Water retaining dam for pumped storage power station

Abstract

The present invention belongs to the technical field of water conservancy and hydropower engineering, and specifically discloses a water retaining dam for a pumped storage power station with better anti-seepage effect and lower project investment. The dam body of the water retaining dam comprises a first panel, a cushion layer, a transition layer, a rockfill area and a second panel which are sequentially arranged on the dam foundation surface. A first toe slab is arranged at the bottom of the first panel, a dam foundation anti-seepage curtain is arranged at the bottom of the first toe slab, a second toe slab is arranged at the bottom of the second panel, and an anti-scouring wall is arranged at the bottom of the second toe slab. The water retaining dam is a rockfill dam, the foundation requirements for its toe slabs are relatively low, the dam height is relatively low, the excavation amount of the dam foundation is small, and the excavation materials of the reservoir basin of the lower reservoir of the power station can be used to build the dam body, and basically the excavation and filling can be balanced, so that the project investment can be reduced and the construction can be facilitated. At the same time, the water retaining dam has good anti-seepage performance and can meet the bidirectional anti-seepage requirements for the lower reservoir of the power station and the river on both sides thereof.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to a water retaining dam for a pumped-storage power station. Background Art

[0002] The lower reservoir of a pumped-storage power station is often built on a river floodplain, and a reservoir basin is formed by excavation and dam construction. The water retaining dam on the riverside of the lower reservoir bears the dual actions of reservoir water storage and river flow. The water retaining dam needs to be impermeable on both the reservoir-facing side and the river-facing side. At present, the water retaining dam on the riverside of the lower reservoir of a pumped-storage power station built on a river floodplain often adopts the form of a concrete gravity dam.

[0003] The problems existing in the current use of a concrete gravity dam to retain water on the riverside of the lower reservoir are as follows: Since the concrete gravity dam has relatively high requirements for the foundation surface, the dam foundation should be excavated to the weakly weathered layer - fresh bedrock, and the excavation volume is large; moreover, the length of the water retaining dam on the riverside of the lower reservoir built on a river floodplain often reaches several kilometers. Building a concrete gravity dam dozens of meters high in a river section several kilometers long will cost hundreds of millions of yuan; in addition, the anti-seepage effect of the concrete gravity dam is general, the requirements for aggregates are relatively high, a stone quarry needs to be exploited, the project investment is high, the environment is affected, and the construction organization is difficult. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a water retaining dam for a pumped-storage power station with better anti-seepage effect and lower project investment.

[0005] The technical solution adopted by the present invention to solve its technical problems is: A water retaining dam for a pumped-storage power station includes a dam body arranged between the lower reservoir of the power station and the river; the dam body includes a rockfill area arranged on the dam foundation surface, a transition layer, a cushion layer, and a first panel arranged in sequence from inside to outside on the reservoir side of the rockfill area, and a second panel arranged on the riverside of the rockfill area; a first toe slab is arranged at the bottom of the first panel, a dam foundation anti-seepage curtain is arranged at the bottom of the first toe slab, the upper end of the dam foundation anti-seepage curtain is connected to the first toe slab, and the lower end extends into the dam foundation; a second toe slab is arranged at the bottom of the second panel, an anti-scouring wall is arranged at the bottom of the second toe slab, the upper end of the anti-scouring wall is connected to the second toe slab, and the lower end extends into the dam foundation.

[0006] Furthermore, the joint between the first panel and the first toe slab is a peripheral joint, and an anti-seepage cushion layer is arranged inside the peripheral joint.

[0007] Furthermore, a clay layer is covered on the first toe slab, the upper end of the clay layer is connected to the first panel, and the lower end is connected to the dam foundation surface.

[0008] Furthermore, a weight layer is covered on the clay layer, the upper end of the weight layer is connected to the first panel, and the lower end is connected to the dam foundation surface.

[0009] Furthermore, the lower reservoir of the power station has a dead water level, and the upper end of the weight layer is lower than the dead water level.

[0010] Furthermore, a foot protection is provided on the second toe slab, and the upper end of the foot protection is connected to the second panel and the lower end is connected to the dam foundation surface.

[0011] Furthermore, the river channel has a perennial water level and a flood control check water level. The upper end of the foot protection is higher than the perennial water level of the river channel, and the upper end of the second panel is higher than the flood control check water level of the river channel.

[0012] Furthermore, a foundation pit is provided on the dam foundation surface. The rockfill area includes a rockfill drainage body arranged in the foundation pit and a main body of the rockfill area arranged on the rockfill drainage body. The cross-section of the rockfill drainage body is an inverted trapezoid, and the cross-section of the main body of the rockfill area is a triangle, and the bottom width of the main body of the rockfill area is greater than the top width of the rockfill drainage body.

[0013] Furthermore, a transition layer extension section is provided at the lower end of the transition layer. The transition layer extension section is arranged along the bottom surface of the main body of the rockfill area and the reservoir side of the rockfill drainage body and extends into the foundation pit.

[0014] Furthermore, a cushion layer extension section is provided at the lower end of the cushion layer. The cushion layer extension section is arranged along the bottom surface of the transition layer extension section and extends into the foundation pit.

[0015] The beneficial effects of the present invention are as follows: The water retaining dam is a rockfill dam, and its toe slab has relatively low foundation requirements, relatively low dam height, small dam foundation excavation volume, and the reservoir basin excavation materials of the lower reservoir of the power station can be used to build the dam body, and basically the excavation and filling can be balanced, without the need to additionally exploit a stone quarry or find a waste dump site. Therefore, it can reduce the project investment, facilitate construction, reduce land acquisition, and reduce the impact on the ecological environment. Compared with the concrete gravity water retaining dam used in pumped storage power stations in the past, the project cost of this water retaining dam is only about one-third of it, and the project benefits are remarkable. At the same time, through the anti-seepage structure on the reservoir side formed by the first panel, the first toe slab and the dam foundation anti-seepage curtain, and the anti-seepage structure on the river side formed by the second panel, the second toe slab and the anti-scouring wall, the water retaining dam has a complete anti-seepage system, good anti-seepage performance, and can meet the two-way anti-seepage requirements for the lower reservoir of the power station and the river channel on both sides of it. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic plan structure diagram of the present invention;

[0017] Figure 2 is a schematic sectional structure diagram of the present invention;

[0018] The markings in the figure are: the lower reservoir 100 of the power station, the dead water level 110, the sump 120, the river channel 200, the perennial water level 210 of the river channel, the flood control check level 220 of the river channel, the dam body 300, the rockfill area 310, the rockfill drainage body 311, the main body 312 of the rockfill area, the transition layer 320, the extended section 321 of the transition layer, the cushion layer 330, the anti-seepage cushion layer 331, the extended section 332 of the cushion layer, the first panel 340, the first toe slab 341, the clay layer 342, the weight layer 343, the anti-scouring wall 350, the second panel 370, the second toe slab 371, the toe protection 372, the anti-seepage curtain 380 of the dam foundation, the foundation surface 410 of the dam foundation, and the dam foundation 420. Detailed implementation manners

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred mechanism or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] Combined with Figure 1 and Figure 2 As shown, the water retaining dam for a pumped storage power station includes a dam body 300 arranged between the lower reservoir 100 of the power station and the river channel 200; the dam body 300 includes a rockfill area 310 arranged on the foundation surface 410 of the dam foundation, and a transition layer 320, a cushion layer 330, and a first panel 340 arranged in sequence from the inside to the outside on the reservoir side of the rockfill area 310, and a second panel 370 arranged on the river side of the rockfill area 310; the reservoir side of the rockfill area 310 refers to the side of the rockfill area 310 close to the lower reservoir 100 of the power station; the river side of the rockfill area 310 refers to the side of the rockfill area 310 close to the river channel 200;

[0022] The bottom of the first panel 340 is provided with a first toe slab 341, the bottom of the first toe slab 341 is provided with an anti-seepage curtain 380 of the dam foundation, and the upper end of the anti-seepage curtain 380 of the dam foundation is connected to the first toe slab 341 and the lower end extends into the dam foundation 420; the anti-seepage curtain 380 of the dam foundation is an anti-seepage facility of the dam body, mainly used for preventing the seepage of reservoir water, and the anti-seepage curtain 380 of the dam foundation is usually formed by cement curtain grouting;

[0023] A second toe slab 371 is provided at the bottom of the second panel 370, and an anti-erosion wall 350 is provided at the bottom of the second toe slab 371. The upper end of the anti-erosion wall 350 is connected to the second toe slab 371, and the lower end extends into the dam foundation 420. The anti-erosion wall 350 is an anti-scouring facility of the dam body 300, which can not only prevent the flood in the river channel 200 from scouring the dam foundation, but also serve as an anti-seepage barrier to prevent the water flow in the river channel 200 from seeping into the dam body 100 and the dam foundation 420. The anti-erosion wall 350 is usually made by casting concrete.

[0024] The water retaining dam is a rockfill dam, and its dam body 300 includes a first panel 340, a cushion layer 330, a transition layer 320, a rockfill area 310, and a second panel 370 that are sequentially arranged on the dam foundation surface 410. A first toe slab 341 is provided at the bottom of the first panel 340, a dam foundation anti-seepage curtain 380 is provided at the bottom of the first toe slab 341, a second toe slab 371 is provided at the bottom of the second panel 370, and an anti-erosion wall 350 is provided at the bottom of the second toe slab 371. Since the water retaining dam is a rockfill dam, compared with the concrete gravity water retaining dam previously used in pumped storage power stations, the foundation requirements for its toe slab are relatively low. Its dam crest elevation only needs to meet the height requirements of the lower reservoir 100 of the power station and exceed the river channel check flood level 220. The dam height is also relatively low, the dam foundation excavation volume is small, and the excavation materials from the reservoir basin of the lower reservoir 100 of the power station can be used to fill the dam body 300, achieving a balance between excavation and filling. There is no need to additionally exploit a stone quarry or find a waste dump site. Therefore, it can reduce the project investment, facilitate construction, reduce land acquisition, and reduce the impact on the ecological environment. According to incomplete statistics, for pumped storage power stations of the same volume, the project cost of this water retaining dam is only about one-third of that of the existing concrete gravity water retaining dam, and the engineering benefits are remarkable. At the same time, through the anti-seepage structure on the reservoir side formed by the first panel 340, the first toe slab 341, and the dam foundation anti-seepage curtain 380, and the anti-seepage structure on the river side formed by the second panel 370, the second toe slab 371, and the anti-erosion wall 350, the water retaining dam has a complete anti-seepage system with good anti-seepage performance, which can meet the bidirectional anti-seepage requirements for the lower reservoir 100 of the power station and the river channel 200 on both sides of it.

[0025] Among them, the lower reservoir 100 of the pumped storage power station is the water storage reservoir of the pumped storage power station, which has a normal storage level and a dead water level 110. The dead water level 110 refers to the lowest water level allowed for the reservoir to draw down under normal operation conditions. The river channel 200 is the passage through which the river flows, which has a river channel normal water level 210 and a river channel check flood level 220. The river channel normal water level 210 is obtained through long-term observation of the water level in the river channel section corresponding to this water retaining dam. Usually, the elevation value at which the water level in the river channel section is equal to or exceeds this level for 50% of the time in one year or several years is called the river channel normal water level 210. The river channel check flood level 220 refers to the highest water level reached by the reservoir in front of the dam when the dam encounters the check flood, also known as the extreme flood level.

[0026] The dam body 300 is the main body of the water retaining dam, and the rockfill area 310 is the main part in the middle of the dam body 300; the transition layer 320 is mainly used to fill the gaps on the surface of the rockfill area 310 and level it to improve the integrity and anti-seepage safety of the dam body 300; the cushion layer 330 is mainly used to disperse the load of the panel; the first panel 340 and the second panel 370 are mainly used to retain water and form the anti-seepage system of the dam body 300; the first panel 340 and the second panel 370 are usually concrete panels, on which there are generally joint structures and joint water stop structures. The toe slab is connected to the panel through the peripheral joint with water stop to form the anti-seepage body above the dam foundation 420, and at the same time, the end is connected to the bedrock after foundation treatment to seal 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, the main function of the toe slab is also to serve as the cover plate for foundation grouting and the pedestal for the panel; the panels of the water retaining dam include the first panel 340 and the second panel 370, and the toe slabs of the water retaining dam include the first toe slab 341 and the second toe slab 371. The first toe slab 341 is a concrete structure arranged at the bottom periphery of the first panel 340 and located on the dam foundation surface 410, and the second toe slab 371 is a concrete structure arranged at the bottom periphery of the second panel 370 and located on the dam foundation surface 410.

[0027] Specifically, the joint between the first panel 340 and the first toe slab 341 is the peripheral joint. In order to prevent leakage at the peripheral joint, as shown in Figure 2 again, an anti-seepage cushion layer 331 is arranged inside the peripheral joint, and the anti-seepage cushion layer 331 is generally located between the peripheral joint and the cushion layer 330.

[0028] In order to further improve the anti-seepage ability of the water retaining dam, as shown in Figure 2 again, a clay layer 342 is covered on the first toe slab 341. The upper end of the clay layer 342 is connected to the first panel 340, and the lower end is connected to the dam foundation surface 410; the clay layer 342 is usually formed by laying clay.

[0029] On the above basis, in order to prevent the clay from being carried away by the water body, as shown in Figure 2 again, a weight layer 343 is covered on the clay layer 342. The upper end of the weight layer 343 is connected to the first panel 340, and the lower end is connected to the dam foundation surface 410; the weight layer 343 is usually formed by laying engineering waste residues.

[0030] In order to prevent the water body in the lower reservoir 100 of the power station from rising and falling and carrying away the clay, it is preferably that the upper end of the first weight layer 343 is lower than the dead water level 110.

[0031] In order to prevent the flood in the river channel 300 from scouring the dam toe and the dam foundation 420, as shown in Figure 2As shown, a foot protection 372 is provided on the second toe slab 371. The upper end of the foot protection 372 is connected to the second panel 370, and the lower end is connected to the dam foundation surface 410. The foot protection 372 is usually formed by masonry of rubble stones.

[0032] To save the project quantity and cost, and ensure the anti-seepage and anti-scouring effects, as shown Figure 2 in another figure, it is preferred that the upper end of the foot protection 372 is higher than the perennial river level 210, and the upper end of the second panel 370 is higher than the checked flood level 220 of the river.

[0033] To drain the seepage water of the dam bodies 300 on the side adjacent to the reservoir and the side adjacent to the river, as shown Figure 2 in another figure, a foundation pit is provided on the dam foundation surface 410. The rockfill area 310 includes a rockfill drainage body 311 arranged in the foundation pit and a main body 312 of the rockfill area arranged on the rockfill drainage body 311. The cross-section of the rockfill drainage body 311 is an inverted trapezoid, and the cross-section of the main body 312 of the rockfill area is a triangle, and the bottom width of the main body 312 of the rockfill area is greater than the top width of the rockfill drainage body 311. The rockfill drainage body 311 is usually arranged longitudinally, that is, along the dam axis, and the rockfill drainage body 311 has a longitudinal slope structure with a higher upstream end and a lower downstream end. It is preferred that its slope is 2%. To facilitate the collection of seepage water, a sump 120 is usually provided downstream of the lower reservoir 100 of the power station, and the downstream end of the rockfill drainage body 311 is communicated with the sump 120.

[0034] To further improve the integrity and anti-seepage ability of the dam 300, as shown Figure 2 in another figure, a transition layer extension section 321 is provided at the lower end of the transition layer 320. The transition layer extension section 321 is arranged along the bottom surface of the main body 312 of the rockfill area and the side adjacent to the reservoir of the rockfill drainage body 311, and extends into the foundation pit.

[0035] To disperse the load and reduce the deformation of the dam foundation surface 410, as shown Figure 2 in another figure, a cushion layer extension section 332 is provided at the lower end of the cushion layer 330. The cushion layer extension section 332 is arranged along the bottom surface of the transition layer extension section 321 and extends into the foundation pit.

Claims

1. A water retaining dam for a pumped storage power station, comprising a dam body (300) arranged between the lower reservoir (100) of the power station and the river channel (200); characterized in that: The dam body (300) includes a rockfill area (310) arranged on the foundation surface (410) of the dam foundation, a transition layer (320), a cushion layer (330), and a first concrete slab (340) arranged in sequence from inside to outside on the reservoir side of the rockfill area (310), and a second concrete slab (370) arranged on the river side of the rockfill area (310); a first toe slab (341) is arranged at the bottom of the first concrete slab (340), a dam foundation anti-seepage curtain (380) is arranged at the bottom of the first toe slab (341), the upper end of the dam foundation anti-seepage curtain (380) is connected to the first toe slab (341), and the lower end extends into the dam foundation (420); a second toe slab (371) is arranged at the bottom of the second concrete slab (370), an anti-scouring wall (350) is arranged at the bottom of the second toe slab (371), the upper end of the anti-scouring wall (350) is connected to the second toe slab (371), and the lower end extends into the dam foundation (420); the joint between the first concrete slab (340) and the first toe slab (341) is a peripheral joint, and an anti-seepage cushion layer (331) is arranged inside the peripheral joint; a clay layer (342) is covered on the first toe slab (341), the upper end of the clay layer (342) is connected to the first concrete slab (340), and the lower end is connected to the foundation surface (410) of the dam foundation; a weight layer (343) is covered on the clay layer (342), the upper end of the weight layer (343) is connected to the first concrete slab (340), and the lower end is connected to the foundation surface (410) of the dam foundation. A foundation pit is arranged on the foundation surface (410) of the dam foundation. The rockfill area (310) includes a rockfill drainage body (311) arranged in the foundation pit and a main body (312) of the rockfill area arranged on the rockfill drainage body (311); the cross-section of the rockfill drainage body (311) is an inverted trapezoid, the cross-section of the main body (312) of the rockfill area is a triangle, and the bottom width of the main body (312) of the rockfill area is greater than the top width of the rockfill drainage body (311); a transition layer extension section (321) is arranged at the lower end of the transition layer (320), and the transition layer extension section (321) is arranged along the bottom surface of the main body (312) of the rockfill area and the reservoir side of the rockfill drainage body (311) and extends into the foundation pit; a cushion layer extension section (332) is arranged at the lower end of the cushion layer (330), and the cushion layer extension section (332) is arranged along the bottom surface of the transition layer extension section (321) and extends into the foundation pit.

2. The water retaining dam for a pumped storage power station according to claim 1, wherein: The lower reservoir (100) of the power station has a dead water level (110), and the upper end of the weight layer (343) is lower than the dead water level (110).

3. The water retaining dam for a pumped storage power station according to claim 2, characterized in that: A foot protection (372) is covered on the second toe slab (371), the upper end of the foot protection (372) is connected to the second concrete slab (370), and the lower end is connected to the foundation surface (410) of the dam foundation.

4. The water retaining dam for a pumped storage power station according to claim 3, characterized in that: The river course (200) has a perennial water level (210) and a flood control check water level (220) of the river course. The upper end of the foot protection (372) is higher than the perennial water level (210) of the river course, and the upper end of the second concrete slab (370) is higher than the flood control check water level (220) of the river course.

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