A rigid-flexible coordinated ecological slope protection structure, construction method and slope protection method

Abstract

The present invention discloses a rigid-flexible coordinated ecological slope protection structure, construction method and slope protection method, which belong to the field of ecological slope protection, including an ecological vegetation protection stone area, a drawdown zone transition area and a plant root anchoring area arranged in sequence from downstream to upstream, wherein the ecological vegetation protection stone area is arranged below the low water level of the slope, the drawdown zone transition area is arranged in the drawdown zone of the slope, the plant root anchoring area is arranged above the high water level of the slope, and the drawdown zone transition area and the plant root anchoring area are also provided with a transverse drainage ditch, and the drawdown zone transition area and the plant root anchoring area are both rigid-flexible coordinated structures. The present invention adopts the above-mentioned rigid-flexible coordinated ecological slope protection structure, construction method and slope protection method, and utilizes the rigid-flexible coordinated structure to improve the hydraulic-mechanical environment and ecological environment of the slope, realize the ecological slope protection against river water scouring, and the slope above the high water level against heavy rainfall scouring, which is conducive to maintaining the long-term stability of the ecological environment.

Description

Technical Field

[0001] The present invention relates to the field of river ecological slope protection, and in particular to a rigid-flexible coordinated ecological slope protection structure, a construction method and a slope protection method. Background Art

[0002] Due to the long-term scouring of the river bank caused by periodic flood storage or flood discharge, the river bank protection foundation is becoming increasingly weak. When the river flow velocity is strong under the action of rainfall during the flood season, the traditional ecological slope protection cannot effectively prevent the scouring of the water flow in the drawdown zone and the scouring of the slope by rainfall, which is prone to problems such as soil erosion, river bank collapse and slope sliding.

[0003] Traditional flexible ecological slope protection, such as bio-blanket slope protection, can support plants that are initially fragile and have low erosion resistance. Although traditional rigid slope protection structures have a certain anti-erosion effect, they cannot provide a good habitat and rooting environment for vegetation, and traditional slope protection structures usually find it difficult to simultaneously take into account the long-term stability of terrestrial and aquatic ecological environments.

[0004] In addition, the use of cement-based materials for slope protection consumes a large amount of materials in ecological protection such as river embankments, and relying solely on exogenous aluminosilicates for ecological slope protection requires long-distance transportation, which not only increases transportation costs, but also does not conform to the green and low-carbon design concept. At the same time, the rigid slope protection method cannot give full play to the flexible role of vegetation in the slope protection process, such as canopy throttling and root anchoring. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a rigid-flexible coordinated ecological slope protection structure, a construction method and a slope protection method. The rigid-flexible coordinated structure can improve the hydraulic-mechanical environment of the slope and the ecological environment of the river channel, and realize the protection of the ecological slope from river water scouring and the protection of the river channel slope above the high water level from heavy rainfall scouring, which is conducive to maintaining the long-term stability of the ecological environment.

[0006] To achieve the above-mentioned purpose, the present invention provides a rigid-flexible coordinated ecological slope protection structure, including an ecological vegetation protection stone area, a drawdown zone transition area and a plant root anchoring area arranged in sequence from downstream to upstream, wherein the ecological vegetation protection stone area is arranged below the low water level of the river slope, the drawdown zone transition area is arranged in the drawdown zone of the river slope, the plant root anchoring area is arranged above the high water level of the river slope, the drawdown zone transition area and the plant root anchoring area are also provided with transverse drainage ditches, and drainage holes are opened on the side of the transverse drainage ditch facing the plant root anchoring area, and the drawdown zone transition area and the plant root anchoring area are both rigid-flexible coordinated structures.

[0007] Preferably, the rigid-flexible cooperative structure comprises a rigid slope consolidation layer and a flexible vegetation layer arranged sequentially from bottom to top, and the rigid slope consolidation layer comprises a double-layer capillary retardation effect barrier layer composed of a fine-grained soil layer, an unsaturated drainage sand layer and a coarse-grained soil layer laid sequentially from bottom to top;

[0008] The rigid-flexible coordinated structure of the transition zone of the drawdown zone also includes a polylactic acid biodegradable geotextile and an ecological vegetation concrete grid sequentially laid on the top of the double-layer capillary retardation effect barrier layer. The flexible vegetation layer in the transition zone of the drawdown zone includes a geobag group fixed on the slope through a folded fiber net and a matrix layer and a seed layer sequentially sprayed on the geobag group. The seed layer is one of cattail, reed, Polygonum perforatum, Artemisia capillaris, Lythrum salicina and any combination thereof. The upper and lower ends of the polylactic acid biodegradable geotextile are respectively anchored to the transverse drainage ditch and the concrete baffle arranged at the bottom of the slope;

[0009] The rigid-flexible coordinated structure of the plant root anchoring zone also includes an ecological vegetation concrete grid and a retaining net sequentially laid on the top of the double-layer capillary barrier layer. The top of the retaining net extends out of the slope and is fixed by concrete pressure. The bottom of the retaining net is anchored to the transverse drainage ditch. The flexible vegetation layer of the plant root anchoring zone includes a matrix layer and a seed layer sequentially sprayed on the ecological vegetation concrete grid. The seed layer is one of sour jujube, alfalfa, meadow fescue, ryegrass, bermudagrass, and awnless bromegrass and any combination thereof.

[0010] The matrix layer includes river sediment, amendments, fertilizers, mixed seeds, water retaining agents, adhesives, and microbial preparations.

[0011] Preferably, the geobag group includes slope-fixing geobags and ecological geobags arranged in a stepped structure from bottom to top, the slope-fixing geobags are filled with sand and gravel, and the ecological geobags are filled with porous ecological ceramsite and planting soil.

[0012] Preferably, a plurality of longitudinal drainage ditches connected to the transverse drainage ditches are evenly arranged on the ecological vegetation concrete grid in the transition zone of the drawdown zone, and an expansion joint is arranged between the longitudinal drainage ditch and the ecological vegetation concrete grid, and the expansion joint is filled with polyethylene closed-cell foam board, asphalt fir board or asphalt sand board;

[0013] The bottom end of the transverse drainage ditch is fixed to the slope through the middle anti-overturning pile.

[0014] Preferably, the ecological vegetation protection stone area includes a plurality of gabions laid on the top of the gravel cushion layer located in the foot protection area, the plurality of gabions are arranged in a stepped manner, and the gabions are filled with blocks of stone and aquatic plant ecological balls, and the aquatic plant ecological balls are arranged close to the inner wall of the gabions;

[0015] The space between the gabion and the bottom concrete baffle is filled with crushed stone or gravel, and an inverted trapezoidal gabion riprap layer is set on the side of the bottom gabion away from the slope;

[0016] The gravel cushion layer is fixed by anti-overturning piles at the bottom.

[0017] A construction method of a rigid-flexible coordinated ecological slope protection structure comprises the following steps:

[0018] S1. Preparation of raw materials:

[0019] S11, preparing porous ecological ceramsite: after 30%-40% of river sediment and 60%-70% of external industrial solid waste are mixed evenly, preheated at a temperature of 400°C-600°C, and then fired at a roasting temperature of 1000°C-1200°C to obtain porous ecological ceramsite with a diameter of 10mm-30mm and a porosity of 40%-50%;

[0020] S12, preparing ecological vegetation concrete grid: using the porous ecological ceramsite prepared in step S11 as coarse aggregate, mixing 60%-70% of coarse aggregate, 10%-20% of cement, 10%-15% of fly ash, 0.3%-1% of water reducer, and 5%-10% of water according to the proportion, and then pouring into a mold, and demoulding after curing for a set time to obtain an ecological vegetation concrete grid;

[0021] S13, preparing aquatic plant eco-balls: filling the porous ecological ceramsite mixed matrix prepared in step S11 with aquatic seeds and microorganisms into a natural fiber net to obtain aquatic plant eco-balls;

[0022] S2. Foundation preparation and footing construction: Drill holes in the footing area of ​​the river channel and insert bottom anti-overturning piles, lay a gravel cushion layer in the footing area of ​​the river channel at the top of the bottom anti-overturning piles, and make the bottom anti-overturning piles embedded in the gravel cushion layer;

[0023] S3, constructing an ecological vegetation protection stone area below the low water level of the river channel: inserting a bottom concrete baffle at the bottom of the river channel slope, and laying a plurality of gabions arranged in a stepped manner on the top of the gravel cushion layer on the side of the bottom concrete baffle away from the slope, and filling the inside of the gabions with stones and the aquatic plant ecological balls prepared in step S13, and making the aquatic plant ecological balls close to the inner wall of the gabion, filling crushed stone or gravel between the gabion and the bottom concrete baffle, and laying a reverse filtration polylactic acid biodegradable geotextile on the side of the gabion facing the slope, and sealing the gabions at the edge at the same time, and finally setting an inverted trapezoidal gabion riprap layer on the side of the bottom gabion away from the slope;

[0024] S4. Construct a transition zone of a drawdown zone in the drawdown zone of the slope: lay a double-layer capillary retardation effect barrier layer and a polylactic acid biodegradable geotextile from bottom to top in the transition zone of the drawdown zone, and fix the bottom end of the polylactic acid biodegradable geotextile to the bottom concrete baffle, then lay the ecological vegetation concrete grid prepared in step S12 on the top of the polylactic acid biodegradable geotextile, and anchor the ecological vegetation concrete grid to the slope, and then lay multiple groups of geobags inside the ecological vegetation concrete grid and along the slope from top to bottom, each group of geobags is positioned by a folded fiber net, and the end of the folded fiber net is fixed on the slope, and each group of geobags includes a slope-fixing geobag and an ecological geobag laid in sequence from bottom to top, the slope-fixing geobag is filled with sand and gravel, and the ecological geobag is filled with porous ecological ceramsite and planting soil prepared in step S11, and finally, the matrix layer and the seed layer are sprayed in sequence;

[0025] S5. Construct the horizontal drainage ditch between the transition zone of the drawdown zone and the anchorage zone of the plant root system: drill a horizontal hole between the transition zone of the drawdown zone and the anchorage zone of the plant root system, and embed the middle anti-overturning pile into the drilled hole, place the horizontal drainage ditch on the top of the middle anti-overturning pile, and make the top of the middle anti-overturning pile inserted into the horizontal drainage ditch, and then anchor the polylactic acid biodegradable geotextile on the horizontal drainage ditch;

[0026] S6. Construct a plant root anchoring area above the high water level of the river channel: lay a double-layer capillary barrier layer, the ecological vegetation concrete grid and the retaining net prepared in step S12 from bottom to top in the plant root anchoring area, extend the retaining net to the top of the slope, and then use concrete to press and fix the retaining net extending out of the slope, anchor the bottom end of the retaining net and the horizontal drainage ditch, and finally spray the matrix layer and the seed layer in sequence.

[0027] Preferably, the composition ratio of the exogenous industrial solid waste described in S11 is: 10%-15% blast furnace slag, 15%-20% fly ash, and 20%-25% sludge;

[0028] In step S12, the prepared ecological vegetation concrete grid is a regular hexagon, and anchors for fixing are set at the intersections;

[0029] In step S2, the diameter of the bottom anti-overturning pile is 30 cm, the spacing is 4 m, and the depth is 2 m; the thickness of the gravel cushion layer is 30 cm, the maximum particle size does not exceed 30 mm, and the width of each side of the gravel cushion layer beyond the outer edge of the foundation is 200 mm-300 mm;

[0030] In step S3, the length of a single gabion is 1.0 m, the width is 0.5 m, the height is 0.5 m, and the filling thickness is not more than 35 cm;

[0031] In step S4, the polylactic acid biodegradable geotextile is an overlap structure or a seam structure. When it is an overlap structure, two adjacent polylactic acid biodegradable geotextiles are overlapped by U-shaped nails, and the overlap range is not less than 50cm. The upstream polylactic acid biodegradable geotextile covers the top of the downstream polylactic acid biodegradable geotextile; the prefabricated strength of the ecological vegetation concrete grid is not less than C20, and the side length is 1.732 meters; the flattened dimensions of the slope fixing geobag and the ecological geobag are: 0.75m long, 0.55m wide, 0.3m thick, and the filling rate is 75%-85%; each group of geobags The height is 1.5m-2m, the length of the reverse fiber mesh wrapping is not less than 2m, and overlap is required along the horizontal direction of the slope, and the overlap length is not less than 0.5m. The reverse fiber mesh is a mesh product made of carbon spring steel wire wrapped with polyvinyl chloride resin; an expansion joint is set every 10m-15m along the longitudinal direction of the ecological vegetation concrete grid, and the expansion joint width is 20-30mm. The expansion joint is filled with polyethylene closed-cell foam board, asphalt fir board or asphalt sand board, and a longitudinal drainage ditch is set at the expansion joint; the seed layer for spraying is one of cattail, reed, peach leaf polygonum, artemisia capillaris, and loosestrife, and any combination thereof;

[0032] In step S5, the depth of the transverse drainage ditch is 0.5m, the width is 0.5m, and a drainage hole is opened on the side of the transverse drainage ditch facing the plant root anchoring area; the diameter of the middle anti-overturning pile is 30mm, the length is 1.5m, the drilling diameter is 35mm, and the grouting material is C30 cement slurry;

[0033] In step S6, the diameter of the barrier net is 30mm-60mm, and the length extending from the slope is 5m; the thickness of the seed layer is 5mm-30mm; the matrix layer for spraying includes 71.35% river sediment, 0.25% improver, 15% fertilizer, 0.4% water retainer, 10% adhesive, 3% microbial preparation, and 35g / m mixed seeds. 2 The seed layer to be sprayed is one of the following: sour jujube, alfalfa, bluegrass, ryegrass, bermudagrass, awnless bromegrass, or any combination thereof;

[0034] The double-layer capillary retardation effect barrier layer described in step S2 and step S6 includes a fine-grained soil layer, an unsaturated drainage sand layer and a coarse-grained soil layer laid in sequence from top to bottom, wherein the particle size of the fine-grained soil layer is 50mm-100mm, the particle size of the unsaturated drainage sand layer is 100mm-200mm, and the particle size of the coarse-grained soil layer is 100mm-200mm; and the unsaturated drainage sand layer is obtained by screening river sediment with a square hole sieve, the cumulative sieve residue of the 0.15mm square hole sieve is 100%-90%, the cumulative sieve residue of the 0.3mm square hole sieve is 85%-55%, the cumulative sieve residue of the 0.6mm square hole sieve is 40%-16%, and the cumulative sieve residue of the 1.18mm square hole sieve is 25%-0%.

[0035] A slope protection method of a rigid-flexible coordinated ecological slope protection structure. Since the roots of plants growing from the planting layer extend into the fine-grained soil layer, on sunny days, the fine-grained soil layer absorbs water under the transpiration of plant stems and leaves, and stores the water required for the growth of the vegetation roots.

[0036] During rainfall, the interface matrix suction between the fine-grained soil layer and the unsaturated drainage sand layer reaches the water inflow value, making the first capillary barrier between the fine-grained soil layer and the unsaturated drainage sand layer invalid, and the interface matrix suction between the unsaturated drainage sand layer and the coarse-grained soil layer is less than the water inflow value, and the second capillary barrier formed by the unsaturated drainage sand layer and the coarse-grained soil layer is effective. At this time, under the lateral drainage action of the unsaturated drainage sand layer, the water is discharged into the river channel in sequence through the drainage holes, transverse drainage ditches and longitudinal drainage ditches.

[0037] The present invention has the following beneficial effects:

[0038] 1. Through the synergistic effect of river sediment and exogenous solid waste, porous vegetation concrete is prepared. Combined with the unsaturated drainage sand layer prepared from river sediment, it can effectively absorb the silted river sand to dredge the river and reduce costs.

[0039] 2. By screening the particles of different sizes in the river sediment, the particles have a uniform particle size distribution, which is convenient for construction and laying. The unsaturated drainage sand layer is made by using the sediment particles with larger particle sizes. The structure is adjacent to the fine-grained soil layer and the coarse-grained soil layer above and below. The difference in the permeability coefficients of different material layers is used to control the distribution and flow of water in the slope protection structure;

[0040] 3. Rigid materials (such as ecological vegetation protection stone areas, ecological vegetation concrete grids, and fiber meshes) provide solid structural support to prevent river water impact and large-scale slope sliding; flexible materials (such as ecological geotextile bags, ecological ceramsite, and vegetation roots) can effectively reduce the direct scouring force of water flow and rainfall by absorbing, buffering, and dispersing stress, while vegetation roots can fix soil particles; the two play a synergistic role of rigidity and flexibility, so that the slope protection structure can maintain structural stability and ecological balance under different water levels and climatic conditions, thereby achieving the dual functions of protection and ecological restoration;

[0041] 4. Using river sediment to prepare ecological expanded clay and adding it to aquatic vegetation eco-balls, eco-bags and eco-vegetation concrete can alleviate the environmental problems caused by the accumulation of river sediment resources, effectively reduce the mining and use of natural mineral materials, and realize the recycling of resources; moreover, the mineral components in the sediment are fired at high temperatures to form expanded clay with a porous structure and high strength, which is conducive to the fixation and growth of aquatic plant roots, providing more growth space and nutrient adsorption points for plant roots, thereby enhancing the physical properties, structural stability and ecological improvement functions of eco-balls and eco-bags.

[0042] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A cross-sectional view of a rigid-flexible coordinated ecological slope protection structure of the present invention;

[0044] Figure 2 A top view of a rigid-flexible coordinated ecological slope protection structure of the present invention;

[0045] Figure 3 It is a schematic diagram of the change of permeability coefficient of the double-layer capillary barrier layer of a rigid-flexible coordinated ecological slope protection structure of the present invention with matrix suction.

[0046] Among them: 1. Concrete capping; 2. Retaining net; 3. Rigid-flexible coordinated structure; 31. Coarse-grained soil layer; 32. Unsaturated drainage sand layer; 33. Fine-grained soil layer; 34. Flexible vegetation layer; 4. Ecological vegetation concrete grid; 5. Horizontal drainage ditch; 6. Middle anti-overturning pile; 7. Slope fixing geobag; 8. Ecological geobag; 9. Polylactic acid biodegradable geotextile; 10. Bottom concrete baffle; 11. Ecological vegetation protection stone area; 111. Gabion; 112. Inverted trapezoidal gabion riprap layer; 12. Gravel cushion layer; 13. Bottom anti-overturning pile; 14. Reverse folded fiber mesh; 15. Expansion joint; 16. Longitudinal drainage ditch. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0048] It should be noted that the terms "include", "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or devices.

[0049] Like reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0050] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0051] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] like Figure 1 and Figure 2 As shown, a rigid-flexible coordinated ecological slope protection structure includes an ecological vegetation protection stone area 11, a drawdown zone transition area and a plant root anchoring area arranged in sequence from downstream to upstream, wherein the ecological vegetation protection stone area 11 is arranged below the low water level of the river slope, the drawdown zone transition area is arranged in the drawdown zone of the river slope, that is, the drawdown zone transition area is laid between the perennial low water level and high water level of the river, the plant root anchoring area is arranged above the high water level of the river slope, and the drawdown zone transition area and the plant root anchoring area are also provided with transverse drainage ditches 5, and drainage holes are opened on the side of the transverse drainage ditch 5 facing the plant root anchoring area, and the drawdown zone transition area and the plant root anchoring area are both rigid-flexible coordinated structures 3.

[0053] Specifically, the rigid-flexible cooperative structure 3 includes a rigid slope-fixing layer and a flexible vegetation layer 34 arranged in sequence from bottom to top, the rigid slope-fixing layer includes a double-layer capillary barrier layer composed of a fine-grained soil layer 33, an unsaturated drainage sand layer 32 and a coarse-grained soil layer 31 laid in sequence from bottom to top; the rigid-flexible cooperative structure 3 in the transition zone of the drawdown zone also includes a polylactic acid biodegradable geotextile 9 and an ecological vegetation concrete grid 4 laid in sequence on the top of the double-layer capillary barrier layer, the flexible vegetation layer 34 in the transition zone of the drawdown zone includes a geobag group fixed on the slope through an inverted fiber mesh 14 and a matrix layer and a seed layer sprayed in sequence on the geobag group, the seed layer is one of cattail, reed, Polygonum aviculare, Artemisia capillaris, Lythrum salicina and any combination thereof, the polylactic acid biodegradable geotextile The upper and lower ends of the work cloth 9 are respectively anchored to the transverse drainage ditch 5 and the concrete baffle arranged at the bottom of the slope; the rigid-flexible cooperative structure 3 in the plant root anchoring area also includes an ecological vegetation concrete grid 4 and a retaining net 2 laid in sequence on the top of the double-layer capillary barrier layer. The top of the retaining net 2 extends out of the slope and is fixed by a concrete pressure top 1. The bottom end of the retaining net 2 is anchored to the transverse drainage ditch 5. The flexible vegetation layer 34 in the plant root anchoring area includes a matrix layer and a seed layer sprayed in sequence on the ecological vegetation concrete grid 4. The seed layer is one of sour jujube, alfalfa, meadow fescue, ryegrass, dogtooth grass, and awnless brome and any combination thereof; the matrix layer includes river sediment, improvers, fertilizers, mixed seeds, water retaining agents, adhesives, and microbial preparations.

[0054] The geobag group includes a slope-fixing geobag 7 and an ecological geobag 8 which are arranged in a stepped structure from bottom to top. The slope-fixing geobag 7 is filled with sand and gravel, and the ecological geobag 8 is filled with porous ecological ceramsite and planting soil.

[0055] A plurality of longitudinal drainage ditches 16 connected to the transverse drainage ditch 5 are evenly arranged on the ecological vegetation concrete grid 4 in the transition zone of the drawdown zone. An expansion joint 15 is arranged between the longitudinal drainage ditch 16 and the ecological vegetation concrete grid 4. The expansion joint 15 is filled with polyethylene closed-cell foam board, asphalt fir board or asphalt sand board; the bottom end of the transverse drainage ditch 5 is fixed to the slope through the middle anti-overturning pile 6.

[0056] The ecological vegetation protection stone area 11 includes a plurality of gabions 111 laid on top of a gravel cushion layer 12 located in the foot protection area. The plurality of gabions 111 are arranged in a stepped manner, and the gabions 111 are filled with stones and aquatic plant ecological balls, and the aquatic plant ecological balls are arranged close to the inner wall of the gabions 111; crushed stone or gravel is filled between the gabions 111 and the bottom concrete baffle 10, and an inverted trapezoidal gabion riprap layer 112 is arranged on the side of the bottom gabion 111 away from the slope; the gravel cushion layer 12 is fixed by the bottom anti-overturning piles 13.

[0057] A construction method of a rigid-flexible coordinated ecological slope protection structure comprises the following steps:

[0058] S1. Preparation of raw materials:

[0059] S11, preparing porous ecological ceramsite: after 30%-40% of river sediment and 60%-70% of external industrial solid waste are mixed evenly, preheated at a temperature of 400°C-600°C, and then fired at a roasting temperature of 1000°C-1200°C to obtain porous ecological ceramsite with a diameter of 10mm-30mm and a porosity of 40%-50%;

[0060] The composition ratio of the external industrial solid waste described in S11 is: 10%-15% blast furnace slag, 15%-20% fly ash, and 20%-25% sludge;

[0061] S12, preparing ecological vegetation concrete grid 4: using the porous ecological ceramsite prepared in step S11 as coarse aggregate, mixing 60%-70% of coarse aggregate, 10%-20% of cement, 10%-15% of fly ash, 0.3%-1% of water reducer, and 5%-10% of water according to the proportion, and then pouring into a mold, and demoulding after curing for a set time to obtain an ecological vegetation concrete grid 4, which has the characteristics of light weight, high strength, and convenient construction, can reduce the overall weight of the structure, and has a large number of interconnected pores, which can provide a good living environment for the growth of slope protection vegetation in the grid;

[0062] In step S12, the prepared ecological vegetation concrete grid 4 is a regular hexagon, and anchors for fixing are set at the intersections;

[0063] S13, preparing aquatic plant eco-balls: filling the porous ecological ceramsite mixed matrix (in this embodiment, the matrix includes river sediment, improver, fertilizer, water retaining agent, adhesive) prepared in step S11 with aquatic seeds and microorganisms into a natural fiber net to obtain aquatic plant eco-balls. In the early stage of seed germination, the natural fiber net is selected to wrap the eco-balls to slow down the loss of the matrix and soil;

[0064] S2, foundation preparation and footing construction: drilling holes in the footing area of ​​the river channel and inserting bottom anti-overturning piles 13, laying gravel cushion layer 12 in the footing area of ​​the river channel at the top of the bottom anti-overturning piles 13, and making the bottom anti-overturning piles 13 embedded in the gravel cushion layer 12;

[0065] In step S2, the bottom anti-overturning piles 13 have a diameter of 30 cm, a spacing of 4 m, and a depth of 2 m; the thickness of the gravel cushion layer 12 is 30 cm, the maximum particle size does not exceed 30 mm, and the width of each side of the gravel cushion layer 12 beyond the outer edge of the foundation is 200 mm-300 mm;

[0066] S3, constructing ecological vegetation protection stone area 11 below the low water level of the river: inserting a bottom concrete baffle 10 at the bottom of the river slope, and laying a plurality of gabions 111 arranged in a stepped manner on the top of the gravel cushion layer 12 on the side of the bottom concrete baffle 10 away from the slope, the stepped structure is used to improve the slope protection and scour protection performance, and filling the inside of the gabion 111 with blocks and the aquatic plant ecological balls prepared in step S13, and making the aquatic plant ecological balls close to the inner wall of the gabion 111, and the gabion 111 and the bottom wall are connected. Fill crushed stone or gravel between the concrete baffles 10, and lay the anti-filtration polylactic acid biodegradable geotextile 9 on the side of the gabion 111 facing the slope, and seal the gabion 111 at the edge at the same time, and finally set the inverted trapezoidal gabion riprap layer 112 on the side of the bottom gabion 111 away from the slope, and the inverted trapezoidal gabion riprap layer 112 is buried at the bottom of the riverbed to improve the overall stability and anti-scouring ability of the structure; and the laying width of the gravel anti-filtration layer is greater than the inverted trapezoidal gabion riprap layer 112 to ensure the stability of the foundation;

[0067] During the construction process, the layers of gabions 111 should be staggered and overlapped without any through seams when they are stacked and assembled to enhance the overall stability. When the upper surface of the gabion 111 wall is filled with gravel to the same plane, the next layer of gabion 111 can be stacked. During the stacking process, check whether the gravel filling of the current gabion 111 stacking layer is dense and whether the upper surface is flat.

[0068] In step S3, the length of a single gabion 111 is 1.0 m, the width is 0.5 m, the height is 0.5 m, and the filling thickness is not more than 35 cm;

[0069] S4, constructing a transition zone of the drawdown zone in the drawdown zone of the slope: laying a double-layer capillary retardation barrier layer and a polylactic acid biodegradable geotextile 9 from bottom to top in the drawdown zone transition zone, and fixing the bottom end of the polylactic acid biodegradable geotextile 9 to the bottom concrete baffle 10, and then laying the ecological vegetation concrete grid 4 prepared in step S12 on the top of the polylactic acid biodegradable geotextile 9, and anchoring the ecological vegetation concrete grid 4 to the slope, and then laying the ecological vegetation concrete grid 4 on the top of the polylactic acid biodegradable geotextile 9. Multiple groups of geobags are laid inside the soil grid 4 and along the slope from top to bottom. Each group of geobags is positioned by the inverted fiber net 14. The end of the inverted fiber net 14 is fixed on the slope to improve the anti-scouring performance. Each group of geobags includes a slope-fixing geobag 7 and an ecological geobag 8 laid in sequence from bottom to top. The slope-fixing geobag 7 is filled with sand and gravel, and the ecological geobag 8 is filled with porous ecological ceramsite and planting soil prepared in step S11. Finally, the matrix layer and the seed layer are sprayed in sequence.

[0070] In step S4, the polylactic acid biodegradable geotextile 9 is an overlapping structure or a seam structure. When it is an overlapping structure, two adjacent polylactic acid biodegradable geotextiles 9 are overlapped by U-shaped nails, and the overlapping overlap range is not less than 50cm. The upstream polylactic acid biodegradable geotextile 9 covers the top of the downstream polylactic acid biodegradable geotextile 9. When it is estimated that the polylactic acid biodegradable geotextile 9 may undergo a large displacement during use and the polylactic acid biodegradable geotextile 9 is pulled apart, seaming is used; the prefabricated strength of the ecological vegetation concrete grid 4 is not less than C20, and the side length is 1.732 meters; the flattened dimensions of the slope fixing geobag 7 and the ecological geobag 8 are: 0.75m long, 0.55m wide, 0.3m thick, and the filling rate is 75%-85%; the height of each group of geobags is 1.5m-2m, and the reverse The length of the folded fiber net 14 is not less than 2m, and it needs to be overlapped along the horizontal direction of the slope, and the overlap length is not less than 0.5m. The folded fiber net 14 is a mesh product made of carbon spring steel wire wrapped with polyvinyl chloride resin, which has high strength, good stability, low elongation and corrosion resistance, and can ensure its anchoring strength in the slope scouring environment; an expansion joint 15 is set every 10m-15m along the longitudinal direction of the ecological vegetation concrete grid 4, and the width of the expansion joint 15 is 20-30mm. The expansion joint 15 is filled with polyethylene closed-cell foam board, asphalt fir board or asphalt sand board, and a longitudinal drainage ditch 16 is set at the expansion joint 15; the seed layer for spraying is one of cattail, reed, peach leaf polygonum, artemisia capillaris, and loosestrife and any combination thereof, which has the characteristics of waterlogging resistance, flood resistance, tenacious vitality, and developed root system;

[0071] S5, constructing a transverse drainage ditch between the transition zone of the drawdown zone and the plant root anchoring zone: drilling a transverse hole between the transition zone of the drawdown zone and the plant root anchoring zone, and embedding the middle anti-overturning pile 6 into the drilled hole, placing the transverse drainage ditch on the top of the middle anti-overturning pile 6, and inserting the top of the middle anti-overturning pile 6 into the transverse drainage ditch, and then anchoring the polylactic acid biodegradable geotextile 9 on the transverse drainage ditch 5;

[0072] In step S5, the depth of the transverse drainage ditch 5 is 0.5m, the width is 0.5m, and a drainage hole is opened on the side of the transverse drainage ditch 5 facing the plant root anchoring area; the diameter of the middle anti-overturning pile 6 is 30mm, the length is 1.5m, the drilling diameter is 35mm, and the grouting material is C30 cement slurry;

[0073] S6. Construct a plant root anchoring area above the high water level of the river channel: lay a double-layer capillary barrier layer, the ecological vegetation concrete grid 4 prepared in step S12 and the retaining net 2 from bottom to top in the plant root anchoring area, and extend the retaining net 2 to the top of the slope, and then use a concrete top 1 to fix the retaining net 2 extending out of the slope, and anchor the bottom end of the retaining net 2 and the horizontal drainage ditch 5, and finally spray the matrix layer and the seed layer in sequence.

[0074] In step S6, the diameter of the barrier net 2 is 30mm-60mm, and the length extending from the slope is 5m; the thickness of the seed layer is 5mm-30mm; the matrix layer for spraying includes 71.35% river sediment, 0.25% improver, 15% fertilizer, 0.4% water retainer, 10% adhesive, 3% microbial preparation, and 35g / m mixed seeds. 2 The seed layer to be sprayed is one of the following: sour jujube, alfalfa, bluegrass, ryegrass, bermudagrass, awnless bromegrass, or any combination thereof, so as to fix the slope with the help of the root system, prevent the slope from being weathered and eroded, and prevent soil and water loss, and beautify the environment and increase the green coverage rate;

[0075] The double-layer capillary retardation effect barrier layer described in step S2 and step S6 includes a fine-grained soil layer 33, an unsaturated drainage sand layer 32 and a coarse-grained soil layer 31 laid in sequence from top to bottom, wherein the particle size of the fine-grained soil layer 33 is 50mm-100mm, the particle size of the unsaturated drainage sand layer 32 is 100mm-200mm, and the particle size of the coarse-grained soil layer 31 is 100mm-200mm; and the unsaturated drainage sand layer 32 is obtained by screening river sediment with a square hole sieve, the composition of the river sediment is inorganic silicate, the cumulative sieve residue of the 0.15mm square hole sieve is 100%-90%, the cumulative sieve residue of the 0.3mm square hole sieve is 85%-55%, the cumulative sieve residue of the 0.6mm square hole sieve is 40%-16%, and the cumulative sieve residue of the 1.18mm square hole sieve is 25%-0%.

[0076] Since the unsaturated drainage sand layer 32 has good lateral drainage effect, it can form two capillary barrier with the fine-grained soil layer 33 and the coarse-grained soil layer 31 respectively, providing good anti-seepage and drainage performance for the slope and enhancing the stability of the slope soil.

[0077] like Figure 3 As shown, a slope protection method of a rigid-flexible coordinated ecological slope protection structure, since the plant roots growing from the planting layer extend into the fine-grained soil layer 33, on sunny days, under the transpiration of plant stems and leaves, the fine-grained soil layer 33 absorbs water, which is stored for the growth of the vegetation roots;

[0078] During rainfall, the interface matrix suction between the fine-grained soil layer 33 and the unsaturated drainage sand layer 32 reaches the water inflow value, making the first capillary barrier between the fine-grained soil layer 33 and the unsaturated drainage sand layer 32 ineffective, and the interface matrix suction between the unsaturated drainage sand layer 32 and the coarse-grained soil layer 31 is less than the water inflow value, and the second capillary barrier formed by the unsaturated drainage sand layer 32 and the coarse-grained soil layer 31 is effective. At this time, the water is discharged into the river channel through the drainage holes, the transverse drainage ditch 5 and the longitudinal drainage ditch 16 in sequence under the lateral drainage action of the unsaturated drainage sand layer 32.

[0079] Moreover, when the water level changes and it rains, the ecological vegetation concrete grid 4 relies on its own weight and anchoring effect to cling to the slope surface, resisting the buoyancy and lateral pressure of the water. When the soil slides, the ecological vegetation concrete grid 4 will also withstand the shear force of the soil to maintain the stability of the slope and play a rigid role; the geobags and vegetation roots absorb and discharge excess water, reduce soil pressure, prevent landslides and sediment loss, and achieve flexible synergy.

[0080] Therefore, the present invention adopts the above-mentioned rigid-flexible coordinated ecological slope protection structure, construction method and slope protection method, and utilizes the rigid-flexible coordinated structure to improve the hydraulic-mechanical environment of the slope and the ecological environment of the river channel, realize the protection of the ecological slope against river water scouring, and the protection of the river channel slope above the high water level against heavy rainfall scouring, which is conducive to maintaining the long-term stability of the ecological environment.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A rigid-flexible coordinated ecological slope protection structure, characterized by: It includes an ecological vegetation protection stone area, a drawdown zone transition area and a plant root anchoring area arranged in sequence from downstream to upstream, wherein the ecological vegetation protection stone area is set below the low water level of the river slope, the drawdown zone transition area is set in the drawdown zone of the river slope, and the plant root anchoring area is set above the high water level of the river slope. The drawdown zone transition area and the plant root anchoring area are also provided with transverse drainage ditches, and drainage holes are opened on the side of the transverse drainage ditch facing the plant root anchoring area, and the drawdown zone transition area and the plant root anchoring area are both rigid-flexible coordinated structures; The rigid-flexible coordinated structure includes a rigid slope consolidation layer and a flexible vegetation layer arranged sequentially from bottom to top. The rigid slope consolidation layer includes a double-layer capillary barrier layer composed of a fine-grained soil layer, an unsaturated drainage sand layer and a coarse-grained soil layer laid sequentially from bottom to top. The rigid-flexible coordinated structure of the transition zone of the drawdown zone also includes a polylactic acid biodegradable geotextile and an ecological vegetation concrete grid sequentially laid on the top of the double-layer capillary retardation effect barrier layer. The flexible vegetation layer in the transition zone of the drawdown zone includes a geobag group fixed on the slope through a folded fiber net and a matrix layer and a seed layer sequentially sprayed on the geobag group. The seed layer is one of cattail, reed, Polygonum perforatum, Artemisia capillaris, Lythrum salicina and any combination thereof. The upper and lower ends of the polylactic acid biodegradable geotextile are respectively anchored to the transverse drainage ditch and the concrete baffle arranged at the bottom of the slope; The rigid-flexible coordinated structure of the plant root anchoring zone also includes an ecological vegetation concrete grid and a retaining net sequentially laid on the top of the double-layer capillary barrier layer. The top of the retaining net extends out of the slope and is fixed by concrete pressure. The bottom of the retaining net is anchored to the transverse drainage ditch. The flexible vegetation layer of the plant root anchoring zone includes a matrix layer and a seed layer sequentially sprayed on the ecological vegetation concrete grid. The seed layer is one of sour jujube, alfalfa, meadow fescue, ryegrass, bermudagrass, and awnless bromegrass and any combination thereof. The matrix layer includes river sediment, amendments, fertilizers, mixed seeds, water retaining agents, adhesives, and microbial preparations.

2. The rigid-flexible coordinated ecological slope protection structure according to claim 1 is characterized by: The geobag group includes slope-fixing geobags and ecological geobags arranged in a stepped structure from bottom to top. The slope-fixing geobags are filled with sand and gravel, and the ecological geobags are filled with porous ecological ceramsite and planting soil.

3. The rigid-flexible coordinated ecological slope protection structure according to claim 2 is characterized by: A plurality of longitudinal drainage ditches connected to the transverse drainage ditches are evenly arranged on the ecological vegetation concrete grid in the transition zone of the drawdown zone. An expansion joint is arranged between the longitudinal drainage ditch and the ecological vegetation concrete grid, and the expansion joint is filled with polyethylene closed-cell foam board, asphalt fir board or asphalt sand board; The bottom end of the transverse drainage ditch is fixed to the slope through the middle anti-overturning pile.

4. The rigid-flexible coordinated ecological slope protection structure according to claim 3 is characterized by: The ecological vegetation protection stone area includes multiple gabions laid on top of the gravel cushion layer located in the foot protection area, the multiple gabions are arranged in a stepped manner, and the gabions are filled with stones and aquatic plant ecological balls, and the aquatic plant ecological balls are arranged close to the inner wall of the gabions; The space between the gabion and the bottom concrete baffle is filled with crushed stone or gravel, and an inverted trapezoidal gabion riprap layer is set on the side of the bottom gabion away from the slope; The gravel cushion layer is fixed by anti-overturning piles at the bottom.

5. A construction method of a rigid-flexible coordinated ecological slope protection structure as described in claim 4, characterized in that: The following steps are involved: S1. Preparation of raw materials: S11, preparing porous ecological ceramsite: after 30%-40% of river sediment and 60%-70% of external industrial solid waste are mixed evenly, preheated at a temperature of 400°C-600°C, and then fired at a roasting temperature of 1000°C-1200°C to obtain porous ecological ceramsite with a diameter of 10mm-30mm and a porosity of 40%-50%; S12, preparing ecological vegetation concrete grid: using the porous ecological ceramsite prepared in step S11 as coarse aggregate, mixing 60%-70% of coarse aggregate, 10%-20% of cement, 10%-15% of fly ash, 0.3%-1% of water reducer, and 5%-10% of water according to the proportion, and then pouring into a mold, and demoulding after curing for a set time to obtain an ecological vegetation concrete grid; S13, preparing aquatic plant eco-balls: filling the porous ecological ceramsite mixed matrix prepared in step S11 with aquatic seeds and microorganisms into a natural fiber net to obtain aquatic plant eco-balls; S2. Foundation preparation and footing construction: Drill holes in the footing area of ​​the river channel and insert bottom anti-overturning piles, lay a gravel cushion layer in the footing area of ​​the river channel at the top of the bottom anti-overturning piles, and make the bottom anti-overturning piles embedded in the gravel cushion layer; S3, constructing an ecological vegetation protection stone area below the low water level of the river channel: inserting a bottom concrete baffle at the bottom of the river channel slope, and laying a plurality of gabions arranged in a stepped manner on the top of the gravel cushion layer on the side of the bottom concrete baffle away from the slope, and filling the inside of the gabions with stones and the aquatic plant ecological balls prepared in step S13, and making the aquatic plant ecological balls close to the inner wall of the gabion, filling crushed stone or gravel between the gabion and the bottom concrete baffle, and laying a reverse filtration polylactic acid biodegradable geotextile on the side of the gabion facing the slope, and sealing the gabions at the edge at the same time, and finally setting an inverted trapezoidal gabion riprap layer on the side of the bottom gabion away from the slope; S4. Construct a transition zone of a drawdown zone in the drawdown zone of the slope: lay a double-layer capillary retardation effect barrier layer and a polylactic acid biodegradable geotextile from bottom to top in the transition zone of the drawdown zone, and fix the bottom end of the polylactic acid biodegradable geotextile to the bottom concrete baffle, then lay the ecological vegetation concrete grid prepared in step S12 on the top of the polylactic acid biodegradable geotextile, and anchor the ecological vegetation concrete grid to the slope, and then lay multiple groups of geobags inside the ecological vegetation concrete grid and along the slope from top to bottom, each group of geobags is positioned by a folded fiber net, and the end of the folded fiber net is fixed on the slope, and each group of geobags includes a slope-fixing geobag and an ecological geobag laid in sequence from bottom to top, the slope-fixing geobag is filled with sand and gravel, and the ecological geobag is filled with porous ecological ceramsite and planting soil prepared in step S11, and finally, the matrix layer and the seed layer are sprayed in sequence; S5. Construct the horizontal drainage ditch between the transition zone of the drawdown zone and the anchorage zone of the plant root system: drill a horizontal hole between the transition zone of the drawdown zone and the anchorage zone of the plant root system, and embed the middle anti-overturning pile into the drilled hole, place the horizontal drainage ditch on the top of the middle anti-overturning pile, and make the top of the middle anti-overturning pile inserted into the horizontal drainage ditch, and then anchor the polylactic acid biodegradable geotextile on the horizontal drainage ditch; S6. Construct a plant root anchoring area above the high water level of the river channel: lay a double-layer capillary barrier layer, the ecological vegetation concrete grid and the retaining net prepared in step S12 from bottom to top in the plant root anchoring area, extend the retaining net to the top of the slope, and then use concrete to press and fix the retaining net extending out of the slope, anchor the bottom end of the retaining net and the horizontal drainage ditch, and finally spray the matrix layer and the seed layer in sequence.

6. The construction method of a rigid-flexible coordinated ecological slope protection structure according to claim 5 is characterized by: The composition ratio of the external industrial solid waste described in S11 is: 10%-15% blast furnace slag, 15%-20% fly ash, and 20%-25% sludge; In step S12, the prepared ecological vegetation concrete grid is a regular hexagon, and anchors for fixing are set at the intersections; In step S2, the diameter of the bottom anti-overturning pile is 30 cm, the spacing is 4 m, and the depth is 2 m; the thickness of the gravel cushion layer is 30 cm, the maximum particle size does not exceed 30 mm, and the width of each side of the gravel cushion layer beyond the outer edge of the foundation is 200 mm-300 mm; In step S3, the length of a single gabion is 1.0 m, the width is 0.5 m, the height is 0.5 m, and the filling thickness is not more than 35 cm; In step S4, the polylactic acid biodegradable geotextile is an overlap structure or a seam structure. When it is an overlap structure, two adjacent polylactic acid biodegradable geotextiles are overlapped by U-shaped nails, and the overlap range is not less than 50cm. The upstream polylactic acid biodegradable geotextile covers the top of the downstream polylactic acid biodegradable geotextile; the prefabricated strength of the ecological vegetation concrete grid is not less than C20, and the side length is 1.732 meters; the flattened dimensions of the slope fixing geobag and the ecological geobag are: 0.75m long, 0.55m wide, 0.3m thick, and the filling rate is 75%-85%; each group of geobags The height is 1.5m-2m, the length of the reverse fiber mesh wrapping is not less than 2m, and overlap is required along the horizontal direction of the slope, and the overlap length is not less than 0.5m. The reverse fiber mesh is a mesh product made of carbon spring steel wire wrapped with polyvinyl chloride resin; an expansion joint is set every 10m-15m along the longitudinal direction of the ecological vegetation concrete grid, and the expansion joint width is 20-30mm. The expansion joint is filled with polyethylene closed-cell foam board, asphalt fir board or asphalt sand board, and a longitudinal drainage ditch is set at the expansion joint; the seed layer for spraying is one of cattail, reed, peach leaf polygonum, artemisia capillaris, and loosestrife, and any combination thereof; In step S5, the depth of the transverse drainage ditch is 0.5m, the width is 0.5m, and a drainage hole is opened on the side of the transverse drainage ditch facing the plant root anchoring area; the diameter of the middle anti-overturning pile is 30mm, the length is 1.5m, the drilling diameter is 35mm, and the grouting material is C30 cement slurry; In step S6, the diameter of the barrier net is 30mm-60mm, and the length extending from the slope is 5m; the thickness of the seed layer is 5mm-30mm; the thickness of the matrix layer for spraying is 100-200mm, including 71.35% of river sediment, 0.25% of improver, 15% of fertilizer, 0.4% of water retainer, 10% of adhesive, 3% of microbial preparation, and 35g / m2 of mixed seeds; the seed layer for spraying is one of sour jujube, alfalfa, meadow grass, ryegrass, bermudagrass, awnless bromegrass and any combination thereof; The double-layer capillary retardation effect barrier layer described in step S2 and step S6 includes a fine-grained soil layer, an unsaturated drainage sand layer of 100-200mm and a coarse-grained soil layer of 100-200mm laid in sequence from top to bottom, wherein the particle size of the fine-grained soil layer is 50mm-100mm, the particle size of the unsaturated drainage sand layer is 100mm-200mm, and the particle size of the coarse-grained soil layer is 100mm-200mm; and the unsaturated drainage sand layer is obtained by screening river sediment with a square hole sieve, the cumulative sieve residue of the 0.15mm square hole sieve is 100%-90%, the cumulative sieve residue of the 0.3mm square hole sieve is 85%-55%, the cumulative sieve residue of the 0.6mm square hole sieve is 40%-16%, and the cumulative sieve residue of the 1.18mm square hole sieve is 25%-0%.

7. A slope protection method of a rigid-flexible coordinated ecological slope protection structure as described in claim 5, characterized in that: Since the roots of plants growing from the planting layer extend into the fine-grained soil layer, on sunny days, the fine-grained soil layer absorbs water under the transpiration of plant stems and leaves, storing the water needed for the growth of vegetation roots; During rainfall, the interface matrix suction between the fine-grained soil layer and the unsaturated drainage sand layer reaches the water inflow value, making the first capillary barrier between the fine-grained soil layer and the unsaturated drainage sand layer invalid, and the interface matrix suction between the unsaturated drainage sand layer and the coarse-grained soil layer is less than the water inflow value, and the second capillary barrier formed by the unsaturated drainage sand layer and the coarse-grained soil layer is effective. At this time, under the lateral drainage action of the unsaturated drainage sand layer, the water is discharged into the river channel in sequence through the drainage holes, transverse drainage ditches and longitudinal drainage ditches.

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