Stilling basin tail sill structure applied to crossing of spillway and pipeline

Abstract

The stilling pool tail sill structure comprises a stilling pool bottom plate connected with a tail sill, a city gate opening type pipeline protection body is arranged above the stilling pool bottom plate, and the two sides of the city gate opening type pipeline protection body are in a slope type and an arc type respectively. The two slope surfaces are respectively an upstream slope surface, an arc-shaped convex surface and a downstream connection arc-shaped slope surface, a gravel inverted filter layer and a coarse sand inverted filter layer are sequentially arranged below the stilling basin bottom plate, a tooth wall is arranged at the tail end of the stilling basin bottom plate, sand gravel backfill is arranged at the joint of the tooth wall, and a lead wire gabion apron is arranged above the sand gravel backfill. According to the stilling pool tail sill structure applied to crossing of the spillway and the pipeline, the water flow state is improved and the impact on a downstream river channel is reduced on the premise that the pipeline structure is not damaged and the pipeline operation is not influenced when the spillway and the pipeline are crossed, and meanwhile, the problem of sediment deposition caused by a single type of a traditional tail sill is solved; the dam safety is protected.

Description

Technical Field

[0001] This utility model belongs to the technical field of water conservancy and municipal engineering equipment, specifically relating to the structure of the tail sill of a stilling basin at the intersection of a spillway and a pipeline. Background Technology

[0002] Stilling basins are commonly used energy dissipation and scour prevention structures in hydraulic engineering projects, serving as bottom flow energy dissipation devices. They are typically used in low-head, high-flow-rate overflow structures, creating a bottom flow hydraulic jump downstream to quickly transform a rapid flow into a slower flow. Due to their simple structure and ease of construction, they are a commonly used energy dissipation method. Existing stilling basin tail sills are usually either vertical or sloping. Vertical stilling basins are prone to siltation, while sloping stilling basins, although effective at removing sediment, have relatively poor energy dissipation performance.

[0003] In most urban planning projects, pipeline routes are intricate and frequently intersect with existing buildings. Therefore, the handling of pipeline intersections during reinforcement and repair is crucial, as it not only affects the pipeline's water supply or irrigation functions but also the structural safety of buildings. In recent years, some projects have also involved rerouting pipelines, impacting their normal functionality and significantly affecting water users. Utility Model Content

[0004] The purpose of this utility model is to provide a stilling basin tail sill structure for use at the intersection of spillway and pipeline. It solves the problem of improving water flow pattern and reducing impact on downstream river channels without damaging the pipeline structure or affecting pipeline operation when the spillway and pipeline intersect. At the same time, it solves the problem of siltation caused by the traditional single type of tail sill and protects the safety of the dam.

[0005] The technical solution adopted in this utility model is as follows: a stilling basin tail sill structure applied to the intersection of spillway and pipeline, including a stilling basin bottom plate connected to the tail sill, a portal-shaped pipeline protection body set above the stilling basin bottom plate, the portal-shaped pipeline protection body having a sloping slope and an arc shape on both sides, namely an upstream sloping surface and an arc-shaped convex surface and a downstream connecting arc-shaped slope surface, a gravel filter layer and a coarse sand filter layer set below the stilling basin bottom plate from top to bottom, a toothed wall set at the end of the stilling basin bottom plate, a gravel backfill set at the junction with the toothed wall, and a gabion seawall set above the gravel backfill.

[0006] The technical solution adopted in this utility model is also characterized by:

[0007] Furthermore, the tunnel-shaped pipe protection structure contains pipes inside.

[0008] Furthermore, the arc-shaped convex surface and the downstream connecting arc-shaped slope surface connect with the gabion seawall.

[0009] Furthermore, below the stilling basin bottom plate is a gravel filter layer, and below the gravel filter layer is a coarse sand filter layer.

[0010] Furthermore, the slope ratio of the upstream slope is gentler than 1:0.5.

[0011] Furthermore, a 0.5m to 1m pipeline maintenance space is reserved on one side of the tunnel-shaped pipeline protection body.

[0012] Furthermore, the top of the arch-shaped pipeline protection structure is at least 0.5m higher than the downstream gabion seawall.

[0013] Furthermore, the toothed wall is located at least 0.5m downstream of the tail sill.

[0014] The beneficial effects of this utility model are:

[0015] The stilling basin tail sill structure of this utility model improves the existing stilling basin tail sill structure without changing the existing line and under the premise that the water supply task cannot be stopped, so as to ensure structural stability and safety and achieve good energy dissipation effect.

[0016] This invention solves the siltation problem caused by the traditional single-type tailrace, improves water flow, reduces impact on downstream river channels, and protects dam safety. The pipeline protection structure adopts a gate-shaped reinforced concrete structure, with the top of the gate at least 0.5m higher than the downstream gabion apron. A 0.5m-1m maintenance space is reserved on one side of the gate for future pipeline repair and maintenance. The stilling basin bottom slab uses a gravel and coarse sand filter layer to filter drainage and increase the stability of the bottom slab. The distance between the downstream toothed wall and the pipeline is determined based on the foundation conditions and stability calculations, with a 0.5m gap reserved to prevent uneven foundation settlement. A gabion apron is used to connect with the downstream river channel, further reducing the water flow velocity to below the allowable velocity of the river channel. The length of the apron is determined based on hydraulic calculations. The overall structure uses structural stability calculations to determine the upstream slope, gate-shaped height and width, bottom slab thickness, and toothed wall depth. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the planar layout of this utility model.

[0019] In the diagram: 1. Stilling basin bottom slab, 2. Upstream slope, 3. Arc-shaped convex surface and downstream connecting arc-shaped slope, 4. City gate-shaped pipe protection body, 5. Pipe, 6. Gravel filter layer, 7. Coarse sand filter layer, 8. Toothed wall, 9. Gravel backfill, 10. Gabion seawall. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] This utility model provides a stilling basin tail sill structure applied to the intersection of spillway and pipeline, such as Figure 1 As shown, it includes: 1. stilling basin bottom plate connected to the tail sill; 2. upstream slope surface; 3. arc-shaped convex surface and downstream connecting arc-shaped slope surface; 4. city gate-shaped pipeline protection body; 5. pipeline; 6. gravel filter layer; 7. coarse sand filter layer; 8. toothed wall; 9. gravel backfill; 10. gabion seawall.

[0022] like Figure 2 As shown, the stilling basin tail sill structure of this utility model improves the existing stilling basin tail sill structure without changing the existing line and under the premise that the water supply task cannot be stopped, so as to ensure structural stability and safety and achieve good energy dissipation effect.

[0023] This utility model discloses a stilling basin tail sill structure that integrates the stilling basin tail sill structure with the protective pipeline structure to form a unified stilling basin tail sill. The protective pipeline structure has reserved maintenance space, and its top elevation is lower than that of the stilling basin tail sill top elevation. The two structures and foundations do not affect each other but are integrated to jointly achieve diverse functional requirements. Its advantage lies in providing a design concept and structural form that achieves structural safety, energy dissipation, and scour prevention goals when the stilling basin of a spillway intersects with existing pipelines without altering the pipeline route.

[0024] The technical solution adopted in this utility model is as follows:

[0025] The existing pipeline is protected by a portal-shaped reinforced concrete structure. The stilling basin's tail sill and the portal-shaped pipeline protection structure are integrated into one unit. The bottom elevation of the portal-shaped structure's base slab is consistent with the top elevation of the stilling basin's base slab. This satisfies the traditional stilling basin depth requirements while protecting the pipeline, significantly enhancing the stilling basin's load-bearing capacity and greatly improving its overall stability. The top elevation of the portal-shaped structure is higher than the downstream apron elevation. The thickness of the portal-shaped structure is determined based on strength and structural requirements, while the minimum width and height are determined based on the stilling basin depth and the pipeline diameter.

[0026] The stilling basin's tail sill uses a combination of sloping and curved surfaces, which not only provides good energy dissipation but also creates a beautiful curved appearance and a pleasant landscape. The specific slope angle is adjusted based on hydraulic calculations and available space. When space is limited, a slightly steeper slope can be used to shorten the length of the stilling basin and reduce downstream land occupation, but it should be gentler than 1:0.5 to ensure good water flow.

[0027] The existing pipeline is located on the arch-shaped base plate. A cavity is reserved above the pipeline to meet the structural design requirements. A space of 0.5m to 1m is reserved on one side to meet maintenance needs and facilitate management by the operating unit. During construction, temporary support measures will be taken at the bottom of the pipeline as needed to ensure that the pipeline is not disturbed.

[0028] The toothed wall of the stilling basin bottom slab is located at least 0.5m downstream of the tail sill to avoid uneven settlement when the foundation is soft soil. The depth of the toothed wall meets the scour depth requirements, and the inner slope ratio of the toothed wall is different for soil foundation and rock foundation respectively.

[0029] The stilling basin floor is reinforced with gravel and coarse sand filters to facilitate drainage, increase the stability of the floor, and prevent seepage damage, heave, and cracking of the floor. The thickness of the gravel and coarse sand filters is determined based on the material gradation, material source, and construction method. Additionally, the presence of drainage holes in the stilling basin floor is determined according to the specific circumstances.

[0030] The downstream end of the stilling basin connects to the gabion seawall, further reducing the water flow velocity to less than the allowable flow velocity of the river channel. The connection between the toothed wall and the gabion is backfilled with gravel to ensure the stability of the foundation. The relative density of the gravel backfill is not less than 0.75.

[0031] The stilling basin has a flat bottom or a sloping bottom in its longitudinal section, and a rectangular cross section. It is arranged with equal width in the plane, and a diffusion type arrangement can be used when the flow velocity is high.

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] Example 1

[0034] The structure of the stilling basin tail sill, which is used at the intersection of spillway and pipeline, includes a stilling basin bottom plate 1 connected to the tail sill. A portal-shaped pipeline protection body 4 is set above the stilling basin bottom plate 1. The portal-shaped pipeline protection body 4 has a sloping slope and an arc shape on both sides, namely an upstream sloping surface 2 and an arc-shaped convex surface and a downstream connecting arc-shaped slope 3.

[0035] Below the bottom slab 1 of the stilling basin, there are gravel filter layer 6 and coarse sand filter layer 7 arranged from top to bottom. At the end of the bottom slab 1 of the stilling basin, there is a toothed wall 8. At the junction with the toothed wall 8, there is a gravel backfill 9. Above the gravel backfill 9, there is a gabion seawall 10.

[0036] This embodiment is applied to the construction of a stilling basin tail sill structure where a spillway intersects with a pipeline, and includes the following steps:

[0037] (1) Excavate the foundation of the spillway to the designed excavation elevation. During the construction process, pay attention to the setting of drainage measures and the use of temporary support to protect the existing pipeline.

[0038] (2) Carry out foundation treatment and inspection. Determine whether to carry out foundation treatment based on the actual geological conditions. After the excavation is completed, clean up the gravel, soil and other debris to ensure that the foundation surface is flat and there are no steep slopes or reverse slopes. Only after the foundation bearing capacity requirements are met can the next step of construction be carried out.

[0039] (3) Coarse sand laying: Select qualified coarse sand to ensure that the sand is uniform and free of impurities. Lay the coarse sand to keep the sand layer uniform and in close contact with the base. Use compaction equipment to compact the sand layer, control the number of compaction passes and the degree of compaction, and conduct quality inspection.

[0040] (4) Gravel laying: Select qualified gravel that meets the gradation requirements, lay the gravel layer in close contact with the coarse sand layer, use compaction equipment to compact the gravel layer, control the number of compaction passes and the degree of compaction, and conduct quality inspection.

[0041] (5) Construction of the stilling basin bottom slab and the main structure of the city gate-shaped protective structure: including formwork installation, rebar tying, and concrete pouring. The formwork and its supports meet the requirements of load-bearing capacity, rigidity, and stability during concrete pouring, and are firmly installed. After the formwork is installed, the rebar is tied, ensuring that the position and quantity of the rebar meet the requirements according to the design drawings. Concrete pouring: the bottom slab is poured first, followed by the sides and top arch of the city gate-shaped structure. During the pouring process, attention should be paid to controlling the pouring speed and vibration of the concrete to ensure that the concrete is dense. After the pouring is completed, the concrete is cured, and the formwork is removed after the concrete reaches the design strength.

[0042] (6) Gravel backfilling: After the formwork is removed, gravel backfilling is carried out behind the stilling pool tooth wall. Gravel that meets the design requirements is selected. Backfilling is carried out by layered compaction. The layer thickness is determined and each layer is compacted as necessary. When the design elevation is close, manual compaction is used. After the backfilling is completed, a quality inspection is carried out.

[0043] (7) Gabion installation: Ensure the foundation surface is flat, erect and accurately position the wire mesh, and tie the four corners, partitions, and body of the gabion to form an open gabion. During assembly, ensure the stability of the gabion structure, select stones of appropriate size to fill the gabion, and place better stones on the outside to avoid filling the center with inferior stones. When filling, ensure that the stones are tightly arranged to prevent loosening. After filling, cover the gabion and twist it with wire mesh to ensure the integrity and safety of the overall gabion structure. According to the design requirements, combine multiple gabions into an integrated structure to achieve the protective function of the gabion.

[0044] (8) Quality inspection and acceptance: Conduct quality inspection and acceptance of the overall structure to ensure that the construction quality of the stilling basin meets the design requirements.

[0045] Example 2

[0046] The difference between this embodiment and Embodiment 1 is that:

[0047] The portal-shaped pipeline protection body 4 houses the pipeline 5. A 0.5m pipeline maintenance space is reserved on one side of the portal-shaped pipeline protection body 4. The stilling basin tail sill structure and the protective pipeline structure are combined to form an integrated stilling basin tail sill. The protective pipeline structure has reserved maintenance space, and the top elevation of the pipe is lower than the top elevation of the stilling basin tail sill. The two structures and foundations do not affect each other but are integrated with each other to jointly achieve diverse functional requirements.

[0048] The arc-shaped convex surface and the downstream connecting arc-shaped slope 3 are connected to the gabion seawall 10;

[0049] Below the stilling basin bottom slab 1 is a gravel filter layer 6, and below the gravel filter layer 6 is a coarse sand filter layer 7. The gravel and coarse sand filter layers beneath the stilling basin bottom slab serve a drainage function, increasing the stability of the bottom slab and preventing seepage damage to the foundation, as well as potential hazards such as slab heaving or cracking. The thickness of the gravel and coarse sand filter layers is determined comprehensively based on material gradation, material source, and construction methods.

[0050] The remaining structures and construction methods are the same as in Example 1.

[0051] Example 3

[0052] The difference between this embodiment and Embodiment 2 is as follows:

[0053] The slope ratio of the upstream slope 2 is 1:0.5. The tail sill of the stilling basin adopts a combination of a sloping surface and an arc-shaped surface, which not only has a good energy dissipation effect, but also has a beautiful curve and creates a good landscape effect. The specific slope is adjusted according to hydraulic calculations and land space. When space is limited, a slightly steeper slope can be used to shorten the length of the stilling basin, thereby reducing the downstream land occupation and ensuring good water flow.

[0054] The top of the four-hole-shaped pipeline protection structure is 0.5m higher than the downstream gabion seawall;

[0055] The toothed wall 8 is located at least 0.5m downstream of the tail sill to avoid uneven settlement when the foundation is soft soil. The depth of the toothed wall meets the scour depth requirements. The inner slope ratio of the toothed wall is different for soil foundation and rock foundation respectively.

[0056] The remaining structures and construction methods are the same as in Example 1.

[0057] Example 4

[0058] The difference between this embodiment and embodiment 3 is as follows:

[0059] The four-hole-shaped pipeline protection body has a 0.5m pipeline maintenance space reserved on both sides inside the hole, which makes it more convenient for operation and maintenance units to carry out maintenance.

[0060] The slope ratio of the upstream slope 2 is 1:0.75, which can ensure good water flow within the limits of available land.

[0061] Toothed wall 8 is located 1.5m downstream of the tail sill, which further prevents long-term water flow from damaging the existing pipeline and enhances the stability of the base plate.

[0062] The top of the four-hole-shaped pipeline protection structure is 0.8m higher than the downstream gabion seawall.

[0063] The remaining structures and construction methods are the same as in Example 1.

[0064] Example 5

[0065] The difference between this embodiment and embodiment 3 is as follows:

[0066] A 1m pipeline maintenance space is reserved on one side inside the four-hole-shaped pipeline protection structure;

[0067] The slope ratio of the upstream slope 2 is 1:1;

[0068] Tooth wall 8 is located 1m downstream of the tail sill;

[0069] The top of the four tunnels of the city gate-shaped pipeline protection structure is 1 meter higher than the downstream seawall. The seawall adopts a masonry structure based on local materials, which can make reasonable use of the materials in the project area and reduce project investment.

[0070] The stilling basin bottom slab 1 adopts a sloping design with a slope ratio of 1:100. It is arranged in a diffused pattern in plan, which is more conducive to the connection with the banks on both sides, reduces the water flow velocity, and reduces the scouring of the downstream river channel.

[0071] The remaining structures and construction methods are the same as in Example 1.

[0072] Example 6

[0073] The difference between this embodiment and embodiment 3 is as follows:

[0074] A φ75 PVC drainage pipe is installed inside the stilling basin bottom slab 1, with a spacing of 1.5m between pipes, extending 0.5m below the foundation, to further reduce the uplift pressure on the bottom slab and ensure its stability.

[0075] The elevation of the arc-shaped convex surface and the downstream connecting arc-shaped slope is set to a height that gradually decreases along the direction of vertical water flow, so that the water flow deflects to one side, which is more conducive to adapting to different river topography and meeting the requirements of good water flow into the channel and downstream river channel erosion protection.

[0076] The remaining structures and construction methods are the same as in Example 1.

Claims

1. A stilling basin tail sill structure applied to the intersection of spillway and pipeline, characterized in that, The structure includes a stilling basin bottom plate (1) connected to the tail sill. A portal-shaped pipe protection body (4) is provided above the stilling basin bottom plate (1). The portal-shaped pipe protection body (4) has a sloping and an arc shape on both sides, namely an upstream sloping surface (2) and an arc-shaped convex surface and a downstream connecting arc-shaped slope surface (3). A gravel filter layer (6) and a coarse sand filter layer (7) are provided below the stilling basin bottom plate (1) from top to bottom. A toothed wall (8) is provided at the end of the stilling basin bottom plate (1). A gravel backfill (9) is provided at the junction with the toothed wall (8). A gabion seawall (10) is provided above the gravel backfill (9).

2. The stilling basin tail sill structure applied at the intersection of spillway and pipeline as described in claim 1, characterized in that, The gate-shaped pipe protection body (4) has a pipe (5) installed inside.

3. The stilling basin tail sill structure applied at the intersection of spillway and pipeline as described in claim 2, characterized in that, The arc-shaped convex surface and the downstream connecting arc-shaped slope (3) are connected to the gabion seawall (10).

4. The stilling basin tail sill structure applied at the intersection of spillway and pipeline as described in claim 3, characterized in that, Below the bottom plate (1) of the stilling pool is a gravel filter layer (6), and below the gravel filter layer (6) is a coarse sand filter layer (7).

5. The stilling basin tail sill structure applied to the intersection of spillway and pipeline as described in claim 1, characterized in that, The slope ratio of the upstream slope (2) is gentler than 1:0.

5.

6. The stilling basin tail sill structure applied at the intersection of spillway and pipeline as described in claim 1, characterized in that, The tunnel-shaped pipeline protection body (4) has a pipeline maintenance space of 0.5m to 1m reserved on one side inside the tunnel.

7. The stilling basin tail sill structure according to claim 6, characterized in that, The top of the gate-shaped pipeline protection body (4) is at least 0.5m higher than the downstream gabion seawall.

8. The stilling basin tail sill structure applied at the intersection of spillway and pipeline as described in claim 6, characterized in that, The toothed wall (8) is located at least 0.5m downstream of the tail sill.

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