slidably installed on the top of the well pipe (2), and a reserved hole is provided on the sealing body (31) for a grouting pipe (32) to pass through; An elastic memory sheet (381) is provided in the reserved hole for clamping the grouting pipe (32); And a sealing strip (382) is provided around the outer periphery of the plugging body (31) for fitting the inner wall of the well pipe (2).

6. The sealing device for the pressure-reducing well in subway construction according to claim 5, characterized in that, The sealing assembly (38) also includes at least three triangular support plates (383), which are radially fixed to the upper surface of the sealing body (31) with the reserved hole as the center.

7. The sealing device for the pressure-reducing well in subway construction according to claim 5, characterized in that, It also includes a grouting mechanism (5) connected to the grouting pipe (32), the grouting mechanism (5) including: a mixing tank (51); a motor (52); a mixing rod (53) driven by the motor (52) and disposed in the mixing tank (51); and a grouting pump (55).

8. The sealing device for the pressure-reducing well in subway construction according to claim 7, characterized in that, An opening and closing baffle (54) is rotatably connected between the outlet of the mixing tank (51) and the inlet of the grouting pump (55).

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