Anti-settling anti-seepage reverse profile panel rockfill dam

Abstract

The application is suitable for the technical field of dam structure of water conservancy and hydropower engineering, and provides an anti-settlement anti-seepage back-shaped face slab rock-fill dam, which comprises: a dam body rock-fill body; a back-shaped face slab, which is covered on the water-approaching side of the dam body, and is formed into a multi-ring nested layout by an inner ring face slab, an outer ring face slab and horizontal connecting face slabs connected between the inner ring face slab and the outer ring face slab; and expansion joints, which are arranged at the joint seams of each divided face slab of the back-shaped face slab and the connection between the back-shaped face slab and the bank slope structure, and are used for adapting the relative displacement between each divided face slab and ensuring the anti-seepage sealing property at the joint seams; the application decomposes the concentrated deformation caused by the uneven settlement of the dam body into local adaptive deformations between each divided face slab through the back-shaped divided structure, eliminates the tensile stress concentration of the traditional continuous face slab, and improves the anti-cracking performance by more than 3 times; in cooperation with the multiple sealing expansion joints, the anti-seepage coefficient is less than or equal to 1*10 ‑8 cm / s, and the risk of seepage and piping is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of dam structure technology for water conservancy and hydropower engineering, specifically to a settlement-resistant and seepage-proof rockfill dam with a concrete panel. Background Technology

[0002] Concrete-faced rockfill dams are widely used in water conservancy projects such as reservoirs and hydropower stations due to their low cost, short construction period, and strong adaptability to terrain. Their seepage prevention function relies entirely on the concrete face panels on the upstream side of the dam. In existing technologies, seepage prevention panels generally adopt a long strip continuous casting structure, with the horizontal length of a single panel often reaching 80-150m. Expansion joints are only provided in the vertical direction, and there is no joint design in the horizontal direction.

[0003] Due to the weight and water pressure, the settlement deformation of the rockfill dam body exhibits a pattern of "greater settlement in the lower and middle parts and smaller settlement in the upper parts." The settlement in the lower and middle parts is typically 2-3 times that of the upper parts (the maximum settlement in the lower and middle parts of rockfill dams over 100m in height can reach 8-15cm). Continuous long strip panels cannot adapt to this uneven settlement, leading to tensile stress concentration in the lower and middle parts, which easily forms penetrating structural cracks. Once the panels crack, not only will reservoir water seep out, but it will also trigger "piping," a phenomenon where seepage water carries fine particles from the dam body, exacerbating the uneven settlement of the dam body and creating a vicious cycle of "cracks-leakage-intensified settlement," ultimately leading to dam instability.

[0004] Therefore, in view of the above situation, there is an urgent need to provide a settlement-resistant and seepage-proof rockfill dam with a concrete panel to overcome the shortcomings in current practical applications. Summary of the Invention

[0005] The purpose of this invention is to provide a settlement-resistant and seepage-proof rockfill dam with a concrete panel, which effectively solves the problems mentioned in the background art.

[0006] This invention is implemented as follows: a settlement-resistant and seepage-proof face rockfill dam, comprising: The dam body is composed of rockfill. A U-shaped panel, which covers the water-facing side of the dam body, is formed by an inner ring panel, an outer ring panel, and at least two horizontal connecting panels connecting the inner ring panel and the outer ring panel to form a multi-ring nested layout, with the horizontal connecting panels spaced apart along the dam height direction; The expansion joint is installed at the joints of the segment panels of the U-shaped panel and at the junction of the U-shaped panel and the slope structure. The expansion joint is used to adapt to the relative displacement between the segment panels and to ensure the seepage prevention and sealing of the joints.

[0007] As a further embodiment of the present invention: the inner ring panel and the outer ring panel are arranged coaxially, the inner diameter of the inner ring panel is / to / of the width of the top of the dam body, the outer diameter of the outer ring panel is adapted to the width of the bottom of the water-facing side of the dam body, and the distance between the inner ring panel and the outer ring panel is 5m to 10m. The horizontal connecting panels are set perpendicular to the inner and outer ring panels. The distance between two adjacent horizontal connecting panels is 5m to 20m, and the distance between adjacent horizontal connecting panels located in the lower part of the dam body is smaller than the distance between adjacent horizontal connecting panels located in the upper part of the dam body.

[0008] As a further aspect of the present invention: the spacing of the horizontal connecting panels increases from bottom to top along the dam height direction, wherein the spacing of the horizontal connecting panels in the lower part of the dam body is 5m to 12m, and the spacing of the horizontal connecting panels in the upper part of the dam body is 12m to 20m.

[0009] As a further embodiment of the present invention: the dam body rockfill comprises, from bottom to top, a layer of boulders, a layer of crushed stone, and a layer of gravel. The boulders in the boulders layer have a particle size of 30cm to 50cm, the crushed stone in the layer has a particle size of 5cm to 20cm, and the gravel in the layer has a particle size of 1cm to 5cm. The compaction degree of the boulders, crushed stone, and gravel layers is ≥0.95, and the compaction degree of the lower and middle regions of the dam's rockfill is ≥0.97.

[0010] As a further aspect of the present invention: the thickness of the block stone layer is 8m to 12m, the thickness of the crushed stone layer is 5m to 8m, and the thickness of the gravel layer is 3m to 5m.

[0011] As a further aspect of the present invention: the U-shaped panel is made of shrinkage-compensating concrete with a concrete grade of C30 to C40. The thickness of the lower region of the U-shaped panel is 40cm to 60cm, and the thickness of the upper region is 30cm to 40cm.

[0012] As a further aspect of the present invention: the inside of the U-shaped panel is provided with a double-layer bidirectional steel mesh, wherein the diameter of the steel bars in the double-layer bidirectional steel mesh is 8mm to 12mm and the mesh spacing is 150mm to 200mm.

[0013] As a further aspect of the present invention: a buffer pad is provided between the back of the U-shaped panel and the dam rockfill body, the buffer pad being a composite structure of geotextile and foam board, and the thickness of the buffer pad being 10mm to 20mm.

[0014] As a further embodiment of the present invention: the telescopic device includes a composite board, a closed-cell foam board, a copper waterstop, and a flat plastic sheet. The composite board is attached to the surface of the two side panels of the splice joint, the closed-cell foam board is filled inside the splice joint, the copper waterstop is located on the bottom water-facing side of the splice joint, and the flat plastic sheet covers the top back water-facing side of the splice joint.

[0015] As a further aspect of the present invention: the telescopic device further includes a rubber rod, filler, bolts and flat steel; the rubber rod is embedded in the middle of the splice joint, the filler is filled in the splice joint and wraps the rubber rod, and the bolts pass through the flat steel to fix the composite plate to the panel surface on both sides of the splice joint.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention employs a "loop-shaped" horizontally segmented closed panel structure, transforming the overall stress distribution mode of the traditional continuous panel into a multi-ring nested, independently segmented stress distribution mode formed by inner ring panels, outer ring panels, and horizontally connected panels. When uneven settlement occurs in the dam body, each segment panel can independently generate adaptive displacement, and concentrated settlement deformation is decomposed into local adaptive deformation between segments, resulting in uniform stress distribution and eliminating the tensile stress concentration phenomenon in the lower part of the traditional panel. Structural stress analysis shows that under extreme conditions where the settlement in the lower part of the dam body reaches 15cm, no structural cracks are generated in any segment of the loop-shaped panel of this invention. The crack resistance is more than 3 times higher than that of the traditional continuous long strip panel, fundamentally solving the cracking problem caused by uneven settlement in rockfill dams.

[0017] This invention incorporates a multi-layered sealing expansion joint at the seams of each panel panel. Through a combination of composite panels, closed-cell foam boards, copper waterstops, and flat plastic sheets, a seepage-proof system is formed that adapts to deformation while maintaining a tight seal. Even with significant relative displacement between the panel panels, the expansion joint can maintain a complete seal, achieving a seepage prevention coefficient of ≤1×10⁻⁶. -8 The flow rate of the dam is cm / s, which is an order of magnitude higher than that of traditional panels, effectively avoiding the risks of leakage and piping, and significantly improving the operational safety of the dam.

[0018] All components of this invention are compatible with the construction techniques of traditional panel rockfill dams, eliminating the need for additional specialized construction equipment and shortening the construction cycle by 5% to 10% compared to traditional solutions. Furthermore, the modular design facilitates later operation and maintenance. When a panel suffers partial damage due to extreme conditions, only that panel needs to be replaced, eliminating the need for extensive repairs of the entire panel and significantly reducing operation and maintenance costs and difficulty.

[0019] The circular panel structure of the present invention can flexibly adjust the block size, block spacing and number of rings according to specific engineering conditions. It is suitable for various panel rockfill dam projects with dam height of 30m to 200m and estimated settlement of 3cm to 15cm. It is especially suitable for high dam water conservancy projects in mountainous areas with complex geological conditions and large settlement, and has good engineering promotion value. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the plan layout of the U-shaped panels of the anti-settlement and seepage-proof U-shaped panel rockfill dam of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the anti-settlement and anti-seepage rockfill dam with face panel according to the present invention. Figure 3 This is a schematic diagram of the longitudinal section structure of the anti-settlement and anti-seepage rockfill dam with face panel according to the present invention. Figure 4 This is a schematic diagram of the telescopic device of the present invention.

[0022] In the attached diagram: 1. Dam rockfill body; 2. U-shaped panel; 2-1. Inner ring panel; 2-2. Outer ring panel; 2-3. Horizontal connecting panel; 3. Bank slope structure; 4. Expansion joint; 4-1. Rubber rod; 4-2. Composite board; 4-3. Filler; 4-4. Bolt; 4-5. Flat steel; 4-6. Closed-cell foam board; 4-7. PVC rod; 4-8. Copper waterstop; 4-9. Flat plastic sheet; 5. Buffer pad. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The present invention will be further explained below with reference to specific embodiments.

[0025] Please see Figures 1-4 The present invention provides an anti-settlement and seepage-proof rockfill dam with a back-shaped panel, comprising a rockfill body 1, a bank slope structure 3, a back-shaped panel 2, an expansion joint 4, and a buffer cushion layer 5.

[0026] The dam's rockfill body 1 is constructed using a graded stacking process, with layers of riprap, crushed stone, and gravel laid sequentially from bottom to top. The riprap layer has riprap with a particle size of 30cm to 50cm, the crushed stone layer has a particle size of 5cm to 20cm, and the gravel layer has a particle size of 1cm to 5cm. When the dam height is 50-100m, the thickness of the riprap layer is 8-12m, the crushed stone layer is 5-8m, and the gravel layer is 3-5m. The compaction degree of each layer is controlled to ≥0.95, and the compaction degree of the lower and middle region of the dam's rockfill body (from 1 / 3 to 2 / 3 of the height from the bottom of the dam) is controlled to ≥0.97. Through this graded stacking and zoned compaction control, the uneven settlement of the dam body is effectively reduced, providing a relatively uniform support foundation for the dam panel.

[0027] A buffer layer 5 is installed between the back of the U-shaped panel 2 and the rockfill body 1 of the dam. The buffer layer 5 is a composite structure of geotextile and foam board, with a total thickness of 10mm to 20mm, and is laid between the back of the U-shaped panel 2 and the water-facing surface of the rockfill body 1. The function of the buffer layer 5 is to absorb some of the deformation energy when the dam settles, thereby mitigating the stress impact of the rockfill body on the panel and playing a role in stress buffering and homogenization.

[0028] like Figure 1 As shown, the U-shaped panel 2 covers the upstream side of the dam body and adopts a U-shaped horizontal segmented closed design. It is formed by an inner ring panel 2-1, an outer ring panel 2-2, and at least two horizontal connecting panels 2-3 connecting the inner ring panel 2-1 and the outer ring panel 2-2, forming a multi-ring nested layout. The inner ring panel 2-1 and the outer ring panel 2-2 are both arranged along the upstream surface of the dam body and are coaxial. The inner diameter of the inner ring panel 2-1 is 1 / 2 to 2 / 3 of the top width of the dam body, and the outer diameter of the outer ring panel 2-2 is adapted to the bottom width of the upstream side of the dam body. The distance between the inner ring panel 2-1 and the outer ring panel 2-2 (i.e., the radial distance) is 5m to 10m. Each horizontal connecting panel 2-3 is set perpendicular to the inner ring panel 2-1 and the outer ring panel 2-2. The distance between two adjacent horizontal connecting panels 2-3 is 5m to 20m, and the distance between adjacent horizontal connecting panels located in the lower middle part of the dam body is smaller than the distance between adjacent horizontal connecting panels located in the upper part of the dam body. Specifically, the spacing of the horizontal connecting panels 2-3 increases from bottom to top along the dam height direction, with the spacing of the horizontal connecting panels in the lower part of the dam body being 5m to 12m and the spacing of the horizontal connecting panels in the upper part of the dam body being 12m to 20m.

[0029] Each panel segment is constructed using shrinkage-compensating concrete, with a concrete grade ranging from C30 to C40. The thickness of the lower section of the panel is 40cm to 60cm, while the upper section is 30cm to 40cm thick. Each panel segment is internally reinforced with a double-layer, two-way steel mesh, with steel bars ranging from 8mm to 12mm in diameter and a mesh spacing of 150mm to 200mm. The shrinkage-compensating concrete undergoes micro-expansion during hydration and hardening, which counteracts the tensile stress generated by concrete shrinkage, further reducing the risk of cracking.

[0030] Expansion joints 4 are installed at the seams of each panel segment and at the junction of the U-shaped panel 2 and the slope structure 3. For example... Figure 4 As shown, the expansion joint 4 employs a multi-layer sealing structure, specifically including: a rubber rod 4-1 embedded in the middle of the joint; filler 4-3 filling the joint and wrapping the rubber rod 4-1; a composite board 4-2 fitted onto the surfaces of the panels on both sides of the joint; bolts 4-4 passing through flat steel 4-5 to fix the composite board 4-2 to the surfaces of the panels on both sides of the joint; a closed-cell foam board 4-6 placed inside the joint; a copper waterstop 4-8 placed on the water-facing side of the closed-cell foam board 4-6; and a flat plastic sheet 4-9 placed on top of the joint and covering the water-repellent side. The expansion joint 4, installed at the junction of the U-shaped panel 2 and the slope structure 3, has one end fixedly connected to the slope structure 3 and the other end connected to the end of the outer ring panel 2-2 or the inner ring panel 2-1 of the U-shaped panel 2. This multi-layer sealing structure maintains the sealing integrity of the joint even when the panels shift relative to each other, ensuring stable seepage prevention performance.

[0031] The construction process of the anti-settlement and seepage-proof rockfill dam with concrete panel in this embodiment is as follows: The tiered embankment construction process is adopted, with layers of riprap (30-50cm in diameter, 8-12m thick), crushed stone (5-20cm in diameter, 5-8m thick), and gravel (1-5cm in diameter, 3-5m thick) laid sequentially from bottom to top. Each layer is compacted with a vibratory roller, and the compaction degree is controlled to be ≥0.95. The compaction degree of the middle and lower part of the dam's embankment (1 / 3 to 2 / 3 of the height from the bottom of the dam) is controlled to be ≥0.97. The embankment is built layer by layer until the designed dam height is reached.

[0032] A composite buffer layer 5 of "geotextile + foam board" with a total thickness of 10mm to 20mm is laid on the water-facing side of the dam body and fixed to the dam body surface with adhesive.

[0033] The U-shaped panels 2 are poured in sections on the buffer layer 5. The outer ring panels 2-2, the horizontal connecting panels 2-3, and the inner ring panels 2-1 are poured sequentially. Expansion joints are reserved at the joints of each panel section, with the joint width determined by the design displacement. The panels are poured with shrinkage-compensating concrete, with a concrete grade of C30 to C40. The thickness in the lower and middle areas is 40cm to 60cm, and the thickness in the upper area is 30cm to 40cm. A double-layer, two-way steel mesh (steel diameter 8~12mm, mesh spacing 150~200mm) is installed inside the panels.

[0034] Expansion joints 4 are installed at the joints of each panel segment and at the junction of the U-shaped panel 2 and the slope structure 3 to form a multi-layer sealing structure.

[0035] In summary, this invention employs a "U-shaped" segmented structure to decompose concentrated settlement deformation into localized adaptive deformation, resulting in uniform stress distribution. No cracks are generated under a settlement of 15cm, and the crack resistance is more than three times that of traditional panels. The expansion joint ensures sealing integrity, with a seepage prevention coefficient ≤1×10⁻⁶. -8 The speed is cm / s, an order of magnitude higher than traditional panels, avoiding the risks of leakage and piping; it is compatible with traditional rockfill dam construction techniques, requiring no additional specialized equipment and shortening the construction cycle by 5%-10%; the segmented design facilitates later maintenance, and individual panels can be replaced individually, reducing operation and maintenance costs; the segment size, spacing, and number of panels can be flexibly adjusted, making it suitable for various types of rockfill dams with panel heights of 30-200m and estimated settlement of 3-15cm, especially suitable for mountainous water conservancy projects with complex geology and large settlement.

[0036] The core mechanism of the “loop-shaped” segmented design of this invention is that when the dam body experiences uneven settlement, each independent segmented panel of the multi-ring nested structure can generate adaptive displacement, decomposing the overall tensile stress concentration of the traditional continuous panel into local displacement between each segment, fundamentally eliminating the tensile stress concentration phenomenon in the lower part of the panel, and achieving the technical effect of “releasing stress by segmentation and ensuring seepage prevention by sealing”.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A settlement-resistant and seepage-proof rockfill dam, comprising a rockfill dam body (1), characterized in that, Also includes: A U-shaped panel (2) covers the water-facing side of the dam body. It is formed by an inner ring panel (2-1), an outer ring panel (2-2), and at least two horizontal connecting panels (2-3) connecting the inner ring panel (2-1) and the outer ring panel (2-2) to form a multi-ring nested layout. The horizontal connecting panels (2-3) are spaced apart along the dam height direction. The expansion joint (4) is installed at the splicing joint of each segment panel of the U-shaped panel (2) and at the connection between the U-shaped panel (2) and the bank slope structure (3). The expansion joint (4) is used to adapt to the relative displacement between each segment panel and to ensure the seepage prevention and sealing of the splicing joint.

2. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 1, characterized in that, The inner ring panel (2-1) and the outer ring panel (2-2) are arranged coaxially. The inner diameter of the inner ring panel (2-1) is 1 / 2 to 2 / 3 of the top width of the dam body. The outer diameter of the outer ring panel (2-2) is adapted to the bottom width of the water-facing side of the dam body. The distance between the inner ring panel (2-1) and the outer ring panel (2-2) is 5m to 10m. The horizontal connecting panels (2-3) are set perpendicular to the inner ring panel (2-1) and the outer ring panel (2-2). The spacing between two adjacent horizontal connecting panels (2-3) is 5m to 20m, and the spacing between adjacent horizontal connecting panels (2-3) located in the lower part of the dam body is smaller than the spacing between adjacent horizontal connecting panels (2-3) located in the upper part of the dam body.

3. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 2, characterized in that, The spacing of the horizontal connecting panels (2-3) increases from bottom to top along the dam height direction. The spacing of the horizontal connecting panels (2-3) in the lower part of the dam body is 5m to 12m, and the spacing of the horizontal connecting panels (2-3) in the upper part of the dam body is 12m to 20m.

4. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 1, characterized in that, The dam body rockfill (1) includes, from bottom to top, a boulders layer, a crushed stone layer and a gravel layer. The boulders in the boulders layer have a boulders diameter of 30cm to 50cm, the crushed stone layer has a crushed stone diameter of 5cm to 20cm, and the gravel layer has a gravel diameter of 1cm to 5cm. The compaction degree of the boulders, crushed stone and gravel layers is ≥0.95, and the compaction degree of the middle and lower part of the dam rockfill (1) is ≥0.

97.

5. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 4, characterized in that, The thickness of the boulders layer is 8m to 12m, the thickness of the crushed stone layer is 5m to 8m, and the thickness of the gravel layer is 3m to 5m.

6. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 1, characterized in that, The U-shaped panel (2) is made of shrinkage-compensating concrete with a concrete grade of C30 to C40. The thickness of the lower region of the U-shaped panel (2) is 40cm to 60cm, and the thickness of the upper region is 30cm to 40cm.

7. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 6, characterized in that, The inside of the U-shaped panel (2) is equipped with a double-layer bidirectional steel mesh, the diameter of the steel bars in the double-layer bidirectional steel mesh is 8mm to 12mm, and the mesh spacing is 150mm to 200mm.

8. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 1, characterized in that, A buffer pad (5) is provided between the back of the U-shaped panel (2) and the dam rockfill body (1). The buffer pad (5) is a composite structure of geotextile and foam board, and the thickness of the buffer pad (5) is 10mm to 20mm.

9. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 1, characterized in that, The telescopic device (4) includes a composite board (4-2), a closed-cell foam board (4-6), a copper waterstop (4-8), and a flat plastic sheet (4-9). The composite board (4-2) is attached to the surface of the two side panels of the splice joint. The closed-cell foam board (4-6) fills the interior of the splice joint. The copper waterstop (4-8) is located on the bottom water-facing side of the splice joint. The flat plastic sheet (4-9) covers the top back water-facing side of the splice joint.

10. The anti-settlement and seepage-proof rockfill dam with concrete panel according to claim 8, characterized in that, The telescopic device (4) also includes a rubber rod (4-1), a filler (4-3), a bolt (4-4), and a flat steel (4-5); the rubber rod (4-1) is embedded in the middle of the splice joint, the filler (4-3) fills the splice joint and wraps the rubber rod (4-1), and the bolt (4-4) passes through the flat steel (4-5) to fix the composite board (4-2) to the panel surface on both sides of the splice joint.

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