Deep well filtration structure

Abstract

To provide a deep well filtering structure that effectively prevents the subsidence and collapse of the well wall. [Solution] The deep well filtration structure of this invention includes a surface loess layer 1 and a well channel 7, with a concrete well side 8 poured onto the surface of the surface loess layer, a reinforced concrete permeable pipe and a reinforced concrete solid pipe 10 installed in sequence inside the well channel, a well pipe pallet 6 placed at the bottom end of the well channel, and below the surface loess layer, in sequence, a gravel-mixed loess layer 2, a gravel layer 3, a crushed stone-mixed loess layer 4 and an underground loess layer 5, and a clay ball-filled sealing layer 9 filled between the surface loess layer, the gravel-mixed loess layer and the reinforced concrete solid pipe.

Description

[Technical Field]

[0001] This invention relates to the field of deep well construction technology, specifically to the deep well filtration structure. [Background technology]

[0002] The technique of filling small gaps in deep wells is mainly used to fill the narrow gaps left after the installation of auxiliary well pipes. If the filtration layer is not filled in timely or densely, the soil layer will collapse and block the water outlet, causing the newly constructed pump well to be abandoned. Therefore, the most important factor in backfilling technology is the selection of the backfilling process. By densely filling the filtration material, it is possible to ensure that the soil wall does not collapse after backfilling, or that the degree of collapse is within an acceptable range. Summary of the Invention [Problem to be solved by the invention]

[0003] The purpose of the present invention is to provide a deep well filtration structure to solve the problem that if the filtration layer of the background art cannot be backfilled in a timely manner or is not backfilled densely, the soil layer will collapse and block the water outlet, causing the newly constructed pump well to be abandoned. [Means for solving the problem]

[0004] The technical solution of this invention is a deep well filtration structure, which includes a surface loess layer and a well channel, with a concrete well side poured onto the surface of the surface loess layer, a reinforced concrete permeable pipe and a reinforced concrete solid pipe installed in sequence inside the well channel, and a well pipe tray placed at the bottom end of the well channel, and below the surface loess layer, there are a gravel-mixed loess layer, a gravel layer, a crushed stone-mixed loess layer and an underground loess layer in that order, and a clay ball-filled sealing layer is filled between the surface loess layer, the gravel-mixed loess layer and the reinforced concrete solid pipe, and a filter material-filled sealing layer is filled between the gravel layer and the reinforced concrete permeable pipe.

[0005] Preferably, the gravel layer is distributed above and below the crushed stone-mixed loess layer, the surface loess layer is distributed above the gravel-mixed loess layer, and the underground loess layer is distributed below the gravel layer.

[0006] Preferably, the clay ball filling sealing layer and the reinforced concrete solid pipe are alternately distributed from top to bottom, and the gravel layer is made of 10 to 20 mm boulders, which increases permeability while preventing the inflow of fine particles.

[0007] Preferably, the reinforced concrete solid pipes and the reinforced concrete permeable pipes are alternately distributed from top to bottom.

[0008] Preferably, the clay sphere filling sealing layer is made of bentonite spheres with a particle size of 5-10 mm, and has a water swelling rate of 200%.

[0009] Preferably, the filter material filling and sealing layer uses gradation quartz sand, the particle size of which is 0.5 to 2 mm, and the pores are filled with the particle gradation, and the permeability coefficient is 1 × 10 -3 It is controlled to cm / s. [Effects of the Invention]

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0011] By selecting the classified material model and controlling the dynamic consolidation, the backfill density can reach 93% or more, effectively avoiding the settlement and collapse of the well wall.

[0012] It is a long-lasting filtering material that significantly extends the well cleaning cycle, has stable water filtering efficiency, and a sediment blocking rate of ≥ 98%, reducing the risk of sediment accumulation in the well. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a structural schematic diagram of the present invention; [Figure 2] FIG. 2 is an enlarged structural schematic diagram of the present invention in FIG. 1A. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1-2, a deep well filtration structure according to one embodiment of the present invention includes a surface loess layer 1 and a well channel 7. A concrete well wall 8 is poured on the surface of the surface loess layer 1. A reinforced concrete permeable pipe 12 and a reinforced concrete solid pipe 10 are installed in the well channel 7 in that order. A well pipe pallet 6 is placed at the bottom end of the well channel 7. Below the surface loess layer 1, there are a gravel-mixed loess layer 2, a gravel layer 3, a crushed stone-mixed loess layer 4 and an underground loess layer 5. A clay ball-filled sealing layer 9 is filled between the soil layer 1, the gravel-mixed loess layer 2 and the reinforced concrete solid pipe 10, a filter material-filled sealing layer 11 is filled between the gravel layer 3 and the reinforced concrete permeable pipe 12, two layers of 75 mesh strainers are wrapped around the outside of the well pipe, and another layer of antiseptic-treated bamboo blinds is wrapped around the outside of the strainers, and gradient crushed stone is backfilled around the blinds to a depth of 0.5 to 2 cm, to a thickness of 15 cm, thereby achieving a sediment filtering effect.

[0015] Furthermore, the gravel layer 3 is distributed above and below the crushed stone mixed loess layer 4, the surface loess layer 1 is distributed above the gravel mixed loess layer 2, the underground loess layer 5 is distributed below the gravel layer 3, the clay ball filled sealing layer 9 and the reinforced concrete solid pipe 10 are distributed alternately from top to bottom, and the gravel layer 3 uses selected 10 to 20 mm boulders to increase permeability while preventing the inflow of fine particles.

[0016] Furthermore, the reinforced concrete solid pipes 10 and the reinforced concrete permeable pipes 12 are alternately distributed from top to bottom, and the clay ball filling sealing layer 9 is made of bentonite balls with a particle size of 5 to 10 mm, which have a water expansion rate of 200%, ensuring a sealing barrier.

[0017] Furthermore, the filter material filling and sealing layer 11 uses gradation quartz sand with a particle size of 0.5 to 2 mm, and fills the pores with particle gradation, resulting in a permeability coefficient of 1×10 -3The flow rate is controlled at cm / s, and during the backfilling operation, density sensors are embedded in advance to monitor the backfill's density target of 93% or higher in real time. When it detects that local density is insufficient, pressure is supplied by directional grouting. On-site detection shows that this technology has increased the backfill density standard achievement rate from the previous 75% to 92%.

[0018] C40 high-performance concrete is used, blended with 5% ultra-fine silica fume and 0.02% steel fiber, to improve the crack resistance of the pipe material, and the flexural strength reaches 5.2 MPa, 30% higher than conventional concrete. The optimal blending ratio is determined through orthogonal testing, and on the premise of ensuring strength, the pipe wall thickness is reduced from the previous 100 mm to 60-80 mm, reducing the self-weight load. A double-wall structure with "ribbed inside and smooth outside" is used, with annular ribs on the inner wall with a pitch of 30 cm to reinforce vertical rigidity and a smooth outer wall, improving friction resistance with the ground. The structure has a maximum deformation of ≦3mm under a lateral pressure of 20MPa. It uses a "prefabrication-lifting-butting" integrated process, and when prefabricated in the factory, grout holes with a diameter of 50mm are left in advance. After installation, micro-expansion cement paste is injected through the holes, with an expansion rate of 1.5% to 2%. This tightly bonds the pipe body to the stratum and improves the overall stability. The backfill material is distributed reasonably and improves the density of the backfill, effectively avoiding the settlement and collapse of the well wall and having a filtering effect, reducing the risk of sedimentation in the well. [Explanation of symbols]

[0019] 1. Surface loess layer, 2. Loess layer mixed with gravel, 3. Gravel layer, 4. Loess layer mixed with crushed stone, 5. Underground loess layer, 6. Well pipe palette, 7. Well channel, 8. Concrete well side, 9. Clay ball filled sealing layer, 10. Reinforced concrete solid pipe, 11. Filter material filled sealing layer, 12. Reinforced concrete permeable pipe.

Claims

1. A deep well filtration structure comprising a surface loess layer and a well channel, wherein the concrete well side is cast and formed on the surface of the surface loess layer, a reinforced concrete permeable pipe and a reinforced concrete solid pipe are installed in order inside the well channel, a well pipe pallet is left at the bottom end of the well channel, a gravel-mixed loess layer, a gravel layer, a crushed stone-mixed loess layer and an underground loess layer are located in that order below the surface loess layer, a clay ball-filled sealing layer is filled between the surface loess layer, the gravel-mixed loess layer and the reinforced concrete solid pipe, and a filter material-filled sealing layer is filled between the gravel layer and the reinforced concrete permeable pipe.

2. The deep well filtration structure according to claim 1, characterized in that the gravel layer is distributed above and below the crushed stone mixed loess layer, the surface loess layer is distributed above the gravel mixed loess layer, and the underground loess layer is distributed below the gravel layer.

3. The deep well filtration structure of claim 1, characterized in that the clay ball filling sealing layer and the reinforced concrete solid pipe are alternately distributed from top to bottom, and the gravel layer is selected to use 10-20 mm boulders, which can increase the water permeability and prevent the inflow of fine particles.

4. The deep well filtration structure according to claim 1, wherein the reinforced concrete solid pipe and the reinforced concrete permeable pipe are alternately distributed from top to bottom.

5. The deep well filtration structure as claimed in claim 1, characterized in that the clay ball filling sealing layer is made of bentonite balls with a particle size of 5-10 mm, and the water expansion rate is 200%.

6. The deep well filtration structure as claimed in claim 1, characterized in that the filter material filling and sealing layer is made of gradient quartz sand, the particle size of which is 0.5-2mm, and the pores are filled by particle gradient.

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