Drainage structure of the drainage horizontal tunnels at the abutments on both sides of the concrete dam

Abstract

The present invention discloses a drainage structure for a drainage horizontal tunnel at the abutments on both sides of a concrete dam. The drainage horizontal tunnel is arranged below the grouting tunnel and downstream of the grouting curtain. Grouped drainage holes are arranged on the end straight wall of the drainage horizontal tunnel. The drainage holes are arranged close to the upstream side wall of the drainage horizontal tunnel. The drainage holes in the same group are located in the same vertical plane and are evenly distributed in a radial pattern within a range of 180° behind the end straight wall. The structure of the present invention is simple and the construction is convenient. It can not only shorten the length of the drainage horizontal tunnel, but also better drain the seepage water of the mountain body to prevent the occurrence of seepage around the abutment. The drainage layout form adopted by the present invention has a small amount of work and a low construction cost, but it can drain the seepage water of the dam body through the drainage ditches of the horizontal tunnel and the gallery to ensure the safety of the dam body and improve the stability of the downstream bank slope.

Description

Technical Field

[0001] The present invention relates to the technical field of reducing uplift pressure at abutments of dams, and in particular to a drainage structure for grouting drainage horizontal tunnels at both banks of a concrete dam abutment. Background Art

[0002] In concrete dam projects, grouting drainage horizontal tunnels are generally arranged at the abutment parts for curtain grouting, and drainage hole curtains are drilled in the grouting tunnels to drain the seepage water in the abutment rock mass and reduce the uplift pressure of the abutment rock mass. At present, the drainage hole curtains arranged in the grouting drainage horizontal tunnels of most projects are only arranged within a certain range of the dam foundation to meet the anti-seepage standard required by the specification; when the groundwater level in the slope downstream of the dam is relatively deep and the rock mass of the abutment rock mass on both banks is relatively poor, it is also necessary to extend the depth of the grouting drainage horizontal tunnel or separately set a sufficiently deep drainage horizontal tunnel, which greatly increases the construction difficulty and construction cost. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides a drainage structure for grouting drainage horizontal tunnels at both banks of a concrete dam with a simple form and convenient construction. Specifically, the following technical solutions can be adopted:

[0004] For the drainage structure of the grouting drainage horizontal tunnels at both banks of the concrete dam of the present invention, the drainage horizontal tunnel is arranged below the grouting tunnel and downstream of the grouting curtain. Grouped drainage holes are arranged on the end wall of the drainage horizontal tunnel. The drainage holes are arranged close to the upstream side wall of the drainage horizontal tunnel. The drainage holes in the same group are located in the same vertical plane and are uniformly distributed radially within a range of 180° behind the end wall.

[0005] The other end of the drainage hole extends into the surrounding rock mass or the grouting tunnel.

[0006] The diameter of the drainage hole is Φ76mm - Φ100mm, and the adjacent drainage holes in the same group are arranged at an angle of 10°.

[0007] The drainage holes are divided into two groups. The first group of drainage holes is 70 - 100 cm away from the upstream side wall of the drainage horizontal tunnel. The second group of drainage holes is located downstream of the first group of drainage holes, and the distance between the second group of drainage holes and the first group of drainage holes is 50 - 100 cm.

[0008] The first group of drainage holes is drilled on the end wall of the drainage horizontal tunnel at an interval of 20 - 30 cm, and the lowest drilling position is 30 - 50 cm away from the floor of the gallery.

[0009] The second group of drainage holes is drilled on the end wall of the drainage horizontal tunnel at an interval of 20 - 30 cm, and the lowest drilling position is 20 - 30 cm away from the floor of the gallery.

[0010] The drainage structure of the grouting drainage horizontal tunnels at both shoulders of the concrete dam provided by the present invention is simple in structure and convenient for construction. It can not only shorten the length of the drainage horizontal tunnels, but also better drain the seepage water in the mountain body, preventing the problem of seepage around the dam shoulders. The drainage layout form adopted by the present invention has a small amount of work and a low construction cost, but it can drain the seepage water of the dam body through the drainage ditches of the horizontal tunnels and galleries, ensuring the safety of the dam body and improving the stability of the downstream bank slope. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural view of the present invention.

[0012] Figure 2 is Figure 1 the sectional view taken along line A-A in

[0013] Figure 3 is Figure 1 the sectional view taken along line B-B in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The embodiments of the present invention will be described in detail below with reference to the drawings. The present embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific construction processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0015] As Figures 1 - 3 shown, for the drainage structure of the grouting drainage horizontal tunnels at both shoulders of the concrete dam described in the present invention, the drainage horizontal tunnel 1 is arranged below the grouting tunnel 2 and downstream of the grouting curtain. Drainage holes 4 are arranged in groups on the end straight wall 3 of the drainage horizontal tunnel 1. The drainage holes 4 are arranged close to the upstream side wall of the drainage horizontal tunnel 1 (i.e., on the upstream side of the center line M of the drainage horizontal tunnel 1). The drainage holes 4 in the same group are located in the same vertical plane and are evenly distributed radially within a range of 180° behind the end straight wall 3. Usually, the diameter of the drainage holes 4 is Φ76mm - Φ100mm, and the adjacent drainage holes 4 in the same group are arranged at an angle of 10°, and the other end of the drainage holes 4 extends into the surrounding rock mass or the grouting tunnel 2.

[0016] In this embodiment, the drainage holes 4 are divided into two groups. The first group of drainage holes 4 is located upstream of the second group of drainage holes, and it is 70 - 100 cm away from the upstream side wall of the drainage horizontal tunnel 1. The second group of drainage holes 4 is 50 - 100 cm away from the first group of drainage holes 4. The above-mentioned first group of drainage holes 4 are drilled on the end straight wall 3 of the drainage horizontal tunnel 1 at an interval of 20 - 30 cm, and the lowest drilling position is 30 - 50 cm away from the gallery floor (see Figure 2 ); the second group of drainage holes 4 are drilled on the end straight wall 3 of the drainage horizontal tunnel 1 at an interval of 20 - 30 cm, and the lowest drilling position is 20 - 30 cm away from the gallery floor (see Figure 3). When the above drainage holes 4 are drilled, the height of the drill is used as the demarcation line for the upward and downward directions of the drill holes.

[0017] It should be noted that in the description of the present invention, terms indicating the orientation or positional relationship such as "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationship shown in the 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 of the present invention.

Claims

1. A drainage structure for the drainage horizontal tunnels at both bank shoulders of a concrete dam, characterized in that: The drainage horizontal tunnel is arranged below the grouting tunnel and downstream of the grouting curtain. Grouped drainage holes are arranged on the end straight wall of the drainage horizontal tunnel. The drainage holes are arranged close to the upstream sidewall of the drainage horizontal tunnel. The drainage holes in the same group are located in the same vertical plane and are evenly distributed in a radial pattern within a range of 180° behind the end straight wall.

2. The drainage structure of the drainage horizontal tunnel for grouting on both sides of the dam shoulder of the concrete dam according to claim 1, characterized in that: The other end of the drainage hole extends into the surrounding rock mass or the grouting tunnel.

3. The drainage structure of the drainage horizontal tunnels at both sides of the dam shoulders of the concrete dam according to claim 1, characterized in that: The diameter of the drainage hole is Φ76mm to Φ100mm, and the adjacent drainage holes in the same group are arranged at an angle of 10°.

4. The drainage structure of the drainage horizontal tunnels at both sides of the dam shoulders of the concrete dam according to claim 3, characterized in that: The drainage holes are divided into two groups. The first group of drainage holes is 70 - 100 cm away from the upstream sidewall of the drainage horizontal tunnel. The second group of drainage holes is located downstream of the first group of drainage holes, and the distance between the second group and the first group is 50 - 100 cm.

5. The drainage structure of the drainage horizontal tunnel at both sides of the dam shoulder of the concrete dam according to claim 4, characterized in that: The first group of drainage holes is drilled on the end straight wall of the drainage horizontal tunnel at intervals of 20 - 30 cm, and the lowest drilling position is 30 - 50 cm away from the floor of the corridor.

6. The drainage structure of the drainage horizontal tunnels at both dam shoulders of the concrete dam according to claim 5, characterized in that: The second group of drainage holes is drilled on the end straight wall of the drainage horizontal tunnel at intervals of 20 - 30 cm, and the lowest drilling position is 20 - 30 cm away from the floor of the corridor.

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