A protection structure of an earthwork membrane for a rockfill dam face
By using a permeable concrete cushion layer and concrete cover plate on the rockfill dam face, combined with a diversion grid partition structure, the problems of low construction efficiency and high leakage risk were solved, achieving a highly efficient and stable seepage prevention effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NAT ENERGY ADMINISTRATION DAM SAFETY SUPERVISION CENT
- Filing Date
- 2025-08-29
- Publication Date
- 2026-07-28
AI Technical Summary
The existing geomembrane for rockfill dams has low construction efficiency, is difficult to hoist, is easily damaged, misaligned, and its permeable path is prone to water accumulation, resulting in a high risk of leakage and increased operation and maintenance costs.
A permeable concrete cushion layer is used as the lower protective layer of the geomembrane. The concrete cover plate is composed of regular polygonal blocks, with closed-cell foam boards filling the gaps. Drainage is guided by a drainage grid partition structure. The concrete cover plate is formed by spraying from bottom to top, and the connection stability is improved by the interlocking structure.
It improves construction efficiency, reduces the risk of geomembrane being broken or misaligned, enhances permeability, reduces leakage risk, and lowers operation and maintenance costs.
Smart Images
Figure CN224565149U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of water conservancy and hydropower engineering technology, specifically to a geomembrane protection structure for seepage prevention on rockfill dam surfaces. Background Technology
[0002] Currently, the common practice for impermeable geomembranes on rockfill dam faces is to use precast concrete slabs as the upper protective layer and no-fines concrete as the lower cushion layer. This approach has systemic flaws. Firstly, each precast concrete slab is heavy (typically exceeding 200 kg), resulting in low hoisting efficiency and a high risk of swaying and falling during slope construction. Engineering statistics show that the risk of geomembrane rupture is over 15%. Secondly, the slabs are only connected by grout, making them prone to misalignment under dam deformation or trampling during maintenance. Repositioning after misalignment is difficult, increasing maintenance costs. Thirdly, the surface of the lower no-fines concrete protective layer is densely covered with loose stones and sharp rocks, posing a significant risk of directly puncturing the geomembrane. More seriously, its disordered permeability paths easily lead to localized water accumulation, forming water pressure bulges, and continuous jacking action causes fatigue damage to the geomembrane. Finally, the functional separation of the upper and lower protective layers prevents them from coordinating to cope with the combined stresses of construction and operation, resulting in leakage risks throughout the entire project lifecycle. Summary of the Invention
[0003] This application provides a geomembrane protection structure for rockfill dams, which makes operation and maintenance more convenient, improves construction efficiency on dam slopes, and reduces the risk of the geomembrane being damaged.
[0004] The geomembrane protection structure for the rockfill dam face provided in this application includes a cushion layer, a permeable concrete cushion layer, a geomembrane, and a concrete cover plate. The cushion layer is laid on the upstream side of the rockfill area of the rockfill dam. The permeable concrete cushion layer is poured on the surface of the cushion layer and serves as the lower protective layer of the geomembrane. The geomembrane is laid on the surface of the permeable concrete cushion layer. The concrete cover plate is formed on the surface of the geomembrane by spraying concrete from bottom to top. The concrete cover plate includes multiple regular polygonal blocks, with a preset gap between two adjacent regular polygonal blocks, and the gap is filled with closed-cell foam board.
[0005] In addition, the geomembrane protection structure for rockfill dam surfaces provided in this application also has the following additional technical features: In one alternative embodiment, the impermeable geomembrane protection structure of the rockfill dam surface further includes a flow-guiding grid partition structure. The flow-guiding grid partition structure is embedded in the permeable concrete cushion layer and is used to divide the permeable concrete cushion layer into multiple independent drainage units. The bottom of each drainage unit is connected to a drainage pipe with a slope of 2% to 5%. The top of the drainage pipe is at a predetermined distance from the laying surface of the geomembrane, and the bottom of the drainage pipe extends to the water collection system at the bottom of the rockfill dam.
[0006] In one optional embodiment, the drainage grid partition structure includes PVC partitions, the drainage pipe is a DN50 HDPE perforated pipe with an opening ratio ≥5%, and the preset distance between the top of the drainage pipe and the laying surface of the geomembrane is 50mm.
[0007] In one alternative, two adjacent regular polygonal blocks are connected by an embedded locking structure, which includes a first latch and a second latch. The two adjacent regular polygonal blocks are connected by the first latch and the second latch located on the side, forming an overall arched structure.
[0008] In one alternative, the aggregate used in the permeable concrete subbase is hard and clean artificial or natural aggregate; the plurality of regular polygonal blocks are arranged in a honeycomb pattern.
[0009] The beneficial effects of this application are as follows: The geomembrane protection structure for the rockfill dam face in this application uses a concrete cover plate formed by bottom-up concrete spraying as the upper protective layer for the geomembrane. This improves construction efficiency on the dam slope and reduces the risk of the geomembrane being punctured. Simultaneously, the honeycomb-like arrangement of regular polygonal blocks creates an arch effect, preventing large-scale misalignment of the cover plate during maintenance and facilitating operation and maintenance. Furthermore, using a permeable concrete cushion layer as the lower protective layer for the geomembrane, which combines permeability and density, directly contacts the geomembrane, further reducing the risk of punctures and bursts.
[0010] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the layout structure of the impermeable geomembrane protection structure for the rockfill dam face provided in this application; Figure 2 This is a schematic diagram of the layout structure of the concrete cover plate and the diversion grid partition structure.
[0012] Figure reference numerals: 1. Subbase layer; 2. Permeable concrete subbase layer; 3. Geomembrane; 4. Concrete cover plate; 41. Regular polygonal block; 42. Closed-cell foam board; 5. Rockfill area; 6. Diversion grid partition structure; 7. Locking structure; 71. First buckle; 72. Second buckle.
[0013] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation
[0014] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0015] It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other technical solutions obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0016] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0017] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0018] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.
[0019] like Figure 1-2 As shown in the embodiment of this application, a geomembrane protection structure for a rockfill dam surface is provided. The geomembrane protection structure for a rockfill dam surface mainly includes a cushion layer 1, a permeable concrete cushion layer 2, a geomembrane 3, and a concrete cover plate 4. The cushion layer 1 is laid on the upstream side of the rockfill area 5 of the rockfill dam. The permeable concrete cushion layer 2 is poured and set on the surface of the cushion layer 1 and serves as the lower protective layer of the geomembrane 3. The geomembrane 3 is laid on the surface of the permeable concrete cushion layer 2. The concrete cover plate 4 is formed on the surface of the geomembrane 3 by spraying concrete from bottom to top. The concrete cover plate 4 includes multiple regular polygonal blocks 41. There is a preset gap between two adjacent regular polygonal blocks 41, and the gap is filled with closed-cell foam board 42. The closed-cell foam board 42 can play a certain deformation buffering function.
[0020] Specifically, in this embodiment, the aggregate used in the permeable concrete cushion layer 2 is hard, durable, and clean artificial or natural aggregate; the permeable concrete strength grade, minimum thickness of the dam surface, porosity, permeability coefficient, and other parameters should meet the relevant engineering requirements. Furthermore, the multiple regular polygonal blocks 41 are arranged in a honeycomb pattern, creating an arch effect after the concrete cover 4 is laid, thus preventing displacement or misalignment during operation and maintenance. It should be noted that the specific dimensions of the regular polygonal blocks 41 can be adjusted appropriately based on the actual construction conditions and the crack development of the shotcrete after construction; therefore, this document does not impose specific limitations.
[0021] In this embodiment, the geomembrane protection structure for the rockfill dam face uses a concrete cover plate 4, formed by bottom-up concrete spraying, as the upper protective layer for the geomembrane 3. This improves construction efficiency on the dam slope and reduces the risk of the geomembrane 3 being punctured. Simultaneously, the honeycomb arrangement of the regular polygonal blocks 41 creates an arch effect, preventing large-scale misalignment of the cover plate during maintenance and facilitating operation and maintenance. Furthermore, a permeable concrete cushion layer 2 serves as the lower protective layer for the geomembrane 3. The permeable concrete balances permeability and density, and its direct contact with the geomembrane 3 reduces the risk of punctures and bursts.
[0022] like Figure 1-2 As shown, in one specific embodiment, the impermeable geomembrane protection structure of the rockfill dam surface also includes a flow-guiding grid partition structure 6. The flow-guiding grid partition structure 6 is embedded in the permeable concrete cushion layer 2. The flow-guiding grid partition structure 6 is used to divide the permeable concrete cushion layer 2 into multiple independent drainage units. The bottom of the drainage unit is connected to a drainage pipe. The slope of the drainage pipe is 2% to 5%, and there is a preset distance between the top of the drainage pipe and the laying surface of the geomembrane 3. The bottom of the drainage pipe extends to the water collection system at the bottom of the rockfill dam.
[0023] In this embodiment, the flow-guiding grid partition structure 6 can guide the directional discharge of seepage water, thereby eliminating the risk of local water pressure rupturing the geomembrane 3 and extending the life of the seepage prevention system.
[0024] like Figure 1-2 As shown, in one specific embodiment, the diversion grid partition structure 6 includes a PVC partition, the drainage pipe is a DN50 HDPE perforated pipe, and the opening rate of the drainage pipe is ≥5%. The preset distance between the top of the drainage pipe and the laying surface of the geomembrane 3 is 50mm.
[0025] Preferably, the diversion grid partition structure 6 uses PVC partitions (20mm thick, height equal to the permeable concrete cushion layer 2), with dimensions of 5m×5m; the vertical drainage pipes are DN50 HDPE perforated pipes with an opening rate ≥5%, vertically pre-embedded in the center of each grid unit. The spacing of the vertical drainage pipes is consistent with the grid units (5m×5m), and the lower end connects to the water collection gallery at the bottom of the dam with a slope of ≥2%; before pouring the permeable concrete cushion layer 2, the PVC grid partitions are laid first, and then the drainage pipes are installed and fixed, with the top of the pipes 50mm lower than the laying surface of the geomembrane 3; the aggregate particle size of the permeable concrete cushion layer 2 is 5~10mm, the porosity is 18±2%, the permeability coefficient is ≥0.1cm / s, and it is poured and vibrated in layers to a design thickness of 200mm.
[0026] like Figure 1 As shown, in one specific embodiment, two adjacent regular polygonal blocks 41 are connected by an embedded locking structure 7. The locking structure 7 includes a first buckle 71 and a second buckle 72. The two adjacent regular polygonal blocks 41 are connected by the first buckle 71 and the second buckle 72 set on the side to form an overall arched structure.
[0027] Specifically, the locking structure 7 can be made of HDPE material, with a length equal to the side of the regular polygonal block 41 (for a standard block size of 1.5m × 1.5m regular hexagon, the length of a single side is 1.5m), and the exposed part is flush with the concrete surface. Before spraying concrete, the locking structure 7 is fixed to the side of the template with bolts; after the concrete is sprayed and formed, the template is removed, and the locking structure 7 is embedded into the side of the regular polygonal block 41; when installing adjacent regular polygonal blocks 41, a robotic arm is used to engage the locking structures 7, and the gap after engagement is ≤2mm; after the locking structures 7 are engaged, closed-cell foam board 42 with a thickness of 40mm and a compression rate ≥30% is filled into the seam of the regular polygonal block 41.
[0028] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A geomembrane protection structure for seepage prevention on the face of a rockfill dam, characterized in that, The structure includes a subbase, a permeable concrete subbase, a geomembrane, and a concrete cover. The subbase is laid on the upstream side of the rockfill area of the rockfill dam. The permeable concrete subbase is poured onto the surface of the subbase and serves as the lower protective layer for the geomembrane. The geomembrane is laid on the surface of the permeable concrete subbase. The concrete cover is formed on the surface of the geomembrane by spraying concrete from bottom to top. The concrete cover includes multiple regular polygonal blocks, with a preset gap between two adjacent regular polygonal blocks, and the gaps are filled with closed-cell foam boards.
2. The geomembrane protection structure for seepage prevention on the face of a rockfill dam according to claim 1, characterized in that, It also includes a flow-guiding grid partition structure, which is embedded in the permeable concrete cushion layer. The flow-guiding grid partition structure is used to divide the permeable concrete cushion layer into multiple independent drainage units. The bottom of each drainage unit is connected to a drainage pipe. The slope of the drainage pipe is 2% to 5%, and there is a preset distance between the top of the drainage pipe and the laying surface of the geomembrane. The bottom of the drainage pipe extends to the water collection system at the bottom of the rockfill dam.
3. The geomembrane protection structure for the rockfill dam face according to claim 2, characterized in that, The drainage grid partition structure includes PVC partitions, the drainage pipe is a DN50 HDPE perforated pipe, and the opening rate of the drainage pipe is ≥5%. The preset distance between the top of the drainage pipe and the laying surface of the geomembrane is 50mm.
4. The geomembrane protection structure for the face of a rockfill dam according to any one of claims 1-3, characterized in that, The two adjacent regular polygonal blocks are connected by an embedded locking structure, which includes a first buckle and a second buckle. The two adjacent regular polygonal blocks are connected by the first buckle and the second buckle, which are set on the side, and form an overall arched structure.
5. The geomembrane protection structure for the face of a rockfill dam according to any one of claims 1-3, characterized in that, The aggregate used in the permeable concrete subbase is hard and clean artificial or natural aggregate; the multiple regular polygonal blocks are arranged in a honeycomb pattern.