Construction method of dam back pressure slope of pumped storage power station

Abstract

The application discloses a construction method of a dam backfill slope of a pumped storage power station, which utilizes the slag produced by dam foundation excavation to fill the outermost part of the backfill slope design area, forms a first-stage backfill slope with a trapezoidal cross section, excavates the reservoir basin, fills the dam with useful materials excavated, fills the backfill slope from outside to inside with the slag until the inner side slope foot of the filled dam and the inner side slope foot of the backfill slope are connected, fills the second-stage backfill slope, continues to fill the dam and the triangular area between the dam and the second-stage backfill slope until the elevation of the triangular area is consistent with the elevation of the second-stage backfill slope, forms a third-stage backfill slope, and fills the dam and the backfill slope to the design elevation respectively. The slag produced by dam foundation excavation and reservoir basin excavation is directly used to fill the dam backfill slope, the filling is performed while the excavation is performed, the filling is performed from outside to inside, no intermediate slag transfer is needed in the construction, the dam engineering construction cost is reduced, the dam construction progress is accelerated, and the construction period is shortened.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower, and in particular to a construction method for slope stabilization behind a pumped storage power station dam. Background Technology

[0002] Pumped storage power stations typically have their upper reservoirs located in hilltop depressions with relatively flat terrain, wide valleys, and generally poor geological conditions. Furthermore, the transportation between the upper and lower reservoirs is inconvenient, resulting in high costs for transporting materials from outside the area. Therefore, in practical engineering, to maximize the use of excavated materials and local resources, the dam body of the upper reservoir usually utilizes these materials.

[0003] Currently, the upper reservoir dams of pumped storage power stations are generally constructed using soil and rock excavated from the reservoir basin (meeting dam construction requirements). Residual excavated material is typically stockpiled behind the dam for slope protection, increasing dam safety and reducing the need for spoil disposal sites. However, current construction processes often require dedicated transfer yards for temporary storage of excavated material, which is then transported to the slope protection area behind the dam. This construction method necessitates a large transfer yard and repeated transport, increasing construction costs. Furthermore, current methods involve constructing the slope protection after the dam body is completed, extending the overall construction period of the upper reservoir. Summary of the Invention

[0004] In view of this, the present invention proposes a construction method for the slope embankment behind the dam of a pumped storage power station, which can realize simultaneous excavation and filling, as well as simultaneous filling of the dam and the slope embankment behind the dam, thereby improving construction efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The construction method for slope stabilization after the dam of a pumped storage power station as described in this invention utilizes the slag material generated from the excavation of the dam foundation and reservoir basin to fill the slope stabilization, specifically including the following steps: The first step is to excavate the dam foundation at the designed dam location and transport the excavated usable materials to the transfer station for later dam filling. The excavated slag is then used to fill the outermost part of the slope design area, forming a first-stage slope with a trapezoidal cross-section and a top width of 8m to 10m, which can be used for road construction. The second step is to excavate the reservoir basin after the dam foundation is excavated, and use the excavated materials and the excavated materials from the first step to fill the dam. The excavated slag is then filled from the outside to the inside until the inner slope toe of the already filled dam and the inner slope toe of the slope are connected, thus completing the second-stage slope. The third step is to continue excavating the reservoir basin and filling the dam. The excavated slag is used to fill the triangular area between the already filled dam and the second-stage slope protection until the elevation of the triangular area is consistent with the elevation of the second-stage slope protection, thus forming the third-stage slope protection. During the filling process, the filling elevation of the triangular area is always lower than the filling elevation of the dam, and the filling elevation of the third-stage slope protection is lower than the filling elevation of the dam. The fourth step is to fill the dam and the slope behind it to the design elevation, thus obtaining the dam body and the slope behind the dam.

[0006] Preferably, the embankment slope of the first-stage slope and the third-stage slope are consistent with the design slope of the slope behind the dam.

[0007] Compared with the prior art, the advantages of the present invention are as follows: The present invention directly uses the slag generated from the dam foundation excavation and reservoir basin excavation to fill the slope behind the dam, and fills while excavating, and fills in the direction from the outside to the inside (i.e. from the outermost edge of the slope behind the dam towards the dam). There is no need to transfer slag during construction, which not only reduces the construction cost of the dam project, but also speeds up the construction progress of the dam and shortens the total construction period of the upper reservoir project. Attached Figure Description

[0008] Figure 1 This is a diagram showing the relationship between the dam's design location and the first-phase slope compaction in this invention.

[0009] Figure 2 This is a diagram showing the positional relationship between the already constructed dam and the second-phase slope reinforcement in this invention.

[0010] Figure 3 This is a schematic diagram of the filling of the triangular area between the dam and the second-stage slope in this invention (the filling height of the triangular area is lower than that of the dam and the second-stage slope).

[0011] Figure 4 This is a schematic diagram of the three-phase slope stabilization and dam filling.

[0012] Figure 5 This is a schematic diagram showing the dam and the slope protection behind the dam after construction is completed in this invention. Detailed Implementation

[0013] The present invention will now be described in detail with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following embodiments.

[0014] The construction method for slope protection after the dam of a pumped storage power station as described in this invention utilizes the slag material generated from the excavation of the dam foundation and reservoir basin to fill the slope, specifically including the following steps: The first step is to excavate the dam foundation (usually earth and rock) at the designed location of the dam, and transport the excavated usable materials (i.e. crushed stone materials that meet the requirements for dam filling) to the transfer station for dam filling. The excavated slag was used to fill the outermost part of the slope design area, and then filled along dam 2 to form the first-phase slope 1 with a trapezoidal cross-section. The top platform of the first-phase slope 1 has a width of 8m to 10m, and this platform can be used for road construction. See details. Figure 1 ; The second step involves excavating the reservoir basin after the dam foundation excavation is completed. The excavated usable material (i.e., stone meeting the dam filling material requirements) and the usable material excavated in the first step are used to fill dam 2. The excavated slag is then used to fill the first-stage slope 1, filling from the outside in until the inner toe of the filled dam 2 meets the inner toe of the slope 1, thus creating the second-stage slope 3. The elevation of the second-stage slope 3 is higher than that of the first-stage slope 1, and the bottom width of the second-stage slope 3 is greater than that of the first-stage slope 1. See details... Figure 2 ; During the filling process, the outer slope of the second-stage slope 3 is consistent with the designed slope of the slope 5 behind the dam; the second-stage slope 3 and the already filled dam 2 form a triangular area to be filled. The third step is to continue excavating the reservoir basin and filling dam 2, using the excavated slag to fill triangular area F, as detailed below. Figure 3 The triangular area was filled with slag until its elevation matched that of the second-stage slope protection 3, forming the third-stage slope protection 4. During the filling process, it was ensured that the filling elevation of the triangular area remained lower than that of the dam 2, and that the resulting third-stage slope protection 4 had a filling elevation lower than that of the dam 2. See details... Figure 4 ; Fourthly, since the already filled height of Dam 2 is higher than the filled height of the third-phase slope protection 4, Dam 2 and the slope protection can be filled to the design elevation separately (construction can be carried out simultaneously to improve construction efficiency), resulting in the dam body of Dam 2 and the slope protection 5 behind the dam. See details below. Figure 5 .

[0015] In this invention, the slag excavated from the dam foundation and reservoir basin is directly used for slope embankment construction. The initial embankment section is trapezoidal, and the embankment is gradually filled from the outside to the inside, realizing simultaneous excavation and embankment construction. There is no need to transfer the excavated slag, thus eliminating the need for temporary storage at transfer sites and saving transfer costs. Furthermore, the embankment construction is directly used for slope embankment construction, which improves construction efficiency to a certain extent. After the dam foundation excavation is completed, the dam 2 is directly embanked, and the dam 2 and the embankment slope 5 are embanked simultaneously, further improving the construction efficiency of the embankment slope embankment of the pumped storage power station and shortening the total construction period of the upper reservoir project.

[0016] Finally, it should be emphasized that 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 make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Therefore, 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 construction method for slope stabilization downstream of a pumped storage power station dam, characterized in that: The construction method utilizes the slag material generated from the excavation of the dam foundation and reservoir basin to fill and compact the slope, specifically including the following steps: The first step is to excavate the dam foundation at the designed dam location, transport the excavated usable materials to the transfer station for later dam filling; and fill the outermost part of the slope design area with the excavated slag to form the first-stage slope with a trapezoidal cross-section and a top width of 8m to 10m, which will be used for road construction. The second step is to excavate the reservoir basin after the dam foundation is excavated, and use the excavated materials and the excavated materials from the first step to fill the dam. The excavated slag is then filled from the outside to the inside until the inner slope toe of the already filled dam and the inner slope toe of the slope are connected, thus completing the second-stage slope. The third step involves continuing to excavate the reservoir basin and fill the dam. The excavated slag is used to fill the triangular area between the already filled dam and the second-stage slope protection until the elevation of the triangular area matches that of the second-stage slope protection, thus forming the third-stage slope protection. During the filling process, the filling elevation of the triangular area is always lower than that of the dam, and the filling elevation of the third-stage slope protection is also lower than that of the dam. The filling slopes of both the first-stage and third-stage slope protection are consistent with the design slope of the slope protection behind the dam. The fourth step is to fill the dam and the slope behind the dam to the design elevation after the completion of the three-phase slope filling.

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