A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers

Abstract

The present invention discloses a deep groove-shallow structure suitable for improving the hydrodynamics of urban rivers, including a deep groove and a shallow beach; the deep groove is arranged on one side of the river channel, and the deep groove is concave from the original riverbed of the river channel; the shallow beach is arranged on the other side of the river channel opposite to the deep groove, and the shallow beach includes a gabion groin arranged perpendicular to the river bank protection, and arc-shaped wood pile walls are arranged on both the upstream and downstream sides of the gabion groin, and one end of the two arc-shaped wood pile walls is fixedly connected to the dam head of the gabion groin, and the other end is fixedly connected to the river bank protection, and a dam front area and a dam back area are formed on both the upstream and downstream sides of the gabion groin, and the dam front area is filled with shoal soil to form a dam front shoal, and the dam back area is filled with shoal soil to form a dam back shoal. The present invention has a stable structure, a simple construction, and a significant hydrodynamic improvement effect, which can greatly reduce the development and damage to the river bank zone, and effectively improve the river hydrodynamics, and realize the diversification of water flow conditions and biological habitats.

Description

Technical Field

[0001] The invention relates to river regulation and water environment management technology, and in particular to a deep trough-shallow beach structure suitable for improving the hydrodynamics of urban rivers. Background Art

[0002] Since the rise of the real estate development market in the early 21st century, the intensity of urban development and construction has increased, resulting in many rivers in the urban river network area being randomly filled, causing the regional water system to shrink and forming a large number of broken bays; in order to serve the development and utilization of urban plots and the construction of road networks, most rivers in the river network area have been straightened, forming a large number of straight river channels. The above situations have led to the single hydrodynamic conditions of the river system, slow river flow, poor pollutant diffusion capacity, and only a poor and unstable ecosystem with a lack of natural recovery capacity.

[0003] The deep trough-shallows were originally riverbed structures formed by the erosion of water flow in natural meandering rivers. The deep troughs are usually fish protection areas and organic matter storage areas, and the gravel bottom of the shallows can serve as the main habitat for many aquatic invertebrates and the main place for fish to forage. However, after the natural river channel was straightened, the original deep trough-shallows structure gradually disappeared, making the riverbed flat, resulting in the loss of the head accumulation area in the deep trough and the water energy dissipation area in the shallows, greatly reducing the habitat and spawning sites of aquatic animals, and seriously damaging the health of the river. Therefore, by artificially constructing a deep trough-shallows structure in the river channel, on the one hand, the surface area of ​​the riverbed can be increased, and the shallows area with low flow rate, the deep trough still water area and the deep trough-shallows waterfall area can be combined to form a diversified habitat condition suitable for different organisms to inhabit, which has good ecological significance; on the other hand, the migration and diffusion capacity of pollutants in the river can be enhanced, which has good environmental benefits.

[0004] However, the biggest problem facing traditional deep trough-shoal structures is structural stability. Long-term strong scouring will cause the shoal to disintegrate. If the river's longitudinal profile gradient is too small, it will cause siltation in the shoal. If the gradient is too large, the riverbed in the deep trough will be cut down, which is not conducive to the stability of the river channel. Summary of the invention

[0005] The purpose of this patent is to address the problem of single hydrodynamic conditions in urban river network areas, and to provide a deep trough-shallow structure with stable structure, simple construction, and significant hydrodynamic improvement effect, combined with the limitations of poor stability of traditional deep trough-shallow structure. Constructing this deep trough-shallow structure in urban rivers can greatly reduce the development and damage to the riverbank, while effectively improving the hydrodynamics of the river and achieving diversification of water flow conditions and biological habitats.

[0006] The technical solution adopted by the present invention is: a deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers, comprising:

[0007] a deep groove, the deep groove being arranged on one side of the river channel, the deep groove being sunken from the original riverbed of the river channel; and

[0008] A shoal is arranged on the other side of the river channel opposite to the deep trough, and the shoal includes a gabion groin, which is arranged perpendicular to the river bank, the root of the gabion groin is fixedly connected to the river bank, and the dam head extends from the river bank into the river channel; arc-shaped wooden pile walls are arranged on both the upstream and downstream sides of the gabion groin, one end of the two arc-shaped wooden pile walls is fixedly connected to the dam head of the gabion groin, and the other end is fixedly connected to the river bank, forming a dam front area on the upstream side of the gabion groin, and a dam back area on the downstream side of the gabion groin; the dam front area is filled with shoal soil to form a dam front shoal, and the dam back area is filled with shoal soil to form a dam back shoal.

[0009] Furthermore, the deep trough has an inverted quadrangular prism structure and an isosceles trapezoidal shape in the cross section of the river channel; the bottom of the deep trough is 0.5m to 1m higher than the original riverbed of the river channel, and the bottom of the deep trough is 2m to 3m long and 0.5m to 1m wide; the four walls of the deep trough have a slope of 40° to 50°.

[0010] Furthermore, the shallows are closer to the upstream of the river channel than the deep trough.

[0011] Furthermore, the gabion groyne is composed of a mesh cage frame and gravel filled in the mesh cage frame; the aperture of the mesh cage frame is less than 3 cm, and the particle size of the gravel is 5 cm to 15 cm.

[0012] Furthermore, the height of the gabion groin is between the normal water level and the flood level, and the length of the gabion groin is ≤ 1 / 3 of the river width.

[0013] Furthermore, the top surfaces of the shoal in front of the dam and the shoal behind the dam are lower than the normal water level and are 0.5m to 1m away from the normal water level.

[0014] Furthermore, plants are planted in the shallows in front of the dam and the shallows behind the dam.

[0015] Furthermore, the arc-shaped wood pile wall is formed by a plurality of wood piles tightly connected to each other, the depth of the wood piles inserted into the riverbed is greater than 30 cm, and the tops of the wood piles are flush with the top surfaces of the shoal in front of the dam and the shoal behind the dam.

[0016] Furthermore, a layer of geotextile is laid between the arc-shaped wood pile wall and the shallow soil.

[0017] Furthermore, in a section of river channel, a plurality of groups of the deep trough-shallow structures are arranged, and the distance between the adjacent deep troughs or the shallows on the same side of the river bank is 3 to 5 times the river width.

[0018] The beneficial effects of the present invention are:

[0019] (1) The deep trough-shallow shoal is arranged in pairs, which conforms to the actual situation of natural rivers, increases the longitudinal meandering and cross-sectional diversity of the river, and plays an important role in improving the hydrodynamic conditions of the river and constructing a diverse habitat for plants and animals.

[0020] (2) The deep trench and shallow beach are constructed by excavating and piling in the river channel, which saves costs, simplifies construction operations, and avoids the large amount of land occupied by the project and the risk of river water pollution caused by foreign materials.

[0021] (3) Gabion groins are set up at the shallows. With the help of the diversion characteristics of the groins, a complex flow field can be formed near the groins, increasing the diversity of river flow patterns and forming a high velocity area on the opposite side of the river to avoid siltation in the deep trough. On the other hand, gabion groins can alleviate the scouring of water flow on the shallows and enhance the stability of the shallows. In addition, the gabion groin itself has a certain degree of permeability and stability, and its height is between the normal water level and the flood level. Therefore, it can meet the requirements of safe flood discharge in towns during the flood season.

[0022] (4) The edge of the shoal is designed to be in an arc shape, which conforms to the actual flow pattern of the river water around the shoal. The outside of the shoal is surrounded by a wooden pile wall and geotextile, which can fix the shape of the shoal and play a role in filtering water and conserving soil.

[0023] (5) Planting cattails and reeds on shallows can fix the surface sediment and form shallow plant shelters to improve the quality of aquatic animal habitats. In addition, cattails and reeds have a certain interception and enrichment effect on pollutants in river water, which has a good effect on improving the water quality of urban rivers.

[0024] (6) Cattails and reeds located in the shallows enhance the aesthetics of the river and the landscape value of the urban river, and can attract birds to feed, nest and breed in the riparian zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : The present invention is applicable to the schematic diagram of the deep trough-shallow structure for improving the hydrodynamics of urban rivers;

[0026] Figure 2 : The present invention is applicable to the top view of the deep trough-shoal structure for improving the hydrodynamics of urban rivers;

[0027] Figure 3 : Schematic diagram of the cross section of a river channel with a hydrodynamically improved deep trough-shoal structure;

[0028] Figure annotation:

[0029] 1——deep trough; 2——shallow beach behind the dam;

[0030] 3——the shallow beach in front of the dam; 4——the arc-shaped wooden pile wall;

[0031] 5 – gabion groin; 6 – cattail;

[0032] 7——Reed; 8——River bank protection;

[0033] 9——normal water level; 10——edge line of land side slope;

[0034] 11——Slope edge of the water area; 12——Contour line of the original riverbed;

[0035] 13——Riverbed contour after transformation; 14——Geotextile. DETAILED DESCRIPTION

[0036] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0037] As attached Figures 1 to 3 As shown, a deep trough-shallows structure suitable for improving the hydrodynamics of urban rivers comprises a deep trough 1 and a shallows.

[0038] The deep trough 1 is arranged on one side of the river channel, near the bank slope edge line 11 of the river channel water area. The deep trough 1 is sunken from the original riverbed of the river channel, and is approximately an inverted quadrangular prism structure as a whole, and is approximately an isosceles trapezoid shape in the cross section of the river channel. The bottom of the deep trough 1 is 0.5m to 1m higher than the original riverbed of the river channel, and the bottom of the deep trough 1 is 2m to 3m long and 0.5m to 1m wide; the four walls of the deep trough 1 have a slope of 40° to 50°.

[0039] The shoal is arranged on the other side of the river channel opposite to the deep trough 1, and is closer to the upstream of the river channel than the deep trough 1. The shoal is in close contact with the river channel bank slope, and is surrounded by an arc-shaped wooden pile wall 4 on the outside to maintain the shape of the shoal; the shoal is divided into two approximately fan-shaped parts by a gabion groin 5 perpendicular to the river channel revetment 8, and is divided into a shoal 3 in front of the dam and a shoal 2 behind the dam according to the direction of water flow.

[0040] The root of the gabion spur 5 is fixedly connected to the river bank 8, and the dam head extends from the river bank 8 into the river. The gabion spur 5 is composed of a mesh frame and gravel filled in the mesh frame, the aperture of the mesh frame is less than 3 cm, and the particle size of the gravel is 5 cm to 15 cm. The height of the gabion spur 5 is between the normal water level 9 and the flood level, and the length of the gabion spur 5 is ≤ 1 / 3 of the river width.

[0041] The upstream and downstream sides of the gabion spur 5 are both provided with arc-shaped wood pile walls 4, one end of each of the two arc-shaped wood pile walls 4 is fixedly connected to the dam head of the gabion spur 5, and the other end is fixedly connected to the river bank 8, forming a dam front area on the upstream side of the gabion spur 5 and a dam back area on the downstream side of the gabion spur 5. The wood pile wall is formed by a plurality of wood piles tightly connected to each other, the depth of the wood piles inserted into the riverbed is greater than 30 cm, and the top of the wood piles is flush with the top surface of the dam front shoal 3 and the dam back shoal 2.

[0042] The shoal soil is filled in the area in front of the dam to form the shoal 3 in front of the dam, and the shoal soil is filled in the area behind the dam to form the shoal 2 behind the dam. The shoal soil is the riverbed soil obtained by excavating the deep trench 1. A layer of geotextile 14 is laid between the shoal soil and the pile wall. The top surfaces of the shoal 3 in front of the dam and the shoal 2 behind the dam are lower than the normal water level 9 and are 0.5m to 1m away from the normal water level 9. Cattail 6 and reed 7 are planted on the shoal 3 in front of the dam and the shoal 2 behind the dam, respectively, at a rate of 20 plants / m 2 With 15 plants / m 2 density of planting.

[0043] In a section of river channel, multiple groups of deep trough-shallow structures are arranged alternately, and the distance between the adjacent deep troughs 1 or the shallows on the same side of the river bank is 3 to 5 times the river width.

[0044] The bank slope edge line 10 on the land side of the river channel and the bank slope edge line 11 on the water side are as follows: Figure 1 As shown, when the project is implemented, first excavation is carried out along the bank slope edge line 11 of the water area to construct a deep trench 1. The four walls of the deep trench 1 have a certain slope to maintain the shape of the trench. Then, the river bank 8 is leveled on the upstream side of the opposite bank, and a gabion groyne 5 that matches the slope of the bank is built, and its dam top is higher than the normal water level 9. Then, a curved timber pile wall 4 is formed by densely driving wooden piles on both sides of the gabion groyne 5, and a geotextile 14 is laid close to the curved timber pile wall 4 on the shore side of the curved timber pile wall 4. The insertion depth of the wooden piles and geotextile 14 in the riverbed is at least 30 cm. Finally, the riverbed subsoil obtained by excavating the deep trench 1 is filled in the two fan-shaped spaces surrounded by the curved timber pile wall 4, the gabion groyne 5 and the river bank 8 to form a shoal 3 in front of the dam and a shoal 2 behind the dam. The tops of the shoals are kept at the same height as the curved timber pile wall 4. 20 plants / m are planted on the shoals 3 in front of the dam and the shoals 2 behind the dam, respectively. 2 With 15 plants / m 2 The density of planting cattail is 6 and reed is 7.

[0045] By constructing this deep trough-shoal structure in the urban river channel, the original single cross-sectional shape of the river channel is changed, and the original riverbed contour line 12 becomes complex and diverse through the construction of the deep trough 1 and the shoal, forming a complex and diverse transformed riverbed contour line 13. When the river water flows through this structure, a deep trough water head accumulation area and a shoal water energy dissipation area will be formed, which improves the original single hydrodynamic conditions and forms a variety of biological habitats, which is of great significance for improving the urban river environment and ecological benefits. In addition, the setting of structures such as the arc-shaped wooden pile wall 4, the gabion groin 5, and the geotextile 14 improves the structural stability of the deep trough 1 and the shoal, which can effectively prevent the siltation of the deep trough caused by the accumulation of sand and soil and the disintegration of the shoal caused by long-term scouring of water.

[0046] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which belong to the scope of protection of the present invention.

Claims

1. A deep trough-shoal structure suitable for improving the hydrodynamics of urban rivers, characterized in that: include: a deep trough (1), the deep trough (1) being arranged on one side of the river channel, the deep trough (1) being recessed from the original riverbed of the river channel; and A shoal, wherein the shoal is arranged on the other side of the river channel opposite to the deep groove (1), and the shoal includes a gabion groin (5), wherein the gabion groin (5) is arranged perpendicular to the river channel revetment (8), the dam root of the gabion groin (5) is fixedly connected to the river channel revetment (8), and the dam head extends from the river channel revetment (8) into the river channel; arc-shaped wood pile walls (4) are arranged on both the upstream and downstream sides of the gabion groin (5), one end of each of the two arc-shaped wood pile walls (4) is fixedly connected to the dam head of the gabion groin (5), and the other end of each of the two arc-shaped wood pile walls (4) is fixedly connected to the river channel revetment (8), forming a dam front area on the upstream side of the gabion groin (5) and a dam back area on the downstream side of the gabion groin (5); the dam front area is filled with shoal soil to form a dam front shoal (3), and the dam back area is filled with shoal soil to form a dam back shoal (2).

2. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: The deep trough (1) is in the form of an inverted quadrangular prism and is in the form of an isosceles trapezoid in the cross section of the river channel; the bottom of the deep trough (1) is 0.5m to 1m higher than the original riverbed of the river channel in elevation, the bottom of the deep trough (1) is 2m to 3m long and 0.5m to 1m wide; the four walls of the deep trough (1) have a slope of 40° to 50°.

3. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: The shallows are closer to the upstream of the river channel than the deep trough (1).

4. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: The gabion groin (5) is composed of a mesh cage frame and gravel filled in the mesh cage frame; the aperture of the mesh cage frame is less than 3 cm, and the particle size of the gravel is 5 cm to 15 cm.

5. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: The height of the gabion groin (5) is between the normal water level (9) and the flood level, and the length of the gabion groin (5) is ≤ 1 / 3 of the river width.

6. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: The top surfaces of the shoal (3) in front of the dam and the shoal (2) behind the dam are lower than the normal water level (9) and are 0.5m to 1m away from the normal water level (9).

7. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: Plants are planted in the shallow beach (3) in front of the dam and the shallow beach (2) behind the dam.

8. The deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: The arc-shaped wood pile wall (4) is formed by a plurality of wood piles tightly connected to each other. The depth of the wood piles inserted into the riverbed is greater than 30 cm, and the tops of the wood piles are flush with the top surfaces of the shoal in front of the dam (3) and the shoal behind the dam (2).

9. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: A layer of geotextile (14) is laid between the arc-shaped wood pile wall (4) and the shallow soil.

10. A deep trough-shallow structure suitable for improving the hydrodynamics of urban rivers according to claim 1, characterized in that: In a section of river channel, a plurality of groups of the deep trough-shallow structures are arranged, and the distance between the adjacent deep troughs (1) or the shallows on the same side of the river bank is 3 to 5 times the river width.

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