Drop structure suitable for soft foundation riverbeds of medium and small rivers
By using timber piles and dry-laid stone structures on soft riverbeds in small and medium-sized rivers, the problems of existing waterfall structures being unsightly, unattractive, complex to construct, costly, and time-consuming have been solved. This has achieved integration with the natural ecological landscape and improved the stability of the riverbed, provided a habitat for aquatic animals, and reduced construction costs and time.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2026-03-10
AI Technical Summary
Existing cascade structures for soft riverbeds in small and medium-sized rivers suffer from problems such as being unsightly, unappealing, complex to construct, costly, time-consuming, and causing severe erosion of the riverbed, and are difficult to integrate with the natural ecological landscape.
The structure employs a combination of timber piles and dry-laid stone blocks, including upstream and downstream dry-laid stone blocks. The timber piles connect to the riverbank, resulting in a simple structure that adapts to foundation deformation, offers good permeability, is easy to construct, has low cost, short construction period, and requires no foundation treatment or diversion measures.
It achieves integration with the natural ecological landscape, reduces riverbed erosion, improves structural stability, reduces construction costs and time, and provides a habitat for aquatic animals, while also having strong adaptability to foundation deformation.
Smart Images
Figure CN223983993U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of ecological governance technology for small and medium-sized rivers, specifically relating to a drop structure suitable for soft riverbeds in small and medium-sized rivers. Background Technology
[0002] The drainage area of my country is between 200 and 3000 km². 2 There are approximately 10,000 small and medium-sized rivers in China, of which more than 6,800 are responsible for flood control. Compared to major rivers, small and medium-sized rivers have a longer total length, connecting more cities, villages, industries, and populations, and the people rely on them more heavily. As an important water conservancy task for people's livelihood, the management of small and medium-sized rivers has seen significant progress in the past decade due to increased national investment, primarily in flood control. However, problems remain, including varying degrees of functional singularity, fragmented management, and river channelization. Systematic management that comprehensively considers ecology, environment, water accessibility, landscape, and water culture is insufficient.
[0003] Waterfalls are a common structure used in the management of small and medium-sized river systems. They primarily address the problem of exposed riverbeds and beaches, serving functions such as water management, diversion, storage, creating ecological landscapes, and providing habitats for aquatic plants and animals. Existing river waterfalls are mostly masonry structures made of concrete or stone, which are neither ecologically sound nor aesthetically pleasing. Furthermore, waterfalls built on soft riverbeds require backfilling and foundation piles, have large cross-sectional dimensions, and are quite high (generally greater than 2 meters). They also necessitate comprehensive energy dissipation works downstream to prevent riverbed erosion, making them uneconomical. Moreover, they require diversion, dry-land construction, and have long construction periods. Utility Model Content
[0004] In view of this, the present invention provides a drop structure suitable for soft riverbeds of small and medium-sized rivers. The structure is simple, easy to connect with the slopes on both sides of the river, blends well with the natural ecological landscape of the river, has little impact on the scouring of the riverbed, has a certain degree of permeability and flexibility, and has a strong ability to adapt to foundation deformation. It does not require foundation treatment or construction diversion measures for soft riverbeds, and has low cost, short construction period, and mature construction technology.
[0005] This utility model is achieved through the following technical solution:
[0006] A drop structure suitable for soft riverbeds in small and medium-sized rivers includes: upstream dry-laid rubble blocks, wooden piles, and downstream dry-laid rubble blocks;
[0007] The wooden stakes are arranged sequentially along the width of the river to form a row of stakes, with each end of the row of stakes connected to the corresponding side of the riverbank, and the bottom of each stake inserted into the riverbed.
[0008] The upstream dry-laid rubble is placed on the upstream side of the pile row and is in contact with the pile row; the downstream dry-laid rubble is placed on the downstream side of the pile row and is in contact with the pile row.
[0009] Furthermore, the height of the wooden pile row is consistent with the maximum height of the upstream dry-laid stone blocks, while the maximum height of the downstream dry-laid stone blocks is 0.2m to 0.5m lower than the height of the wooden pile row.
[0010] Furthermore, the upstream dry-laid riprap section includes an uphill section and a horizontal section I. The upstream end of the uphill section connects to the riverbed, and the downstream end connects to one end of the horizontal section I. The other end of the horizontal section I connects to the pile bank. The height of the horizontal section I is the same as the height of the pile bank. The slope of the uphill section is not steeper than 1:1.5.
[0011] Furthermore, the downstream dry block includes horizontal section II and downslope section. The upstream end of horizontal section II is in contact with the pile bank, and the downstream end is connected to the upstream end of the downslope section. The downstream end of the downslope section is connected to the riverbed. The height of horizontal section II is 0.2m to 0.5m lower than the height of the pile bank. The slope of the downslope section is not steeper than 1:1.5.
[0012] Furthermore, the top width of the upstream and downstream dry-laid blocks is 1.0m to 3.0m.
[0013] Furthermore, pine wood piles were used for the wooden stakes.
[0014] Beneficial effects:
[0015] (1) The present invention provides a drop structure suitable for soft riverbeds in small and medium-sized rivers. First, the upstream dry-laid stone blocks are supported by wooden piles to resist water erosion and prevent displacement. In addition to the functions of water retention and water storage in the river channel and the creation of a water ecological landscape, the upstream dry-laid stone blocks also have the function of soil compaction. In addition to the functions of preventing downstream riverbed erosion and support, the downstream dry-laid stone blocks also have the function of soil compaction. The soil compaction function of the upstream and downstream dry-laid stone blocks can improve the performance of the wooden piles embedded in the soil layer, so that the drop structure has high stability. Second, the use of wooden piles makes it easy to connect with the slopes on both sides of the river channel. The soft riverbed does not require foundation treatment and is well integrated with the natural ecological landscape environment of the river channel. Third, the wooden piles, upstream dry-laid stone blocks and downstream dry-laid stone blocks have good permeability. On the one hand, the gaps between the stones can provide habitat for aquatic animals. On the other hand, during the dry season, artificial or mechanical wetland construction can be carried out without the need for construction diversion. Finally, the drop structure has a simple structure, low construction cost and short construction period.
[0016] (2) The drop structure provided by this utility model is suitable for soft riverbeds of small and medium-sized rivers. The height of the wooden pile row is consistent with the maximum height of the upstream dry-laid stone blocks, and the maximum height of the downstream dry-laid stone blocks is 0.2m to 0.5m lower than the height of the wooden pile row. It can not only play a step-like effect, but also has a small drop height (<1.0m) and little impact on riverbed scouring.
[0017] (3) The setting of the upstream dry-laid stone slope of this utility model can effectively control the water flow speed, avoid the water flow being too fast and causing strong scouring to the bottom of the waterfall structure, and also make the dry-laid stones fit more tightly under the action of gravity, thereby enhancing the stability of the overall structure.
[0018] (4) The setting of the downstream dry-laid stone slope of this utility model can effectively control the water flow speed, avoid the water flow being too fast and causing strong scouring of the riverbed, and also make the dry-laid stones fit more tightly under the action of gravity, thereby enhancing the stability of the overall structure.
[0019] (5) The wooden stakes in this utility model are made of pine wood, which has good anti-corrosion ability, is lightweight, has high strength and good toughness, and is easy to process and transport. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the plan layout of the drop structure;
[0021] Figure 2 This is a plan view of the waterfall structure;
[0022] Figure 3 This is a cross-sectional view of the waterfall structure;
[0023] Figure 4 Detailed plan of the timber pile layout;
[0024] Among them, 1-riverbank, 2-riverbed, 3-cascade structure, 4-wooden pile, 5-upstream dry-laid stone blocks, 6-downstream dry-laid stone blocks, 7-water flow direction. Detailed Implementation
[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0026] Example 1:
[0027] This embodiment provides a drop structure suitable for soft riverbeds in small and medium-sized rivers. See Appendix. Figure 1 Several waterfall structures 3 can be distributed at intervals upstream and downstream along the flow direction 7 of small and medium-sized rivers; see appendix. Figure 2 Each drop structure 3 includes an upstream dry-laid stone block 5, a wooden pile 4, and a downstream dry-laid stone block 6;
[0028] The wooden piles 4 are arranged sequentially along the width of the river to form a row of wooden piles. The two ends of the row of wooden piles are connected to the riverbank 1 on the corresponding side, and the bottom of each wooden pile 4 is inserted into the riverbed 2.
[0029] The upstream dry-laid stone block 5 is located on the upstream side of the wooden pile row and is in contact with the wooden pile row; the downstream dry-laid stone block 6 is located on the downstream side of the wooden pile row and is in contact with the wooden pile row.
[0030] This embodiment provides a drop structure 3 suitable for soft riverbeds 2 in small and medium-sized rivers. First, the upstream dry-laid stone blocks 5 are supported by a row of wooden piles to resist water erosion and prevent displacement. In addition to the functions of water retention and water storage and the creation of a water ecological landscape, the upstream dry-laid stone blocks 5 also have the function of soil tamping. The downstream dry-laid stone blocks 6, in addition to preventing downstream riverbed erosion and supporting the drop structure, also have the function of soil tamping. The soil tamping effect of the upstream dry-laid stone blocks 5 and the downstream dry-laid stone blocks 6 can improve the performance of the wooden piles 4 in embedding the soil layer, so that the drop structure 3 has high stability. Second, the use of wooden piles 4 makes it easy to connect with the slopes on both sides of the river. The soft riverbed 2 does not require foundation treatment and integrates well with the natural ecological landscape environment of the river. Third, the wooden pile row, the upstream dry-laid stone blocks 5 and the downstream dry-laid stone blocks 6 have good permeability. On the one hand, the gaps between the stones can provide habitat for aquatic animals. On the other hand, during the dry season, construction can be carried out manually or mechanically in wetlands without the need for construction diversion. Finally, the drop structure 3 has a simple structure, low construction cost and short construction period.
[0031] The height of the wooden pile row is consistent with the highest height of the upstream dry-laid riprap 5 (i.e., the top elevation of the drop), while the highest height of the downstream dry-laid riprap 6 is 0.2m to 0.5m lower than the height of the wooden pile row. This not only achieves a first-step effect but also results in a smaller drop height (<1.0m), minimizing the impact of riverbed scouring. The top width of the upstream dry-laid riprap 5 and downstream dry-laid riprap 6 is 1.0m to 3.0m; the individual stone diameter of the upstream dry-laid riprap 5 and downstream dry-laid riprap 6 is greater than 20cm, and the gaps between the stones are filled with small pebbles.
[0032] The upstream dry-laid stone section 5 includes an uphill section and a horizontal section I. The upstream end of the uphill section connects to the riverbed 2, and the downstream end connects to one end of the horizontal section I. The other end of the horizontal section I connects to the pile row. The height of the horizontal section I is the same as the height of the pile row. The slope of the uphill section is not steeper than 1:1.5.
[0033] The downstream dry-laid block section includes horizontal section II and downslope section. The upstream end of horizontal section II is in contact with the pile bank, and the downstream end is connected to the upstream end of the downslope section. The downstream end of the downslope section is connected to the riverbed 2. The height of horizontal section II is 0.2m to 0.5m lower than the height of the pile bank. The slope of the downslope section is not steeper than 1:1.5.
[0034] The particle size and unit weight of the upstream dry-laid riprap (5mm diameter) and downstream dry-laid riprap (6mm diameter) are related to the flow velocity under the design flood standard of the river channel. In practical applications, they should be calculated and determined according to formulas (D.3.4-1) and (D.3.4-2) in Appendix D of the "Code for Design of Embankment Engineering".
[0035]
[0036] In equations (D.3.4-1) and (D.3.4-2):
[0037] d—Converted particle size (m), calculated based on spherical shape;
[0038] W—Weight of a single stone (kN);
[0039] V—Water flow velocity (m / s);
[0040] g—acceleration due to gravity (m / s²);
[0041] C—Stability coefficient of the stone movement; take C = 0.9;
[0042] γ s —The bulk density of the stone (kN / m3);
[0043] γ — Specific density of water (kN / m3).
[0044] The parameters such as the length, tail diameter, pile spacing, and embedment depth of the pine piles are related to the mechanical properties of the riverbed soil and rock and the characteristics of the design flood of the river channel. They should be able to ensure that the drop structure 3 meets the overall stability requirements. In practical applications, the upstream and downstream water pressures of the drop structure can be equivalent to additional forces. Based on the experience of pine pile retaining wall projects, and according to the stability calculation principles of the plate-mounted retaining wall without anchorage in the "Code for Design of Retaining Walls" and the calculation principles of the support piles in the "Technical Specification for Foundation Pit Support", the parameters are determined by calculation and analysis using Lizheng software.
[0045] Working principle:
[0046] Multiple cascading structures 3, spaced at intervals along a river section, form a cascading system that appropriately increases the water depth, creating an aquatic ecological landscape and a habitat for aquatic plants and animals. As water flows through the cascading structures, upstream dry-laid stone blocks 5 impound and store the water. Most of the water overflows from the top of the cascading structure, while a small portion flows downstream through the interior of the cascading structure. The gaps between the stones provide habitats for aquatic animals. The cascading structure 3 includes wooden piles 4, upstream dry-laid stone blocks 5, and downstream dry-laid stone blocks 6. It offers advantages such as simple structure, good integration with the natural ecological landscape of the river, no need for foundation treatment for soft riverbeds 2, minimal impact on riverbed scouring, good permeability and flexibility, easy connection to the riverbank slopes, no need for diversion measures, short construction time, mature construction technology, and relatively lower cost compared to masonry cascading structures.
[0047] Example 2:
[0048] Based on Example 1, this embodiment provides a specific implementation method. The wooden piles 4 are made of pine wood, and the wooden piles are driven into the wetland using a diesel pile driver, without the need for construction diversion. Each pine wood pile has a tail diameter of 15cm, a pile length of 4.0m, an embedment depth of 3.2m, and 20.8m exposed above the riverbed. The distance between the cores of any two adjacent pine wood piles is 25cm.
[0049] The highest point of the upstream dry-laid rubble block 5 is 0.8m, the top width is 1.0m, and the slope of the uphill section is 1:2.0;
[0050] The maximum height of the downstream dry-laid rubble masonry section 6 is 0.5m, the top width is 1.0m, and the slope of the downhill section is 1:2.0.
[0051] According to formulas (D.3.4-1) and (D.3.4-2), the particle size of the single stone of the upstream dry-laid stone block 5 and the downstream dry-laid stone block 6 is 0.25m and the weight of the single stone is 30kg, which meets the requirements of water flow erosion resistance. The gaps between the stones are filled with smaller stones.
[0052] In summary, the above are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A drop structure suitable for soft foundation riverbeds of small and medium rivers, characterized in that, The application relates to a dry-laid block stone riverbank protection structure. The upstream dry-laid block stone, the wooden pile and the downstream dry-laid block stone are arranged in sequence along the width direction of the river to form a wooden pile row, the two ends of the wooden pile row are connected with the corresponding riverbanks respectively, and the bottom of each wooden pile is inserted into the riverbed. The upstream dry-laid block stone is arranged on the upstream side of the wooden pile row and is in contact with the wooden pile row. The downstream dry-laid block stone is arranged on the downstream side of the wooden pile row and is in contact with the wooden pile row. The height of the wooden pile row is consistent with the highest height of the upstream dry-laid block stone, and the highest height of the downstream dry-laid block stone is 0.2-0.5 m lower than the height of the wooden pile row.
2. The drop structure according to claim 1, wherein the drop structure is adapted to be used in a soft riverbed of a small or medium-sized river. The upstream dry-laid block stone comprises an uphill section and a horizontal section I, the upstream end of the uphill section is connected with the riverbed, the downstream end of the uphill section is connected with one end of the horizontal section I, the other end of the horizontal section I is connected with the wooden pile row, the height of the horizontal section I is consistent with the height of the wooden pile row, and the slope of the uphill section is not steeper than 1:1.
5.
3. The drop structure according to claim 2, wherein the drop structure is adapted to be used in a soft riverbed of a small or medium-sized river. The downstream dry-laid block stone comprises a horizontal section II and a downhill section, the upstream end of the horizontal section II is in contact with the wooden pile row, the downstream end of the horizontal section II is connected with the upstream end of the downhill section, the downstream end of the downhill section is connected with the riverbed, the height of the horizontal section II is 0.2-0.5 m lower than the height of the wooden pile row, and the slope of the downhill section is not steeper than 1:1.
5.
4. The structure according to claim 2, wherein the structure is used for the small and medium-sized river soft foundation riverbed. The top width of the upstream dry-laid block stone and the downstream dry-laid block stone is 1.0-3.0 m.
5. The drop structure according to any one of claims 1 to 4, wherein the drop structure is suitable for use in a soft riverbed of a small or medium-sized river. The wooden pile is made of pine.
6. The drop structure according to any one of claims 1-4, wherein the drop structure is suitable for use in a soft riverbed of a small or medium river.