Grass planting ditch system with hierarchical control structure

Abstract

The utility model discloses a grassed swale system with a hierarchical control structure. The grassed swale system comprises a plurality of grassed swale units and ecological percolation weirs, wherein the grassed swale units are arranged in a stepped and hierarchical mode, and the ecological percolation weirs are arranged between every two adjacent grassed swale units. The top surfaces of the ecological percolation weirs are higher than the top surfaces of the adjacent grassed swale units which are positioned at higher levels, and the height difference is smaller than the elevation of a rainwater runoff water surface line in a two-year recurrence period; a gravel layer, a planting soil layer, a first layer of water-permeable geotextile, a graded gravel layer, a second layer of water-permeable geotextile and a plain soil layer are sequentially laid on each grass planting ditch unit from top to bottom. The ecological percolation weir comprises a multi-stage filler layer for adsorbing impurities, a gabion rust-free welding net arranged on the periphery of the multi-stage filler layer and a supporting base layer. According to the utility model, layer-by-layer treatment of rainwater is realized, the problems of overlarge runoff load and low pollutant reduction efficiency are avoided, and the on-site purification capacity of initial rainfall is improved.

Description

Technical Field

[0001] This utility model relates to the field of low impact development facilities engineering, and in particular to a graded control structure grassed swale system suitable for bare ground cover on sloping orchards. Background Technology

[0002] Vegetated swales are ecological drainage systems that enhance the natural infiltration and retention of rainwater through turf or vegetation. Their functions include reducing rainwater runoff, filtering pollutants, replenishing groundwater, and improving urban landscapes and microclimates. However, current applications of vegetated swales present several challenges. First, traditional designs often follow a single, continuous channel, making it difficult to adapt to varying elevations and resulting in poor drainage or insufficient infiltration in some areas. Second, rainwater is frequently discharged directly through a single channel without process control, easily leading to runoff concentration and exceeding the capacity of subsequent systems. Furthermore, existing vegetated swales have limited functionality, with insufficient water storage and purification capabilities, failing to effectively address the needs of reducing different target pollutants. Finally, comprehensive design and long-term maintenance are inadequate, failing to adequately consider rainwater retention and resource utilization. Therefore, future designs need to be optimized to better adapt to terrain changes, enhance water storage and purification functions, and incorporate refined management to improve overall ecological benefits and stormwater management capabilities. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention proposes a graded control structure for grassed swales, which can adapt to terrain differences, treat rainwater in stages, and improve the initial rainwater purification effect.

[0004] The specific technical solution is as follows:

[0005] A graded control structure for grassed swales includes multiple grassed swale units and multiple ecological infiltration weirs. The grassed swale units are arranged in a stepped grade, with an ecological infiltration weir arranged between two adjacent grassed swale units. The top surface of the ecological infiltration weir is higher than the top surface of the adjacent grassed swale unit located at a higher grade, and the height difference is less than the elevation of the rainwater runoff water surface line during the two-year return period.

[0006] The grassed swale unit is laid from top to bottom as follows: gravel layer, planting soil layer, first layer of permeable geotextile, graded crushed stone layer, second layer of permeable geotextile, and plain soil layer; the thickness of the planting soil layer is greater than that of the graded crushed stone layer.

[0007] The ecological infiltration weir comprises: a multi-stage packing layer, a rust-free gabion mesh, and a supporting foundation layer; the multi-stage packing layer uses natural materials with the ability to adsorb impurities, and the particle size of the packing gradually decreases from the inlet end to the outlet end; the multi-stage packing layer is divided into multiple layers according to particle size, and rust-free gabion mesh is arranged between different layers on the outer periphery and inside of the multi-stage packing layer; the supporting foundation layer is arranged below the multi-stage packing layer and includes, from top to bottom, a concrete cushion layer, a crushed stone cushion layer, and a plain soil layer.

[0008] Furthermore, the horizontal direction of the different grassed swale unit steps is defined as the Y direction, and the horizontal direction perpendicular to this direction is defined as the X direction; the width direction of the grassed swale unit is along the X direction, and the length direction is along the Y direction; the width direction of the ecological infiltration weir is along the Y direction, and the length direction is along the X direction; the width of the swale opening of each grassed swale unit is adjusted according to the elevation of its location and the actual needs for pollutant reduction.

[0009] Furthermore, the gravel diameter of the gravel layer ranges from Φ30 to 50 mm, and the unit area mass of both layers of permeable geotextile is greater than or equal to 200 g / m². 2 The diameter range of the graded crushed stone is Φ30~50mm, and the compaction coefficient of the subgrade in the subgrade layer is greater than or equal to 0.95.

[0010] Furthermore, the multi-level filler layer uses natural materials with the ability to adsorb impurities, including volcanic rock, waste bricks, coal slag, and cement blocks.

[0011] Furthermore, the upper surface of the ecological infiltration weir is covered with a soil layer and planted with evergreen herbaceous plants.

[0012] Furthermore, the slope protection on both sides of the system adopts a trapezoidal or triangular cross-section design with a slope ratio of less than or equal to 1:3.

[0013] The beneficial effects of this utility model are:

[0014] This invention overcomes the problems of excessive runoff load and low pollutant reduction efficiency caused by centralized rainwater discharge in traditional vegetated swales by constructing a tiered control system. The tiered design adapts to changes in terrain elevation, enabling layered treatment of rainwater and significantly improving the on-site purification capacity of initial rainfall. This design effectively reduces pressure on rain gardens and other downstream facilities, improving the overall operational efficiency of the rainwater management system. Simultaneously, it reduces soil erosion and runoff pollution, improving the sustainability of the urban environment. Attached Figure Description

[0015] Figure 1 This is a plan view of the hierarchical control structure of the grassed swale system proposed in this embodiment of the utility model.

[0016] Figure 2 This is a longitudinal cross-sectional view of the hierarchical control structure of the grassed swale system proposed in this embodiment of the utility model.

[0017] Figure 3 This is a cross-sectional view of the ecological infiltration weir and slope protection in an embodiment of this utility model.

[0018] Figure 4 This is a cross-sectional view of the grassed ditch unit and slope protection in an embodiment of this utility model.

[0019] In the diagram, the layers are: 1. Water storage layer; 2. Gravel layer; 3. Planting soil layer; 4. Permeable geotextile; 5. Graded crushed stone layer; 6. Plain soil layer; 7. Primary crushed stone layer; 8. Secondary crushed stone layer; 9. Tertiary crushed stone layer; 10. Quaternary crushed stone layer; 11. Concrete cushion layer; 12. Graded crushed stone cushion layer; 13. Rust-free welded gabion mesh. Detailed Implementation

[0020] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer as a result. Further detailed description of the present invention will be provided below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0021] like Figure 1 and Figure 2 As shown, a tiered controlled vegetated swale system includes multiple vegetated swale units and multiple ecological infiltration weirs. The different vegetated swale units are constructed in a stepped design, with an ecological infiltration weir positioned between two adjacent units. The ecological infiltration weirs enable the vegetated swale units to collect water in stages, effectively preventing direct impact on the end of the flow. Simultaneously, they regulate water flow velocity and purify the water, ensuring that rainwater flows progressively into the next level of vegetated swale unit. This guarantees the water storage and purification capacity of each level of vegetated swale unit, ensuring that rainwater is treated layer by layer as it flows through each level of vegetated swale, achieving tiered purification. This tiered controlled vegetated swale structure better adapts to terrain changes, while possessing water storage and purification functions, stormwater management capabilities, alleviating runoff concentration problems, and improving the absorption efficiency of initial rainfall and pollutant removal rates. The horizontal direction extending from the different vegetated swale units is defined as the Y-direction, and the horizontal direction perpendicular to this direction is defined as the X-direction. The width of the grassed swale unit is along the X direction, and its length is along the Y direction; the width of the ecological infiltration weir is along the Y direction, and its length is along the X direction.

[0022] The width of the ditch opening in each vegetated swale unit can be flexibly adjusted according to the actual needs of the ground elevation and the target pollutant reduction, thereby enhancing the absorption and purification capacity of initial rainwater. In this embodiment, the ditch opening width is set within the range of 0.5 to 3 meters. The ditch depth is reasonably designed, with the top surface of the ecological infiltration weir higher than the top surface of the adjacent, higher-level vegetated swale unit, and the height difference between the two top surfaces is less than the elevation of the rainwater runoff surface line during the two-year return period, in order to achieve water storage. In this embodiment, this height difference is set within the range of 0.3 to 0.5 meters. This design ensures that an effective height difference is formed between the bottom of the ditch (i.e., the top surface of the vegetated swale unit) and the ecological infiltration weir, which is conducive to water flow guidance and infiltration.

[0023] Each grassed swale unit has a relatively gentle longitudinal slope in the Y direction, which can effectively control the flow rate of rainwater between each level, avoid water erosion and runoff concentration. This design helps rainwater to gradually infiltrate and achieve layer-by-layer reduction of pollutants in each level, thereby improving the overall treatment effect of the system.

[0024] like Figure 2 As shown, each vegetated swale unit is laid from top to bottom as follows: gravel layer 2, planting soil layer 3, first layer of permeable geotextile 4, graded gravel layer 5, second layer of permeable geotextile 4, and plain soil layer 6. The top surface of gravel layer 2 is lower than the top surface of the adjacent ecological infiltration weir (located between this level of vegetated swale unit and the next level of vegetated swale unit), and the two top surfaces form a water storage layer 1. In this embodiment, the gravel diameter of gravel in gravel layer 2 ranges from Φ30 to 50 mm, which is used to prevent the planting soil layer 3 from being washed away by rainwater and to perform water storage and drainage functions, while also filtering impurities in the process of drainage. Planting soil layer 3 provides favorable conditions for vegetation growth, and its thickness is 400 mm, which is greater than the thickness of gravel layer 2, ensuring sufficient growth space for vegetation, which is conducive to the healthy growth of green plants, and at the same time improving the ecological function of the overall system. The unit area mass of both layers of permeable geotextile 4 is greater than or equal to 200 g / m². 2 The graded gravel layer 5 is used to further filter impurities in the water. The thickness of the graded gravel layer 5 is 500mm, and the diameter of the graded gravel ranges from Φ30 to 50mm. This thickness gives the graded gravel layer 5 stronger water storage and drainage capacity, allowing it to hold more rainwater, thereby alleviating water flow pressure during heavy rain and improving overall water storage efficiency. The thickness of the graded gravel layer 5 is not necessarily related to the thickness of the planting soil layer 3; the thickness of the graded gravel layer 5 can be greater than, less than, or equal to the thickness of the planting soil layer 3. This embodiment only provides one implementation method. The subsoil in the subsoil layer 6 is compacted, with a compaction coefficient greater than or equal to 0.95. This layered design ensures that rainwater undergoes multiple layers of filtration during infiltration, improving rainwater purification efficiency.

[0025] In actual production, rainwater infiltrates through a series of layers: gravel layer 2, planting soil layer 3, first layer of permeable geotextile 4, graded gravel layer 5, second layer of permeable geotextile 4, and plain soil layer 6. This layer-by-layer filtration and infiltration drainage effectively enhances the water absorption, infiltration, purification, and storage capacity of the vegetated swale unit, preventing water accumulation on its surface. Simultaneously, the multi-layer filtration system effectively removes pollutants, ensuring that the discharged water meets ecological standards.

[0026] As an intermediate buffer zone in the tiered drainage system, the ecological infiltration weir extends in the same direction (length) as the vegetated swale unit, ensuring even distribution of rainwater. Furthermore, the weir creates effective flow regulation zones between different levels, increasing retention time and purification efficiency. The length of the ecological infiltration weir is greater than the width of the vegetated swale unit to effectively intercept and regulate rainwater flow.

[0027] like Figure 2 and Figure 3 As shown, the ecological infiltration weir includes: a multi-stage packing layer, a rust-free gabion mesh 13, and a supporting foundation layer. The height of the ecological infiltration weir is adjusted according to the depth of each vegetated swale unit to ensure that the height difference between the top surface of the ecological infiltration weir and the top surface of the adjacent, higher-level vegetated swale unit is within a set range. The multi-stage packing layer can use natural materials with the ability to adsorb impurities, such as volcanic rock, waste bricks, cinders, and cement blocks. The particle size of the packing gradually decreases from 5-8 cm at the inlet end to 1-2 cm at the outlet end (at least four layers are designed), forming a distinct layered structure to ensure that rainwater is fully filtered and purified. The rust-free gabion mesh 13 is arranged on the outer periphery of the multi-stage packing layer and between the internal layers. Its pore size changes with the particle size of the internal packing, serving to separate filter media of different particle sizes and regulate and guide water flow. In this embodiment, the multi-stage packing layer is designed as four layers, which are sequentially arranged from the inlet end to the outlet end as follows: primary crushed stone layer 7, secondary crushed stone layer 8, tertiary crushed stone layer 9, and quaternary crushed stone layer 10; wherein, the gravel particle size of the primary crushed stone layer 7 is Φ50mm, the particle size of the secondary crushed stone layer 8 is Φ30mm, the particle size of the tertiary crushed stone layer 9 is Φ20~30mm, and the particle size of the quaternary crushed stone layer 10 is Φ10~15mm.

[0028] The supporting foundation layer of the ecological infiltration weir is arranged below the multi-stage filler layer. Its design emphasizes stability and permeability. Through the synergistic effect of the multi-layer structure, it provides solid support to ensure the overall stability of the weir while enhancing the infiltration effect and promoting the natural infiltration of rainwater. The supporting foundation layer is constructed of strong and highly permeable materials, consisting of a concrete cushion layer 11, a graded crushed stone cushion layer 12, and a plain soil layer 6 from top to bottom. This ensures the long-term durability of the structure while reducing the impact of foundation settlement and water erosion on the weir. This layered design provides a reliable guarantee for the efficient operation of the ecological infiltration weir. In addition, the concrete cushion layer 11 is impermeable, serving to support and separate different levels of vegetated swale units; the graded crushed stone cushion layer 12, while providing support, also supports water flow, playing a role in auxiliary drainage.

[0029] To enhance the purification effect, a soil layer can be placed on the upper surface of the ecological infiltration weir, and evergreen herbaceous plants can be planted. This design not only enhances infiltration and filtration capacity, but also effectively controls eutrophication of water bodies by allowing plants to absorb nutrients such as nitrogen and phosphorus from the water.

[0030] like Figure 4 As shown, the slopes on both sides of the vegetated swale system under graded control structure are gentle, with a slope ratio of less than or equal to 1:3, exhibiting high stability and meeting safety and functional requirements. The trapezoidal or triangular cross-section design of the slopes ensures smooth water flow, enhances rainwater infiltration, and guarantees simple construction and more economical and efficient maintenance in the later stages.

[0031] It will be understood by those skilled in the art that the above descriptions are merely preferred embodiments of the utility model and are not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the utility model should be included within the protection scope of the utility model.

Claims

1. A graded control system for constructing grassed swales, characterized in that, It includes multiple grassed swale units and multiple ecological infiltration weirs. The grassed swale units are arranged in a stepped manner, and an ecological infiltration weir is arranged between two adjacent grassed swale units. The top surface of the ecological infiltration weir is higher than the top surface of the adjacent grassed swale unit located at a higher level, and the height difference is less than the elevation of the rainwater runoff water surface line during the two-year return period. The grassed swale unit is laid from top to bottom as follows: gravel layer, planting soil layer, first layer of permeable geotextile, graded crushed stone layer, second layer of permeable geotextile, and plain soil layer; the thickness of the planting soil layer is greater than that of the graded crushed stone layer. The ecological infiltration weir comprises: a multi-stage packing layer, a rust-free gabion mesh, and a supporting foundation layer; the multi-stage packing layer uses natural materials with the ability to adsorb impurities, and the particle size of the packing gradually decreases from the inlet end to the outlet end; the multi-stage packing layer is divided into multiple layers according to particle size, and rust-free gabion mesh is arranged between different layers on the outer periphery and inside of the multi-stage packing layer; the supporting foundation layer is arranged below the multi-stage packing layer and includes, from top to bottom, a concrete cushion layer, a crushed stone cushion layer, and a plain soil layer.

2. The hierarchical control structure of the grassed swale system according to claim 1, characterized in that, The horizontal direction extending from different grassed swale units is defined as the Y direction, and the horizontal direction perpendicular to this direction is defined as the X direction. The width of the grassed swale unit is along the X direction, and its length is along the Y direction. The width of the ecological infiltration weir is along the Y direction, and its length is along the X direction. The width of the swale opening of each grassed swale unit is adjusted according to the elevation of its location and the actual needs for pollutant reduction.

3. The hierarchical control structure of the grassed swale system according to claim 1, characterized in that, The gravel in the gravel layer has a diameter range of Φ30~50mm, and the unit area mass of both layers of permeable geotextile is greater than or equal to 200g / m². 2 The diameter range of the graded crushed stone is Φ30~50mm, and the compaction coefficient of the subgrade in the subgrade layer is greater than or equal to 0.

95.

4. The hierarchical control structure of the grassed swale system according to claim 1, characterized in that, The upper surface of the ecological infiltration weir is covered with a soil layer and planted with evergreen herbaceous plants.

5. The hierarchical control structure of the grassed swale system according to claim 1, characterized in that, The slope protection on both sides of the system adopts a trapezoidal or triangular cross-section design with a slope ratio of less than or equal to 1:3.

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