Drainage structure of concrete faced rockfill dam foundation

Abstract

The utility model discloses a concrete faced rockfill dam foundation drainage structure, and relates to the technical field of drainage structures, the concrete faced rockfill dam foundation drainage structure comprises a concrete faced rockfill dam, a drainage hole is arranged in a foundation of the concrete faced rockfill dam, a reinforced gabion is arranged on the outer side of an inlet of the drainage hole, and a concrete retaining wall is arranged on the inner side of the inlet of the drainage hole. And a concrete toe board is arranged on the concrete faced rockfill dam. The foundation drainage structure is arranged in the dam foundation range of the concrete face rockfill dam with higher terrain at the downstream of the concrete toe board, seepage water of the dam is drained, and the possibility that reverse water pressure is generated at the bottom of a face plate, and safety is affected is avoided; the outlet of the drainage tunnel is located at the downstream of the dam and can be provided with a road or an inspection channel, and daily maintenance personnel can conveniently enter and exit; the drainage tunnel structure is large in drainage capacity, not prone to clogging and capable of effectively draining seepage water of the dam, and therefore reverse water pressure borne by the dam panel is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of drainage structures, in particular to a foundation drainage structure for a concrete face rockfill dam. Background Art

[0002] In hydropower and water conservancy projects, the concrete face rockfill dam is a common dam type. After the foundation excavation, the terrain downstream of the toe slab of the concrete face rockfill dam is generally higher than the elevation of the toe slab foundation, resulting in poor foundation drainage. The reverse water pressure acting on the face slab formed by rainfall during the construction period, construction water use and seepage during the operation period may cause damage to the face slab and engineering failure.

[0003] Most concrete face rockfill dams are located in river beds and valleys, and the terrain downstream is only slightly higher than the toe slab. During the construction period, a reverse drainage structure or drainage channel can be used to solve the problem. Before impoundment, the reverse drainage structure is blocked, and the drainage channel can continue to be used for drainage during the operation period; during the operation period, the drainage channel excavated during the construction period can be used to continue drainage, or considering that the terrain downstream is only slightly higher than the toe slab and the upstream of the face slab is backfilled with some stone slag, which can effectively level the pressure, no special foundation drainage measures are set during the operation period.

[0004] For some existing projects, due to terrain reasons, a secondary dam needs to be set on the reservoir bank. The terrain of the toe slab is much higher than the toe slab foundation, and it is difficult and costly to excavate the drainage channel. Moreover, due to the large terrain height difference, the reverse water pressure acting on the face slab during the sudden drop of the water level during the operation period cannot be effectively leveled by backfilling with stone slag, and the risk of face slab damage is great. Content of the Utility Model

[0005] In order to improve the problems mentioned above, that is, for some existing projects, due to terrain reasons, a secondary dam needs to be set on the reservoir bank. The terrain of the toe slab is much higher than the toe slab foundation, and it is difficult and costly to excavate the drainage channel. Moreover, due to the large terrain height difference, the reverse water pressure acting on the face slab during the sudden drop of the water level during the operation period cannot be effectively leveled by backfilling with stone slag, and the risk of face slab damage is great. The utility model provides a foundation drainage structure for a concrete face rockfill dam.

[0006] The utility model provides a foundation drainage structure for a concrete face rockfill dam, adopting the following technical scheme:

[0007] A foundation drainage structure for a concrete face rockfill dam includes a concrete face rockfill dam. A drainage tunnel is arranged in the foundation of the concrete face rockfill dam. A reinforced stone cage is arranged outside the inlet of the drainage tunnel, and a concrete retaining wall is arranged inside the inlet of the drainage tunnel. A concrete toe slab is arranged on the concrete face rockfill dam, and curtain grouting is arranged below the concrete toe slab.

[0008] Optionally, in the above foundation drainage structure for a concrete face rockfill dam, stone slag backfill is laid upstream of the concrete face rockfill dam.

[0009] Optionally, in the above-mentioned foundation drainage structure of a concrete face rockfill dam, the diameter of the drainage tunnel is 3 m, and the periphery of the drainage tunnel is lined with C25 concrete with a thickness of 30 cm.

[0010] Optionally, in the above-mentioned foundation drainage structure of a concrete face rockfill dam, the longitudinal slope of the bottom slab of the drainage tunnel is 5%.

[0011] Optionally, in the above-mentioned foundation drainage structure of a concrete face rockfill dam, the length, height and width of the reinforced gabion are all 100 cm. The inside of the reinforced gabion is filled with pebbles, and the particle size of the pebbles is 8 - 20 cm.

[0012] Optionally, in the above-mentioned foundation drainage structure of a concrete face rockfill dam, the concrete retaining wall is a C20 concrete structure, and the height of the concrete retaining wall is the same as the height of the drainage tunnel.

[0013] Optionally, in the above-mentioned foundation drainage structure of a concrete face rockfill dam, the concrete retaining wall adopts a gravity-type concrete wall structure. The top width of the concrete retaining wall is 1 m, the upstream face is vertical, and the downstream face is 1:0.5.

[0014] Optionally, in the above-mentioned foundation drainage structure of a concrete face rockfill dam, drainage holes are arranged on the wall body of the concrete retaining wall, and the aperture of the drainage holes is 50 cm.

[0015] In summary, the present utility model has at least the following beneficial effects:

[0016] A foundation drainage structure is arranged within the range of the dam foundation of a concrete face rockfill dam with a relatively high terrain downstream of the concrete toe slab to discharge the seepage water of the dam, avoiding the possibility of generating reverse water pressure at the bottom of the concrete face and affecting safety;

[0017] The outlet of the drainage tunnel is located downstream of the dam, and a road or inspection passage can be set up to reach it directly, facilitating the access of daily maintenance personnel;

[0018] The drainage tunnel structure has a large drainage capacity and is not easily silted up, and can effectively discharge the seepage water of the dam, thereby reducing the reverse water pressure borne by the dam concrete face. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the longitudinal sectional view of the rockfill dam drainage tunnel of the present utility model;

[0020] Figure 2 is the sectional view of the concrete retaining wall of the present utility model;

[0021] Figure 3 is the three-dimensional structure diagram of the reinforced gabion of the present utility model.

[0022] In the figure: 1. Concrete face rockfill dam; 2. Drainage tunnel; 3. Reinforced gabion; 4. Concrete retaining wall; 5. Concrete toe slab; 6. Curtain grouting; 7. Rockfill backfill; 8. Pebbles; 9. Drainage holes. Detailed implementation manners

[0023] The following further elaborates on the present utility model Figures 1-3 in conjunction with the appended drawings.

[0024] Please refer to the drawings in the specification Figure 1 , Figure 2 and Figure 3 . An embodiment provided by the present utility model: A drainage structure for the foundation of a concrete face rockfill dam, comprising a concrete face rockfill dam 1, and a rockfill backfill 7 is laid upstream of the concrete face rockfill dam 1.

[0025] A drainage tunnel 2 is provided in the foundation of the concrete face rockfill dam 1, and the drainage tunnel is constructed together with the excavation of the dam foundation by the drill and blast method; the diameter of the drainage tunnel 2 is 3 m, the periphery of the drainage tunnel 2 is lined with C25 concrete with a thickness of 30 cm, and the longitudinal slope of the bottom plate of the drainage tunnel 2 is 5%. Lining the periphery of the drainage tunnel 2 with a layer of C25 concrete with a thickness of 30 cm facilitates increasing the stability and drainage effect of the drainage tunnel 2, and at the same time facilitates the operator to enter the drainage tunnel 2 for maintenance.

[0026] A reinforced gabion 3 is arranged outside the inlet of the drainage tunnel 2. The length, height and width of the reinforced gabion 3 are all 100 cm. The reinforced gabion 3 is filled with pebbles 8, and the particle size of the pebbles 8 is 8 - 20 cm. The reinforced gabions 3 are neatly stacked upstream of the inlet of the drainage tunnel 2 for reverse filtration drainage and can avoid the possibility of the dam filling stones entering the drainage tunnel 2.

[0027] A concrete retaining wall 4 is arranged inside the inlet of the drainage tunnel 2. The concrete retaining wall 4 is a C20 concrete structure. The height of the concrete retaining wall 4 is the same as the height of the drainage tunnel 2. The concrete retaining wall 4 adopts a gravity-type concrete wall structure. The top width of the concrete retaining wall 4 is 1 m, and the upstream surface is vertical, and the downstream surface is 1:0.5. Drainage holes 9 with a pore diameter of 50 cm are arranged on the wall of the concrete retaining wall 4. The concrete retaining wall can provide support for the dam rockfill and the reinforced gabion, and the drainage holes 9 are used to discharge the seepage water of the dam.

[0028] A concrete toe plate 5 is provided on the face rockfill dam 1, and a basic drainage structure is provided within the dam foundation of the face rockfill dam 1 with higher terrain downstream of the concrete toe plate 5 to drain the seepage of the dam and avoid the possibility of reverse water pressure at the bottom of the face plate and affecting safety; the concrete toe plate 5 is connected to the face plate as a whole through a peripheral seam with a water stop to form an anti-seepage body above the dam foundation, and is also connected to the bedrock after foundation treatment to close the leakage channel below the ground, so that the upper and lower anti-seepage structures are connected as a whole. In addition to anti-seepage, its main function is to serve as a cover plate for foundation grouting and a base for the face plate.

[0029] Curtain grouting 6 is arranged below the concrete toe plate 5. Curtain grouting 6 is a grouting project in which slurry is poured into cracks and pores of rock or soil to form a continuous water-blocking curtain to reduce seepage flow and lower penetration pressure. The curtain grouting 6 is used to reduce the seepage flow of the stone dam.

[0030] The above are all preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A foundation drainage structure for a concrete face rockfill dam, comprising a concrete face rockfill dam (1), characterized in that: A drainage tunnel (2) is provided in the foundation of the concrete face rockfill dam (1). A reinforced gabion (3) is arranged outside the inlet of the drainage tunnel (2), and a concrete retaining wall (4) is arranged inside the inlet of the drainage tunnel (2). A concrete toe slab (5) is arranged on the concrete face rockfill dam (1), and curtain grouting (6) is arranged below the concrete toe slab (5).

2. The drainage structure for the face rockfill dam foundation according to claim 1, wherein: Rockfill backfill (7) is paved on the upstream of the concrete face rockfill dam (1).

3. The drainage structure for the face rockfill dam foundation according to claim 1, wherein: The diameter of the drainage tunnel (2) is 3m, and the circumference of the drainage tunnel (2) is lined with C25 concrete with a thickness of 30cm.

4. The drainage structure for the face rockfill dam foundation according to claim 3, characterized in that: The longitudinal slope of the bottom slab of the drainage tunnel (2) is 5%.

5. The foundation drainage structure of the concrete face rockfill dam according to claim 1, characterized in that: The length, height and width of the reinforced gabion (3) are all 100cm. The inside of the reinforced gabion (3) is filled with pebbles (8), and the particle size of the pebbles (8) is 8 - 20cm.

6. The drainage structure for the face rockfill dam foundation according to claim 1, characterized in that: The concrete retaining wall (4) is a C20 concrete structure, and the height of the concrete retaining wall (4) is the same as the tunnel height of the drainage tunnel (2).

7. The drainage structure for the face rockfill dam foundation according to claim 6, wherein: The concrete retaining wall (4) adopts a gravity-type concrete wall structure. The top width of the concrete retaining wall (4) is 1m, the upstream face is vertical, and the downstream face is 1:0.

5.

8. The drainage structure for the face rockfill dam foundation according to claim 7, characterized in that: Drainage holes (9) with a pore diameter of 50cm are arranged on the wall of the concrete retaining wall (4).

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