Vertical subsurface flow wetland structure and construction method

Abstract

The invention relates to the technical field of sewage treatment and ecological restoration, in particular to a vertical subsurface flow wetland structure and a construction method.The vertical subsurface flow wetland structure comprises a water collecting wetland, water collecting and distributing channels and a collecting system, the water collecting and distributing channels are arranged on the two sides of the water collecting wetland, and the collecting system is arranged on the surface of the water collecting wetland; the catchment wetland is composed of a rammed earth layer, composite impermeable geotechnical cloth, a coarse sand backfill layer, a gravel filler layer and an emergent aquatic plant layer from bottom to top, rectangular zigzag protrusions are arranged on the top surfaces of the canal walls on the two sides of the catchment and distribution canal, and stepping water falling devices facing the inner side of the catchment and distribution canal are arranged in the intervals of the protrusions; the collecting system is composed of a longitudinal perforated water collecting main pipe and a transverse water collecting branch pipe. And the water collecting wetland is provided with a breather pipe system. The system has the beneficial effects that efficient sewage treatment and collaborative optimization of structural stability and ecological landscapes are realized, and the system has remarkable technical innovation and practicability and has a wide application prospect in the fields of sewage treatment and ecological restoration.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sewage treatment and ecological restoration, and particularly relates to a vertical subsurface flow wetland structure and a construction method. BACKGROUND

[0002] The subsurface flow wetland is an artificial wetland system for purifying sewage through water flow in a filler layer, including horizontal subsurface flow type and vertical subsurface flow type. The core working mechanism is to use sand, gravel and other medium layers for physical filtration, rely on plant root exudates to promote chemical adsorption, and complete biological degradation through biological membrane and microbial community on the surface of the filler. Compared with the surface flow wetland, the subsurface flow wetland has the advantages of good sanitary condition, high treatment efficiency and good heat preservation.

[0003] The traditional vertical subsurface flow wetland has problems of single water flow state, poor structural stability and single ecological function. In the prior art, the water distribution system is mostly designed as a single channel, the water distribution is uneven, the anchoring system often uses a single material, and the shear strength is insufficient, and the plant configuration lacks systematic design. The present application solves the above technical bottlenecks through innovative structural design. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the present application provides a vertical subsurface flow wetland structure and a construction method, which realizes the synergistic optimization of efficient sewage treatment, structural stability and ecological landscape through the innovative design of the three-dimensional water distribution system, the multi-layer composite anchoring system, the air pipe system and the top covering system. The structure has significant technical innovation and practicality, and has a wide application prospect in the field of sewage treatment and ecological restoration.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme: A vertical subsurface flow wetland structure, comprising a water collection wetland, a water distribution channel and a collection system, the water collection wetland is provided with the water distribution channel on both sides, the water collection wetland is provided with the collection system, the water collection wetland is provided with a soil ramming layer, a composite anti-seepage geotextile, a coarse sand backfill layer, a gravel filler layer and a emergent plant layer from bottom to top, the top surface of the channel wall on both sides of the water distribution channel is provided with a rectangular sawtooth-shaped protrusion, the protrusion height is 15-20 cm, the interval is 30-40 cm, a step waterfall device facing the inner side of the water distribution channel is arranged in the interval of the protrusion, the surface of the step waterfall device is provided with a gravel buffer zone, the outer channel wall tail end of the water distribution channel is provided with an overflow outflow wall, and the top of the overflow outflow wall is provided with an outward inclined surface; the composite anti-seepage geotextile is laid to the position of the inner side of the channel wall to form a geotextile anchoring structure; the collection system is composed of a longitudinally perforated water collection main pipe and a transversely perforated water collection branch pipe, and the water collection main pipe and the water collection branch pipe are arranged at the top and the bottom of the gravel filler layer respectively; and the water collection wetland is provided with an air pipe.

[0006] Furthermore, the composite impermeable geotextile in the water-collecting wetland adopts an HDPE-GCL composite structure with an overlap width of 20-30cm; the crushed stone filling layer adopts 10mm-15mm graded crushed stone with a porosity of 35%-40%; and the coarse sand backfill layer adopts 0.5mm-2mm coarse sand with a thickness of 200mm-250mm.

[0007] Furthermore, the water collection channel is constructed of reinforced concrete with a wall thickness of 200-300mm. The inner wall is coated with waterproof paint, and a movable cover plate is installed on the top of the water collection channel, with an artificial turf covering layer on the cover plate.

[0008] Furthermore, the stepping stone cascading device is arranged in an inverted isosceles triangular stepped pattern at the distance between the protrusions.

[0009] Furthermore, the overflow wall is 300mm to 350mm thick and has honeycomb-shaped overflow holes on its surface.

[0010] Furthermore, the geotextile anchoring structure includes a layer of lime-soil and a thick plain concrete layer from bottom to top, and the composite impermeable geotextile is provided with an asphalt sand filling layer at the channel wall position.

[0011] Furthermore, in the geotextile anchoring structure, the lime-soil layer is made of a 3:7 lime-soil mass ratio and has a thickness of 150-200mm; the plain concrete layer is made of concrete with a thickness of 50-100mm and a crack-resistant steel mesh is set on the surface.

[0012] Furthermore, the water collection branch pipe includes an upper branch pipe and a lower branch pipe. The upper branch pipe is 20-30cm away from the top of the crushed stone filling layer, and the lower branch pipe is 30-50cm away from the bottom of the crushed stone filling layer. The water collection branch pipe runs horizontally through the main water collection pipe, and the water collection branch pipe and the main water collection pipe form a crisscross water collection grid. The water collection branch pipe and the main water collection pipe are made of HDPE material with a pipe diameter of 110-120mm. The pipe wall has circular water collection holes with a diameter of 10-12mm and a hole spacing of 20-30cm.

[0013] Furthermore, the ventilation pipes are installed at the four corners and center of the wetland, with rain caps on the top of the pipes. The ventilation pipes are made of PVC material with a diameter of 50-70mm, and the pipe walls have ventilation holes with a diameter of 3-5mm and a hole spacing of 50-70cm to form a three-dimensional ventilation network.

[0014] A construction method for a vertical subsurface flow wetland structure, the specific method including the following: S1. Construction of the catchment wetland: s1.1, Compacted subgrade layer: The layered compaction process is adopted, with each layer being 300mm thick. A 12-ton vibratory roller is used for compaction, with a compaction degree of ≥95%, ensuring that the foundation bearing capacity is ≥200kPa. s1.2 Composite impermeable geotextile: Utilizing hot-melt welding technology, with a welding temperature of 280–300℃ and a welding speed of 1.5 m / min, the permeability coefficient is ≤1×10⁻⁶. -12 cm / s; s1.3 Construction of geotextile anchoring system: Lime-soil layer: After mechanical mixing, it is manually compacted to a compaction degree of ≥93%, and a non-woven fabric isolation layer is laid between it and the composite impermeable geotextile; Plain concrete layer: After pouring, it is covered with wet burlap bags for curing for 7 days; Asphalt sand filling layer: The filling width is 20cm and the depth is 10cm. Petroleum asphalt and quartz sand are mixed at a temperature of 160-180℃. After mechanical filling, it is manually compacted to a compaction degree of ≥98%; s1.4 Coarse sand backfill layer: Backfill in layers, each layer 50-80mm, compacted with a plate vibrator, porosity ≤30%; s1.5 Crushed stone filling layer: Crushed stone thickness 800-1000mm, washed to remove mud and sand after laying; s1.6, Emergent plant layer: Water thoroughly after planting to ensure a survival rate of ≥95%; S2. Construction of the water collection and distribution channel: s2.1, Water collection and distribution channels: Waterproof coating thickness ≥ 2mm, two channels arranged in parallel with a spacing of 8m; s2.2, Sawtooth stepping stone cascade device: gravel buffer strip with a particle size of 5-10mm, a thickness of 10-15cm, and a slope of 1:1.5; s2.3 Overflow outlet wall: A stainless steel grating is installed on the top to prevent debris from entering; S3, Vent pipe installation s3.1 Vent pipe: An airtightness test shall be conducted after installation; S4, Top Covering System Construction s4.1 Movable cover plate: bolted to the embedded parts of the water collection and distribution channel; s4.2 Artificial turf cover layer: bonded to the movable cover plate with special adhesive, with a strength ≥0.5MPa, and trimmed after laying to ensure the landscape effect.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1) The vertical subsurface flow wetland structure achieves uniform hydraulic distribution through a three-dimensional wetland structure and a collection and distribution channel. The sawtooth drop system provides aeration and oxygenation functions, and the multi-layer composite anchoring system ensures structural stability, increases shear strength, expands the scope of application, and has strong practicality.

[0016] 2) The vertical layered structure enables wastewater to be purified layer by layer. The crushed stone filler layer filters suspended solids, the coarse sand backfill layer provides support and reduces leakage, and the purified wastewater is discharged through the collection and distribution channel, which improves the wastewater discharge capacity of the wetland and enhances its ecological function.

[0017] 3) Emergent plant layers remove pollutants through root absorption and microbial degradation, reducing pollutant accumulation, achieving self-cleaning, reducing wetland maintenance workload, and lowering wetland maintenance costs.

[0018] 4) The ventilation system maintains an alternating anaerobic / aerobic environment, promotes microbial metabolic activity, and enables biodegradation through microorganisms, thereby improving environmental governance capabilities.

[0019] 5) The top cover system combines ecological landscape functions with structural protection, forming an efficient, stable, and beautiful wetland ecosystem.

[0020] 6) Through the innovative design of the three-dimensional water collection and distribution system, multi-layer composite anchoring system, venting pipe system and top covering system, the system achieves synergistic optimization of efficient sewage treatment, structural stability and ecological landscape. It has significant technological innovation and practicality, and has broad application prospects in the field of sewage treatment and ecological restoration. Attached Figure Description

[0021] Figure 1 This is a longitudinal structural cross-sectional view of a vertical subsurface flow wetland structure according to the present invention.

[0022] Figure 2 This is a cross-sectional view of the vertical subsurface flow wetland structure described in this invention.

[0023] Figure 3 This is a partial view of the geotextile anchoring of a vertical subsurface flow wetland structure according to the present invention.

[0024] Figure 4 This is a partial view of the stepping stone construction method for a vertical subsurface flow wetland structure as described in this invention.

[0025] Figure 5 This is a partial overflow diagram of a vertical subsurface flow wetland structure described in this invention.

[0026] Figure 6 This is a top plan view of a vertical subsurface flow wetland structure as described in this invention.

[0027] Figure 7 This is a bottom plan layout diagram of a vertical subsurface flow wetland structure according to the present invention.

[0028] In the diagram: 1. Water collection wetland; 2. Water collection channel; 3. Collection system; 1-1. Compacted soil layer; 1-2. Composite impermeable geotextile; 1-3. Coarse sand backfill layer; 1-4. Crushed stone fill layer; 1-5. Emergent vegetation layer; 1-6. Lime-soil layer; 1.7. Plain concrete layer; 1.8. Asphalt sand filling layer; 2-1. Channel wall; 2-2. Stepping stone drop device; 2-3. Protrusion; 2-4. Overflow wall; 2-5. Movable cover plate; 2-6. Artificial turf covering layer; 3-1. Main water collection pipe; 3-2. Branch water collection pipe; 4. Ventilation pipe. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figures 1-7 The diagram illustrates a vertical subsurface flow wetland structure, comprising a catchment wetland 1, a collection channel 2, and a collection system 3. The catchment wetland 1 has collection channels 2 on both sides, and a collection system 3 is installed within it. The catchment wetland 1, from bottom to top, consists of a compacted soil layer 1-1, a composite impermeable geotextile 1-2, a coarse sand backfill layer 1-3, a crushed stone fill layer 1-4, and an emergent plant layer 1-5. The top surface of the channel walls 2-1 on both sides of the collection channel 2 is... Rectangular sawtooth protrusions 2-3 are provided, with a height of 15-20cm and a spacing of 30-40cm. Stepping stones 2-3 facing the inner side of the water collection channel 2 are installed within the spacing of the protrusions 2-3. A gravel buffer strip is provided on the surface of the stepping stones 2-2. An overflow wall 2-4 is provided at the tail end of the outer channel wall 2-1 of the water collection channel 2, with an outward-facing slope at the top of the overflow wall 2-4. The composite impermeable geotextile 1... -2 A geotextile anchoring structure is installed on the inner side of the channel wall 2-1. The collection system 3 consists of a longitudinally perforated main water collection pipe 3-1 and a transverse water collection branch pipe 3-2. The main water collection pipe 3-1 and the branch pipe 3-2 are respectively located at the top and bottom of the crushed stone filling layer 1-4. The branch pipe 3-2 includes an upper branch pipe and a lower branch pipe. The upper branch pipe is 20-30cm away from the top of the crushed stone filling layer 1-4, and the lower branch pipe is 30-50cm away from the bottom of the crushed stone filling layer 1-4. The branch pipe 3-2 crosses the main water collection pipe 3-1, and the branch pipe 3-2 and the main water collection pipe 3-1 form a crisscrossing water collection grid. The branch pipe 3-2 and the main water collection pipe 3-1 are made of HDPE material with a pipe diameter of 110-120mm. Circular water collection holes with a diameter of 10-12mm are opened on the pipe wall, with a hole spacing of 20-30cm. The water collection wetland 1 is equipped with a ventilation pipe 4.

[0030] Catchment wetland: Composite impermeable geotextile 1-2 adopts HDPE-GCL composite structure with an overlap width of 20cm; The crushed stone packing layers 1-4 use 10-15mm graded crushed stone with a porosity of 35-40%, which effectively filters suspended solids in wastewater and provides a carrier for microbial attachment. Coarse sand backfill layers 1-3 use 0.5-2mm coarse sand with a thickness of 200mm to provide good permeability and support, and prevent the backfill layer from settling. Emergent plant layers 1-5 are selected from native species such as reeds and cattails, with a planting density of 25 plants / m². 2 With its well-developed root system, it enhances the soil's ability to consolidate while also providing ecological and landscape benefits.

[0031] Geotextile anchoring structure: In the geotextile anchoring structure, the lime-soil layers 1-6 are made of lime-soil in a 3:7 mass ratio, with a thickness of 150-200mm; Plain concrete layers 1-7 are made of C20 concrete, with a thickness of 50-100mm, and are reinforced with Φ6@200mm anti-crack steel mesh to enhance crack resistance. Jibu Water Channel 2: The water collection channel 2 is constructed of reinforced concrete, with a wall thickness of 200mm and the inner wall coated with waterproof paint.

[0032] The top surface of the water collection channel 2 includes 12 rectangular sawtooth protrusions 2-3, with a height of 15-20cm and a spacing of 30-40cm.

[0033] The surface of the stepping stone cascade device 2-2 is equipped with an ecological gravel buffer strip with a particle size of 5-10mm and a thickness of 10cm, which enhances the buffering function of water flow and ecological habitat.

[0034] Overflow outlet walls 2-4 are made of reinforced concrete with a thickness of 300-350mm. The surface is provided with honeycomb overflow holes with a diameter of 50mm and a spacing of 20cm to achieve uniform overflow.

[0035] Ventilation tube 4: Ventilation pipes 4 are installed at the four corners and center of the water collection wetland 1 to maintain an alternating anaerobic / aerobic environment and promote microbial metabolic activities; Ventilation pipe 4 is made of PVC pipe with a diameter of 50mm. The pipe wall has 3mm diameter ventilation holes with a hole spacing of 50cm to form a three-dimensional ventilation network. A rain cap is installed on the top of the pipe to prevent rainwater from flowing back in and to ensure the normal operation of the ventilation system.

[0036] Top Coverage: The top of the water collection channel 2 is equipped with a movable cover plate 2-5. The movable cover plate 2-5 is made of fiberglass with a thickness of 8mm and has an anti-slip texture pressed on the surface, which facilitates daily inspection and maintenance. The top surface of the movable cover plate 2-5 is equipped with an artificial turf covering layer 2-6. The artificial turf is woven from polyethylene fiber, with a grass height of 20mm and a density of 2kg / m², and has good weather resistance and landscape effect.

[0037] A construction method for a vertical subsurface flow wetland structure, the specific method including the following: S1. Construction of the catchment wetland: s1.1, Compacted subgrade layer 1-1: A layered compaction process is adopted, with each layer being 300mm thick. A 12-ton vibratory roller is used for compaction, with a compaction degree ≥95%, ensuring the foundation bearing capacity ≥200kPa.

[0038] s1.2, Composite impermeable geotextile 1-2: Utilizing hot-melt welding technology, the welding temperature is 280-300℃, the welding speed is 1.5m / min, and the permeability coefficient is ≤1×10⁻⁶. -12 cm / s, and after laying, an electric spark test is performed to ensure there are no leaks.

[0039] s1.2.1, Lime-soil layer 1-6: Lay in layers with a layer thickness of 150mm, mechanically mixed and then manually compacted, with a compaction degree ≥93%, and lay a non-woven fabric isolation layer between it and the impermeable geotextile.

[0040] s1.2.2 Plain concrete layer 1-7: C20 concrete, 50mm thick, with Φ6@200mm anti-crack steel mesh on the surface, and covered with wet burlap bags for curing for 7 days after pouring.

[0041] s1.2.3, Asphalt Sand Filling Layer 1-8: Set between the channel wall 2-1 and the plain concrete layer 1-7, with a filling width of 20cm and a depth of 10cm. It is made of 60# road petroleum asphalt and quartz sand, with a temperature of 160-180℃. After mechanical filling, it is manually compacted with a compaction degree ≥98%.

[0042] s1.3, Coarse sand backfill layer 1-3: Backfill in layers of 50mm each, compacted with a plate vibrator, with a porosity ≤30%.

[0043] s1.4, Crushed stone filler layer 1-4: Crushed stone thickness 800mm, after laying, it is washed to remove mud and sand to ensure filtration and microbial adhesion functions.

[0044] S1.5, Emergent plant layer 1-5: Root trimming retains 15cm of the main root. After planting, water thoroughly to ensure a survival rate of ≥95%.

[0045] Construction of S2 and Distribution Channel 2: s2.1, Water collection and distribution channel 2: It adopts C30 reinforced concrete structure, and the inner wall is coated with polyurethane waterproof coating with a thickness of ≥2mm. The two channels are arranged in parallel with a spacing of 8m.

[0046] s2.2, Stepping Stone Waterfall Device 2-2: Stepping stone waterfall device 2-2 consists of 12 downward-facing isosceles triangular protrusions. The surfaces of the isosceles triangular protrusions are provided with a gravel buffer zone with a slope of 1:1.5.

[0047] s2.3, Stainless steel grating is installed on the top of the overflow water outlet wall 2-4 to prevent debris.

[0048] S3, Vent pipe 4 installation s3.1, Ventilation pipe 4: Grid-like arrangement with a spacing of 2m, and an airtightness test shall be conducted after installation.

[0049] S4, Top Covering System Construction s4.1 Movable cover plate 2-5: Anti-slip texture size 1000mm×500mm, bolted to the embedded part of the water collection channel 2.

[0050] s4.2 Artificial turf cover layer 2-6: Bonded to the movable cover plate 2-5 with special adhesive, with a strength ≥0.5MPa, ensuring a firm connection, preventing rainwater seepage, and extending service life. Trimming after installation ensures optimal landscaping effect.

[0051] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A vertical subsurface flow wetland structure, comprising a catchment wetland, a collection and distribution channel, and a collection system, characterized in that, The wetland is equipped with water collection channels on both sides and a collection system. From bottom to top, the wetland consists of a compacted soil layer, a composite impermeable geotextile, a coarse sand backfill layer, a gravel filler layer, and an emergent plant layer. Rectangular sawtooth protrusions, 15-20 cm high and spaced 30-40 cm apart, are installed on the top surface of the channel walls on both sides. Stepping stones facing inwards are installed within the protrusion spacing, with a gravel buffer strip on their surface. An overflow wall is constructed at the end of the outer channel wall, with an outward-sloping top. The composite impermeable geotextile is anchored to the inner side of the channel wall. The collection system consists of a longitudinally perforated main collection pipe and transverse branch collection pipes, located at the top and bottom of the gravel filler layer, respectively. A venting pipe is also provided in the wetland.

2. The vertical subsurface flow wetland structure according to claim 1, characterized in that, The composite impermeable geotextile in the water collection wetland adopts an HDPE-GCL composite structure with an overlap width of 20-30cm; the crushed stone filling layer adopts 10mm-15mm graded crushed stone with a porosity of 35%-40%; the coarse sand backfill layer adopts 0.5mm-2mm coarse sand with a thickness of 200mm-250mm.

3. A vertical subsurface flow wetland structure according to claim 1, characterized in that, The water collection channel is made of reinforced concrete with a wall thickness of 200-300mm. The inner wall is coated with waterproof paint. The top of the water collection channel is equipped with a movable cover plate, and an artificial turf covering layer is installed on the cover plate.

4. A vertical subsurface flow wetland structure according to claim 1, characterized in that, The stepping stone cascade device is arranged in an inverted isosceles triangular stepped pattern at the distance between the protrusions.

5. A vertical subsurface flow wetland structure according to claim 1, characterized in that, The overflow wall is 300mm to 350mm thick and has honeycomb-shaped overflow holes on its surface.

6. A vertical subsurface flow wetland structure according to claim 1, characterized in that, The geotextile anchoring structure includes a layer of lime-soil and a thick plain concrete layer from bottom to top, and the composite impermeable geotextile is filled with an asphalt sand layer at the channel wall location.

7. A vertical subsurface flow wetland structure according to claim 6, characterized in that, The geotextile anchoring structure is composed of a 3:7 lime-soil mass ratio and has a thickness of 150-200mm; the plain concrete layer is made of concrete with a thickness of 50-100mm and is reinforced with anti-crack steel mesh on the surface.

8. A vertical subsurface flow wetland structure according to claim 1, characterized in that, The water collection branch pipe includes an upper branch pipe and a lower branch pipe. The upper branch pipe is 20-30cm away from the top of the crushed stone filling layer, and the lower branch pipe is 30-50cm away from the bottom of the crushed stone filling layer. The water collection branch pipe runs across the main water collection pipe, and the water collection branch pipe and the main water collection pipe form a crisscross water collection grid. The water collection branch pipe and the main water collection pipe are made of HDPE material with a pipe diameter of 110-120mm. The pipe wall has circular water collection holes with a diameter of 10-12mm and a hole spacing of 20-30cm.

9. A vertical subsurface flow wetland structure according to claim 1, characterized in that, The ventilation pipes are installed at the four corners and center of the wetland. Rain caps are installed on the top of the pipes. The ventilation pipes are made of PVC pipes with a diameter of 50-70mm. Ventilation holes with a diameter of 3-5mm are opened on the pipe wall with a hole spacing of 50-70cm to form a three-dimensional ventilation network.

10. A construction method for a vertical subsurface flow wetland structure according to any one of claims 1 to 9, characterized in that, The specific methods include the following: S1. Construction of the catchment wetland: s1.1, Compacted subgrade layer: The layered compaction process is adopted, with each layer being 300mm thick. A 12-ton vibratory roller is used for compaction, with a compaction degree of ≥95%, ensuring that the foundation bearing capacity is ≥200kPa. s1.2 Composite impermeable geotextile: Utilizing hot-melt welding technology, with a welding temperature of 280–300℃ and a welding speed of 1.5 m / min, the permeability coefficient is ≤1×10⁻⁶. -12 cm / s; s1.3 Construction of geotextile anchoring system: Lime-soil layer: After mechanical mixing, it is manually compacted to a compaction degree of ≥93%, and a non-woven fabric isolation layer is laid between it and the composite impermeable geotextile; Plain concrete layer: After pouring, it is covered with wet burlap bags for curing for 7 days; Asphalt sand filling layer: The filling width is 20cm and the depth is 10cm. Petroleum asphalt and quartz sand are mixed at a temperature of 160-180℃. After mechanical filling, it is manually compacted to a compaction degree of ≥98%; s1.4 Coarse sand backfill layer: Backfill in layers, each layer 50-80mm, compacted with a plate vibrator, porosity ≤30%; s1.5 Crushed stone filling layer: Crushed stone thickness 800-1000mm, washed to remove mud and sand after laying; s1.6, Emergent plant layer: Water thoroughly after planting to ensure a survival rate of ≥95%; S2. Construction of the water collection and distribution channel: s2.1, Water collection and distribution channels: Waterproof coating thickness ≥ 2mm, two channels arranged in parallel with a spacing of 8m; s2.2, Sawtooth stepping stone cascade device: gravel buffer strip with a particle size of 5-10mm, a thickness of 10-15cm, and a slope of 1:1.5; s2.3 Overflow outlet wall: A stainless steel grating is installed on the top to prevent debris from entering; S3, Ventilation Piping System Installation s3.1 Vent pipe: An airtightness test shall be conducted after installation; S4, Top Covering System Construction s4.1 Movable cover plate: bolted to the embedded parts of the water collection and distribution channel; s4.2 Artificial turf cover layer: bonded to the movable cover plate with special adhesive, with a strength ≥0.5MPa, and trimmed after laying to ensure the landscape effect.

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