Stepped ecological blocking dam construction method for debris flow solid source area

Abstract

The invention relates to the technical field of blocking dams, in particular to a construction method of a stepped ecological blocking dam in a debris flow solid source area. Comprising the steps of construction preparation, foundation construction, frame component installation and ecological function construction, water flow is allowed to pass through the structure, hydraulic scouring is reduced, meanwhile, vegetation root systems can enhance the soil stability, a'step-vegetation 'dual protection system is formed, a step type structure effectively disperses water flow energy, and a self-embedded structure enhances the overall stability; the functions of drainage holes are protected through reverse filtration treatment, water flow is allowed to pass through gravelly soil filling, the water plant platform further slows down the flow speed, vegetation roots enhance the soil stability, the multi-layer greening effect is formed, and biodiversity is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of retaining dam, in particular to a ladder-type ecological retaining dam construction method for solid source area of debris flow. BACKGROUND

[0002] The debris flow basin refers to the same surface water basin where the debris flow is formed and active, and is the basic unit of debris flow development and activity. Its formation requires three elements: steep catchment topography, accumulation of loose solid materials, and sudden water source. According to the valley geomorphology, it can be divided into valley type debris flow basin (narrow and long with large scale) and slope type debris flow basin (short and steep with small scale). A complete debris flow basin is composed of source area, flow area and accumulation area, and an incomplete basin has no obvious division.

[0003] The ladder-type slope protection ecological frame is not only a simple protection facility, but also an innovative product integrating ecological concept and engineering wisdom. Its unique ladder shape provides a buffer space for water flow, effectively reducing the impact of water flow on the slope, thereby greatly reducing the risk of water and soil loss.

[0004] The material of this ecological frame is usually environmentally friendly, which is not only durable but also compatible with the natural environment. It provides a good growing environment for various plants, allowing vegetation to grow and root on the slope. As the plants grow, their roots act as natural ties, tightly holding the soil, further enhancing the stability of the slope.

[0005] The ladder-type slope protection ecological frame is widely used in the slope protection of water conservancy projects such as rivers and reservoirs. On both sides of the river, it blocks the erosion of river water on the embankment, protecting the surrounding areas from the threat of floods. On the slope of the reservoir dam, it stabilizes the dam body and prevents damage caused by water erosion.

[0006] For example, the Chinese patent with publication number CN104018471B discloses a retaining overflow dam structure, belonging to the technical field of hydraulic structure design and manufacturing. It provides a retaining overflow dam structure with low foundation setting requirements, simple construction, and low construction cost. The retaining overflow dam structure includes block stones and a net-like water-permeable framework, the block stones are filled in the net-like water-permeable framework, and the retaining overflow dam structure is fixed in the river or channel outside the area where the retaining overflow dam structure is needed through the net-like water-permeable framework; the water flowing along the river or channel flows through the gap between the net-like water-permeable framework and the adjacent block stones, and the solid materials or push materials wrapped in the water flow are filtered and blocked on the water-facing side of the retaining overflow dam structure.

[0007] However, the dam in the prior art has poor control on the flow rate of water flow, and fast water flow rate is easy to take away a large amount of soil, resulting in soil erosion, and plants are difficult to plant, and the difficulty of greening is increased.

[0008] In order to solve the above problems, the application provides a stepped ecological retaining dam construction method for a debris flow solid source area. SUMMARY

[0009] The application aims to provide a stepped ecological retaining dam construction method for a debris flow solid source area to solve the problems in the background art.

[0010] In order to solve the above technical problems, the application provides the following technical scheme: a stepped ecological retaining dam construction method for a debris flow solid source area, comprising the following steps:

[0011] S1, construction preparation, using a total station to accurately measure the center axis of the retaining wall, and setting control points; using a steel ruler to determine the foundation boundary line, and using a level to measure the elevation of each point to determine the excavation depth; precasting concrete components with a size of 1000*1000*500mm; preparing auxiliary materials including steel bars, geotextiles, and planting soil;

[0012] S2, foundation construction, excavating according to the layout position using an excavator, and piling the excavated earth at least 3m away from the foundation pit; manually cleaning the base, backfilling and tamping the over-excavated part, excavating the water storage tank and sand settling tank; using a frog type tamper or stone tamper to compact the base, and the compaction degree is not less than the original ground; then removing the sundries on the surface of the foundation and washing; pouring C20 rubble concrete stepped foundation with a thickness of not less than 400mm every 30cm, and leaving a interception ditch; vibrating and compacting, and curing for not less than 28 days;

[0013] S3, frame component installation, assembling the reinforced concrete frame, ensuring the accurate position of the frame, firm support, and tight joint; installing the prefabricated frame from bottom to top layer by layer, using a self-embedded structure; connecting adjacent frames with M20 bolts, checking the horizontal and vertical direction error after each layer is installed, and the error standard is ±3cm per 3m;

[0014] S4, ecological function construction, filling gravel soil (thickness 0.3-0.5m) in the frame, using geotextile to back up, and setting a water outlet, and surrounding the filter treatment to prevent blockage; finally, setting a hydrophyte platform at the bottom of the wall, selecting plant varieties suitable for local conditions, and finally maintaining a vegetation coverage of more than 67%.

[0015] More preferably, in step S2, the number of stepped foundation layers is more than 9, and the stepped inclination angle is 30°.

[0016] More preferably, in step S2, the cross-section of the intercepting ditch is rectangular, with dimensions of 0.3*0.4m-0.8*0.8m.

[0017] More preferably, in step S2, the water storage pool is set in three levels, with a height of 50m 3 , 100m 3 , and 200m 3 , respectively, and is equipped with PE pipes for water delivery.

[0018] More preferably, in step S2, the sand settling pool has an internal size of 1.5*1.0*1.0m and is constructed by using brick or concrete.

[0019] More preferably, in step S4, the width of the aquatic plant platform is 2m.

[0020] More preferably, in step S4, the plant species include rye grass, alfalfa, shrubs, trees, reeds, or acorus.

[0021] More preferably, in step S4, the bearing capacity of the foundation fak is greater than or equal to 210kPa, and the compressive strength of the concrete is 2.5Mpa.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) The present application reduces the water flow speed and the direct impact force on the slope surface by dispersing the water flow into multiple levels through layer-by-layer reduction of the slope height.

[0024] (2) In the present application, the stable structure can provide sufficient foundation support area for the retaining wall, ensure that the foundation is not affected by underground water, and prevent uneven settlement of the foundation through over-excavation backfill treatment. The precast concrete component is designed in a stepped shape, and the precast component is produced in a factory and quickly installed on site. The concrete material has strong durability, the self-growth of vegetation reduces manual intervention, can promote biodiversity, and improves the microclimate.

[0025] (3) The structure of the present application allows water flow, reduces hydraulic scouring, and the vegetation root system can enhance the stability of the soil body, forming a "ladder-vegetation" double protection system. The stepped structure effectively disperses the water flow energy, the self-embedded structure enhances the overall stability, the inverse filtration treatment protects the drainage hole function, the gravel soil filling allows water flow, the aquatic plant platform further slows down the flow speed, the vegetation root system enhances the stability of the soil body, forms a multi-level greening effect, and promotes biodiversity. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of the present application.

[0027] The present application provides a ladder type ecological retaining dam construction method for a debris flow solid source area to solve the problems in the background art.

[0028] To solve the above technical problems, the present application provides the following technical solutions: a ladder type ecological retaining dam construction method for a debris flow solid source area, comprising the following steps:

[0029] S1, construction preparation, using a total station to accurately measure and set a retaining wall center axis, and setting a control point; using a steel ruler to determine a foundation boundary line, and using a level to measure the elevation of each point to determine the excavation depth; prefabricating a concrete component with a size of 1000*1000*500mm; and preparing auxiliary materials including reinforcing steel bars, geotextile, and planting soil.

[0030] In this step, the water flow is dispersed into multiple levels by reducing the slope height layer by layer, significantly reducing the water flow speed and reducing the direct impact force on the slope.

[0031] S2, foundation construction, excavating according to the layout position using an excavator, and piling the excavated earth at least 3m away from the foundation pit; manually cleaning the foundation, backfilling and tamping the over-excavated part, excavating a water storage pool and a sand settling pool; using a frog type tamper or a stone tamper to tamp the foundation, and the compaction degree is not less than the original ground; then removing the sundries on the surface of the foundation and washing; pouring C20 rubble concrete ladder foundation in layers with a thickness of 30cm per layer, and the total thickness is not less than 400mm, and a intercepting ditch is left; vibrating and compacting, and curing for not less than 28 days.

[0032] In this step, the number of layers of the ladder foundation is greater than 9, the inclination angle of the ladder is 30°, the water storage pool is set in three levels of 50m 3 , 100m 3 , and 200m 3 , and is matched with PE pipe water conveying, the intercepting ditch adopts a rectangular cross section with a size of 0.3*0.4m-0.8*0.8m, the water storage pool is set in three levels of 50m 3 , 100m 3 , and 200m 3 , and is matched with PE pipe water conveying, and the inner empty size of the sand settling pool is 1.5*1.0*1.0m, and the sand settling pool adopts a brick or concrete structure.

[0033] In this step, the stable structure can provide sufficient foundation support area for the retaining wall, ensure that the foundation is not affected by groundwater, and prevent uneven settlement of the foundation by over-excavation backfill treatment. The precast concrete component is designed in a stepped shape, precast component, factory production, on-site rapid installation, strong durability of concrete material, self-growth of vegetation reduces artificial intervention, can promote biodiversity, and improve microclimate.

[0034] S3, frame member installation, assemble the reinforced concrete frame, ensure that the frame position is accurate, the support is firm, and the joint is tight; install the precast frame from bottom to top layer by layer, adopt a self-embedded structure; adjacent frame bodies are connected by M20 bolts, and the horizontal and vertical direction errors are checked after each layer is installed, and the error standard is ± 3 cm per 3 m;

[0035] S4, ecological function construction, fill the gravel soil (thickness 0.3-0.5m) in the frame, adopt the reverse package of geotextile, and set the water outlet hole, and the surrounding is subjected to reverse filtration treatment to prevent blockage; finally, a hydrophyte platform is arranged at the bottom of the wall, and plant varieties suitable for local conditions are selected for planting, and finally more than 67% of the vegetation coverage is maintained.

[0036] In this step, the width of the hydrophyte platform is 2m, the plant varieties include reed or calamus, the foundation bearing capacity fak is greater than or equal to 210kPa, and the compressive strength of the concrete reaches 2.5Mpa.

[0037] In this step, the structure allows water flow, reduces hydraulic scouring, and the vegetation root system can enhance the stability of the soil body, forming a "ladder-vegetation" double protection system, the stepped structure effectively disperses the water flow energy, the self-embedded structure enhances the overall stability, the reverse filtration treatment protects the function of the water outlet hole, the gravel soil filling allows the water flow to pass, the hydrophyte platform further slows down the flow rate, the vegetation root system enhances the stability of the soil body, forms a multi-level greening effect, and promotes biodiversity.

[0038] The present application verifies the effect of the present application and the prior art scheme, wherein the present application is an example, and the prior art scheme includes comparative examples 1-4, which are respectively for the dam, the horizontal terrace, the vegetation cover and the drainage system scheme, and the specific results are shown in Table 1.

[0039] Table 1 Comparison table of core effect indicators of examples and comparative examples

[0040]

[0041]

[0042] As shown in Table 1, although the present application has the highest implementation cost, it has the best effect on reducing the flow rate of water flow, has a long service life, has low maintenance difficulty, has a short effect time, and has obvious comprehensive advantages.

[0043] The above merely describes optional embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation made by the present application specification, or directly or indirectly applied in other related technical fields under the inventive concept of the present application, are also included in the patent protection scope of the present application.

Claims

1. A method for constructing stepped ecological barrier dams in debris flow source areas, characterized in that, Includes the following steps: S1. Construction preparation: Use a total station to accurately measure and set the centerline of the retaining wall and mark the control points; use a steel ruler to determine the foundation edge line and use a level to measure the elevation of each point to determine the excavation depth; precast concrete components with dimensions of 1000×1000×500mm; prepare auxiliary materials, including steel bars, geotextile, and planting soil. S2, Foundation Construction: Excavate using an excavator according to the marked location, and pile the excavated soil at least 3m outside the foundation pit; manually clean the foundation, backfill and compact the over-excavated part, and excavate a water storage tank and sedimentation tank; use a frog-type rammer or stone rammer to compact the foundation, with a compaction degree not lower than the original ground level; then remove debris from the foundation surface and wash it; pour C20 rubble concrete stepped foundation in 30cm layers, with a total thickness of not less than 400mm, and leave an interception ditch; vibrate to compact, and cure for not less than 28 days; S3, Frame component installation: Assemble the reinforced concrete frame, ensuring accurate frame positioning, firm support, and tight joints; install precast frames layer by layer from bottom to top, using a self-embedding structure; connect adjacent frames with M20 bolts, and check the horizontal and vertical errors after each layer is installed, with an error standard of ±3cm per 3m; S4, ecological function construction, fill the frame with crushed stone soil (thickness 0.3-0.5m), use geotextile to wrap it, and set up drainage holes. The surrounding area is treated with reverse filtration to prevent clogging. Finally, set up an aquatic plant platform at the bottom of the wall, select plant varieties adapted to local conditions for planting, and finally maintain a vegetation coverage of more than 67%.

2. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 1, characterized in that: In step S2, the number of basic steps is greater than 9, and the step angle is 30°.

3. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 1, characterized in that: In step S2, the interception ditch adopts a rectangular cross-section with dimensions of 0.3×0.4m-0.8×0.8m.

4. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 1, characterized in that: In step S2, the water storage tank is 50m. 3 100m 3 200m 3 It is equipped with a three-stage water supply system and PE pipes.

5. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 4, characterized in that: In step S2, the internal dimensions of the sedimentation tank are 1.5×1.0×1.0m, and it is constructed using masonry bricks or concrete.

6. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 1, characterized in that: In step S4, the width of the aquatic plant platform is 2m.

7. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 1, characterized in that: In step S4, the plant varieties include ryegrass, alfalfa, shrubs, trees, reeds, or calamus.

8. The method for constructing a stepped ecological barrier dam in a debris flow source area according to claim 1, characterized in that: The foundation bearing capacity fak obtained in step S4 is ≥210kPa, and the concrete compressive strength reaches 2.5MPa.

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