A broken-line face rockfill dam with arc transition and its construction method

Abstract

The present invention provides a zigzag-line panel rockfill dam with circular arc transition and a construction method thereof. The panel rockfill dam is arranged in a river valley composed of a bottom riverbed and mountains on both sides. The axis of the panel rockfill dam is arranged in a zigzag shape convex to the downstream. The turning part of the dam axis is located in the area of ​​the bottom riverbed. The turning part of the dam axis adopts a circular arc-shaped uniform transition. The panel rockfill dam includes multiple panels facing the upstream direction, and the multiple panels are spliced ​​in sequence. The panels at the turning part of the dam axis are arranged in a fan shape. The present invention has the advantages of improving the stress state of the panel and simplifying the water-stopping structure.

Description

Technical Field

[0001] The invention relates to the field of panel rockfill dam engineering, and in particular to a zigzag-line panel rockfill dam with circular arc transition and a construction method thereof. Background Art

[0002] At present, some reservoir projects have adopted panel rockfill dams with the dam axis arranged as a broken line due to geological reasons or storage capacity requirements. The existing panel rockfill dams have two turning arrangements: 1. For example, the Chinese utility model patent with application number 2019210979933 sets a connecting plate at the turning point to connect the panels on both sides of the panel rockfill dam with a broken line arrangement. 2. For the relatively low dam height, the panel rockfill dam with a broken line arrangement adopts a layout in which the panels on both sides are directly connected. However, no matter which scheme is adopted, there are the following problems: there are too many water stop joints, which is not conducive to anti-seepage; the tensile stress is concentrated at the turning point, and the turning angle is limited; there is a contradiction between the panel structure at the corner and the turning point, that is, the corner is small and the tensile stress concentration is small, but there are sharp corners in the panel at the turning point, and the panel is easily damaged locally. Summary of the invention

[0003] In view of the shortcomings of the prior art, the first object of the present invention is to provide a curved transition zigzag face rockfill dam and a construction method thereof. The present invention has the advantages of improving the stress state of the face plate and simplifying the water-stop structure.

[0004] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0005] A zigzag-line face-rockfill dam with circular arc transition, characterized in that: the face-rockfill dam is arranged in a river valley composed of the bottom riverbed and the mountains on both sides, the axis of the face-rockfill dam is arranged in a zigzag shape convex to the downstream, the turning point of the dam axis is located in the area of ​​the bottom riverbed, and the turning point of the dam axis adopts a circular arc-shaped uniform transition; the face-rockfill dam includes multiple panels facing the upstream direction, the multiple panels are spliced ​​in sequence, and the panels at the turning point of the dam axis are arranged in a fan shape. In the drawings of this embodiment, as shown in the figure, the panel arranged in a fan shape is the first panel, and the remaining panels are the second panels.

[0006] Furthermore: the panel rockfill dam is provided with a high toe wall in a horizontal section on the bottom riverbed, and the panel at the turning point of the dam axis is connected to the high toe wall; the panel rockfill dam is provided with a toe plate structure on the mountains on both sides, and the lower part of the toe plate structure is connected to the end of the high toe wall, and the panel at the edge of the panel rockfill dam is connected to the toe plate structure of the mountains on both sides.

[0007] Furthermore: the top plane arc radius of the panel at the turning point of the dam axis is not greater than twice the plane arc radius of the high toe wall.

[0008] Furthermore: the toe plate structures of the mountains on both sides are connected to the wave-breaking wall at the top; and the multiple panels of the panel rockfill dam facing upstream are connected to the wave-breaking wall at the top.

[0009] Furthermore: a special cushion material area is set downstream of the peripheral seam where the toe plate structure and the panel are connected; a special cushion material area is set downstream of the peripheral seam where the high toe wall and the panel are connected.

[0010] Furthermore: the panel rockfill dam sequentially fills the cushion layer area, transition area and transition of the dam rockfill area from the high toe wall to the downstream direction, and sequentially wraps the special cushion layer area with the cushion layer area and transition area.

[0011] Furthermore: the toe plate structure adopts a structural form without structural joints, the high toe wall is provided with multiple structural joints at intervals, and the multiple structural joints of the high toe wall are arranged correspondingly to the connecting structural joints between the multiple panels.

[0012] Furthermore: the rock mass at the bottom of the toe plate and the high toe wall is reinforced and treated for seepage prevention by grouting.

[0013] The second object of the present invention is to provide a construction method for a curved-line face rockfill dam with circular arc transition, characterized in that the construction method comprises the following steps:

[0014] S1: Excavate the dam foundation according to the design requirements, and simultaneously strip the toe plate structure and high toe wall foundation cover layer and full weathering layer;

[0015] S2: Determine the control line and excavation elevation requirements of the toe plate structure and high toe wall, and excavate the foundation surface of the toe plate structure and high toe wall from top to bottom on both sides of the mountain;

[0016] S3: construct the high toe wall at the bottom of the riverbed, set structural joints at the high toe wall joints, set copper waterstops in the joints, embed copper waterstops in the structural joints between the mountains on both sides and the high toe wall, and embed copper waterstops at the bottom of the peripheral joints of the toe board structure close to the panel side to provide temporary protection;

[0017] S4: Construct the toe plate structure from bottom to top until the bottom of the dam crest wave-breaking wall, bury the copper sheet at the bottom of the peripheral seam to stop water, and make temporary protection;

[0018] S5: Construct the face rockfill dam body, including the special cushion material area, cushion area, transition area and dam rockfill area, to the bottom of the dam crest wave-breaking wall; during the construction of the face rockfill dam body, carry out the grouting treatment of the toe plate structure and the bottom foundation of the high toe wall;

[0019] S6: After the panel is constructed and the copper sheet at the bottom of the horizontal seam between the panel and the wave-breaking wall is buried on the top of the panel to stop water, the wave-breaking wall, the dam top transition material and the dam top pavement structure are constructed.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] The arc-shaped broken-line panel rockfill dam of the present invention protrudes toward the downstream at the riverbed, and can effectively increase the natural reservoir capacity and reduce the dam height for projects of building dams and reservoirs in valleys with poor natural reservoir capacity conditions.

[0022] The present invention utilizes the turning of the dam axis on both sides of the arc transition to eliminate the problem of tensile stress concentration at the turning part of the dam body; it is simplified to a vertical seam structure between panels, effectively reducing the length of the seam and the number of water stop joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the plan layout diagram of the dam body of the present invention.

[0024] Figure 2 It is a typical structural diagram of the mountain parts on both sides of the bank of the present invention.

[0025] Figure 3 It is a typical structural diagram of the riverbed part of the present invention.

[0026] Figure numbers: 1-mountains on both sides; 2-bottom riverbed; 3-panel rockfill dam; 4-dam axis; 5-toe plate structure; 6-high toe wall; 7-panels of equal width on both sides; 8-arc segment trapezoidal panel; 9-wave-breaking wall; 10-special cushion material area; 11-cushion area; 12-transition area; 13-dam rockfill area; 14-dam top pass and dam top pavement structure; 15-grouting. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be understood as limiting the present invention. In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationship described in the drawings is only for illustrative purposes and cannot be understood as limiting the present invention.

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0029] like Figures 1 to 3As shown, a zigzag panel rockfill dam with circular arc transition, the panel rockfill dam 3 is arranged in a river valley composed of the bottom riverbed 2 and the mountains 1 on both sides, the dam axis 4 of the panel rockfill dam 3 is arranged in a zigzag shape convex to the downstream, the turning part of the dam axis 4 is located in the area of ​​the bottom riverbed 2, and the turning part of the dam axis 4 adopts a circular arc uniform transition; the panel rockfill dam 3 includes a plurality of panels facing the upstream direction, and the plurality of panels are spliced ​​in sequence, and the panels at the turning part of the dam axis 4 are arranged in a fan shape. In the drawings of this embodiment, as shown in the figure, the panels arranged in a fan shape are circular arc segment fan-shaped panels 8, and the remaining panels are equal-width panels 7 on both sides. The equal-width panels 7 on both sides and the circular arc segment fan-shaped panels 8 of the panel rockfill dam 3 are made of concrete materials for anti-seepage, and a vertical seam is set every 6 to 18 meters on the panels of the panel rockfill dam 3.

[0030] The panel rockfill dam 3 is provided with a high toe wall 6 of a horizontal section on the bottom riverbed 2, and the panel at the turning point of the dam axis 4 is connected to the high toe wall; the panel rockfill dam 3 is provided with a toe plate structure 5 on the mountains 1 on both sides, and the lower part of the toe plate structure 5 is connected to the end of the high toe wall 6, and the panel at the edge of the panel rockfill dam 3 is connected to the toe plate structure 5 of the mountains 1 on both sides.

[0031] The function of the high toe wall 6 is to increase the range of the horizontal section of the riverbed in the turning area. On the one hand, it can provide more space for the turning angle; on the other hand, when the turning angle is the same, it can reduce the difference between the top arc and the bottom arc of the arc segment fan-shaped panel 8, increase the width of the bottom of the arc segment fan-shaped panel 8, and avoid the appearance of a panel structure that is unfavorable to the resistance of the arc segment fan-shaped panel 8.

[0032] The top plane arc radius of the panel at the turning point of the dam axis 4 is not greater than twice the plane arc radius of the high toe wall 6.

[0033] The toe plate structures 5 of the mountains 1 on both sides are connected to the wave-breaking wall 9 at the top; the multiple panels facing the upstream direction of the face rockfill dam 3 are connected to the wave-breaking wall 9 at the top. The wave-breaking wall 9 is provided with a structural seam every 6 to 18 meters, and the structural seam of the wave-breaking wall 9 and the vertical seams of the equal-width panels 7 and the arc-section fan-shaped panels 8 on both sides are arranged at the same pile number.

[0034] A special cushion material area 10 is set downstream of the peripheral joint between the toe plate structure 5 and the panel; a special cushion material area 10 is set downstream of the peripheral joint between the high toe wall 6 and the panel. The special cushion material is a well-graded gravel with a maximum particle diameter of less than 40 mm. The specific requirements are: the content of particles less than 20 mm should be 90% to 100%, the content of particles less than 5 mm should be 45% to 90%, and the content of particles less than 0.075 mm should be 2% to 8%, with continuous grading. The permeability coefficient is 1×10 -3 cm / s~1×10 -4 cm / s. Thin layer filling, layer thickness 20cm.

[0035] The face rockfill dam 3 is constructed from the high toe wall 6 to the downstream direction, with the cushion area 11, transition area 12 and dam rockfill area 13 being filled in sequence, and the special cushion area 10 is sequentially wrapped with the cushion area 11 and transition area 12. The dam rockfill area 13 generally uses the main rockfill upstream, and the secondary rockfill area with relatively poor material quality is used downstream above the normal water level.

[0036] The toe plate structure 5 adopts a structural form without structural joints, and the high toe wall 6 is provided with multiple structural joints at intervals, and the high toe wall 6 is provided with a structural joint every 12m, and the multiple structural joints of the high toe wall 6 are arranged corresponding to the connecting structural joints between multiple panels.

[0037] The rock mass at the bottom of the toe plate 5 and the high toe wall 6 is reinforced and anti-seepage treated by grouting 15 .

[0038] The present invention also provides a construction method for a curved-arc transitional zigzag face rockfill dam, the construction method comprising the following steps:

[0039] S1: Excavate the dam foundation according to the design requirements, and simultaneously strip the base covering layer and the whole weathering layer of the toe plate structure 5 and the high toe wall 6; after stripping the base covering layer and the whole weathering layer of the toe plate structure 5 and the high toe wall 6, check and compare the terrain line after excavation with the design data to determine whether to adjust the toe plate control line;

[0040] S2: Determine the control line and excavation elevation requirements of the toe plate structure 5 and the high toe wall 6, and excavate the foundation surface of the toe plate structure 5 and the high toe wall 6 from top to bottom on the mountain 1 on both sides;

[0041] S3: construct the high toe wall 6 at the bottom riverbed 2, set structural joints at the joints of the high toe wall 6, set copper sheet waterproofing in the joints, embed copper sheet waterproofing at the structural joints of the mountain 1 on both sides and the high toe wall 6, and embed copper waterproofing at the bottom of the peripheral joints of the toe plate structure 5 near the panel side to provide temporary protection;

[0042] S4: construct the toe plate structure 5 from bottom to top until the bottom of the dam top wave-breaking wall 9, bury the copper sheet at the bottom of the peripheral seam to stop water, and make temporary protection;

[0043] S5: Construct the dam body of the face rockfill dam 3, including the special cushion material area 10, cushion area 11, transition area 12 and dam rockfill area 13, to the bottom of the dam crest wave-breaking wall 9; during the construction of the face rockfill dam 3, carry out the foundation grouting 15 of the toe plate structure 5 and the bottom of the high toe wall 6; during the filling process, carry out slope repair and slope consolidation treatment on the upstream surface at a certain height interval;

[0044] S6: Use sliding film technology to construct equal-width panels 7 and arc-section fan-shaped panels 8 on both sides, and bury copper sheets at the bottom of the horizontal seams between the panels and the wave-breaking wall on the top of the equal-width panels 7 and the arc-section fan-shaped panels 8 on both sides to stop water, and then construct the wave-breaking wall 9, dam top transition material and dam top pavement structure 14.

[0045] As a general requirement, the structural joints between the panel and the high toe wall 6 and the toe plate structure 5 of the said arc transition zigzag panel rockfill dam adopt the peripheral joint structure, and the surface plastic filler and the bottom copper sheet are used for water stopping; a horizontal joint is set between the panel and the wave-breaking wall 9, and the surface plastic filler and the bottom copper sheet are used for water stopping; the vertical joints between the panels adopt the vertical joint structure (generally tension joints, with a small number of compression joints in some places), and the surface plastic filler and the bottom copper sheet are used for water stopping; A middle copper sheet waterstop is set at the structural joint of the wave-breaking wall 9; a surface plastic filler waterstop and a middle copper sheet waterstop are set at the structural joint of the high toe wall 6; a surface plastic filler waterstop and a middle copper sheet waterstop are set at the structural joint between the toe board structure 5 and the high toe wall 6; the copper sheet waterstop between the wave-breaking wall-panel and the panel-high toe wall (toe board structure) adopts a "T"-shaped copper sheet waterstop joint. When the vertical seam of the panel coincides with the structural seam of the wave-breaking wall and the structural seam of the high toe wall (toe board structure), a "cross"-shaped copper sheet waterstop joint is adopted.

[0046] For the face rockfill dam, the face plate is laid on the upstream slope of the dam. After the water load acts, two forces will be generated, one is the horizontal thrust and the other is the vertical pressure. For the face rockfill dam with a convex downstream fold line, due to the horizontal thrust at the turning point, the two adjacent dam sections are subjected to different forces, resulting in a displacement trend that deviates from each other, thereby generating a tensile trend at the turning point. The larger the turning angle, the more obvious this tensile trend is. However, under the action of vertical pressure, the dam will further settle, resulting in horizontal compression stress in the middle of the face plate and tensile stress on both sides. Whether it is the pulling-up trend generated by the horizontal force or the pulling-up and compression trend generated by the vertical pressure, there will be a sudden change problem at the turning point, resulting in a complex stress state of the face plate at the turning point. In addition, the face plates of the dam sections on both sides of the corner need to be connected by connecting plates. There will be a sharp corner area near the connecting plate at the connection point, and the operating conditions of the face plate are poor. Therefore, for the face rockfill dam at the turning point, the selection of the turning point and the setting of the turning angle are key technical issues. The use of arc-shaped transition can even out the impact of the above-mentioned forces, and the panel does not have the problem of sharp corners. The stress state and operating conditions of the panel are significantly improved.

[0047] In terms of panel structural seams and water stop design, there are not only two peripheral seams of the same length as the connecting plates between the panels and the connecting plates on both sides of the fold line, but also many T-joints where the vertical seams of the panels are butted against the peripheral seams, making the anti-seepage structure design complicated. However, after adopting the arc-shaped transition, the panels with a wide top and a narrow bottom eliminate this multi-seam butt joint situation, and the structural seams will be greatly simplified, which is conducive to anti-seepage safety.

[0048] According to the description and drawings of the present invention, those skilled in the art can easily manufacture or use the arc-transition broken-line panel rockfill dam and the construction method thereof of the present invention, and can produce the positive effects described in the present invention.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A zigzag face rockfill dam with arc transition. Features: The panel rockfill dam is arranged in a river valley formed by a bottom riverbed (2) and mountains (1) on both sides of the river. The axis (4) of the panel rockfill dam is arranged in a broken line shape convex to the downstream. The turning point of the dam axis (4) is located in the area of ​​the bottom riverbed (2). The turning point of the dam axis (4) adopts an arc-shaped uniform transition. The panel rockfill dam includes a plurality of panels facing the upstream direction. The plurality of panels are spliced ​​in sequence. The panels at the turning point of the dam axis (4) are arranged in a fan shape. A vertical seam is arranged on the panels of the panel rockfill dam every 6 to 18 meters.

2. A curved-arc transitional zigzag face rockfill dam according to claim 1, Features: The panel rockfill dam is provided with a horizontal section of a high toe wall (6) on the bottom riverbed (2), and the panel at the turning point of the dam axis (4) is connected to the high toe wall; the panel rockfill dam is provided with a toe plate structure (5) on the mountains (1) on both sides, the lower part of the toe plate structure (5) is connected to the end of the high toe wall (6), and the panel at the edge of the panel rockfill dam is connected to the toe plate structure (5) of the mountains (1) on both sides.

3. A curved-arc transitional zigzag face rockfill dam according to claim 2, Features: The top plane arc radius of the panel at the turning point of the dam axis (4) is no greater than twice the plane arc radius of the high toe wall (6).

4. The curved-arc transition zigzag face rockfill dam according to claim 2, Features: The toe plate structures (5) of the mountains (1) on both sides are connected to the wave-breaking wall (9) at the top; and the multiple panels of the face-plate rockfill dam facing the upstream direction are connected to the wave-breaking wall (9) at the top.

5. The curved-arc transition zigzag face rockfill dam according to claim 2, Features: A cushion material area (10) is arranged downstream of the peripheral seam connecting the toe plate structure (5) and the panel; and a cushion material area (10) is arranged downstream of the peripheral seam connecting the high toe wall (6) and the panel.

6. A curved-arc transitional zigzag face rockfill dam according to claim 5, Features: The face rockfill dam is constructed by sequentially filling a cushion layer area (11), a transition area (12) and a dam rockfill area (13) from a high toe wall (6) toward the downstream, and the cushion layer area (11) and the transition area (12) are used to sequentially wrap the cushion layer material area (10).

7. The curved-arc transition zigzag face rockfill dam according to claim 2, Features: The toe plate structure (5) adopts a structural form without structural joints, the high toe wall (6) is provided with multiple structural joints at intervals, and the multiple structural joints of the high toe wall (6) are arranged correspondingly to the connecting structural joints between the multiple panels.

8. The curved-arc transition zigzag face rockfill dam according to claim 2, Features: The rock mass at the bottom of the toe plate structure (5) and the high toe wall (6) is reinforced and treated for seepage prevention by grouting (15).

9. A construction method for a curved-line face rockfill dam with circular arc transition. It is characterized in that The construction method comprises the following steps: S1: Excavate the dam foundation according to the design requirements, and simultaneously strip the foundation cover layer and the weathered layer of the toe plate structure (5) and the high toe wall (6); S2: Determine the control line and excavation elevation requirements of the toe plate structure (5) and the high toe wall (6), and excavate the foundation surface of the toe plate structure (5) and the high toe wall (6) from top to bottom on both sides of the mountain (1); S3: construct the high toe wall (6) at the bottom riverbed (2), set structural joints at the joints of the high toe wall (6), set copper sheet waterproofing in the joints, embed copper sheet waterproofing in the structural joints between the mountain (1) on both sides and the high toe wall (6), and embed copper waterproofing at the bottom of the peripheral joint of the toe plate structure (5) close to the panel side to provide temporary protection; S4: construct the toe plate structure (5) from bottom to top until the bottom of the dam top wave-breaking wall (9), bury the copper sheet at the bottom of the peripheral seam to stop water, and make temporary protection; S5: Constructing the face rockfill dam body, including the cushion material area (10), cushion area (11), transition area (12) and dam rockfill area (13), to the bottom of the dam crest wave-breaking wall (9); during the construction of the face rockfill dam body, simultaneously carrying out the foundation grouting (15) treatment of the toe plate structure (5) and the bottom of the high toe wall (6); S6: Panel construction is performed. The axis line (4) of the panel rockfill dam is arranged in a zigzag shape convex to the downstream. The turning point of the dam axis line (4) is located in the area of ​​the bottom riverbed (2). The turning point of the dam axis line (4) adopts an arc-shaped uniform transition. The panel at the turning point of the dam axis line (4) is arranged in a fan shape, and after the copper sheet water stop at the bottom of the horizontal seam between the panel and the wave-breaking wall is buried on the top of the panel, the wave-breaking wall (9), the dam top transition material and the dam top pavement structure (14) are constructed.

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