CN111501669A - River course revetment ecological restoration method suitable for different scouring conditions - Google Patents

Abstract

The invention belongs to the technical field of ecological restoration, and in particular relates to a river course slope protection ecological restoration method suitable for different scour conditions, comprising the following steps: investigating the scouring conditions of the river banks on both sides of the river course; selecting a construction area of a slope protection project, the construction area The conditions to be met are: 1. River slope protection with different scour degrees; 2. Engineering implementation conditions near the slope protection; construction of slope protection structures with different scour conditions; maintenance and management of river slope protection. The invention designs the structure of the ecological slope protection in a targeted manner, which not only ensures the stability of the ecological slope protection, but also improves the diversity and integrity of the ecological slope protection.

Description

An ecological restoration method for river slope protection suitable for different erosion conditions

technical field

The invention belongs to the field of ecological technology, and in particular relates to an ecological restoration method for river slope protection suitable for different scour conditions.

Background technique

The degree of erosion of the slope protection on both sides of the river channel is different due to the degree of its curvature and the direction of the river flow. At present, in the design and construction of the river slope protection, the different environmental conditions of the river slope protection on both sides are usually not fully considered, so that the same design scheme and construction content are adopted for the river channels on both sides, which is not conducive to the construction of the diversity of the river slope protection ecosystem. It is also not conducive to making full use of the existing conditions to realize the multiple functions of river slope protection as much as possible. Therefore, it is necessary to fully investigate the different types of environmental conditions on both sides, especially the water conservancy and hydrological conditions, when designing and constructing the river course slope protection, and design the ecological slope protection structure in a targeted manner according to the degree of erosion, so as to ensure the stability of the ecological slope protection. It is necessary to improve the diversity and integrity of ecological slope protection.

SUMMARY OF THE INVENTION

The purpose of the present invention is to: provide a kind of river course slope protection ecological restoration method suitable for different scour conditions,

In order to achieve the above-mentioned purpose, the technical scheme of the present invention is to provide a river course slope protection ecological restoration method suitable for different scour conditions, comprising the following steps:

S1: Investigate the scour conditions on both sides of the river;

S2: Select the construction area of the slope protection project. The conditions to be met by the construction area are: 1. River slope protection with different scour degrees; 2. Project implementation conditions are available near the slope protection;

S3: Build slope protection structures with different scour conditions;

S4: Maintain and manage the river slope protection.

Preferably, the specific investigation process of step S1 is:

S1-1: The scour depth of the river banks on both sides of the river channel is used as the main basis for judging the scour conditions, and the scour depth depends on the flood flow, flow velocity, flow potential and river bed particle size of the river;

S1-2: Calculate the scour depth caused by water flow parallel to the bank slope

h _B =h _p +[(V _cp /V _allow ) ⁿ -1]; where, in the formula: h _B is the local scour depth from the water surface, the unit is m; h _p is the water depth at the scour place, the unit is m; V _cp is the average flow velocity, the unit is m/s; V _allow is the allowable non-rush flow velocity of the river bed, the unit is m/s; n is the coefficient;

S1-3: Calculate the scour depth caused by the current oblique scouring of the bank protection slope

Among them, Δh _p is the depth of the local scour pit from the river bottom, the unit is m; V _j is the local scouring velocity of the water flow, the unit is m/s; g is the acceleration of gravity, the unit is m/s ² ; d is the slope The calculated particle size of the soil at the foot is in cm; α is the intersection angle between the water flow and the bank; m is the slope coefficient of the protective building;

According to the way the water flow on both sides of the river impinges on the slope protection, the above formula is used to calculate and determine the scour depth, and the scour degree of the slope protection on both sides of the river channel is judged accordingly.

Preferably, the specific conditions to be satisfied for the selection of the construction area in step S2 are: the bank slope is between 5-60°, and the construction vehicle work site and road are available.

Preferably, constructing slope protection structures with different scour conditions in step S3 specifically includes constructing slope protection structures with high scour conditions and building slope protection structures with low scour conditions;

The specific method of constructing the slope protection structure under high scour conditions is as follows:

S3-11: Flatten the slope to form a 40-60° slope;

S3-12: Lay two layers of geonets in the water level fluctuation area and the slope below the water level fluctuation area, lay out fixed piles at 1m intervals, and construct ecological concrete precast blocks on the geonet. The prefabricated blocks overlap each other;

S3-13: Reserve a square hole with a side length of 110-120mm in the center of the ecological concrete precast block, add local soil and organic fertilizer in the hole, and the mass ratio of soil and organic fertilizer is 100-150:1;

S3-14: Lay in-situ soil on the slope above the water level fluctuation area.

Preferably, the method for restoring vegetation on slope protection under high scour conditions is: planting any one or a combination of reeds, cattails, iris and canna under the water level fluctuation area, and spraying dogs evenly in the holes of the ecological concrete prefabricated blocks in the water level fluctuation area Any one or a combination of tooth root and clover, and any one or a combination of sedge grass, bullbena, vetch, and ryegrass are planted above the water level change area.

Preferably, constructing slope protection structures with different scour conditions in step S3 specifically includes constructing slope protection structures with high scour conditions and building slope protection structures with low scour conditions;

The specific method of constructing the slope protection structure under low scour conditions is as follows:

S3-21: The slope protection structure under low scour conditions is divided into three layers. Cohesive soil is laid under the water level fluctuation area, and the slope is 20-50°; 5-20°; local soil is laid above the water level fluctuation area with a slope of 20-50°.

Preferably, the method for restoring vegetation on slope protection under low scour conditions is: planting any one or a combination of reeds and cattails below the water level fluctuation area, planting shrubs in the water level fluctuation area, and planting any of bermudagrass and sedge under the shrubs One or several combinations, and any one or several combinations of wild chrysanthemum and Malantou are planted above the water level change area.

Preferably, the maintenance and management of the river course slope protection in step S4 specifically includes: 1. Regularly checking and maintaining the stability of the broken surface of the embankment; 2. Planting seedlings, fertilizing and watering the slope surface; 3. Regularly maintaining and managing vegetation, Focus on preventing pests and human factors from damaging vegetation, and arrange harvesting and removal in time after vegetation declines.

Preferably, the frequency of regular inspection and maintenance of the stability of the broken surface of the embankment is once a month; the frequency of regular maintenance and management of vegetation is once a month.

Beneficial effects of the present invention:

1. Determine the slope protection structure according to the erosion conditions. In the severe erosion section, the combination of ecological concrete + geonet + fixed pile is adopted to ensure the stability of the slope protection structure. In the light scour section, a three-layer structure of slope protection is set up according to different water conservancy conditions, which not only ensures that the slope protection soil is not lost, but also restores the natural ecosystem of the slope protection.

2. Restoring a diverse ecosystem. The three-layer structure slope protection adopted in the light scour section, each layer has different slope protection structures, different soil types, and different types of vegetation to be restored, which is conducive to the self-organized restoration of different types of ecosystems, and also Facilitates the natural introduction of other organisms. In the heavier scour section, the stable slope protection is mainly used in the hydrological change area and below, and at the same time, the advantages of ecological concrete are used for greening. Above the water level fluctuation area, natural slope protection is adopted.

3, to form different styles of landscape patterns. In the severely eroded section, the slope is relatively large, mainly hardening, supplemented by greenery, and combined with a small amount of natural ecosystems, forming a relatively vertical landscape pattern of hardening and greening. In the lightly scoured section, the three-story slope protection structure and slope are different, forming a larger and longer gentle slope. The landscapes of different nodes of the gentle slope have their own characteristics, forming a multi-type natural landscape pattern.

4. Maintenance is simple and convenient. The maintenance and management of the slope protection structure basically does not require special personnel to be responsible, and only needs to be checked regularly. The maintenance and management of vegetation are mainly extensive management, mainly natural restoration and self-organized restoration.

Description of drawings

FIG. 1 is a schematic diagram of the ecological structure of the river course slope protection according to the first embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present invention.

The invention provides an ecological restoration method for river slope protection suitable for different scour conditions, comprising the following steps:

S1: Investigate the scour conditions on both sides of the river;

S2: Select the construction area of the slope protection project. The conditions to be met by the construction area are: 1. River slope protection with different scour degrees; 2. Project implementation conditions are available near the slope protection;

S3: Build slope protection structures with different scour conditions;

S4: Maintain and manage the river slope protection.

Preferably, the specific investigation process of step S1 is:

S1-1: The scour depth of the river banks on both sides of the river channel is used as the main basis for judging the scour conditions, and the scour depth depends on the flood flow, flow velocity, flow potential and river bed particle size of the river;

S1-2: Calculate the scour depth caused by water flow parallel to the bank slope

h _B =h _p +[(V _cp /V _allow ) ⁿ -1]; where, in the formula: h _B is the local scour depth from the water surface, the unit is m; h _p is the water depth at the scour place, the unit is m; V _cp is the average flow velocity, the unit is m/s; V _allow is the allowable non-rush flow velocity of the river bed, the unit is m/s; n is the coefficient;

S1-3: Calculate the scour depth caused by the current oblique scouring of the bank protection slope

Among them, Δh _p is the depth of the local scour pit from the river bottom, the unit is m; V _j is the local scour velocity of the water flow, the unit is m/s; g is the acceleration of gravity, the unit is m/s ² ; d is the slope The calculated particle size of the soil at the foot is in cm; α is the intersection angle between the water flow and the bank; m is the slope coefficient of the protective building;

According to the way the water flow on both sides of the river impinges on the slope protection, the above formula is used to calculate and determine the scour depth, and the scour degree of the slope protection on both sides of the river channel is judged accordingly.

The specific conditions that need to be met for the selection of the construction area in step S2 are: the bank slope is between 5-60°, and the construction vehicle working site and road are available.

Constructing slope protection structures with different scour conditions in step S3 specifically includes building a slope protection structure with high scour conditions and building a slope protection structure with low scour conditions;

The specific method of constructing the slope protection structure under high scour conditions is as follows:

S3-11: Flatten the slope to form a 40-60° slope;

S3-12: Lay two layers of geonets in the water level fluctuation area and the slope below the water level fluctuation area, lay out fixed piles at 1m intervals, and construct ecological concrete precast blocks on the geonet. The prefabricated blocks overlap each other;

S3-13: Reserve a square hole with a side length of 110-120mm in the center of the ecological concrete precast block, add local soil and organic fertilizer in the hole, and the mass ratio of soil and organic fertilizer is 100-150:1;

S3-14: Lay in-situ soil on the slope above the water level fluctuation area.

The vegetation restoration method for slope protection under high erosion conditions is: planting any one or a combination of reeds, cattails, iris and canna under the water level fluctuation area, and evenly spraying bermudagrass and clover in the holes of ecological concrete prefabricated blocks in the water level fluctuation area Any one or a combination of any of them, and any one or a combination of any one or more of sedge grass, bullbena, wild pea, and ryegrass is planted above the water level change area.

Constructing slope protection structures with different scour conditions in step S3 specifically includes building a slope protection structure with high scour conditions and building a slope protection structure with low scour conditions;

The specific method of constructing the slope protection structure under low scour conditions is as follows:

S3-21: The slope protection structure under low scour conditions is divided into three layers. Cohesive soil is laid under the water level fluctuation area, and the slope is 20-50°; 5-20°; local soil is laid above the water level fluctuation area with a slope of 20-50°.

The method for vegetation restoration of slope protection under low scour conditions is: planting any one or a combination of reeds and cattails below the water level fluctuation area, planting shrubs in the water level fluctuation area, and planting any one of bermudagrass and sedge grass under the shrubs. Several combinations, any one or a combination of wild chrysanthemum and Malantou are planted above the water level change area.

The maintenance and management of the river slope protection in step S4 specifically includes: 1. Regularly check and maintain the stability of the broken surface of the embankment; 2. Plant seedlings, fertilize and water the slope surface; 3. Regularly maintain and manage vegetation, focusing on preventing pests The destruction of vegetation by human factors and human factors should be arranged for harvesting and removal in time after the vegetation declines.

The frequency of regular inspection and maintenance of the stability of the broken surface of the embankment is once a month; the frequency of regular maintenance and management of vegetation is once a month.

Please refer to Fig. 1, as Embodiment 1 of the present invention, the specific content is as follows:

1. Investigate the scour conditions on both sides of the river.

Set up 20 research sample points on both sides of the section from Zhongpai Primary School to the estuary of the Paihe River in the Guangming Dayan River in Hefei, 10 on each side, to investigate and analyze the flood flow, flow velocity, flow potential and river bed quality and particle size.

①The scour depth generated by the water flow parallel to the bank slope is calculated by the following formula:

h _B =h _p +[(V _cp /V _allow ) ⁿ -1]; where, in the formula: h _B is the local scour depth from the water surface, the unit is m; h _p is the water depth at the scour place, the unit is m; V _cp is the average flow velocity, the unit is m/s; V _allow is the allowable non-rush flow velocity of the river bed, the unit is m/s; n is the coefficient;

②Calculate the scour depth caused by the oblique scouring of the revetment slope by the current

Among them, Δh _p is the depth of the local scour pit from the river bottom, the unit is m; V _j is the local scour velocity of the water flow, the unit is m/s; g is the acceleration of gravity, the unit is m/s ² ; d is the slope The calculated particle size of the soil at the foot is in cm; α is the intersection angle between the water flow and the bank; m is the slope coefficient of the protective building;

According to the way the water flow on both sides of the river impinges on the slope protection, the above formula is used to calculate and determine the scour depth. The scour depth on the left side of the section from Zhongpai Primary School to the estuary of Paihe River in Guangming Dayan River is between 1.2-1.5m, and the scour depth on the right side is 0.5m. -1.0m, according to this, it is determined that the left side of the section from Zhongpai Primary School to the estuary of the Paihe River is the high-scour section I, and the right side is the low-scour section II.

2. Select the construction area of the slope protection project.

Guangming Dayanhe River Road Zhongpai Primary School to the vicinity of the estuary section of Paihe River has the conditions for project implementation: construction vehicles (mixers, transport vehicles, etc.) work sites and roads (generally available). The current bank slope is between 30-60°.

3. The slope protection structure is constructed in the section from Zhongpai Primary School to the left side of the estuary of Paihe River in Guangming Dayan River.

After the slope is flat and compacted, a slope of 40-60° is formed. The slope protection structure is divided into two layers. Two layers of geonets are laid on the slope surface in and below the water level fluctuation area, fixed piles 1 are arranged at intervals of 1m, and ecological concrete precast blocks 2 are constructed on the geonet. The precast blocks 2 are nested side by side, and the adjacent precast blocks are The prefabricated blocks are overlapped with each other, and the volume and weight of a single prefabricated block are small, which is convenient for manual operation. A square hole with a side length of 110-120mm is reserved in the center of the ecological concrete precast block 2, and local soil and organic fertilizer are added in the hole, and the mass ratio of soil and organic fertilizer is 100-150:1. Lay in-situ soil on the slope above the water level fluctuation area.

4. Revegetation of slope protection vegetation from Zhongpai Primary School in Guangming Dayan River to the left section of Paihe estuary.

Reeds, cattails, iris and canna are planted below the water level fluctuation area, and bermudagrass and clover are evenly sprayed into the holes of the ecological concrete prefabricated blocks in the water level fluctuation area. Above the water level change area, plant sedge grass, bougainvillea, vetch and ryegrass.

5. Construction of slope protection structure from Zhongpai Primary School to the right side of Paihe estuary in Guangming Dayan River.

The slope protection structure in this section is divided into three layers. Cohesive soil is laid below the water level fluctuation area with a slope of 20-50 degrees. Cohesive soil and local soil are laid in the water level fluctuation area, mainly cohesive soil, with a slope of 5-20 degrees. Lay local soil above the water level fluctuation area with a slope of 20-50 degrees.

6. Vegetation restoration in the section on the right side of the estuary of Paihe River from Zhongpai Primary School in Guangming Dayan River.

Reeds and cattails are planted in the area 3 below the water level fluctuation area. Small shrubs such as wolfberry are planted in area 4 of the water level fluctuation area, and bermudagrass and sedge are planted under the shrubs. Wild chrysanthemum and Malan first are planted in the area 5 above the water level fluctuation area.

7. Maintenance and management.

Take certain maintenance and management measures: 1) Regular inspection (once a month) to maintain the stability of the broken surface of the embankment; 2) In addition to the early planting, fertilization and watering, extensive management of slope protection vegetation is adopted. 3) Regularly (once a month) maintain and manage vegetation, focusing on preventing pests and human factors from damaging vegetation. Arrange for harvesting and removal, etc. after vegetation declines.

The specific arrangement of the slope protection structure with low scour conditions in the present invention is as follows:

The slope protection structure under low scour conditions is set to three different structures from top to bottom, the middle layer is a first-level platform, and the layer below the first-level platform is laid with 500g/ ^m2 geotextile, and the geotextile is covered with cohesive soil. The slope is 1:4-1:5. The first-level platform is paved with pebble concrete, and the thickness of the paving is 0.15m; the layer structure above the first-level platform is set with a melon seed sheet cushion thickness of 0.1m, and the melon seed sheet cushion is covered with in-situ soil with a slope of 1:3- 1:4. Vegetation planting method on slope protection under low scour conditions: plant reeds and cattails below the water level fluctuation area. Small shrubs such as wolfberry are planted in the water level fluctuation area, and bermudagrass and sedge are planted under the shrubs. Plant wild chrysanthemum and Malan first above the water level fluctuation area.

The specific arrangement of the slope protection structure with high scour conditions in the present invention is as follows:

Flatten and compact the slope to form a 40-60° slope. The slope protection structure for high scour conditions is divided into two layers. Lay two layers of geonets in the water level fluctuation area and the slope below the water level fluctuation area, lay out fixed piles at intervals of 1m, and construct ecological concrete precast blocks on the geonet. The precast blocks are nested side by side, and the adjacent precast blocks and The blocks are overlapped with each other, and the single prefabricated block is small in size and light in weight, which is convenient for manual operation. A square hole with a side length of 110-120mm is reserved in the center of the ecological concrete precast block, and local soil and organic fertilizer are added in the hole. The mass ratio of soil and organic fertilizer is 100-150:1. In the area above the water level fluctuation area, natural stones are mainly laid, and in-situ soil is implanted in the middle of the stones.

The vegetation engineering of the slope protection structure under high scour conditions also includes three aspects: first, plant reeds, cattails, irises and canna below the water level fluctuation area to ensure the diversity of water surface species; second, the ecological concrete prefabricated blocks in the water level fluctuation area are evenly sprayed in the holes Bermudagrass, clover and ryegrass have strong adaptability and can survive in both wet and dry conditions. The third is to plant sedge grass, bullbena, wild peas, etc. above the water level fluctuation area, and combine grass and shrubs, such as paper mulberry, wolfberry, etc. The shore is dominated by spring flowers and willow trees.

In the present invention, the judgment of the high and low scour conditions on both sides of the river channel is based on the judgment of the scour depth determined by the calculation on both sides of the river bank. One side of the river bank is a low scour condition bank, which is suitable for a slope protection structure with low scour conditions.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope is determined by the scope of the appended claims.

Claims (9)

1. a river course slope protection ecological restoration method applicable to different scour conditions, is characterized in that, comprises the following steps: S1: Investigate the scour conditions on both sides of the river; S2: Select the construction area of the slope protection project. The conditions to be met by the construction area are: 1. River slope protection with different scour degrees; 2. Project implementation conditions are available near the slope protection; S3: Build slope protection structures with different scour conditions; S4: Maintain and manage the river slope protection. 2. the river course slope protection ecological restoration method suitable for different scour conditions according to claim 1, is characterized in that, the concrete investigation process of step S1 is: S1-1: The scour depth of the river banks on both sides of the river channel is used as the main basis for judging the scour conditions, and the scour depth depends on the flood flow, flow velocity, flow potential and river bed particle size of the river; S1-2: Calculate the scour depth caused by water flow parallel to the bank slope h _B =h _p +[(V _cp /V _allow ) ⁿ -1]; where, in the formula: h _B is the local scour depth from the water surface, the unit is m; h _p is the water depth at the scour place, the unit is m; V _cp is the average flow velocity, the unit is m/s; V _allow is the allowable non-rush flow velocity of the river bed, the unit is m/s; n is the coefficient; S1-3: Calculate the scour depth caused by the current oblique scouring of the bank protection slope

Among them, Δh _p is the depth of the local scour pit from the river bottom, the unit is m; V _j is the local scouring velocity of the water flow, the unit is m/s; g is the acceleration of gravity, the unit is m/s ² ; d is the slope The calculated particle size of the soil at the foot is in cm; α is the intersection angle between the water flow and the bank; m is the slope coefficient of the protective building; According to the way the water flow on both sides of the river impinges on the slope protection, the above formula is used to calculate and determine the scour depth, and the scour degree of the slope protection on both sides of the river channel is judged accordingly. 3. The method for ecological restoration of river course slope protection suitable for different scour conditions according to claim 1, characterized in that the specific conditions to be satisfied in the selection of the construction area in step S2 are: the bank slope is between 5-60°, and the Construction vehicle work site and road. 4. The method for ecological restoration of river course slope protection suitable for different scour conditions according to claim 1, characterized in that, in step S3, constructing slope protection structures with different scour conditions specifically includes constructing slope protection structures with high scour conditions and constructing slope protection structures with low scour conditions. slope protection structure; The specific method of constructing the slope protection structure under high scour conditions is as follows: S3-11: Flatten the slope to form a 40-60° slope; S3-12: Lay two layers of geonets in the water level fluctuation area and the slope below the water level fluctuation area, lay out fixed piles at 1m intervals, and construct ecological concrete precast blocks on the geonet. The prefabricated blocks overlap each other; S3-13: Reserve a square hole with a side length of 110-120mm in the center of the ecological concrete precast block, add local soil and organic fertilizer in the hole, and the mass ratio of soil and organic fertilizer is 100-150:1; S3-14: Lay in-situ soil on the slope above the water level fluctuation area. 5. the river course slope protection ecological restoration method suitable for different scour conditions according to claim 4, is characterized in that, the method for high scour condition slope protection vegetation restoration is: plant any reed, cattail, iris and canna below the water level fluctuation zone. One or several combinations, the holes of the ecological concrete prefabricated blocks in the water level fluctuation area are evenly sprayed with any one or a combination of bermudagrass and clover, and moss grass, bullbena, and wild peas are planted above the water level fluctuation area. , any one or a combination of ryegrass. 6. The river course slope protection ecological restoration method suitable for different scour conditions according to claim 1, is characterized in that, constructing slope protection structures with different scour conditions in step S3 specifically includes constructing slope protection structures with high scour conditions and constructing slope protection structures with low scour conditions. slope protection structure; The specific method of constructing the slope protection structure under low scour conditions is as follows: S3-21: The slope protection structure under low scour conditions is divided into three layers. Cohesive soil is laid under the water level fluctuation area, and the slope is 20-50°; 5-20°; local soil is laid above the water level fluctuation area with a slope of 20-50°. 7. the method for ecological restoration of river course slope protection suitable for different scour conditions according to claim 6, is characterized in that, the method for restoration of slope protection vegetation with low scour conditions is: plant any one or more of reeds and cattails below the water level fluctuation zone. Combination of species, planting shrubs in the water level fluctuation area, planting any one or a combination of bermudagrass and sedge grass under the shrubs, planting any one or several combinations of wild chrysanthemum and maranthus above the water level fluctuation area . 8. The river course slope protection ecological restoration method suitable for different scour conditions according to claim 1, is characterized in that, the maintenance and management of the river course slope protection in step S4 specifically includes: 1. Regularly check and maintain the stability of the broken surface of the embankment 2. Plant seedlings, fertilize and water the slopes; 3. Regularly maintain and manage vegetation, focusing on preventing pests and human factors from damaging vegetation, and arrange harvesting and removal in time after vegetation declines. 9. The method for ecological restoration of river course slope protection suitable for different scour conditions according to claim 8, wherein the frequency of regular inspection and maintenance of the stability of the broken surface of the embankment is once a month; the frequency of regular maintenance and management of vegetation is every month once.

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