Disc-fold-shaped fishway structure adopting cemented sand gravel foundation and construction method of disc-fold-shaped fishway structure

Abstract

The invention relates to a coiled fishway structure adopting a cemented sand gravel foundation and a construction method. The method is suitable for the technical field of water conservancy and hydropower engineering. The technical problem to be solved by the invention is to provide the coiled fishway structure adopting the cemented sand gravel foundation and the construction method. According to the technical scheme, the folded fishway structure adopting the cemented sand gravel foundation comprises a fishway folded behind a dam in a reciprocating mode, a partition plate is arranged in the fishway, the cemented sand gravel foundation is arranged at the bottom of the fishway and located on bed rock, and the elevation of a bottom plate of the fishway is gradually reduced in the water flow direction.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy and hydropower engineering, and in particular to a disc-shaped fishway structure using a cemented gravel foundation and a construction method. Background Art

[0002] The river-blocking gates, dams and other structures built in water conservancy and hydropower projects block the upstream passage of fish. In order to meet the reproduction needs of migratory fish, fishways are generally built as remedial measures to provide an artificial passage for fish to swim upstream from the downstream river to the upstream reservoir. The slope of the fishway is generally small to avoid excessive flow velocity in the fishway affecting the upstream migration of fish; when the water level difference between the upstream and downstream of the river-blocking structure is large, the elevation difference between the upstream outlet and the downstream inlet of the fishway is also large, and a longer fishway needs to be built to connect the fishway inlet and outlet. There are many fishways in China that are at the kilometer level, among which the fishway of DG Hydropower Station is more than 3km long. If the fishway is arranged in a straight line, the slopes or rivers along the fishway need to be excavated and supported. The treatment range is large, and it is easy to exceed the cofferdam range to cause waterside construction, and it is difficult to avoid unfavorable geological conditions and other unfavorable conditions. The technical difficulty, construction period and investment of the fishway project are relatively large.

[0003] Cemented gravel is a new type of material that uses a small amount of cement, fly ash, admixtures and unscreened, unwashed sand, gravel and stone and other local raw materials to form a material with certain compression, shear strength and erosion resistance. Compared with concrete, cemented gravel has low aggregate requirements and less cementitious material usage. It has the advantages of safety, reliability, low investment, short construction period and environmental friendliness, and is suitable for large-volume backfill areas.

[0004] Therefore, it is of practical significance to optimize the fishway structure, arrange it in a centralized manner, and use cemented gravel as the foundation of the fishway, thereby effectively reducing the difficulty of engineering technology, saving construction period and investment costs. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the background technology and provide a folded fishway structure and construction method using a cemented gravel foundation, so that fishways with longer axes are concentrated in an area with good geological conditions in a folded form, and after the overburden layer is removed, the fishway is located on the bedrock through the cemented gravel foundation, which can reduce the technical difficulty of the fishway project and save construction time and investment.

[0006] The technical solution adopted by the present invention is as follows: a folded fishway structure using a cemented gravel foundation, including a fishway that is reciprocatingly folded behind a dam, a partition is provided in the fishway, the bottom of the fishway is a cemented gravel foundation, the cemented gravel foundation is located on bedrock, and the elevation of the bottom plate of the fishway gradually decreases along the direction of water flow.

[0007] In a further solution, the fishway is a reinforced concrete structure, with steel bars in the bottom plate and side walls of the fishway. Structural joints are set at regular intervals in the longitudinal and transverse directions of the reinforced concrete structure, and copper sheets are used to stop water and asphalt fir boards are used to fill the joints.

[0008] In a further solution, the fishway is arranged within a cofferdam with dry land construction conditions.

[0009] In a further solution, the fishway has a plurality of folded sections, and adjacent folded sections share a side wall.

[0010] In a further solution, the boundary elevation between the reinforced concrete structure of the fishway and the cemented gravel foundation changes in a step-like manner, and the elevation of each boundary section is lower than the lowest elevation of the bottom plate of the corresponding folding section.

[0011] In a further solution, the height of the outermost side wall of the fishway is higher than the highest flood control level.

[0012] In a further solution, a rest pool is provided at the bend of the fishway.

[0013] In a further solution, a slurry-rich cemented gravel anti-seepage layer is provided on the bottom and side surfaces of the cemented gravel bedrock.

[0014] Another technical solution of the present invention is: a construction method for the above-mentioned folded fishway structure using a cemented gravel foundation, comprising the following steps:

[0015] S1. Locate and excavate the covering layer of the fishway to the bedrock surface according to the control points and excavation slope ratio given in the design drawings;

[0016] S2. Level the foundation: remove steep slopes, sharp corners and loose rocks on the bedrock surface; clean the soil, rust and calcium film on the structural surface;

[0017] S3. After leveling the foundation, lay a layer of cement mortar first, and before the mortar begins to set, lay the cemented gravel and the cemented gravel above it. Lay the cemented gravel continuously to the boundary elevation between the cemented gravel and concrete at the bottom of the fishway;

[0018] S4. Prepare and install fishway reinforcement and waterstop; pour concrete for the bottom plate, side walls and partitions of the fishway by pumping after the formwork is erected.

[0019] In a further solution, in step S1, if the excavated material is sand and gravel, it is used as a source of cemented sand and gravel;

[0020] In step S3, the upper layer of cemented gravel should be paved before the initial setting of the current layer of cemented gravel. After the initial setting of the cemented gravel and before the final setting, 3 cm to 5 cm of cement mortar needs to be paved before the upper layer of cemented gravel is paved. After the final setting of the cemented gravel, it needs to be roughened or flushed and 3 cm to 5 cm of cement mortar needs to be paved before the upper layer of cemented gravel is paved.

[0021] The thickness of the cemented gravel compacted layer is greater than or equal to 3 times the maximum stone particle size and less than or equal to 60 cm.

[0022] The beneficial effects of the present invention are as follows: (1) in case of a long fishway axis, the fishway is arranged in a disc shape, and the fishway can be concentrated within the cofferdam range with good geological conditions and dry land construction conditions. The fishway structure is located on the bedrock through a cemented gravel foundation, which reduces the technical difficulty of the fishway project, reduces the scope of excavation and support treatment, and saves construction time and investment; (2) the new dam-building material cemented gravel is innovatively applied to the fishway project, expanding the application scenarios of cemented gravel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the planar structure of an embodiment of the present invention.

[0024] Figure 2 It is a cross-sectional view along the AA direction of an embodiment of the present invention.

[0025] Figure 3 It is a cross-sectional view along the BB direction of an embodiment of the present invention.

[0026] Figure 4 It is a typical cross-sectional view of the arrangement of the water-stopping copper sheet for the fishway according to an embodiment of the present invention.

[0027] The attached drawings are marked with: fishway 1, cemented gravel foundation 2, reinforced concrete structure 3, steel bars 4, slurry-rich cemented gravel anti-seepage layer 5, water-stop copper sheet 6, platform behind the dam 7, gate 8, power station tailwater outlet 9, sand retaining bank 10, rest pool 11, baffle 12, side wall 13. DETAILED DESCRIPTION

[0028] In order to enable ordinary technicians in the field to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0029] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0030] like Figure 1 As shown, the folded fishway structure provided by the present invention adopts a cemented gravel foundation, and has a fishway 1 that folds back and forth behind the dam. The fishway 1 is a vertical seam type and is arranged in a folded shape. The inlet of the fishway is arranged between the tailwater outlet 9 of the power station and the sand retaining bank 10.

[0031] like Figure 2 , 3 As shown, the fishway 1 is a reinforced concrete structure 3, and steel bars 4 are arranged in the bottom plate and side walls 13 of the fishway 1. The bottom of the fishway 1 is a cemented gravel foundation 2, and the cemented gravel foundation 2 is located on the bedrock behind the dam rear platform 7. The bottom plate elevation of the fishway 1 gradually decreases along the water flow direction, and the slope must meet the design requirements. A rest pool 11 is set at the bend of the fishway 1, and the rest pool 11 is a flat slope or a slightly gentle slope.

[0032] Cemented gravel is a new type of material that uses a small amount of cement, fly ash, admixtures and unscreened, unwashed sand, gravel and stone and other local raw materials to form a material with certain compression, shear strength and erosion resistance. Compared with concrete, cemented gravel has low aggregate requirements and less cementitious material usage. It has the advantages of safety, reliability, low investment, short construction period and environmental friendliness, and is suitable for large-volume backfill areas.

[0033] like Figure 4 As shown, a structural joint is provided every 12m to 15m in the longitudinal and transverse directions of the fishway 1, and a water-stop copper sheet 6 and an asphalt fir board are provided at the structural joint to fill the joint, and no structural joint is provided in the cemented gravel foundation.

[0034] Furthermore, it is recommended that the layout location of the fishway 1 be selected within the cofferdam range so that the fishway 1 has dry land construction conditions; and select a location with good geological conditions and a higher bedrock surface to reduce the amount of excavation, treatment and backfilling of the fishway foundation.

[0035] Furthermore, it is recommended that the direction of the fishway 1 is longer according to the site conditions, so as to minimize the number of turns of the fishway 1. Adjacent turns of the fishway 1 share side walls to reduce the area occupied by the fishway.

[0036] Furthermore, considering the slope of the fishway 1, the boundary elevation between the reinforced concrete of the fishway 1 and the cemented gravel foundation 2 at the bottom should be selected according to the lowest elevation of the bottom plate of the fishway in the folded section, such as Figure 2 As shown in the figure, the boundary elevation changes in a step-like manner, and the elevation of each boundary section is lower than the lowest elevation of the bottom plate of the corresponding folding section. For the convenience of construction, the concrete step elevation is selected to be 0.5m below the lowest elevation of the bottom plate of the fishway of the corresponding folding section.

[0037] Furthermore, the height of the outermost side wall 13 of the fishway is selected according to the highest flood control level of the fishway 1. Generally speaking, the height of the outermost side wall 13 of the fishway is higher than the highest flood control level.

[0038] Furthermore, the width of the fishway 1, the slope of the bottom plate, the type of the partition 12, the length of the rest pool 11, the inlet position, the outlet position, etc. refer to conventional fishways and are formulated according to the characteristics of migratory fish and engineering features. A gate 8 is provided at the inlet of the fishway 1.

[0039] Furthermore, in order to improve the durability of the cemented gravel foundation 2, a slurry-rich cemented gravel anti-seepage layer 5 is provided on the bottom and side surfaces of the cemented gravel foundation.

[0040] The present invention also provides a construction method for the construction of the folded fishway structure using a cemented gravel foundation, comprising the following steps:

[0041] S1. Locate and excavate the overburden at the fishway 1 to the bedrock surface according to the control points and excavation slope ratio given in the design drawings. If the excavated material is sand and gravel, it can be used as a source of cemented sand and gravel;

[0042] S2. Level the foundation: remove steep slopes, sharp corners and loose rocks on the bedrock surface; clean the dirt, rust, calcium film, etc. on the structural surface;

[0043] S3. After leveling the foundation, first lay 10 cm cement mortar, and before the mortar is initially set, lay the rich cementing gravel 5 and the cementing gravel above it. The cementing gravel 2 uses less cementing material and has a low hydration temperature rise, so it can be laid continuously to the boundary elevation between the cementing gravel and concrete at the bottom of the fishway;

[0044] The upper layer of cemented gravel should be laid before the initial setting of the current layer of cemented gravel; if it is after the initial setting of the current layer of cemented gravel but before the final setting, it is necessary to first lay 3cm~5cm cement mortar and then lay the upper layer of cemented gravel; if it is after the final setting of the current layer of cemented gravel, it is necessary to first chisel or flush the roughness and lay 3cm~5cm cement mortar and then lay the upper layer of cemented gravel;

[0045] Both cemented gravel and slurry-rich cemented gravel are prepared by machine mixing. Dump trucks can be used for transportation, excavators and bulldozers can be used for warehousing and unloading, and vibratory rollers can be used for rolling. The thickness of the cemented gravel rolling layer should not be less than 3 times the maximum stone particle size and not exceed 60cm. The recommended number of rolling times is "2 times of non-vibration rolling + 8 times of vibration rolling". The recommended speed of the rolling machine is controlled at 1.0km / h~1.5km / h. The relevant parameters should be finally determined based on on-site process tests. During the construction process, spray maintenance should be carried out to keep the surface moist and not white.

[0046] S4. Prepare and install fishway steel bars 4 and water-stop copper sheets 6. The bottom plate, side walls and partitions of the fishway are thin and the steel bars are dense. To facilitate pouring, concrete is poured by pumping after the formwork is erected. The concrete layer height is 3m.

[0047] The above is only a preferred embodiment of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A folded fishway structure using a cemented gravel foundation, characterized in that: It includes a reciprocating fishway behind the dam, with partitions inside the fishway. The bottom of the fishway is a cemented gravel foundation, the cemented gravel foundation is located on the bedrock, and the elevation of the bottom plate of the fishway gradually decreases along the direction of water flow.

2. The disc-shaped fishway structure using a cemented gravel foundation according to claim 1 is characterized in that: The fishway is a reinforced concrete structure. Reinforcements are arranged in the bottom plate and side walls of the fishway. Structural joints are arranged at regular intervals in the longitudinal and transverse directions of the reinforced concrete structure. Copper sheets are used to stop water and asphalt fir boards are used to fill the joints.

3. The disc-shaped fishway structure using a cemented gravel foundation according to claim 2 is characterized in that: The fishway is arranged within the cofferdam range with dry land construction conditions.

4. The disc-shaped fishway structure using a cemented gravel foundation according to claim 3 is characterized by: The fishway has a plurality of folding sections, and adjacent folding sections share a side wall.

5. The disc-shaped fishway structure using a cemented gravel foundation according to claim 4 is characterized in that: The boundary elevation between the reinforced concrete structure of the fishway and the cemented gravel foundation changes in a step-like manner, and the elevation of each boundary section is lower than the lowest elevation of the bottom plate of the corresponding folding section.

6. The disc-shaped fishway structure using a cemented gravel foundation according to claim 5 is characterized in that: The height of the outermost side wall of the fishway is higher than the highest flood control level.

7. The disc-shaped fishway structure using a cemented gravel foundation according to claim 6 is characterized by: A rest pool is provided at the bend of the fishway.

8. The disc-shaped fishway structure using a cemented gravel foundation according to claim 7 is characterized in that: The bottom and side surfaces of the cemented gravel bedrock are provided with slurry-rich cemented gravel anti-seepage layers.

9. A construction method for the disc-shaped fishway structure with a cemented gravel foundation as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Locate and excavate the covering layer of the fishway to the bedrock surface according to the control points and excavation slope ratio given in the design drawings; S2. Level the foundation: remove steep slopes, sharp corners and loose rocks on the bedrock surface; clean the soil, rust and calcium film on the structural surface; S3. After leveling the foundation, lay a layer of cement mortar first, and before the mortar begins to set, lay the cemented gravel and the cemented gravel above it. Lay the cemented gravel continuously to the boundary elevation between the cemented gravel and concrete at the bottom of the fishway; S4. Prepare and install fishway reinforcement and waterstop; pour concrete on the bottom plate, side walls and partitions of the fishway by pumping after the formwork is erected.

10. The construction method according to claim 9, characterized in that: In step S1, if the excavated material is sand and gravel, it is used as a source of cemented sand and gravel; In step S3, the upper layer of cemented gravel should be paved before the initial setting of the current layer of cemented gravel. After the initial setting of the cemented gravel and before the final setting, 3 cm to 5 cm of cement mortar needs to be paved before the upper layer of cemented gravel is paved. After the final setting of the cemented gravel, it needs to be roughened or flushed and 3 cm to 5 cm of cement mortar needs to be paved before the upper layer of cemented gravel is paved. The thickness of the cemented gravel compacted layer is greater than or equal to 3 times the maximum stone particle size and less than or equal to 60 cm.

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