Dam crest structure with plastic concrete diaphragm wall
By using trapezoidal two-stage anti-seepage walls and geogrids in the earth-rock dam in a segmented manner, the problems of uneven settlement and cracks in the dam crest structure were solved, achieving a stable anti-seepage effect and traffic capacity at the dam crest.
Patent Information
- Application Number
- CN202520447236.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-03-14
AI Technical Summary
During the construction of earth-rock dams, after the plastic concrete cutoff wall is poured, the uneven strength of the dam crest structure leads to uneven bonding between soft and hard materials, resulting in cracks that affect traffic and project safety.
The trapezoidal structure of the second-stage cutoff wall and different types of geogrids are laid in sections on the dam crest. Combined with the removal of the guide wall and the pouring of the second-stage cutoff wall, a stable dam crest structure is formed, eliminating settlement and cracking problems caused by inconsistent strength.
This improved the seepage prevention effect, ensured the quality of the project, and guaranteed the traffic capacity and safety of the dam crest.
Smart Images
Figure CN223893329U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of earth-rock dam construction technology, and in particular to a dam crest structure with a plastic concrete anti-seepage wall. Background Technology
[0002] In the reinforcement and strengthening of earth-rock dams, concrete cutoff walls are typically used to address seepage and stability issues in the dam body and foundation. Based on materials, concrete cutoff walls can be classified into plastic concrete and reinforced concrete. Plastic concrete cutoff walls have a certain degree of flexibility, lower strength, and better bonding with the dam soil, making them more commonly used in seepage control for earth dams. To ensure the borehole inclination and construction quality, guide walls are usually installed on both sides of the cutoff wall before pouring the plastic concrete. Typically, the guide walls are about 1m deep and 0.5m wide, using normal concrete structures with a strength generally not less than C20. However, the strength of plastic concrete cutoff walls is generally not greater than 5MPa. Therefore, after the cutoff wall is poured, uneven bonding between the soft and hard surfaces of the dam crest structure can occur, leading to cracks in the road surface above the dam crest, affecting traffic and project safety. Summary of the Invention
[0003] To address the aforementioned problems, this utility model provides a dam crest structure with a plastic concrete anti-seepage wall that is resistant to settlement and cracking. Specifically, the following technical solution can be adopted:
[0004] The dam crest structure with a plastic concrete cutoff wall of this utility model includes a dam body. A wave-breaking wall is installed on the water-facing side of the dam body's crest, and a retaining wall is installed on the water-repellent side of the dam body's crest. A primary cutoff wall is installed within the dam body. The top of the primary cutoff wall is a trapezoidal structure with gradually decreasing spacing on both sides. A secondary cutoff wall is installed above the primary cutoff wall. The top surface of the secondary cutoff wall is at the same height as the top surface of the dam body, and the bottom surface of the secondary cutoff wall is the same as the bottom surface of the trapezoidal structure of the primary cutoff wall. The two-stage cutoff wall is set at the same height, and its width is equal to the sum of the widths of the first-stage cutoff wall and the original guide wall. A type A geogrid is installed above the second-stage cutoff wall, a type B geogrid is installed on the top surface of the dam soil, and a type C geogrid is installed at the junction of the second-stage cutoff wall and the top surface of the dam soil. The heights of the type A, type B, and type C geogrids are equal, and the subgrade and surface layer are set above the type A, type B, and type C geogrids.
[0005] The first-stage anti-seepage wall is set near the upstream side of the dam body, and the first-stage anti-seepage wall is a plastic concrete wall with a thickness of 0.4~0.8m.
[0006] The original guide walls are symmetrically arranged on both sides of the top of the first-phase seepage barrier wall, and the width of each original guide wall is 0.55~0.65m and the depth is 1m.
[0007] The second-phase seepage barrier wall is constructed from plastic concrete with a compressive strength of 1.5~2.5MPa.
[0008] The aperture size of the type A geogrid is 25×25mm, the aperture size of the type B geogrid is 50×50mm, and the aperture size of the type C geogrid is 20×20mm.
[0009] Both the roadbed and the surface layer are sloped downwards at a 2% gradient along the direction of water flow.
[0010] The surface layer comprises, from bottom to top, a 120mm thick 5% cement-stabilized crushed stone layer, a 6mm thick emulsified asphalt seal layer, a 50mm thick AC-16 dense-graded asphalt concrete mixture layer, and a 30mm thick AC-13 dense-graded asphalt concrete mixture layer.
[0011] The dam crest structure with plastic concrete anti-seepage wall provided by this utility model is easy to construct and structurally stable. By removing the guide wall and pouring the second-stage anti-seepage wall, and by laying different types of geogrids in sections on the dam crest, the uneven settlement of the dam crest and cracking of the dam crest road surface caused by inconsistent concrete strength in the dam body are eliminated. This improves the anti-seepage effect of the anti-seepage wall, ensures the quality of the project, and at the same time ensures the normal passage of personnel and vehicles on the dam crest. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of this utility model.
[0013] Figure 2 yes Figure 1 Schematic diagram of the laying of the grid layer on the top of the dam.
[0014] Figure 3 yes Figure 2 Enlarged view of part A in the image.
[0015] Figure 4 yes Figure 3 BB cross-section diagram.
[0016] Figure 5 This is a structural schematic diagram of the present invention before the second-stage anti-seepage wall is poured. Detailed Implementation
[0017] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific construction processes. However, the protection scope of this utility model is not limited to the following embodiments.
[0018] like Figure 1-5As shown, the dam crest structure with a plastic concrete cutoff wall according to this utility model includes a dam body 1. A wave wall 2 is provided on the water-facing side of the top of the dam body 1, and a retaining wall 3 is provided on the water-repellent side of the top of the dam body 1. A primary cutoff wall 4, which is a plastic concrete wall with a thickness of 0.4~0.8m, is provided inside the dam body 1 near the upstream side. The top of the primary cutoff wall 4 is a trapezoidal structure with the distance between the two sides gradually decreasing, and a secondary cutoff wall 5 is provided on top of it. The secondary cutoff wall 5 is cast from plastic concrete with a compressive strength of 1.5~2.5MPa. Its top surface is set at the same height as the top surface of the dam body 1, and its bottom surface is set at the same height as the bottom surface of the trapezoidal structure of the primary cutoff wall 4. Its width is equal to the sum of the widths of the primary cutoff wall 4 and the original guide wall 6. The original guide wall 6 is symmetrically arranged on both sides of the top of the primary cutoff wall 4. The width of the original guide wall 6 on each side is 0.55~0.65m, and the depth is 1m. Type A geogrid 7 is laid above the second-phase seepage barrier 5, Type B geogrid 8 is laid on the top surface of the soil of dam body 1, and Type C geogrid 9 is laid at the junction of the second-phase seepage barrier 5 and the top surface of the soil of dam body 1. Subgrade 10 and surface layer 11 are constructed on top of Type A geogrid 7, Type B geogrid 8, and Type C geogrid 9. The heights of the aforementioned Type A geogrid 7, Type B geogrid 8, and Type C geogrid 9 are equal, and each is constructed by passing 1.5mm diameter steel wire 71 through and fixing it to 3×3mm geogrid strips 72. The aperture size of Type A geogrid 7 is 25×25mm, that of Type B geogrid 8 is 50×50mm, and that of Type C geogrid 9 is 20×20mm. Furthermore, both the subgrade 10 and surface layer 11 are sloped downwards at a 2% gradient along the water flow direction. In this embodiment, the surface layer 11 includes, from bottom to top, a 120mm thick 5% cement-stabilized crushed stone layer, a 6mm thick emulsified asphalt seal layer, a 50mm thick AC-16 dense-graded asphalt concrete mixture layer, and a 30mm thick AC-13 dense-graded asphalt concrete mixture layer.
[0019] During construction, the top of the first-stage cutoff wall 4 is first shaped into a trapezoidal structure, then the original guide wall 6 is demolished, followed by the pouring of the second-stage cutoff wall 5, and finally the laying of geogrid, roadbed 10, and surface layer 11. Because the outer side of the original guide wall 6 is a soil formwork, it is tightly bonded to the dam soil and therefore difficult to remove. This embodiment uses the following method to remove the original guide wall 6: First, a road grooving machine is used to cut grooves (15cm wide) along the outer sides of the left and right guide walls 6, separating their sides from the dam soil. Then, a pneumatic pick and gas cutting equipment are used to cut its bottom, and an excavator bucket is used to grip the top of the guide wall 6, pushing it towards the first-stage cutoff wall 4 in the middle. The guide wall 6 tilts along the trapezoidal structure at the top of the first-stage cutoff wall 4, separating it from the dam soil. It is then lifted out by a crane, and the second-stage cutoff wall 5 is poured into the aforementioned groove. This method of removing the guide wall and pouring the cutoff wall effectively avoids any adverse effects on the dam's seepage prevention performance. Furthermore, by laying different types of geogrids in sections on the dam crest, the uneven settlement of the dam crest and cracking of the dam crest road surface caused by inconsistent strength of the concrete structure inside the dam were eliminated, thus improving the seepage prevention effect of the anti-seepage wall, ensuring the quality of the project, and at the same time ensuring the normal passage of personnel and vehicles on the dam crest.
[0020] It should be noted that in the description of this utility model, terms such as "front", "rear", "left", "right", "vertical", "horizontal", "inner", and "outer" indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
Claims
1. A dam crest structure with a plastic concrete seepage barrier, characterized in that: The dam body includes a wave-breaking wall on the water-facing side of its top and a retaining wall on the water-repellent side. A primary seepage barrier wall is installed within the dam body. The top of the primary seepage barrier wall is a trapezoidal structure with gradually decreasing spacing on both sides. A secondary seepage barrier wall is installed above the primary seepage barrier wall. The top surface of the secondary seepage barrier wall is at the same height as the top surface of the dam body, and the bottom surface of the secondary seepage barrier wall is at the same height as the bottom surface of the trapezoidal structure of the primary seepage barrier wall. The width of the secondary seepage barrier wall is equal to the sum of the widths of the primary seepage barrier wall and the original guide wall. A type A geogrid is installed above the secondary seepage barrier wall, a type B geogrid is installed on the top surface of the dam body soil, and a type C geogrid is installed at the junction of the secondary seepage barrier wall and the top surface of the dam body soil. The heights of the type A, type B, and type C geogrids are equal, and a roadbed and surface layer are installed above the type A, type B, and type C geogrids.
2. The dam crest structure with a plastic concrete seepage barrier as described in claim 1, characterized in that: The first-stage anti-seepage wall is set near the upstream side of the dam body, and the first-stage anti-seepage wall is a plastic concrete wall with a thickness of 0.4~0.8m.
3. The dam crest structure with a plastic concrete seepage barrier as described in claim 1, characterized in that: The original guide walls are symmetrically arranged on both sides of the top of the first-phase seepage barrier wall, and the width of each original guide wall is 0.55~0.65m and the depth is 1m.
4. The dam crest structure with a plastic concrete seepage barrier according to claim 1, characterized in that: The second-phase seepage barrier wall is constructed from plastic concrete with a compressive strength of 1.5~2.5MPa.
5. The dam crest structure with a plastic concrete seepage barrier according to claim 1, characterized in that: The aperture size of the type A geogrid is 25×25mm, the aperture size of the type B geogrid is 50×50mm, and the aperture size of the type C geogrid is 20×20mm.
6. The dam crest structure with a plastic concrete seepage barrier according to claim 1, characterized in that: Both the roadbed and the surface layer are sloped downwards at a 2% gradient along the direction of water flow.
7. The dam crest structure with a plastic concrete seepage barrier according to claim 1, characterized in that: The surface layer comprises, from bottom to top, a 120mm thick 5% cement-stabilized crushed stone layer, a 6mm thick emulsified asphalt seal layer, a 50mm thick AC-16 dense-graded asphalt concrete mixture layer, and a 30mm thick AC-13 dense-graded asphalt concrete mixture layer.