A dam back seepage monitoring drainage structure capable of being rapidly constructed

Abstract

The application discloses a dam-back seepage monitoring and drainage structure capable of being rapidly constructed, relates to the field of hydroelectric and hydraulic engineering, and comprises a ditch, a dam, a dam drainage body and a pressure slope body, further comprises a concrete connecting body, an anti-seepage layer, a water measuring weir retaining wall and a permeable drainage channel, the concrete connecting body is arranged along the lengthways of the two banks of the ditch, the lower part of the concrete connecting body penetrates into a relatively impermeable layer, the anti-seepage layer is laid from the top of the dam drainage body slope to the downstream along the ditch, is embedded in the water measuring weir retaining wall in the downstream, is embedded in the concrete connecting body on the two sides, the permeable drainage channel is arranged below the anti-seepage layer, is arranged along the bottom of the ditch, is connected with the dam drainage body in the upstream and reaches the front of the water measuring weir retaining wall in the downstream, and the pressure slope body is filled above the anti-seepage layer and along the ditch, the upstream of the pressure slope body is relied on the dam back, and the downstream slope foot reaches the front of the water measuring weir retaining wall. The relatively closed anti-seepage structure is formed by combining the anti-seepage layer and the concrete connecting body with the relatively impermeable layer, the dam seepage and the pressure slope body seepage are separated, the dam seepage can be accurately monitored, the water measuring weir retaining wall structure can monitor the pressure slope body seepage and the dam seepage respectively, and the stability of the pressure slope body and the dam can be respectively evaluated.

Description

Technical Field

[0001] This invention relates to the field of hydropower and water conservancy engineering, specifically to a dam-back seepage monitoring and drainage structure that can be constructed quickly. Background Technology

[0002] Pumped storage hydroelectric power stations, as highly efficient power peak-shaving, frequency regulation, and energy storage facilities, offer advantages such as high flexibility, fast response, and long service life, and are widely used in power systems. They achieve rational allocation and balance of electricity by pumping water to a high-level reservoir for storage during periods of low electricity demand and releasing the water flow to generate electricity during periods of peak demand. As a major global energy consumer, my country has a particularly urgent need for pumped storage hydroelectric power stations.

[0003] During the construction of pumped storage power stations, a large amount of earth and rock excavation and backfilling is involved, resulting in a huge amount of waste. Due to increasingly stringent water conservation requirements, the selection and approval of waste disposal sites are becoming increasingly difficult, and the disposal of construction waste has become a major obstacle to project progress. To mitigate water conservation risks, for reservoir projects using roller-compacted earth-rock dams, most projects, when conditions permit, choose to stockpile the waste behind the dam as a slope retainer, filling it simultaneously with the dam. Because the slope retainer encroaches on the dam's toe, the dam's seepage will converge at the toe, then merge with the seepage flow from the slope retainer, finally flowing out from the toe of the slope retainer. At this point, the outflow differs significantly from the dam's seepage flow, making dam seepage monitoring difficult.

[0004] To address this issue, some projects opted to bury steel pipes at the bottom to divert seepage water from the retaining wall behind the dam to the toe of the slope cap. However, this approach suffers from blockages and difficulties in maintenance. Other projects chose to bury box culverts at the lower part of the slope cap, with one end connected to the drainage holes in the retaining wall at the toe of the dam slope and the other end connected to a measuring weir at the toe of the slope cap. This separates the dam seepage from the slope cap seepage, allowing for accurate monitoring of the dam seepage flow. However, to prevent damage to the box culverts during slope cap placement, the bottom of the culverts needs to be placed on stable bedrock. Given that box culverts are generally laid along the bottom of gullies with deep overburden, extensive excavation is required during construction. Furthermore, most use cast-in-place reinforced concrete structures, requiring dry-land construction conditions and diversion measures. This makes construction difficult and time-consuming, significantly impacting the normal stockpiling of waste from the upper slope cap. Waste disposal requires transfer and storage, greatly increasing waste disposal costs and construction organization difficulties. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a rapidly constructible seepage monitoring and drainage structure for dams, which effectively solves the issues of large seepage monitoring errors, difficult construction, and long construction time associated with existing technologies.

[0006] The present invention is achieved through the following technical solution.

[0007] A rapidly constructable seepage monitoring and drainage structure for dams includes a ditch, a dam, a dam drainage body, and a slope protection structure. It also includes a concrete connector, a seepage barrier, a measuring weir, and a permeable drainage channel. The concrete connector runs along both banks of the ditch, its lower part extending into a relatively impermeable layer. The seepage barrier is laid downstream from the top of the dam drainage body slope, embedded in the measuring weir downstream, and embedded in the concrete connector on both sides. The permeable drainage channel is located below the seepage barrier, along the bottom of the ditch, connecting upstream to the dam drainage body and downstream to the measuring weir, directing dam seepage to the measuring weir for monitoring dam seepage flow. The slope protection structure is built above the seepage barrier, along the ditch, with its upstream end against the dam and its downstream slope to the measuring weir, directing slope seepage to the measuring weir for monitoring slope seepage flow.

[0008] Furthermore, the concrete connector has a quadrilateral cross-section.

[0009] Furthermore, the drainage channel is formed by a pile of slightly weathered boulders.

[0010] Furthermore, when the flow rate of the channel is large, the upper part of the permeable drainage channel protrudes in an arch shape.

[0011] Furthermore, the impermeable layer is made of geomembrane and laid in a corrugated pattern.

[0012] Furthermore, the measuring weir retaining wall consists of a retaining wall, a trench, drainage holes, an outflow channel, a measuring flume, and an erosion-resistant base plate. The retaining wall is a gravity structure, with its bottom foundation and both ends reaching relatively impermeable layers. The trench is located on the upper part of the retaining wall, and the drainage holes are located on the lower part of the retaining wall. The bottom elevation of the trench is higher than the elevation of the geomembrane embedded in the retaining wall. The drainage holes are arranged in multiple staggered layers, with the top layer's drainage holes located below the elevation of the geomembrane embedded in the retaining wall. The measuring flume consists of a funnel-shaped water collection section and a straight water collection section. The bottom elevation of the funnel-shaped water collection section is below the drainage holes at the bottom layer of the retaining wall. The outflow channel connects to the trench and extends to the outside of the funnel-shaped water collection section. Both the outflow channel and the measuring flume flow onto the erosion-resistant base plate, which is arranged along the natural topography of the ditch bottom, lower in the middle and higher on both sides, connecting smoothly to the existing ditch.

[0013] Furthermore, the drainage channel is laid upwards in sequence with a lower transition material, a lower cushion layer, a geomembrane, an upper cushion layer, and an upper transition material. The slope compaction body is filled on top of the upper transition material. Both the upper and lower cushion layers are made of gravel, and both the lower and upper transition materials are made of crushed stone.

[0014] Furthermore, when the relatively impermeable layer of the ditch is relatively deep, the bottom is filled with the first lower transition material and the first lower cushion layer, the first geomembrane is laid, the first upper cushion layer and the first upper transition material are filled in sequence, and then the drainage channel and the upper lower transition material and lower cushion layer are filled in. The first geomembrane at the bottom and the upper geomembrane are welded together, and then the upper upper cushion layer and the upper transition material are filled in.

[0015] Furthermore, the first geomembrane is laid straight, the first upper layer and the first lower layer are both made of gravel, and the first lower transition layer and the first upper transition layer are both made of crushed stone.

[0016] The beneficial effects of this invention are:

[0017] A relatively closed seepage-proof structure is formed by combining a seepage-proof layer, a concrete connector, and a relatively impermeable layer, separating the dam seepage from the slope seepage, allowing for accurate monitoring of the dam's seepage flow. The drainage channels formed by dredging and filling the bottom of the trench can drain upstream water during construction and seepage from the dam later, eliminating the need for additional diversion measures. The drainage structure is simple, easy to construct, quick, and cost-effective. The layered drainage holes and the measuring weir retaining wall structure allow for monitoring of slope seepage at the top and dam seepage at the bottom, concentrating functions and compact layout, facilitating separate assessments of the slope and dam stability. This drainage structure effectively solves the problems of large seepage monitoring errors, difficult construction, and long construction times associated with existing technologies. Attached Figure Description

[0018] Figure 1 This is a plan view of the drainage structure for seepage monitoring after the dam in this invention;

[0019] Figure 2 This is a longitudinal section view of the drainage structure for monitoring seepage downstream of the dam according to the present invention;

[0020] Figure 3 This is a longitudinal section view of the water measuring weir retaining wall structure of the present invention;

[0021] Figure 4 This is a plan view of the water measuring weir retaining wall of the present invention;

[0022] Figure 5 This is a front view of the water-measuring weir retaining wall of the present invention;

[0023] Figure 6 This is a cross-sectional view of the drainage structure for seepage monitoring behind the dam in Example 1;

[0024] Figure 7 This is a cross-sectional view of the drainage structure for seepage monitoring after the dam in Example 2;

[0025] Figure 8 This is a cross-sectional view of the drainage structure for seepage monitoring behind the dam in Example 3;

[0026] Figure 9 This is a cross-sectional view of the drainage structure for seepage monitoring after the dam in Example 4.

[0027] In the picture:

[0028] 1-Drainage channel, 2-Lower transition material, 3-Lower cushion layer, 4-Geomembrane, 5-Upper cushion layer, 6-Upper transition material, 7-Water measuring weir retaining wall, 8-Concrete connector, 701-Retaining wall, 702-Trench, 703-Drainage hole, 704-Outflow channel, 705-Water measuring channel, 706-Impact slab, 7051-Flute-mouth water collection section, 7052-Straight water measuring section, 21-First lower transition material, 31-First lower cushion layer, 41-First geomembrane, 51-First upper cushion layer, 61-First upper transition material, 9-Dam, 10-Dam drainage body, 11-Slope protection body, 12-Ditch, 13-Relatively impermeable layer. Detailed Implementation

[0029] The following description further illustrates the structures involved in this invention and the technical terms used therein. These descriptions are merely illustrative of how the invention is implemented and do not constitute any limitation on the invention.

[0030] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the indicated position or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, unless otherwise explicitly specified and limited, terms such as "connection" and "fixation" should be interpreted broadly. For example, "fixation" can mean a fixed connection, a detachable connection, or an integral part; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] Example 1

[0033] like Figures 1-6As shown, when the ditch is relatively shallow compared to the impermeable layer 13 and the ditch flow is small, a rapidly constructable seepage monitoring drainage structure after the dam includes a ditch 12, a dam 9, a dam drainage body 10, a slope 11, a permeable drainage channel 1, a lower transition material 2, a lower cushion layer 3, a geomembrane 4, an upper cushion layer 5, an upper transition material 6, a measuring weir wall 7, and a concrete connector 8. The permeable drainage channel 1 is formed by slightly weathered boulders and is arranged along the bottom of the ditch after the excavation of the cover layer. Its upstream end connects to the dam drainage body 10, and its downstream end reaches the measuring weir wall 7. From the permeable drainage channel 1 upwards, the lower transition material 2, the lower cushion layer 3, the geomembrane 4, the upper cushion layer 5, and the upper transition material 6 are filled or laid in layers. A slope 11 (waste material) is then constructed on top of the upper transition material 6. Both the upper cushion layer 5 and the lower cushion layer 3 are made of gravel to protect the geomembrane 4 from being punctured by the gravel; both the lower transition material 2 and the upper transition material 6 are made of crushed stone to protect the upper cushion layer 5 and the lower cushion layer 3 from being carried away by the flowing water; the slope body 11 is filled along the ditch 12, with its upstream end relying on the back of the dam and its downstream slope toe reaching the front of the measuring weir retaining wall 7.

[0034] Among them, the dam drainage body 10 is located at the bottom downstream of the dam 9. Its main function is to divert seepage water from upstream to downstream and enhance the stability of the downstream dam slope.

[0035] The geomembrane 4 is located between the lower cushion layer 3 and the upper cushion layer 5. It is laid in a wave pattern from the top of the slope of the dam drainage body 10 downstream along the ditch 12. It is embedded in the water measuring weir wall 7 downstream and embedded in the concrete connector 8 on both sides. The concrete connector 8 has a quadrilateral cross section and is arranged along both banks of the ditch 12. Its lower part extends into the relatively impermeable layer 13, forming a relatively closed seepage prevention structure with the geomembrane 4 embedded in it on the sides.

[0036] The measuring weir retaining wall 7 is a concrete structure located at the toe of the slope of the slope stabilizing body 11. It consists of a retaining wall 701, a trench 702, drainage holes 703, an outflow channel 704, a measuring channel 705, and an anti-scouring base slab 706. The retaining wall 701 is a gravity structure, with its bottom foundation and both ends extending to a relatively impermeable layer 13. A trench 702 is formed on its upper part, and drainage holes 703 are formed on its lower part. The bottom elevation of the trench 702 is higher than the elevation of the geomembrane 4 embedded in the retaining wall. The drainage holes 703 are arranged in multiple staggered layers, with the top layer of drainage holes 704... 3 is located below the elevation of the geomembrane 4 embedded in the retaining wall 701; the measuring flume 705 consists of a funnel-shaped water collection section 7051 and a straight measuring section 7052, with the bottom elevation of the funnel-shaped water collection section 7051 located below the bottom drainage hole 703 of the retaining wall 701; the outflow channel 704 is connected to the ditch 702 and extends to the outside of the funnel-shaped water collection section 7051; both the outflow channel 704 and the measuring flume 705 flow onto the erosion-resistant base plate 706, which is arranged along the natural topography of the ditch bottom, with a lower middle section and higher sides, connecting smoothly to the existing ditch.

[0037] The dam seepage converges at point 11 of the dam drainage body, flows through the permeable drainage channel 1 to the measuring weir wall 7, then flows out through the drainage hole 703 to the measuring channel 705. After monitoring the flow rate in the straight measuring section 7052, it connects to the scour-resistant base plate 706 and flows into the existing channel. The slope seepage converges at its toe, i.e., above the measuring weir wall 7. The flow rate is monitored as it flows through the channel 702, and then flows through the outflow channel 704 to the scour-resistant base plate 706 and merges into the existing channel.

[0038] Example 2

[0039] like Figure 7 As shown, when the channel is relatively shallow compared to the impermeable layer 13 and the channel flow is large, the upper part of the drainage channel 1 is arched to increase the water flow cross-section. Other aspects are the same as in Example 1.

[0040] Example 3

[0041] like Figure 8 As shown, when the ditch is relatively deep to the impermeable layer 13 and the ditch flow is small, after the bottom of the ditch is cleared and leveled, the first lower transition material 21 and the first lower cushion layer 31 are filled at the bottom, the first geomembrane 41 is laid, the first upper cushion layer 51 and the first upper transition material 61 are filled in sequence, and then the drainage channel 1 and the upper lower transition material 2 and lower cushion layer 3 are filled in. The first geomembrane 41 at the bottom is welded to the upper geomembrane 4, and then the upper upper cushion layer 5 and the upper transition material 6 are filled in.

[0042] The first geomembrane 41 is laid straight. The first upper cushion layer 51 and the first lower cushion layer 31 are both made of gravel to protect the first geomembrane 41 from being punctured by gravel. The first lower transition material 21 and the first upper transition material 61 are both made of crushed stone to protect the first upper cushion layer 51 and the first lower cushion layer 31 from being carried away by flowing water.

[0043] Example 4

[0044] like Figure 9 As shown, when the channel is relatively deep to the impermeable layer 13 and the channel flow is large, the upper part of the drainage channel 1 is arched to increase the water flow cross-section. Other aspects are the same as in Example 3.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dam back seepage monitoring drainage structure capable of rapid construction, comprising a ditch, a dam, a dam drainage body and a pressure slope body, characterized in that: The concrete connecting body is arranged along the length of the ditch on both banks, and the lower part thereof is deep into the relatively impermeable layer.

2. The rapidly constructible post-dam seepage monitoring drainage structure of claim 1, wherein: The upper part of the permeable drainage channel is arched when the flow of the ditch is large.

3. The rapidly constructible post-dam seepage monitoring drainage structure of claim 1, wherein: The impermeable layer is made of geomembrane and is laid in a wave shape.

4. The rapidly constructible post-dam seepage monitoring drainage structure of claim 1, wherein: The weir retaining wall is composed of a retaining wall, a groove, a drainage hole, an outlet channel, a measuring channel and a scour-resistant bottom plate.

5. The rapidly constructible post-dam seepage monitoring drainage structure of claim 4, wherein: The upper part of the permeable drainage channel is arched when the flow of the ditch is large. The impermeable layer is made of geomembrane and is laid in a wave shape.

6. The rapidly constructible post-dam seepage monitoring drainage structure of claim 4, wherein: The weir retaining wall is composed of a retaining wall, a groove, a drainage hole, an outlet channel, a measuring channel and a scour-resistant bottom plate.

7. The rapidly constructible post-dam seepage monitoring drainage structure of claim 6, wherein: The upper part of the permeable drainage channel is arched when the 8. The rapidly constructible post-dam seepage monitoring drainage structure of claim 7, wherein: The first geomembrane is laid flat, the first upper cushion layer and the first lower cushion layer are made of gravel, and the first lower transition layer and the first upper transition layer are made of crushed stone. The first geomembrane is laid flat, the first upper cushion layer and the first lower cushion layer are made of gravel, and the first lower transition layer and the first upper transition layer are made of crushed stone.

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