Drainage structure for bank slope dam section of gravity dam

Abstract

The utility model discloses a drainage structure for a bank slope dam section of a gravity dam, which comprises a drainage steel pipe embedded in the bank slope dam section, a lower drainage unit arranged in a dam foundation and an upper drainage unit arranged in a dam body, and the lower drainage unit comprises lower drainage holes arranged side by side and permeable pipes arranged in the lower drainage holes. The upper drainage unit comprises upper drainage holes which are arranged side by side, and the upper drainage holes and the permeable pipe are coaxially arranged; an end cap is arranged at the top of each upper drainage hole, the upper drainage holes are communicated with a drainage steel pipe, and the bottom of the drainage steel pipe is communicated with a drainage gallery. Seepage water is converged into the lower drainage gallery through the drainage steel pipe through the permeable pipe, the upper drainage hole and the drainage steel pipe, the uplift pressure of a dam foundation is reduced, the safety of the dam body is improved, the drainage layout problem of a small bank slope section dam body is solved, only drilling and burying of the drainage steel pipe are needed, the self weight of the dam body is basically not reduced, and the construction cost is reduced. And dam body stability and safety are facilitated, and the influence on dam body construction is small.

Description

Technical Field

[0001] The utility model relates to drainage technology in water conservancy and hydropower engineering, in particular to a drainage structure used for a bank slope dam section of a gravity dam. Background Art

[0002] In actual engineering, the common method of grouting drainage in gravity dams is to set up corridors in the dam. In the bank slope dam section, when the slope is gentle (generally not steeper than 45°), drainage corridors can also be set up. However, when the bank slope is steep, it is difficult to set up corridors, and the dam body of some dam sections near the dam shoulders on both sides is generally small. Setting up corridors will cause large voids, affecting the anti-floating, anti-sliding and structural safety of the dam body. Because the bank slope dam section has a relatively low dam height and is generally located in a part with relatively poor rock conditions, in order to maintain the stability of the dam section, it is still necessary to reduce the dam foundation uplift pressure through drainage. However, for steep slope sections, corridor layout is often difficult or impossible, which in turn affects the drainage of steep slope sections; in addition, since the size of the corridor is often large, laying out the corridor in the bank slope dam section will greatly reduce the deadweight of this section of the dam body and affect the construction progress. Therefore, it is crucial to solve the drainage problem of the steep slope section of the gravity dam on the basis of reducing the impact on the dam body and ensuring the construction progress of the dam body. Summary of the invention

[0003] In view of this, the utility model proposes a drainage structure for a bank slope section of a gravity dam, which is particularly suitable for drainage of a steep slope section of a gravity dam, thereby reducing the uplift pressure on the dam foundation and improving the safety of the dam body.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model discloses a drainage structure for a bank slope section of a gravity dam, wherein the drainage structure comprises a drainage steel pipe buried in the bank slope section, a lower drainage unit arranged in the dam foundation and an upper drainage unit arranged in the dam body, wherein the lower drainage unit comprises a plurality of lower drainage holes arranged side by side and a water-permeable pipe arranged in each of the lower drainage holes, and the upper drainage unit comprises a plurality of upper drainage holes arranged side by side, wherein the upper drainage holes are connected to the water-permeable pipes one by one in upper and lower correspondence and are arranged coaxially; an end cap is arranged on the top of each upper drainage hole, and each upper drainage hole is connected to the drainage steel pipe, and the bottom of the drainage steel pipe is connected to the drainage gallery.

[0006] The beneficial effect is that the permeable pipe and the upper drainage hole of the utility model are connected one by one and are concentric, and each upper drainage hole penetrates the drainage steel pipe, so that water flows through the drainage steel pipe to the drainage gallery below to achieve drainage, reduce the uplift pressure of the dam foundation, and improve the safety of the dam body. In addition, the utility model achieves drainage by drilling and burying pipes instead of galleries, which solves the drainage layout problem of the small-sized bank slope section dam body, and the utility model only needs to drill holes and bury drainage steel pipes, which basically does not reduce the deadweight of the dam body, which is conducive to the stability and safety of the dam body; furthermore, the upper drainage holes of the utility model can be post-drilled to reduce the impact on the dam body construction and shorten the total construction period of the dam body.

[0007] Preferably, the direction of the drainage steel pipe is consistent with the slope of the bank, and the drainage steel pipe is located at least 3m above the dam foundation, which is conducive to the smooth return of water to the drainage corridor.

[0008] Preferably, the plane center axis of the drainage steel pipe coincides with the plane center axes of the multiple side-by-side upper drainage holes.

[0009] Preferably, the lower drainage holes are arranged at equal intervals, and the depth of the lower drainage holes is ≥10 m.

[0010] Preferably, the water-permeable pipe is also coated with a filter element. In actual engineering, the filter element is preferably a permeable geotextile to prevent impurities from entering the water-permeable pipe and clogging it, thereby ensuring normal drainage.

[0011] Compared with the prior art, the utility model pre-buries a large-diameter drainage steel pipe in the dam body to replace the traditional corridor, which not only solves the problem that it is difficult to arrange the drainage corridor in the small-sized bank slope section, but also has less impact on the deadweight of the dam body in the bank slope section, which is beneficial to the stability of the dam body; the utility model realizes drainage of the bank slope section through drainage holes, permeable pipes and drainage steel pipes, and finally discharges the water into the drainage corridor of the non-bank slope section through the drainage steel pipe, thereby realizing drainage of the bank slope section, effectively reducing the dam foundation uplift pressure of the bank slope section, and making the dam section stable and meeting the requirements of the specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the utility model.

[0013] Figure 2 yes Figure 1 1-1 schematic diagram of.

[0014] Figure 3 yes Figure 2 2-2 direction schematic diagram.

[0015] Figure 4 It is a connection diagram of the permeable pipe and the lower drainage hole. DETAILED DESCRIPTION

[0016] The following is a detailed description of an embodiment of the utility model in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the utility model, and a detailed implementation method and a specific operation process are given, but the protection scope of the utility model is not limited to the following embodiment.

[0017] It should be noted that, in the description of the present utility model, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0018] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connection" that may appear should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0019] like Figure 1-2 As shown, the drainage structure for the bank slope dam section of the gravity dam described in the utility model is arranged in each bank slope dam section of the gravity dam, that is, each bank slope dam section is provided with the drainage structure of the utility model, and each drainage structure is connected to the drainage gallery 1 of the non-bank slope dam section, and finally the water is gathered into the drainage gallery 1, so as to ensure the smooth drainage of the bank slope dam section, thereby reducing the uplift pressure of the dam foundation and ensuring the stability of the dam body.

[0020] Combination Figure 1-4 It can be seen that the drainage structure of the utility model includes a drainage steel pipe 2 buried in the dam body, a lower drainage unit arranged in the dam foundation, and an upper drainage unit arranged in the dam body. The lower drainage unit includes a plurality of lower drainage holes 3 arranged side by side and a water-permeable pipe 4 (Supiron synthetic resin water-permeable pipe can be used) arranged in each lower drainage hole 3. The upper drainage unit includes a plurality of upper drainage holes 5 arranged side by side. The upper drainage holes 5 are connected to the water-permeable pipe 4 one by one and arranged coaxially. An end cap is arranged at the top of each upper drainage hole 5. Each upper drainage hole 5 is connected to the drainage steel pipe 2. The bottom of the drainage steel pipe 2 is connected to the drainage gallery 1 of the non-bank slope dam section. The infiltration water in the dam foundation penetrates into the lower drainage hole 3, then penetrates into the water-permeable pipe 4, enters the upper drainage hole 5 through the water-permeable pipe 4, then enters the drainage steel pipe 2 through the upper drainage hole 5, and converges into the drainage gallery 1 of the non-bank slope dam section through the drainage steel pipe 2, so as to realize the drainage of the infiltration water of the dam foundation, thereby reducing the uplift pressure of the dam foundation.

[0021] During actual construction, the drainage steel pipe 2 is arranged as a whole with an inclination angle consistent with the slope of the bottom of the dam body (i.e., the slope at the junction of the dam body and the dam foundation), so that the water entering the drainage steel pipe 2 can be smoothly converged into the drainage gallery 1; the plane center axis L of the drainage steel pipe 2 coincides with the plane center axis of the plurality of upper drainage holes 5 arranged side by side, and the drainage steel pipe 2 is located at least 3m above the dam foundation, so that the drainage steel pipe 2 passes through each upper drainage hole 5, as shown in detail. Figure 1-2 .

[0022] In actual construction, the lower drainage holes 3 are located in the dam foundation, and the lower drainage holes 3 are arranged at equal intervals (the interval can be 3m, or other values ​​within 2m to 3m), the depth of each lower drainage hole 3 is at least 10m, and the aperture of the lower drainage hole 3 is consistent with the aperture of the upper drainage hole 5, which can be controlled at 110mm-150mm, which is convenient for installing the permeable pipe 4. To meet the drainage requirements, the aperture of the drainage steel pipe 2 is ≥500mm.

[0023] During actual construction, the permeable pipe 4 is also covered with a filter element, and the filter element is preferably a permeable geotextile 6. The permeable geotextile 6 has a certain filtering effect to prevent gravel in the bedrock from entering the permeable pipe 4. The permeable geotextile is tied to the permeable pipe 4 and is one or more layers to prevent gravel in the bedrock from entering the permeable pipe 4.

[0024] The construction process of the drainage structure described in the utility model is as follows: During the construction of the dam body, Figure 2 The drainage steel pipe 2 is embedded in the direction shown; the dam body of the bank slope dam section is constructed to 0.8-1.5m below the dam top (that is, 0.8m-1.5m is reserved and not cast for the time being, and will be cast after the permeable pipe construction is completed), and holes are drilled at intervals along the plane center axis of the drainage steel pipe 2, so that the center of each hole is located on the plane center axis of the drainage steel pipe 2, and the hole spacing is 2m-3m; when drilling, the top of the dam body casting section is drilled from top to bottom into the dam foundation, the hole section in the dam body is the upper drainage hole 5, and the upper drainage 5 holes penetrate the drainage steel pipe 2; the hole section in the dam foundation is the lower drainage hole 3; a permeable pipe 4 wrapped with a permeable geotextile is placed in each lower drainage hole 3, and after the permeable pipe construction is completed, a cap is installed on the top of each upper drainage hole 5 to prevent blockage; finally, the dam body is cast to the designed elevation.

[0025] In the present invention, the lower drainage hole 3 and the upper drainage hole 5 are connected one by one and are concentric, and each upper drainage hole 5 penetrates the drainage steel pipe 2, so that water flows through the drainage steel pipe 2 to the drainage gallery 1 below, achieving drainage, reducing the dam foundation uplift pressure, and improving the safety of the dam body. In addition, the present invention achieves drainage by drilling and burying pipes instead of galleries, which solves the problem of gallery drainage layout for small-sized bank slope sections of dam bodies, and the present invention only needs to drill holes and bury drainage steel pipes 2, which basically does not reduce the deadweight of the dam body, which is conducive to the stability and safety of the dam body; furthermore, the present invention adopts the post-drilling method to reduce the impact on the dam body construction and shorten the total construction period of the dam body.

[0026] Finally, it should be emphasized that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Therefore, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A drainage structure for a gravity dam bank slope section, characterized in that: The drainage structure includes a drainage steel pipe buried in the bank slope dam section, a lower drainage unit arranged in the dam foundation and an upper drainage unit arranged in the dam body, the lower drainage unit includes a plurality of lower drainage holes arranged side by side and a permeable pipe arranged in each of the lower drainage holes, the upper drainage unit includes a plurality of upper drainage holes arranged side by side, the upper drainage holes are connected to the permeable pipes one by one up and down and are arranged coaxially; an end cap is provided on the top of each upper drainage hole, each upper drainage hole is connected to the drainage steel pipe, and the bottom of the drainage steel pipe is connected to the drainage gallery.

2. The drainage structure for a gravity dam bank slope section according to claim 1, characterized in that: The direction of the drainage steel pipe is consistent with the slope of the bank, and the drainage steel pipe is located at least 3m above the dam foundation.

3. The drainage structure for a gravity dam bank slope section according to claim 1, characterized in that: The plane center axis of the drainage steel pipe coincides with the plane center axes of the multiple side-by-side upper drainage holes.

4. The drainage structure for a gravity dam bank slope section according to claim 1, characterized in that: The lower drainage holes are arranged at equal intervals, and the depth of the lower drainage holes is ≥10 m.

5. The drainage structure for a gravity dam bank slope section according to claim 1, characterized in that: The water permeable pipe is also coated with a filter element.

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