Urban rain garden cover structure

Abstract

The utility model discloses a kind of urban rainwater garden covering structures, including main structure, the perimeter of main structure is equipped with side slope, main structure sequentially includes from below to above: anti-seepage layer, gravel layer, sand layer, filter layer, replacement soil layer, covering layer, water storage flower mirror layer, superhigh water layer;Overflow well is equipped in main structure and passes through each layer, water storage flower mirror layer and the height between the top of overflow well form superhigh water layer, superhigh water layer is lower than side slope top;Permeable blind pipe is laid in gravel layer, one end of permeable blind pipe is communicated with overflow well, the other end extends out ground through main structure.

Description

Technical Field

[0001] This utility model relates to a sponge city water storage and purification structure, and more particularly to an urban rain garden covering structure. Background Technology

[0002] In recent years, with rapid economic development and continuous expansion of urban scale and population, the available green space and water storage capacity of green areas have gradually decreased. Traditional drainage system designs often focus only on short-term rainwater discharge, neglecting rainwater collection, utilization, and ecological protection. These problems not only restrict the sustainable development of waterfront landscapes but may also lead to bottlenecks in their construction. Unlike traditional urban drainage systems, rain gardens emphasize naturalness and multifunctionality. By constructing green infrastructure, they combine the collection, purification, storage, utilization, and discharge of rainwater resources, achieving the recycling of water resources and effective protection of the ecological environment.

[0003] Currently, the construction of urban waterfront green space rain gardens mostly adopts simple covering treatments, resulting in inconsistent construction techniques that directly restrict the quality of site drainage and subsequent plant maintenance. How to systematically and efficiently improve urban rain garden covering methods and reduce construction costs is a significant challenge in organizing construction. Furthermore, research on optimizing and improving urban rain garden construction methods is still incomplete, and a complete and effective technical system and operational procedures have not yet been established.

[0004] Therefore, there is an urgent need for a sponge facility for urban waterfront green spaces that is simple in structure, easy to construct, and can better meet the requirements of sponge city rainwater resource management. Summary of the Invention

[0005] Purpose of the utility model: The purpose of this utility model is to provide an urban rain garden covering structure that is simple in structure, easy to construct, and can better meet the requirements of sponge city rainwater resource management.

[0006] Technical Solution: The urban rain garden covering structure of this utility model includes a main structure with slopes around its perimeter. From bottom to top, the main structure comprises: an impermeable layer, a gravel layer, a sand layer, a filter layer, a replacement soil layer, a covering layer, a water-retaining flower bed layer, and a super-high water layer. Overflow wells are installed within each layer of the main structure. A super-high water layer is formed between the top of the water-retaining flower bed layer and the top of the overflow wells, and this super-high water layer is lower than the top of the slopes. Permeable blind pipes are laid within the gravel layer, with one end connected to the overflow well and the other end extending through the main structure to the ground.

[0007] The gravel layer has a thickness of 300-350 mm and consists of two layers: a lower layer with gravel particles of 30-50 mm in diameter and a thickness of 200-230 mm, and an upper layer with gravel particles of 5-10 mm in diameter and a thickness of 100-120 mm. This particle size difference achieves functional stratification, allowing for "larger particle size drainage and smaller particle size filtration," ensuring rapid rainwater discharge while enhancing the system's purification capacity and stability.

[0008] A debris-blocking net is installed below the overflow outlet.

[0009] The permeable blind pipe has an observation port at its end extending above the ground; the permeable pipe is wrapped with a mesh.

[0010] The impermeable layer is a composite geomembrane; the filter layer is a non-woven geotextile, preferably two layers of non-woven geotextile, each layer of non-woven geotextile having a thickness of not less than 0.5 mm.

[0011] The replacement soil layer has a thickness of 500-600 mm and consists of two layers, each with a thickness of 250-300 mm. By controlling the compaction degree, settlement, and elevation accuracy through layering, the structure's stability and construction controllability are improved while ensuring soil permeability, providing a fundamental guarantee for the core functions of the rain garden, such as water collection, infiltration, and vegetation growth.

[0012] The sand layer has a thickness of 80-100 mm; the medium-coarse sand has a moderate porosity and its permeability coefficient is between that of the replacement soil layer and the gravel layer, which can play a buffering role; the permeability of the sand layer ensures that rainwater is quickly conducted to the gravel layer, avoiding water accumulation that affects the permeability of the upper soil and protecting the root system of plants.

[0013] The water-retaining flower bed layer has a thickness of 200-250 mm; it enhances pollutant purification by adsorbing and intercepting suspended particulate matter in rainwater on the surface of the water-retaining flower bed layer, reducing the pollutant load entering the lower soil layer, and forming a "multi-layer purification system" with the lower sand and gravel layers, significantly improving water quality, while also giving the facility landscape and cultural value.

[0014] The overflow outlet is 200-250 mm above the bottom surface of the rain garden cover structure to ensure that some rainwater can be stored and the excess water can be discharged through the overflow outlet.

[0015] The top surface of the observation port is 100-150 mm higher than the overflow water level, and the height of the ultra-high water layer is 80-100 mm.

[0016] The covering layer has a thickness of 50-75 mm and is made of organic or inorganic mulch material. The covering layer effectively buffers the impact of rainwater, preventing surface soil erosion. Simultaneously, the 50-75 mm thickness forms a physical barrier, maintaining soil porosity, ensuring unobstructed rainwater infiltration channels, enhancing the rain garden's water retention capacity, and providing a continuous moisture environment for underlying microbial activity and plant roots.

[0017] The overflow well is connected to the municipal pipeline network or river.

[0018] Beneficial effects: Compared with the prior art, this utility model achieves the following significant effects:

[0019] (1) This utility model can make the covering layer system stable for a long time, with low construction cost, good durability, and simple and flexible construction and maintenance. The technical system is complete, ensuring the safety of construction and shortening the construction period. (2) This utility model has strong ecological and sustainable characteristics. (3) It is highly flexible, has low operating cost, and is highly integrated with the site. It is suitable for public facilities land, centralized green spaces, open areas in the suburbs and other open spaces, and has ecological engineering advantages. (4) It has low construction cost, wide applicability, and can effectively retain and purify rainwater runoff. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0021] The technical solution of this utility model will be further described below with reference to the accompanying drawings.

[0022] An urban rain garden covering structure includes a main structure with slopes 13 around its perimeter. The main structure, from bottom to top, comprises: an impermeable layer 1, a gravel layer 2, a sand layer 3, a filter layer 4, a replacement soil layer 5, a cover layer 6, a water-retaining flower bed layer 7, and a superhigh water layer 8. Overflow wells 11 are installed within the main structure, passing through each layer and connected to municipal pipe networks or waterways. A debris-blocking net is installed below the overflow outlet 12 within the overflow well 11. A superhigh water layer 8 is formed between the top of the water-retaining flower bed layer 7 and the top of the overflow well 11, and is lower than the top of the slope 13. A permeable blind pipe 9 is laid within the gravel layer 2, with one end connected to the overflow well 11 and the other end extending through the main structure to the ground surface. An observation port 10 is installed at the end extending to the ground surface, with the top of the observation port 10 100-150 mm above the overflow water level.

[0023] Gravel layer 2 consists of two layers: the lower layer is composed of gravel with a particle size of 30-50 mm and a thickness of 200-230 mm; the upper layer is composed of gravel with a particle size of 5-10 mm and a thickness of 100-120 mm; the total thickness of gravel layer 2 is 300-350 mm.

[0024] The permeable pipe 9 laid in the gravel layer 2 is a perforated permeable blind pipe made of PE material with an opening rate of 1%; the outer periphery of the permeable blind pipe is wrapped with hydrolysis-resistant 80-mesh mesh.

[0025] The impermeable layer 1 is laid using a composite geomembrane, and its nominal tensile strength should not be less than 16 kN / m. During the installation of the impermeable layer 1, the edges of the material should overlap by a certain width, which should not be less than 200 mm.

[0026] The thickness of sand layer 3 is 80-100 mm, and clean medium-coarse sand is used as the material for rain garden sand layer 3.

[0027] A filter layer 4 is laid on top of the sand layer 3. The filter layer 4 is made of two layers of non-woven geotextile. The thickness of the non-woven geotextile should not be less than 0.5 mm, and the longitudinal and transverse tensile strength should not be less than 10 kN / m.

[0028] The thickness of the replacement soil layer 5 is 500-600 mm; the replacement soil layer 5 consists of two layers, upper and lower; each layer is 250-300 mm thick. To prevent uneven settlement, the filling height can be slightly increased, but controlled within 50 mm.

[0029] The overflow outlet 12 is 200-250 mm above the bottom surface of the rain garden cover structure to ensure that some rainwater can be stored and the excess water can be discharged through the overflow outlet 12.

[0030] The mulch layer 6 should be 50-75 mm thick and should use organic or inorganic mulch materials, such as pebbles, volcanic rock, or bark. Acid-loving plants are best suited to bark mulch, while alkaline-loving plants are best suited to nutshell mulch. In windy environments, heavier inorganic stone mulch can be chosen, while plants that prefer good drainage are best suited to porous volcanic rock. The thickness of the surface mulch layer 6 should be controlled to 50-75 mm, with organic mulch being the preferred choice. Pebbles should be used in suitable locations to prevent rainwater from washing away the organic mulch and to ensure continuous nutrient release.

[0031] The height of the water-retaining flower bed layer 7 is 200-250 mm. Plants with well-developed root systems, rapid growth, and lush foliage are selected for planting in the water-retaining flower bed layer 7. Native or domesticated introduced plant varieties are preferred to ensure that the plant roots are well-developed, effectively remove pollutants in the facility, and have minimal impact on the foundations of surrounding buildings.

[0032] The overflow outlet 12 of the overflow well 11 is surrounded by a pile of rubble with a particle size of 30-100 mm to protect the overflow outlet 12 and prevent debris such as leaves from clogging it. The overflow outlet 12 is about 200-250 mm above the bottom of the rain garden to ensure that some rainwater can be stored and the excess can be discharged through the overflow outlet 12.

[0033] The overflow outlet 12 has an extra-high water layer 8 of 80-100 mm from the top of the overflow well, ensuring that the rain garden as a whole has enough drainage space to ensure smooth water flow and no short-circuiting.

Claims

1. A rain garden cover structure for urban areas, characterized in that, The main structure includes a main structure with slopes (13) around its perimeter. The main structure, from bottom to top, includes: a seepage-proof layer (1), a gravel layer (2), a sand layer (3), a filter layer (4), a replacement soil layer (5), a cover layer (6), a water-retaining flower mirror layer (7), and an ultra-high water layer (8). An overflow well (11) is provided through each layer in the main structure. An ultra-high water layer (8) is formed between the top of the water-retaining flower mirror layer (7) and the top of the overflow well (11). The ultra-high water layer (8) is lower than the top of the slope (13). A permeable blind pipe (9) is laid in the gravel layer (2). One end of the permeable blind pipe (9) is connected to the overflow well (11), and the other end extends through the main structure to the ground.

2. The urban rain garden cover structure according to claim 1, characterized in that, The gravel layer (2) consists of two layers: the upper layer is gravel with a particle size of 5-10 mm, and the lower layer is gravel with a particle size of 30-50 mm.

3. The urban rain garden cover structure according to claim 2, characterized in that, The upper layer has a thickness of 100-120 mm, and the lower layer has a thickness of 200-230 mm.

4. The urban rain garden cover structure according to claim 1, characterized in that, The thickness of the sand layer (3) is 80-100 mm, the height of the water-retaining flower mirror layer (7) is 200-250 mm, and the height of the ultra-high water layer (8) is 80-100 mm.

5. The urban rain garden cover structure according to claim 1, characterized in that, The thickness of the replacement soil layer (5) is 500-600 mm; the replacement soil layer (5) includes upper and lower layers; the thickness of each layer is 250-300 mm.

6. The urban rain garden cover structure according to claim 1, characterized in that, The overflow outlet (12) is 200-250 mm above the bottom surface of the rain garden cover structure to ensure that some rainwater can be stored and the excess water can be discharged through the overflow outlet (12).

7. The urban rain garden cover structure according to claim 1, characterized in that, The top surface of the observation port (10) is 100-150 mm higher than the overflow water level.

8. The urban rain garden cover structure according to claim 1, characterized in that, The thickness of the covering layer (6) is 50-75 mm, and the covering layer (6) is an organic or inorganic covering material.

9. The urban rain garden cover structure according to claim 1, characterized in that, The impermeable layer (1) is a composite geomembrane; the filter layer (4) is a non-woven geotextile.

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