A closed drainage structure for dam foundation or reservoir bottom drainage observation gallery and its construction method

Abstract

The present invention discloses a closed drainage structure for a dam foundation or a reservoir bottom drainage observation gallery and its construction method, aiming to overcome the problem in the prior art that for the dam foundation of a concrete dam or an earth-rock dam provided with a drainage observation gallery, or the reservoir bottom of a pumped-storage power station with full reservoir basin anti-seepage, the seepage water discharged to the gallery through drainage holes makes the inside of the gallery relatively humid and the operation and inspection conditions are poor. The structure includes a drainage observation gallery, the drainage observation gallery is provided with gallery drainage holes, drainage ditches are arranged on both sides of the bottom surface of the drainage observation gallery, drainage collection pipes are arranged in the drainage ditches, wall surface drainage pipes are arranged on the inner wall surface of the drainage observation gallery, the wall surface drainage pipes communicate the gallery drainage holes and the drainage collection pipes, and water measuring weirs are arranged in sections at the intersection of the drainage observation galleries.

Description

Technical Field

[0001] The present invention relates to the technical field of drainage structures for dam foundations or reservoir bottoms in hydropower and water conservancy projects, and particularly to a closed drainage structure for a drainage observation gallery at a dam foundation or reservoir bottom. Background Art

[0002] In the dam foundations of concrete dams and earth-rock dams, or at the reservoir bottoms of pumped-storage power stations with overall basin anti-seepage, drainage observation galleries are generally provided to meet the requirements of draining seepage water from the dam body or reservoir basin, safety monitoring, and inspection by operation and maintenance personnel during the operation period. The seepage water discharged into the gallery through drainage holes keeps the air humidity in the gallery at a relatively high level, causing the laid cable lines, safety monitoring facilities, etc. to be in a humid or even waterlogged state for a long time, seriously affecting their service life. At the same time, the locally waterlogged and humid gallery floor also causes great inconvenience to the daily inspection work of operation and maintenance personnel. How to properly handle the seepage water discharged into the gallery through certain measures to keep the gallery dry and create good conditions for operation and maintenance is an important technology in hydropower and water conservancy projects. Summary of the Invention

[0003] The present invention aims to overcome the problem in the prior art that for the dam foundations of concrete dams and earth-rock dams provided with drainage observation galleries, or the reservoir bottoms of pumped-storage power stations with overall basin anti-seepage, the seepage water discharged into the gallery through drainage holes makes the gallery relatively humid and the operation and inspection conditions are poor, and provides a closed drainage structure that is convenient for construction, safe and reliable, keeps the gallery dry, and creates good conditions for operation and maintenance, namely, a closed drainage structure for a drainage observation gallery at a dam foundation or reservoir bottom and its construction method.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A closed drainage structure for a drainage observation gallery at a dam foundation or reservoir bottom of the present invention includes a drainage observation gallery. The drainage observation gallery is provided with gallery drainage holes. Drainage ditches are provided on both sides of the bottom surface of the drainage observation gallery. Drainage collecting pipes are provided in the drainage ditches. Wall surface drainage pipes are provided on the inner wall surfaces of the drainage observation gallery. The wall surface drainage pipes communicate the gallery drainage holes and the drainage collecting pipes. Water measuring weirs are arranged in sections at the intersections of the drainage observation galleries.

[0006] Preferably, the drainage collecting pipes are disconnected not less than 150 cm in front of the water measuring weir and not less than 50 cm behind the water measuring weir, and concrete plugs are provided at the disconnected ports of the drainage collecting pipes.

[0007] Preferably, the concrete plugs are respectively made of plain concrete with a thickness of 10 cm and a grade not lower than C25.

[0008] Preferably, a transparent moisture-proof protective cover is provided above the concrete plugs.

[0009] Preferably, a drain pipe fixing member is provided on the wall drain pipe, and the wall drain pipe is fixed to the inner wall surface of the drainage observation corridor through the drain pipe fixing member.

[0010] Preferably, the corridor drain holes are arranged on the top wall and both side walls of the drainage observation corridor, and the wall drain pipe is provided with a drain pipe tee or a drain pipe three-way to connect the corridor drain holes.

[0011] The present invention also provides a construction method for the closed drainage structure of the above-mentioned dam foundation or reservoir bottom drainage observation corridor. The method steps include:

[0012] Step 1: After the seepage water in the dam foundation of the dam or the reservoir bottom of the pumped-storage power station with full reservoir basin anti-seepage is basically stable, according to the basic leakage volume of the foundation and the actual sizes of the existing drainage observation corridor, wall drainage holes, and drainage ditches, make the wall drain pipe 3, drainage collecting pipe 4, drain pipe tee 601, drain pipe three-way 602, and moisture-proof protective cover 9 of transparent organic glass;

[0013] Step 2: Clean the wall drainage holes of the drainage observation corridor to ensure unobstructed foundation drainage. Install the transparent organic glass drain pipe on-site. Use the drain pipe fixing member 5 to fix the wall drain pipe 3 as a whole to the wall surface of the drainage observation corridor. The drainage collecting pipe 4 is fixed in the drainage ditch. Connect the wall drain pipe 3 and the drainage collecting pipe 4 using the drain pipe tee 601 and drain pipe three-way 602, and seal the connection part with glass glue to form a closed drainage structure;

[0014] Step 3: Set water gauges at each section of the drainage observation corridor 1 to monitor the change of seepage water. At a position 5 m upstream of the intersection of each section of the drainage observation corridor 1, disconnect the drainage collecting pipe 4 in the drainage ditch 101, and reserve a range of not less than 2.0 m to arrange the water gauge 7 and the supporting water scale;

[0015] Step 4: Place the made transparent organic glass moisture-proof protective cover 9 above the concrete plug. The wall thickness of the organic glass moisture-proof protective cover is the same as that of the organic glass drain pipe.

[0016] Preferably, in the step 3, the water gauge 7 is installed at a distance of not less than 150 cm from the upstream end of the drainage collecting pipe and not less than 50 cm from the downstream end of the drainage collecting pipe. Both ends of the drainage collecting pipe 4 are backfilled and sealed with concrete plugs 8.

[0017] Preferably, in the step 3, the width of the concrete plug is the same as that of the drainage ditch of the drainage observation corridor, the top is 5 cm - 10 cm higher than the drainage ditch, the thickness is 10 cm, the grade is not less than C25, and it is not reinforced.

[0018] The beneficial effects of the present invention are as follows: 1. A closed drainage structure is provided in the drainage observation corridor at the dam foundation or the bottom of the entire reservoir basin of the pumped-storage power station for seepage prevention, keeping the corridor in a dry environment and creating good working conditions for operation and maintenance personnel; 2. The dry environment in the corridor ensures that the safety monitoring facilities and the laid cable lines can function normally, extending the service life of the instrument equipment; 3. The transparent organic glass drain pipe has good visualization effect; the water measuring weirs set in sections can effectively measure the change of seepage water in the corridor; 4. The transparent organic glass pipe has low cost, is convenient for installation and replacement. If the seepage water volume of individual drainage holes increases during the operation period, the organic glass pipe with a larger diameter can be replaced in time; if the drain pipe is locally damaged during the operation period, it can also be replaced in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. is a typical sectional view of the closed drainage structure of the dam foundation or reservoir bottom drainage observation corridor of the present invention.

[0020] Figure 2 is Figure 1 the sectional view of A-A of

[0021] Figure 3 FIG. is a partial enlarged view of the closed drainage structure of the dam foundation or reservoir bottom drainage observation corridor of the present invention.

[0022] Figure 4 is Figure 3 the sectional view of B-B of

[0023] The labels in the figure: 1. Drainage observation corridor; 101. Drainage ditch; 2. Corridor drainage hole; 3. Wall drain pipe; 4. Drainage collecting pipe; 5. Drain pipe fixing part; 601. Drain pipe tee; 602. Drain pipe cross; 7. Water measuring weir; 8. Concrete plug; 9. Moisture-proof protective cover; 10. Schematic seepage water surface line. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0025] As Figure 1 、 Figure 2 shown, a closed drainage structure of the dam foundation or reservoir bottom drainage observation corridor of the present invention includes a drainage observation corridor 1. The drainage observation corridor 1 is provided with a corridor drainage hole 2. Drainage ditches 101 are provided on both sides of the bottom surface of the drainage observation corridor 1. A drainage collecting pipe 4 is provided in the drainage ditches 101. Wall drain pipes 3 are provided on the inner wall surface of the drainage observation corridor 1. The wall drain pipes 3 communicate the corridor drainage holes 2 and the drainage collecting pipe 4. Water measuring weirs 7 are set in sections at the intersections of the drainage observation corridors 1.

[0026] As Figure 3 、 Figure 4As shown, the drainage collecting pipe 4 is disconnected at a position not less than 150 cm in front of the weir 7 and not less than 50 cm at the rear, and concrete plugs 8 are provided at the disconnected ports of the drainage collecting pipe 4. The concrete plugs 8 are respectively made of plain concrete with a thickness of 10 cm and a grade not lower than C25. For the convenience of description, in the attached Figure 3 the water seepage water surface line 10 is marked inside the weir 7, and the indicated water seepage water surface line 10 is not actually provided at the construction site. A transparent moisture-proof protective cover 9 is provided above the concrete plug 8.

[0027] As Figure 2 shown, the wall drain pipe 3 is provided with drain pipe fixing parts 5, and the wall drain pipe 3 is fixed to the inner wall surface of the drainage observation gallery 1 through the drain pipe fixing parts 5. The gallery drain holes 2 are arranged on the top wall and both side walls of the drainage observation gallery 1, and the wall drain pipe 3 is provided with drain pipe tees and elbows 6 to connect the gallery drain holes 2.

[0028] The present invention also provides a construction method for the above-mentioned closed drainage structure of a dam foundation or reservoir bottom drainage observation gallery. The method steps include:

[0029] Step 1: After the seepage water of the dam foundation or the reservoir bottom of the pumped storage power station with full reservoir basin anti-seepage is basically stable, according to the basic leakage amount of the foundation and the actual sizes of the existing drainage observation gallery, wall drainage holes, and drainage ditches, make the wall drain pipe 3, drainage collecting pipe 4, drain pipe tee 601, drain pipe elbow 602, and moisture-proof protective cover 9 made of transparent plexiglass.

[0030] Step 2: Clean the wall drainage holes of the drainage observation gallery to ensure smooth foundation drainage. Install the transparent plexiglass drain pipes on-site. Use the drain pipe fixing parts 5 to fix the wall drain pipe 3 as a whole on the wall of the drainage observation gallery. The drainage collecting pipe 4 is fixed in the drainage ditch. Connect the wall drain pipe 3 and the drainage collecting pipe 4 by using the drain pipe tee 601 and drain pipe elbow 602. The connection parts are sealed with glass glue to form a closed drainage structure.

[0031] The drain pipe fixing parts 5 are made of stainless steel strips. A stainless steel strip with a length of 400 mm, a width of 20 mm, and a thickness of 1 mm is set every 80 cm - 100 cm to fix the wall drain pipe 3 and the drainage collecting pipe 4, and the stainless steel strips are fixed by nail guns.

[0032] Step 3: Set weirs at sections of the drainage observation gallery 1 to monitor the change of seepage water. At a position 5 m upstream of the intersection of sections of the drainage observation gallery 1, disconnect the drainage collecting pipe 4 in the drainage ditch 101, and reserve a range of not less than 2.0 m to arrange the weir 7 and the supporting water gauge.

[0033] The water measuring weir 7 is installed at a distance of not less than 150 cm from the end of the upstream drainage collecting pipe and not less than 50 cm from the end of the downstream drainage collecting pipe. A matching water gauge is installed upstream of the water measuring weir to ensure smooth water flow measurement and accurate data. Both ends of the drainage collecting pipe 4 are backfilled and sealed with concrete plugs 8. The width of the concrete plug is the same as that of the drainage observation corridor drainage ditch, the top is 5 cm to 10 cm higher than the drainage ditch, the thickness is 10 cm, the grade is not lower than C25, and it is not reinforced. According to the actual project, other sealing materials can also be used for construction.

[0034] Step 4: Place the fabricated transparent acrylic moisture-proof protection cover 9 above the concrete plug. The wall thickness of the transparent acrylic moisture-proof protection cover is the same as that of the transparent acrylic drainage pipe.

[0035] The technical solution of this invention application sets a closed drainage structure in the drainage observation corridor at the dam foundation of the dam or the bottom of the pumped-storage power station with full reservoir basin anti-seepage, keeping the corridor in a dry environment and creating good working conditions for operation and maintenance personnel. The dry environment in the corridor ensures that the safety monitoring facilities and the laid cable lines can function normally and extends the service life of the instrument equipment. The transparent acrylic drainage pipe has good visualization effect; the water measuring weirs set in sections can effectively measure the change of seepage water in the corridor. The transparent acrylic pipe has low cost, is convenient to install and replace. If the seepage water volume of individual drainage holes increases during the operation period, the acrylic pipe with a larger diameter can be replaced in time; if the drainage pipe is partially damaged during the operation period, it can also be replaced in time.

Claims

1. A closed drainage structure for dam foundation or reservoir bottom drainage observation gallery, comprising a drainage observation gallery (1), the drainage observation gallery (1) is provided with gallery drainage holes (2), and drainage ditches (101) are arranged on both sides of the bottom surface of the drainage observation gallery (1), and the feature is that, A drain pipe (4) is provided in the drainage ditch (101), and a wall drain pipe (3) is provided on the inner wall surface of the drainage observation corridor (1). The wall drain pipe (3) communicates with the corridor drainage hole (2) and the drain pipe (4). A weir (7) is provided in sections at the intersection of the drainage observation corridors (1). The drain pipe (4) is disconnected not less than 150 cm in front of the weir (7) and not less than 50 cm at the back, and a concrete plug (8) is provided outside the disconnected port of the drain pipe (4). The concrete plug (8) seals the gap between the drain pipe (4) and the drainage ditch (101). The concrete plug (8) is made of plain concrete with a thickness of 10 cm and a grade not lower than C25. A transparent moisture-proof protective cover (9) is provided above the concrete plug (8).

2. The closed drainage structure for dam foundation or reservoir bottom drainage observation gallery according to claim 1, characterized in that, The wall drain pipe (3) is provided with a drain pipe fixing member (5), and the wall drain pipe (3) is fixed to the inner wall surface of the drainage observation corridor (1) through the drain pipe fixing member (5).

3. The closed drainage structure for dam foundation or reservoir bottom drainage observation gallery according to claim 1, characterized in that, The corridor drainage hole (2) is arranged on the top wall and both side walls of the drainage observation corridor (1). The wall drain pipe (3) is provided with a drain pipe tee (601) or a drain pipe three-way (602) to connect the corridor drainage hole (2).

4. A construction method of a closed drainage structure for a dam foundation or reservoir bottom drainage observation gallery, which applies the closed drainage structure for a dam foundation or reservoir bottom drainage observation gallery described in any one of the above claims 1 to 3, characterized in that, The method includes the following steps: Step 1: After the seepage of the pumped-storage power station reservoir bottom for the dam foundation or the whole reservoir basin to be impermeable is stabilized, according to the basic seepage volume and the actual sizes of the existing drainage observation corridors, wall drainage holes, and drainage ditches, make transparent organic glass wall drain pipes (3), drain pipes (4), drain pipe tees (601), drain pipe three-ways (602), and moisture-proof protective covers (9). Step 2: Clean the wall drainage holes of the drainage observation corridor to ensure unobstructed basic drainage. Install transparent organic glass drain pipes on site. Use the drain pipe fixing member (5) to fix the wall drain pipe (3) as a whole on the wall of the drainage observation corridor. The drain pipe (4) is fixed in the drainage ditch. Use the drain pipe tee (601) and the drain pipe three-way (602) to connect the wall drain pipe (3) and the drain pipe (4). The connection part is sealed with glass glue to form a closed drainage structure. Step 3: Weirs (7) are arranged in sections in the drainage observation corridor (1) to monitor the change of seepage. At a position 5 m upstream of the intersection of the sections of the drainage observation corridor (1), disconnect the drain pipe (4) in the drainage ditch (101), and reserve a range of not less than 2.0 m to arrange the weir (7) and the supporting water gauge. Step 4: Place the made transparent organic glass moisture-proof protective cover (9) above the concrete plug. The wall thickness of the organic glass moisture-proof protective cover is the same as that of the organic glass drain pipe.

5. The construction method of a closed drainage structure for dam foundation or reservoir bottom drainage observation gallery according to claim 4, characterized in that, In the above Step 3, the weir (7) is installed not less than 150 cm from the upstream end of the drain pipe and not less than 50 cm from the downstream end of the drain pipe. The two ends of the drain pipe (4) are respectively backfilled and sealed with concrete plugs (8).

6. The construction method of a closed drainage structure for dam foundation or reservoir bottom drainage observation gallery according to claim 5, characterized in that, In the above Step 3, the width of the concrete plug is the same as that of the drainage ditch of the drainage observation corridor, the top is 5 cm - 10 cm higher than the drainage ditch, the thickness is 10 cm, the grade is not lower than C25, and it is not reinforced.

Images