Pipe-in-pipe double-layer filter material gravity well dewatering structure and construction method

Abstract

The invention relates to the technical field of foundation pit construction, in particular to a pipe-in-pipe double-layer filter material artesian well dewatering structure and a construction method.The pipe-in-pipe double-layer filter material artesian well dewatering structure comprises a first filter pipe, a second filter pipe, a first filter material layer and a second filter material layer, first water permeable holes are formed in the first filter pipe at intervals, and second water permeable holes are formed in the second filter pipe at intervals; the periphery of the second filter pipe is sleeved with the first filter pipe, an avoiding distance is formed between the first filter pipe and the side wall of the precipitation drill hole, the space between the side wall of the precipitation drill hole and the first filter pipe is filled with the first filter material layer, an avoiding distance is formed between the first filter pipe and the second filter pipe, and the space between the first filter pipe and the second filter pipe is filled with the second filter material layer; the diameter of the coarse filter material of the first filter material layer is greater than that of the fine filter material of the second filter material layer. According to the invention, surrounding underground water is in contact with the coarse filter material in the first filter material layer and the fine filter material in the second filter material layer in sequence; therefore, the condition that soil particles are deposited in the precipitation drilling well is reduced, and the foundation pit precipitation effect is improved.

Description

A pipe-in-pipe double-layer filter material gravity flow well dewatering structure and construction method Technical Field

[0001] This application relates to the field of foundation pit construction technology, and in particular to a pipe-in-pipe double-layer filter material gravity flow well dewatering structure and construction method. Background Technology

[0002] Dewatering technology is a core component of deep foundation pit construction. Among them, gravity-flow wells are simple to operate, economical, efficient, and highly practical, making them a common method for deep foundation pit dewatering and widely used in the industry.

[0003] However, in complex geological areas such as silty soils, due to factors such as poor soil permeability, high water content, and poor drainage, groundwater entering the wells through the permeable filter material is prone to carrying soil particles and depositing inside the pipes. This leads to a gradual decrease in water output, and the outflowing water is often turbid. This not only significantly weakens the dewatering effect of the foundation pit but also affects the stability of the soil and water inside and outside the pit, negatively impacting construction progress and project quality. In particular, when turbid water appears in the dewatering wells outside the foundation pit, the stability of the entire foundation pit slope cannot be effectively guaranteed, posing a significant hidden safety hazard. Summary of the Invention

[0004] To improve the dewatering effect of foundation pits, this application provides a pipe-in-pipe double-layer filter material gravity flow well dewatering structure and construction method.

[0005] This application provides a pipe-in-pipe double-layer filter material gravity-flow well dewatering structure and construction method, adopting the following technical solution: A pipe-in-pipe double-layer filter material gravity-flow well dewatering structure, wherein a dewatering borehole is drilled on the ground, and the gravity-flow well dewatering structure is fixed in the dewatering borehole; including a first filter pipe, a second filter pipe, a first filter material layer, and a second filter material layer, wherein the first filter pipe has a first permeable hole spaced apart, the second filter pipe has a second permeable hole spaced apart, the first filter pipe is sleeved on the outer periphery of the second filter pipe, and a clearance distance is provided between the first filter pipe and the side wall of the dewatering borehole, the first filter material layer fills the space between the side wall of the dewatering borehole and the first filter pipe, and a clearance distance is provided between the first filter pipe and the second filter pipe, the second filter material layer fills the space between the first filter pipe and the second filter pipe, and the diameter of the coarse filter material in the first filter material layer is larger than the diameter of the fine filter material in the second filter material layer.

[0006] By adopting the above technical solution, the groundwater infiltration in the foundation pit follows a graded interception path. The surrounding groundwater first comes into contact with the coarse filter material in the first filter layer, initially blocking large-diameter soil particles. Then, the groundwater passes through the first permeable hole on the first filter pipe and enters the annular gap between the first and second filter pipes. Subsequently, the groundwater undergoes secondary filtration in the second filter layer, trapping fine impurities, and finally enters the second filter pipe through the second permeable hole on the second filter pipe. This ensures that the water entering the second filter pipe is basically clean water, thereby reducing the deposition of soil particles in the dewatering well, solving the problem of turbid water from traditional technologies, improving the dewatering effect of the foundation pit, and improving the quality of the project.

[0007] Optionally, it also includes a first dense mesh and a second dense mesh, wherein the first dense mesh covers the outer periphery of the first filter tube and covers the first water-permeable hole, and the second dense mesh covers the outer periphery of the second filter tube and covers the second water-permeable hole.

[0008] By adopting the above technical solution, a dual filtration system combining filter media, dense mesh, and filter pipe is formed through the coordinated operation of the first filter media layer, the first dense mesh, the first filter pipe, the second filter media layer, the second dense mesh, and the second filter pipe. This improves the filtration effect of groundwater, enhances the dewatering effect of the foundation pit, and ensures the quality of the project.

[0009] Optionally, it also includes a first disturbance element, which is spaced apart on the outer periphery of the first filter tube and inserted into the first filter material layer; the upper end of the first filter tube is externally connected to a rotation drive device, which forces the first filter tube to perform forward and reverse reciprocating motion.

[0010] By adopting the above technical solution, during the filling of the first filter layer, the staff can use an external rotation drive device to force the first filter tube to rotate slightly and periodically in the forward or reverse direction, so that the first disturbance element on the outer periphery of the first filter tube vibrates the coarse filter material in the first filter layer, thereby reducing the existence of large pores inside the first filter layer and improving the filtration effect of the first filter layer on groundwater.

[0011] Optionally, it also includes a second disturbance element, which is spaced apart on the outer periphery of the second filter tube and inserted into the second filter material layer; the upper end of the second filter tube is externally connected to a rotation drive device, which forces the second filter tube to perform forward and reverse reciprocating motion.

[0012] By adopting the above technical solution, during the filling of the second filter layer, the staff can use an external rotation drive device to force the second filter tube to rotate slightly and periodically in the forward or reverse direction, so that the second disturbance component on the outer periphery of the second filter tube vibrates the fine filter material in the second filter layer, thereby reducing the existence of large pores inside the second filter layer and improving the filtration effect of the second filter layer on groundwater.

[0013] Optionally, it also includes an elastic support member disposed at the bottom of the precipitation borehole, the elastic support member being used to support the first filter pipe.

[0014] By adopting the above technical solution, and by setting an elastic support at the bottom of the first filter pipe, the first filter pipe and the first disturbance component can vibrate in the vertical direction, so as to improve the vibration effect of the first disturbance component on the first filter material layer, further reduce the large pores in the first filter material layer, and improve the filtration effect of the first filter material layer on groundwater.

[0015] Optionally, the elastic support includes a support base plate, a support top plate, a support spring, and a flexible shell; the support spring is fixed between the support base plate and the support top plate, the flexible shell is sleeved on the outer periphery of the support spring, and both ends of the flexible shell are fixedly connected to the support base plate and the support top plate, respectively; the support top plate is used to support the first filter tube.

[0016] By adopting the above technical solution, the first filter tube and the first disturbance component can vibrate in the vertical direction, thereby further reducing the large pores in the first filter layer and improving the filtration effect of the first filter layer on groundwater.

[0017] Optionally, it also includes a first closed base plate and a first disturbance rope; the first closed base plate is fixed to the bottom of the first filter tube in the first section, and the diameter of the first closed base plate is larger than the diameter of the first filter tube; a plurality of first mounting holes are circumferentially formed on the outer periphery of the first closed base plate; one end of the first disturbance rope passes through the first mounting hole, the disturbance rope is fixedly connected to the first closed base plate, and the first disturbance element has a second mounting hole for the disturbance rope to pass through, and the first disturbance rope is arranged along the length direction of the first filter tube.

[0018] By adopting the above technical solution, by setting a first disturbance rope around the outer periphery of the first filter pipe, the vibration range of the first filter material layer is expanded, so that the coarse filter material in the first filter material layer is evenly distributed, thereby improving the filtration effect of the first filter material layer on groundwater.

[0019] Optionally, the first disturbance rope includes a first steel wire rope and a first disturbance spring. The first disturbance spring is fixed between adjacent first steel wire ropes. The first steel wire rope passes through the second mounting hole of the first disturbance member in the vertical direction. The first disturbance spring is disposed between adjacent first disturbance members.

[0020] By adopting the above technical solution, the synergistic effect of the first wire rope and the first disturbance spring can improve the vibration and loosening effect of the first disturbance rope on the first filter material layer.

[0021] Optionally, the first wire rope is provided with a first disturbance knot, and there is a clearance distance between the first disturbance knot and the first disturbance member.

[0022] By adopting the above technical solution, and by setting a first disturbance knot on the first wire rope, the vibration effect of the first wire rope on the first filter material layer is improved.

[0023] A construction method for a pipe-in-pipe double-layer filter media gravity-flow well dewatering structure includes the following steps: Processing the first and second filter pipes: First permeable holes are machined on the first filter pipe, and a first dense mesh is wrapped around its outer periphery; second permeable holes are machined on the second filter pipe, and a second dense mesh is wrapped around its outer periphery; Construction of the first filter pipe: After the dewatering borehole is drilled, the first filter pipes are vertically inserted into the borehole sequentially, with the ends of adjacent first filter pipes fixedly connected, and the opening of the last section of the first filter pipe being higher than the ground surface; Construction of the first filter media layer: Coarse filter media is prepared and evenly poured around the outer wall of the first filter pipe in a circular direction, filling the annular gap between the first filter pipe and the sidewall of the dewatering borehole to form the first filter media layer; Well washing construction: After the first filter media layer construction is completed, the nozzle of a high-pressure water gun is inserted into the first filter pipe. After the nozzle reaches the bottom of the pipe, the pressurization is activated. The device utilizes high-pressure water flow to impact the inner wall of the first filter tube and the gaps in the coarse filter media in the first filter layer until the water overflowing from the first filter tube is clear and free of visible sediment particles. The second filter tube is constructed by sequentially placing it inside the first filter tube, with adjacent second filter tubes fixedly connected. The second filter tubes are concentrically aligned with the first filter tubes, with a gap between them. The second filter layer is constructed by preparing fine filter media and evenly pouring it around the outer wall of the first filter tube in a circular direction, filling the annular gap between the second and first filter tubes with coarse filter media to form the second filter layer. A submersible pump is installed at the bottom of the second filter tube, and a test pump is started. The water output and clarity are observed to determine if the dewatering effect meets design standards. During formal drainage, the submersible pump pumps the water from the dewatering borehole to the intercepting ditch outside the foundation pit.

[0024] By adopting the above technical solution, high-pressure water flow is used to impact the inner wall of the coarse filter pipe and the gaps between the surrounding coarse filter media, loosening the residual mud, fine soil particles and other impurities between the filter media, opening up a flow channel for groundwater infiltration, so that the groundwater can flow smoothly into the second filter pipe, thereby improving the dewatering efficiency of the foundation pit.

[0025] In summary, this application includes at least one of the following beneficial technical effects: Groundwater infiltration in the foundation pit follows a graded interception path. The surrounding groundwater first contacts the coarse filter material in the first filter layer, initially blocking large-diameter soil particles. Next, the groundwater passes through the first permeable hole on the first filter pipe and enters the annular gap between the first and second filter pipes. Subsequently, the groundwater undergoes secondary filtration in the second filter layer, trapping fine impurities, and finally enters the second filter pipe through the second permeable hole. This ensures that the water entering the second filter pipe is essentially clean water, thereby reducing soil particle deposition in the dewatering well and solving the problem of turbid water produced by traditional techniques. The problem is to improve the dewatering effect of the foundation pit and improve the quality of the project. During the filling of the first filter layer, the workers can use an external rotation drive device to force the first filter pipe to rotate slightly and periodically in the forward or reverse direction. This causes the first disturbance element on the outer periphery of the first filter pipe to vibrate the coarse filter material in the first filter layer, thereby reducing the existence of large pores inside the first filter layer and improving the filtration effect of the first filter layer on groundwater. High-pressure water flow is used to impact the inner wall of the coarse filter pipe and the gaps between the coarse filter materials, loosening the residual mud, fine soil particles and other impurities between the filter materials, opening up the flow channel for groundwater infiltration, so that the groundwater can flow smoothly into the second filter pipe, thereby improving the dewatering efficiency of the foundation pit. Attached Figure Description

[0026] Figure 1 is a cross-sectional view of the gravity flow well dewatering structure in Example 1.

[0027] Figure 2 is an enlarged view of point A in Figure 1.

[0028] Figure 3 is a construction flowchart of the gravity well dewatering structure in Example 1.

[0029] Figure 4 is a cross-sectional view of the gravity well dewatering structure in Example 2.

[0030] Figure 5 is an enlarged view of point B in Figure 4.

[0031] Figure 6 is a cross-sectional view of the gravity well dewatering structure in Example 3.

[0032] Figure 7 is an enlarged view of point C in Figure 6.

[0033] Figure 8 is a cross-sectional view of the gravity well dewatering structure in Example 4.

[0034] Figure 9 is an enlarged view of point D in Figure 8.

[0035] Explanation of reference numerals in the attached drawings: 1. Rainwater borehole; 2. First filter assembly; 21. First filter pipe; 211. First permeable hole; 22. First dense mesh screen; 3. Second filter assembly; 31. Second filter pipe; 311. Second permeable hole; 32. Second dense mesh screen; 4. First filter media layer; 5. Second filter media layer; 61. First agitator; 611. Second mounting hole; 62. First closed base plate; 621. First mounting hole; 63. First agitator rope; 631. 6311 First wire rope; 632 First disturbance spring; 71 Second disturbance component; 711 Fourth mounting hole; 72 Second closed bottom plate; 721 Third mounting hole; 73 Second disturbance rope; 732 Second wire rope; 7321 Second disturbance knot; 733 Second disturbance spring; 8 Elastic support component; 81 Support bottom plate; 82 Support top plate; 83 Support spring; 84 Flexible shell; 9 Submersible pump. Detailed Implementation

[0036] The present application will be further described in detail below with reference to Figures 1-9.

[0037] Example 1: This application discloses a pipe-in-pipe double-layer filter media gravity flow well dewatering structure and its construction method. Referring to Figure 1, a pipe-in-pipe double-layer filter media gravity flow well dewatering structure is provided, with a dewatering borehole 1 drilled in the ground, and the gravity flow well dewatering structure fixed in the borehole 1. The pipe-in-pipe double-layer filter media gravity flow well dewatering structure includes a first filter component 2, a second filter component 3, a first filter media layer 4, and a second filter media layer 5.

[0038] Referring to Figures 1 and 2, the first filter assembly 2 includes a first filter tube 21 and a first dense mesh 22. The first filter tube 21 has first water-permeable holes 211 spaced apart. The first dense mesh 22 covers the outer periphery of the first filter tube 21 and covers the first water-permeable holes 211. The first dense mesh 22 has at least three layers to improve the filtration effect of the first dense mesh 22 on particles. In this embodiment, the first dense mesh 22 has three layers.

[0039] Referring to Figures 1 and 2, the second filter assembly 3 includes a second filter tube 31 and a second fine-mesh screen 32. The second filter tube 31 has second water-permeable holes 311 spaced apart. The second fine-mesh screen 32 covers the outer periphery of the second filter tube 31 and covers the second water-permeable holes 311. The second fine-mesh screen 32 has at least three layers to improve the filtration effect of the second fine-mesh screen 32 on particles. In this embodiment, the second fine-mesh screen 32 has three layers.

[0040] Referring to Figures 1 and 2, the first filter tube 21 is sleeved around the second filter tube 31. There is a clearance distance between the first filter tube 21 and the side wall of the rainwater borehole 1. The first filter material layer 4 is filled between the side wall of the rainwater borehole 1 and the first filter tube 21. There is a clearance distance between the first filter tube 21 and the second filter tube 31. The second filter material layer 5 is filled between the first filter tube 21 and the second filter tube 31. The diameter of the coarse filter material in the first filter material layer 4 is larger than the diameter of the fine filter material in the second filter material layer 5.

[0041] In this embodiment, the coarse filter material of the first filter layer 4 is fine pebbles, and the fine filter material of the second filter layer 5 is medium-coarse sand; the first filter pipe 21 is a corrugated pipe with a diameter of 300 mm, and the second filter pipe 31 is a corrugated pipe with a diameter of 180 mm. In other embodiments, the first filter pipe 21 and the second filter pipe 31 can also be galvanized steel pipes.

[0042] The implementation principle of the pipe-in-pipe double-layer filter material gravity flow well dewatering structure in this application embodiment is as follows: Referring to Figures 1 and 2, through the coordinated cooperation of the first filter material layer 4, the first dense mesh 22, the first filter pipe 21, the second filter material layer 5, the second dense mesh 32, and the second filter pipe 31, a dual filtration system combining filter material, dense mesh, and filter pipe is formed; the groundwater infiltration of the foundation pit follows a graded interception path, with the surrounding groundwater first contacting the coarse filter material in the first filter material layer 4, initially blocking large-diameter soil particles; then, the groundwater passes through the first dense mesh 22 and... The first permeable hole 211 on the first filter pipe 21 enters the annular gap between the first filter pipe 21 and the second filter pipe 31. Subsequently, the groundwater undergoes secondary filtration through the second filter layer 5, trapping fine impurities, and finally enters the second filter pipe 31 through the second dense mesh 32 and the second permeable hole 311 on the second filter pipe 31. This ensures that the water entering the second filter pipe 31 is basically clean water, thereby reducing the deposition of soil particles in the dewatering well, solving the problem of turbid water from traditional technologies, improving the dewatering effect of the foundation pit, and improving the quality of the project.

[0043] Referring to Figure 3, a construction method for a pipe-in-pipe double-layer filter material gravity flow well dewatering structure includes the following steps: Measurement and positioning: Technical personnel review the design drawings, measure and position the foundation pit, and use drilling equipment to drill dewatering borehole 1.

[0044] Processing of the first filter tube 21 and the second filter tube 31: A first water-permeable hole 211 is processed on the first filter tube 21, and a first dense mesh 22 is wrapped around the outer periphery of the first filter tube 21. A second water-permeable hole 311 is processed on the second filter tube 31, and a second dense mesh 32 is wrapped around the outer periphery of the second filter tube 31.

[0045] Construction of the first filter pipe 21: After the first dewatering borehole 1 is completed, the first filter pipe 21 is vertically inserted into the dewatering borehole 1 in sequence. The ends of adjacent first filter pipes 21 are fixedly connected. The opening of the last section of the first filter pipe 21 is higher than the ground. The opening of the last section of the first filter pipe 21 is at least 500mm higher than the ground.

[0046] Construction of the first filter layer 4: Prepare coarse filter material, which is fine gravel flakes. Evenly pour the coarse filter material in a circular motion around the outer wall of the first filter pipe 21, filling the annular gap between the first filter pipe 21 and the sidewall of the dewatering borehole 1 to form the first filter layer 4. During the filling process, after every 30cm of coarse filter material, gently tap the outer wall of the first filter pipe 21 2-3 times to promote natural settling and compaction of the coarse filter material, reducing the porosity inside the first filter layer 4.

[0047] Well washing operation: After the first filter layer 4 is completed and within 4 hours of the first filter pipe 21 being lowered, well washing operation is initiated to prevent the mud skin on the borehole wall of the dewatering borehole 1 from aging and hardening due to prolonged storage, which would affect the subsequent seepage effect. Technicians insert the nozzle of a high-pressure water gun into the first filter pipe 21. Once the nozzle reaches the bottom of the pipe, the pressurization device is activated, using high-pressure water to impact the inner wall of the first filter pipe 21 and the gaps between the coarse filter media in the first filter layer 4 until the water overflowing from the first filter pipe 21 is clear and free of visible mud and sand particles. This high-pressure water impact breaks up the protective mud skin adhering to the sidewall of the dewatering borehole 1 during the drilling process, while simultaneously loosening residual mud, fine soil particles, and other impurities between the coarse filter media in the first filter layer 4, thus opening a flow channel for groundwater infiltration.

[0048] Construction of the second filter tube 31: The second filter tube 31 is placed into the first filter tube 21 in sequence, and adjacent second filter tubes 31 are fixedly connected. The second filter tube 31 and the first filter tube 21 are concentrically aligned and there is a gap between the second filter tube 31 and the first filter tube 21.

[0049] Construction of the second filter layer 5: Prepare fine filter material, which is medium to coarse sand. Around the outer wall of the first filter pipe 21, pour the fine filter material evenly in a circular direction so that the coarse filter material fills the annular gap between the second filter pipe 31 and the first filter pipe 21 to form the second filter layer 5.

[0050] Dewatering construction: Install submersible pump 9 at the bottom of the second filter pipe 31, start submersible pump 9 for trial pumping, and judge whether the dewatering effect meets the design standards by observing the water output and water clarity; during formal drainage, submersible pump 9 pumps the water in the dewatering borehole 1 to the intercepting ditch outside the foundation pit.

[0051] Well plugging: During the construction of the foundation slab, the dewatering wells are plugged.

[0052] In this construction method, the nozzle of the high-pressure water gun is slowly inserted into the coarse filter pipe, ensuring that the nozzle reaches the bottom of the pipe. Then, the pressurization device is turned on, and the high-pressure water flow impacts the inner wall of the coarse filter pipe and the gaps in the surrounding coarse filter material, effectively breaking the protective mud skin attached to the pipe wall during the drilling process. At the same time, it loosens the mud, fine soil particles and other impurities remaining between the filter materials, opening up a flow channel for groundwater infiltration. Thus, the groundwater can flow smoothly into the second filter pipe 31 to improve the dewatering efficiency of the foundation pit. Example 2: This example discloses a pipe-in-pipe double-layer filter material gravity flow well dewatering structure. The difference between Example 2 and Example 1 is that, referring to Figures 4 and 5, the pipe-in-pipe double-layer filter material gravity flow well dewatering structure also includes a first disturbance element 61 and a second disturbance element 71. First disturbance members 61 are spaced apart on the outer periphery of the first filter tube 21 and inserted into the first filter material layer 4. A rotation drive device (e.g., drilling equipment) is externally connected to the upper end of the first filter tube 21, forcing the first filter tube 21 to perform forward and reverse reciprocating motion. Second disturbance members 71 are spaced apart on the outer periphery of the second filter tube 31 and inserted into the second filter material layer 5. A rotation drive device is externally connected to the upper end of the second filter tube 31, forcing the second filter tube 31 to perform forward and reverse reciprocating motion. In this embodiment, the first filter tube 21 and the second filter tube 31 can be made of galvanized steel pipe to improve the structural rigidity of the first filter tube 21 and the second filter tube 31.

[0053] The implementation principle of the pipe-in-pipe double-layer filter material gravity flow well dewatering structure in this application embodiment is as follows: Referring to Figures 4 and 5, during the filling of the first filter material layer 4, the operator can use an external rotation drive device to force the first filter pipe 21 to rotate slightly and periodically in the forward or reverse direction, so that the first disturbance member 61 on the outer periphery of the first filter pipe 21 vibrates the coarse filter material in the first filter material layer 4, thereby reducing the existence of large pores inside the first filter material layer 4 and improving the filtration effect of the first filter material layer 4 on groundwater.

[0054] Referring to Figures 4 and 5, during the filling of the second filter layer 5, the operator can use an external rotation drive device to force the second filter tube 31 to rotate slightly and periodically in the forward or reverse direction, causing the second disturbance member 71 on the outer periphery of the second filter tube 31 to vibrate the fine filter material in the second filter layer 5, thereby reducing the presence of large pores inside the second filter layer 5 and improving the filtration effect of the second filter layer 5 on groundwater.

[0055] Referring to Figures 4 and 5, after the gravity flow well dewatering structure has been in operation for a period of time, soil particles in the groundwater may block the flow channels between the coarse filter media in the first filter layer 4 and between the fine filter media in the second filter layer 5, thereby affecting the flow of groundwater. At this time, the staff can force the first filter pipe 21 or the second filter pipe 31 to rotate again to loosen the filter media in the first filter layer 4 or the second filter layer 5, so as to restore the porosity and permeability of the first filter layer 4 and the second filter layer 5 and improve the infiltration efficiency of groundwater.

[0056] Example 3 discloses a pipe-in-pipe double-layer filter material gravity flow well dewatering structure. The difference between Example 3 and Example 2 is that, referring to Figures 6 and 7, the pipe-in-pipe double-layer filter material gravity flow well dewatering structure further includes a first closed bottom plate 62, a first disturbance rope 63, a second closed bottom plate 72, and a second disturbance rope 73.

[0057] Referring to Figures 6 and 7, the first closed base plate 62 is fixed to the bottom of the first filter tube 21, and the diameter of the first closed base plate 62 is larger than the diameter of the first filter tube 21; a plurality of first mounting holes 621 are circumferentially formed on the outer periphery of the first closed base plate 62; one end of the first disturbance rope 63 passes through the first mounting hole 621, and the disturbance rope is fixedly connected to the first closed base plate 62; the first disturbance member 61 is provided with a second mounting hole 611 for the disturbance rope to pass through, and the first disturbance rope 63 is arranged along the length direction of the first filter tube 21.

[0058] Referring to Figures 6 and 7, in this embodiment, the first disturbance rope 63 includes a first wire rope 631 and a first disturbance spring 632. The first disturbance spring 632 is fixed between adjacent first wire ropes 631. The first wire ropes 631 pass through the second mounting hole 611 of the first disturbance member 61. In the vertical direction, the first disturbance spring 632 is disposed between adjacent first disturbance members 61. A first disturbance knot 6311 is provided on the first wire rope 631, and a clearance distance is provided between the first disturbance knot 6311 and the first disturbance member 61.

[0059] Referring to Figures 6 and 7, the second closed base plate 72 is fixed to the bottom of the first section of the second filter tube 31, and the diameter of the second closed base plate 72 is larger than the diameter of the second filter tube 31; a plurality of third mounting holes 721 are circumferentially formed on the outer periphery of the second closed base plate 72; one end of the second disturbance rope 73 passes through the third mounting hole 721, and the disturbance rope is fixedly connected to the second closed base plate 72; the second disturbance member 71 is provided with a fourth mounting hole 711 for the disturbance rope to pass through, and the second disturbance rope 73 is arranged along the length direction of the second filter tube 31.

[0060] Referring to Figures 6 and 7, in this embodiment, the second disturbance rope 73 includes a second steel wire rope 732 and a second disturbance spring 733. The second disturbance spring 733 is fixed between adjacent second steel wire ropes 732. The second steel wire ropes 732 pass through the fourth mounting hole 711 of the second disturbance member 71. In the vertical direction, the second disturbance spring 733 is disposed between adjacent second disturbance members 71. A second disturbance knot 7321 is provided on the second steel wire rope 732, and a clearance distance is provided between the second disturbance knot 7321 and the second disturbance member 71.

[0061] The implementation principle of the pipe-in-pipe double-layer filter material gravity flow well dewatering structure in this application embodiment is as follows: Referring to Figures 6 and 7, by setting a first disturbance rope 63 around the outer periphery of the first filter pipe 21, the vibration range of the first filter material layer 4 is expanded, so that the coarse filter material in the first filter material layer 4 is evenly distributed, thereby improving the filtration effect of the first filter material on groundwater. Furthermore, through the synergistic effect of the first wire rope 631 and the first disturbance spring 632, and by setting a first disturbance knot 6311 on the first wire rope 631, the vibration and loosening effect of the first disturbance rope 63 on the first filter material layer 4 is improved.

[0062] Referring to Figures 6 and 7, the second disturbance rope 73, which has the same effect as the first disturbance rope 63, is provided on the outer periphery of the second filter tube 31 to improve the vibration and loosening effect on the second filter material layer 5.

[0063] Example 4 discloses a pipe-in-pipe double-layer filter media gravity flow well dewatering structure. The difference between Example 4 and Example 2 is that, referring to Figures 8 and 9, the pipe-in-pipe double-layer filter media gravity flow well dewatering structure further includes an elastic support member 8. The elastic support member 8 is disposed at the bottom of the dewatering borehole 1 and is used to support the first filter pipe 21. In this example, the elastic support member 8 includes a supporting base plate 81, a supporting top plate 82, a supporting spring 83, and a flexible shell 84. The supporting spring 83 is fixed between the supporting base plate 81 and the supporting top plate 82. The flexible shell 84 is sleeved on the outer periphery of the supporting spring 83, and both ends of the flexible shell 84 are fixedly connected to the supporting base plate 81 and the supporting top plate 82, respectively. The supporting top plate 82 is used to support the first filter pipe 21.

[0064] The implementation principle of the pipe-in-pipe double-layer filter material gravity flow well dewatering structure in this application embodiment is as follows: Referring to Figures 8 and 9, by setting an elastic support member 8 at the bottom of the first filter pipe 21, the first filter pipe 21 and the first disturbance member 61 can vibrate in the vertical direction to improve the vibration effect of the first disturbance member 61 on the first filter material layer 4, thereby further reducing the large pores in the first filter material layer 4 and improving the filtration effect of the first filter material layer 4 on groundwater.

[0065] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pipe-in-pipe double-layer filter material gravity-flow well dewatering structure, wherein a dewatering borehole (1) is opened on the ground, and the gravity-flow well dewatering structure is fixed in the dewatering borehole (1); characterized in that: The filter includes a first filter tube (21), a second filter tube (31), a first filter layer (4), and a second filter layer (5). The first filter tube (21) is provided with a first water-permeable hole (211) spaced apart, and the second filter tube (31) is provided with a second water-permeable hole (311) spaced apart. The first filter tube (21) is sleeved on the outer periphery of the second filter tube (31). There is a clearance distance between the first filter tube (21) and the side wall of the rainwater borehole (1). The first filter layer (4) is filled between the side wall of the rainwater borehole (1) and the first filter tube (21). There is a clearance distance between the first filter tube (21) and the second filter tube (31). The second filter layer (5) is filled between the first filter tube (21) and the second filter tube (31). The diameter of the coarse filter material in the first filter layer (4) is larger than the diameter of the fine filter material in the second filter layer (5).

2. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 1, characterized in that: It also includes a first dense mesh (22) and a second dense mesh (32). The first dense mesh (22) covers the outer periphery of the first filter tube (21) and covers the first water-permeable hole (211). The second dense mesh (32) covers the outer periphery of the second filter tube (31) and covers the second water-permeable hole (311).

3. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 1, characterized in that: It also includes a first disturbance element (61), which is spaced apart on the outer periphery of the first filter tube (21) and inserted into the first filter material layer (4); the upper end of the first filter tube (21) is externally connected to a rotation drive device, which forces the first filter tube (21) to perform forward and reverse reciprocating motion.

4. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 1, characterized in that: It also includes a second disturbance element (71), which is spaced apart on the outer periphery of the second filter tube (31) and inserted into the second filter material layer (5); the upper end of the second filter tube (31) is externally connected to a rotation drive device, which forces the second filter tube (31) to perform forward and reverse reciprocating motion.

5. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 1, characterized in that: It also includes an elastic support (8), which is disposed at the bottom of the water-retaining borehole (1) and is used to support the first filter pipe (21).

6. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 5, characterized in that: The elastic support member (8) includes a support base plate (81), a support top plate (82), a support spring (83), and a flexible shell (84); the support spring (83) is fixed between the support base plate (81) and the support top plate (82), the flexible shell (84) is sleeved on the outer periphery of the support spring (83), and the two ends of the flexible shell (84) are fixedly connected to the support base plate (81) and the support top plate (82) respectively. The support top plate (82) is used to support the first filter tube (21).

7. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 3, characterized in that: It also includes a first closed base plate (62) and a first disturbance rope (63); the first closed base plate (62) is fixed to the bottom of the first filter tube (21) in the first section, and the diameter of the first closed base plate (62) is larger than the diameter of the first filter tube (21); a plurality of first mounting holes (621) are provided in a ring around the outer periphery of the first closed base plate (62); one end of the first disturbance rope (63) passes through the first mounting hole (621), the disturbance rope is fixedly connected to the first closed base plate (62), the first disturbance member (61) is provided with a second mounting hole (611) for the disturbance rope to pass through, and the first disturbance rope (63) is arranged along the length direction of the first filter tube (21).

8. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 7, characterized in that: The first disturbance rope (63) includes a first wire rope (631) and a first disturbance spring (632). The first disturbance spring (632) is fixed between adjacent first wire ropes (631). The first wire rope (631) passes through the second mounting hole (611) of the first disturbance member (61). In the vertical direction, the first disturbance spring (632) is disposed between adjacent first disturbance members (61).

9. The pipe-in-pipe double-layer filter media gravity-flow well dewatering structure according to claim 8, characterized in that: The first wire rope (631) is provided with a first disturbance knot (6311), and there is a clearance distance between the first disturbance knot (6311) and the first disturbance member (61).

10. A construction method for a pipe-in-pipe double-layer filter material gravity-flow well dewatering structure as described in any one of claims 1-9, characterized in that: Includes the following steps; Processing of the first filter tube (21) and the second filter tube (31): A first permeable hole (211) is processed on the first filter tube (21), and a first dense mesh (22) is wrapped around the outer periphery of the first filter tube (21). A second permeable hole (311) is processed on the second filter tube (31), and a second dense mesh (32) is wrapped around the outer periphery of the second filter tube (31). Construction of the first filter tube (21): After the dewatering borehole (1) is completed, the first filter tubes (21) are vertically inserted into the dewatering borehole (1) in sequence, and the ends of adjacent first filter tubes (21) are fixedly connected. The opening of the last section of the first filter pipe (21) is higher than the ground; Construction of the first filter layer (4): Prepare coarse filter material, and pour it evenly around the outside of the pipe wall of the first filter pipe (21) in a circular direction, so that the coarse filter material fills the annular gap between the first filter pipe (21) and the side wall of the dewatering borehole (1) to form the first filter layer (4); Well washing construction: After the construction of the first filter layer (4) is completed, insert the nozzle of the high-pressure water gun into the inside of the first filter pipe (21). After the nozzle of the high-pressure water gun reaches the bottom of the pipe, turn on the pressurization device and use the high-pressure water flow Impact the inner wall of the first filter tube (21) and the gaps in the coarse filter media in the first filter media layer (4) until the water overflowing from the first filter tube (21) is clear and free of visible mud and sand particles; Construction of the second filter tube (31): Place the second filter tubes (31) into the first filter tube (21) in sequence, fix adjacent second filter tubes (31) together, align the second filter tubes (31) and the first filter tube (21) concentrically, and provide a gap between the second filter tubes (31) and the first filter tube (21); Construction of the second filter media layer (5): Prepare fine filter media, Fine filter material is evenly poured around the outside of the first filter pipe (21) in a circular direction, so that coarse filter material fills the annular gap between the second filter pipe (31) and the first filter pipe (21) to form the second filter material layer (5); Dewatering construction: a submersible pump (9) is installed at the bottom of the second filter pipe (31), and the submersible pump (9) is started for trial pumping. By observing the water output and water clarity, it is determined whether the dewatering effect meets the design standards; During formal drainage, the submersible pump (9) pumps the water in the dewatering borehole (1) to the intercepting ditch outside the foundation pit.

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