Repair structure for scouring defects of geomembrane foundation

Abstract

The utility model relates to a geomembrane foundation scouring defect repairing structure, a geomembrane foundation comprises a transition layer or a foundation layer, a lower cushion layer, a three-dimensional composite drainage network and a geomembrane which are laid in sequence, the repairing structure is used for repairing scouring pits formed by water flow scouring of the geomembrane foundation, and the repairing structure comprises an opening part, a backfilling layer and a reinforced geomembrane; the opening part is formed by cutting and opening the three-dimensional composite drainage net and the geomembrane, the opening part is located above the scouring pit, and the opening part can open and close the three-dimensional composite drainage net and the geomembrane above the scouring pit; the backfill layer is arranged in the scouring pit, and geotechnical cloth is laid on the top of the backfill layer; the reinforcing geomembrane covers the upper portion of the opening part after the opening part is closed, the reinforcing geomembrane can completely cover a kerf of the opening part, and the reinforcing geomembrane and the geomembrane are connected through welding. The repairing structure can repair the pit defect of the geomembrane, so that the risk that the geomembrane is punctured and damaged is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of water conservancy and hydropower engineering, and in particular to a repair structure for scour defects in geomembrane foundations. Background Art

[0002] With the continuous development and progress of geosynthetics technology, geomembranes have become more and more adaptable to deformation and aging resistance, and more and more water conservancy and hydropower projects are using geomembranes for anti-seepage. Compared with asphalt concrete panels and reinforced concrete panels, geomembranes have great advantages in adaptability to deformation, construction convenience, and economy. Many pumped storage power stations in China have adopted geomembranes for anti-seepage, especially for projects with high slag fill at the bottom of the reservoir, where it is difficult for other anti-seepage types to adapt to deformation. The use of geomembranes is more suitable for the characteristics of the project. In addition, there are also many projects that use geomembranes for the entire reservoir basin, and geomembranes for anti-seepage on the slopes of dams or inlets and outlets.

[0003] When geomembranes are used for anti-seepage on sloped surfaces such as reservoir banks or water inlets and outlets, according to the on-site construction procedures, the upper end of the geomembrane is usually sealed and anchored after the geomembrane is laid and welded on the slope surface. During the construction process, due to improper geomembrane protection or sudden rainfall, the upper end of the geomembrane is not sealed in time, and water flows into the lower part of the geomembrane, causing the sub-base layer at the bottom of the geomembrane to be scoured and the fine particles of the sub-base material to be carried away, forming scour pit defects. If the pit defects in the sub-base layer of the geomembrane are not treated, when the reservoir is filled with water, the geomembrane will be subjected to water pressure, and the uneven foundation and large-sized sharp rocks will bring puncture damage risks to the geomembrane, affecting the safe operation of the project. Utility Model Content

[0004] The present application provides a repair structure for scour defects in geomembrane foundations, which can repair pit defects in geomembrane, thereby reducing the risk of puncture and damage to the geomembrane.

[0005] The present application provides a repair structure for scour defects in a geomembrane foundation, wherein the geomembrane foundation includes a transition layer or a base layer, a sub-base, a three-dimensional composite drainage network, and a geomembrane laid in sequence. The repair structure is used to repair scour pits formed in the geomembrane foundation due to water scour. The repair structure includes:

[0006] An opening portion is formed by cutting openings in the three-dimensional composite drainage net and the geomembrane, the opening portion is located above the scouring pit, and the opening portion can open and close the three-dimensional composite drainage net and the geomembrane above the scouring pit;

[0007] A backfill layer is provided in the scouring pit, and a geotextile is laid on top of the backfill layer;

[0008] A reinforced geomembrane is provided to cover the top of the opening after the opening is closed, and the reinforced geomembrane can completely cover the slit of the opening, and the reinforced geomembrane is connected to the geomembrane by welding.

[0009] In addition, the repair structure provided by this application may also have the following additional technical features:

[0010] In an optional scheme, the reinforced geomembrane includes a first reinforced geomembrane and a second reinforced geomembrane, the area of ​​the second reinforced geomembrane is larger than the area of ​​the first reinforced geomembrane, the first reinforced geomembrane covers above the opening, and the second reinforced geomembrane covers above the first reinforced geomembrane.

[0011] In an optional solution, the shape of the first reinforced geomembrane is the same as the shape of the slit of the opening, and the coverage of the first reinforced geomembrane exceeds the slit by a distance of not less than 10 cm. The first reinforced geomembrane and the geomembrane are welded by hot melt full welding, and the weld width is not less than 2 cm.

[0012] In an optional solution, the second reinforced geomembrane can completely cover the first reinforced geomembrane, and the coverage of the second reinforced geomembrane exceeds the boundary width of the first reinforced geomembrane by not less than 20 cm. The second reinforced geomembrane and the geomembrane are welded by single-sided welding, and the weld width is not less than 2 cm.

[0013] In an optional solution, the second reinforced geomembrane is covered with a geomembrane reinforcement cover sheet at a corner position, and the geomembrane reinforcement cover sheet is welded to the second reinforced geomembrane and the geomembrane by full hot melt welding.

[0014] In an optional solution, the backfill layer is layered in the scour pit after the scour pit is cleaned, the filling material of the backfill layer is the same as that of the underlying layer, and the top of the backfill layer is flush with the top of the underlying layer.

[0015] The beneficial effects of this application are:

[0016] The repair structure in the present application provides openings in the geomembrane and the three-dimensional composite drainage net, thereby facilitating the backfilling of the scour pits, avoiding the complicated process problems and impact on the geomembrane caused by the complete lifting of the geomembrane; in addition, the reinforced geomembrane covering the opening position can enhance the anti-seepage effect of the cut part, ensuring the safety and reliability of the entire anti-seepage structure.

[0017] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a repair structure provided by the present application in a specific embodiment;

[0019] Figure 2 for Figure 1 A schematic structural diagram of the repair structure when the opening is opened;

[0020] Figure 3 Schematic diagram of the connection structure of the first reinforced geomembrane provided for this application;

[0021] Figure 4 Schematic diagram of the connection structure of the second reinforced geomembrane provided for this application;

[0022] Figure numerals: geomembrane 1, three-dimensional composite drainage net 2, underlying layer 3, transition layer or foundation layer 4, scour pit 5, opening 6, slit 61, backfill layer 7, reinforced geomembrane 8, first reinforced geomembrane 81, second reinforced geomembrane 82, geomembrane reinforced cover sheet 83.

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0024] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0025] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other technical solutions obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0027] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0028] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.

[0029] like Figure 1-4 As shown, an embodiment of the present application provides a repair structure for scour defects of a geomembrane foundation. The geomembrane foundation includes a transition layer or foundation layer 4, a sub-base layer 3, a three-dimensional composite drainage net 2 and a geomembrane 1 laid in sequence. The repair structure is used to repair scour pits 5 formed on the geomembrane foundation due to scour of water flow.

[0030] Specifically, the repair structure includes an opening 6, a backfill layer 7 and a reinforced geomembrane 8, wherein the opening 6 is formed by cutting an opening in the three-dimensional composite drainage net 2 and the geomembrane 1, and the opening 6 is located above the scouring pit 5, and the opening 6 can open and close the three-dimensional composite drainage net 2 and the geomembrane 1 above the scouring pit 5; the backfill layer 7 is arranged in the scouring pit 5, and the top of the backfill layer 7 is paved with a geotextile (200-500g / m 2 ); the reinforced geomembrane 8 is covered on the top of the opening 6 after the opening 6 is closed, and the reinforced geomembrane 8 can completely cover the slit 61 of the opening 6, and the reinforced geomembrane 8 is connected to the geomembrane 1 by welding.

[0031] Specifically, the anti-seepage structure of the geomembrane on the slope generally consists of a geomembrane 1, a three-dimensional composite drainage net 2, a sub-base 3, a transition layer or a foundation layer 4 from top to bottom. The surface of the geomembrane 1 is inspected to see if there are scour pits 5 with a depth of more than 3 cm in the sub-base 3. The geomembrane 1 and the three-dimensional composite drainage net 2 at this location are cut to form an opening 6. The shape of the slit 61 can be a "]" shape. The opening 6 is opened, and the loose cushion layer and large stones in the scour pit 5 are cleaned. The original foundation is compacted manually, and then backfilled with a backfill layer 7 of the same grade as the sub-base 3. The layers are compacted and then a layer of geotextile is laid. When backfilling, it is necessary to ensure that the top of the backfill layer 7 is flush with the top of the sub-base 3. The cut three-dimensional composite drainage net 2 is tied with a cable tie. After the slits 61 of the geomembrane 1 are aligned, the upper part is covered with a reinforced geomembrane 8 for sealing, and then welded by hot melt welding.

[0032] The repair structure in the embodiment of the present application provides openings 6 in the geomembrane 1 and the three-dimensional composite drainage net 2, thereby facilitating the backfilling of the scour pit 5 with the backfill layer 7, thereby avoiding the complicated process problems and the impact on the geomembrane 1 caused by the complete lifting of the geomembrane 1; in addition, the reinforced geomembrane 8 covering the opening 6 can enhance the anti-seepage effect of the cut 61, thereby ensuring the safety and reliability of the entire anti-seepage structure.

[0033] In one specific embodiment, the slits 61 at the location of the three-dimensional composite drainage net 2 can be tied with tie wraps. A layer of geotextile is added to its lower portion (on top of the backfill layer 7), and then another layer of geotextile is heat-welded to the composite geomembrane 1 atop the three-dimensional composite drainage net 2, thereby further improving the protective function of the three-dimensional composite drainage net 2 on the geomembrane 1. Furthermore, the sub-base 3 and the backfill layer 7 can be a fine-grained sub-base 3.

[0034] like Figure 1 As shown, in a specific embodiment, the reinforced geomembrane 8 includes a first reinforced geomembrane 81 and a second reinforced geomembrane 82, the area of ​​the second reinforced geomembrane 82 is larger than the area of ​​the first reinforced geomembrane 81, the first reinforced geomembrane 81 covers the opening 6, and the second reinforced geomembrane 82 covers the first reinforced geomembrane 81.

[0035] like Figure 3 As shown, in a specific embodiment, the shape of the first reinforced geomembrane 81 is the same as the shape of the slit 61 of the opening 6, and the coverage of the first reinforced geomembrane 81 exceeds the slit 61 by a distance of not less than 10 cm. The first reinforced geomembrane 81 and the geomembrane 1 are welded by hot melt full welding, and the weld width is not less than 2 cm.

[0036] like Figure 4 As shown, in a specific embodiment, the second reinforced geomembrane 82 can completely cover the first reinforced geomembrane 81, and the coverage of the second reinforced geomembrane 82 exceeds the boundary width of the first reinforced geomembrane 81 by no less than 20 cm. The second reinforced geomembrane 82 is welded to the geomembrane 1 by single-side welding, and the weld width is no less than 2 cm. In addition, the second reinforced geomembrane 82 is covered with a geomembrane reinforcement cover sheet 83 at the corner position, and the geomembrane reinforcement cover sheet 83 is welded to the second reinforced geomembrane 82 and the geomembrane 1 by hot melt full welding. The second reinforced geomembrane 82 can be of various shapes, such as the rectangle shown in the figure. The shape of the second reinforced geomembrane 82 is not specifically limited in this article.

[0037] like Figure 3 As shown in the figure, the thick line portion is the welding position between the first reinforced geomembrane 81 and the geomembrane 1. Figure 4The thick line in the figure indicates the weld location between the second geomembrane reinforcement layer 82 and the geomembrane 1. The first geomembrane reinforcement layer 81 is constructed using a hot-melt full-weld process, which improves the anti-seepage performance at the slit 61. The second geomembrane reinforcement layer 82 covers the first geomembrane reinforcement layer 8 and the defect treatment area, further enhancing the anti-seepage effect at the slit 61. A geomembrane reinforcement cover 83 is provided at the weak corners to avoid the risk of damage to the geomembrane 1 from long-term operation, thereby improving the safety and reliability of the entire repair structure.

[0038] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A repair structure for scour defects in a geomembrane foundation, wherein the geomembrane foundation comprises a transition layer or a foundation layer, a sub-base, a three-dimensional composite drainage net, and a geomembrane, which are laid in sequence. The repair structure is used to repair scour pits formed in the geomembrane foundation due to water scour, and is characterized in that: The repair structure comprises: An opening portion is formed by cutting openings in the three-dimensional composite drainage net and the geomembrane, the opening portion is located above the scouring pit, and the opening portion can open and close the three-dimensional composite drainage net and the geomembrane above the scouring pit; A backfill layer is provided in the scouring pit, and a geotextile is laid on top of the backfill layer; A reinforced geomembrane is provided to cover the top of the opening after the opening is closed, and the reinforced geomembrane can completely cover the slit of the opening, and the reinforced geomembrane is connected to the geomembrane by welding.

2. The repair structure for scour defects of geomembrane foundation according to claim 1 is characterized in that: The reinforced geomembrane includes a first reinforced geomembrane and a second reinforced geomembrane, the area of ​​the second reinforced geomembrane is larger than that of the first reinforced geomembrane, the first reinforced geomembrane covers above the opening, and the second reinforced geomembrane covers above the first reinforced geomembrane.

3. The repair structure for scour defects of geomembrane foundation according to claim 2, characterized in that: The shape of the first reinforced geomembrane is the same as the shape of the slit of the opening, and the coverage of the first reinforced geomembrane exceeds the slit by a distance of not less than 10 cm. The first reinforced geomembrane and the geomembrane are welded by hot melt full welding, and the weld width is not less than 2 cm.

4. The repair structure for scour defects of geomembrane foundation according to claim 2 or 3, characterized in that: The second reinforced geomembrane can completely cover the first reinforced geomembrane, and the coverage of the second reinforced geomembrane exceeds the boundary width of the first reinforced geomembrane by no less than 20 cm. The second reinforced geomembrane and the geomembrane are welded by single-sided welding, and the weld width is no less than 2 cm.

5. The repair structure for scour defects of geomembrane foundation according to claim 4, characterized in that: The second reinforced geomembrane is covered with a geomembrane reinforcement cover sheet at a corner position, and the geomembrane reinforcement cover sheet is welded to the second reinforced geomembrane and the geomembrane by full hot melt welding.

6. The repair structure for scour defects of geomembrane foundation according to any one of claims 1 to 3 or 5, characterized in that: The backfill layer is filled in the scour pit in layers after the scour pit is cleaned. The filling material of the backfill layer is the same as that of the underlying layer, and the top of the backfill layer is flush with the top of the underlying layer.

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