Construction method of polyurea anti-seepage membrane rockfill dam

Abstract

The invention relates to a construction method of a polyurea anti-seepage face film rock-fill dam, which is used for construction of the polyurea anti-seepage face film rock-fill dam and comprises the following steps: excavation of a rock-fill dam body foundation, pouring of a toe board, filling of the rock-fill dam body, construction of foundation anti-seepage treatment and filling of a wave wall and the back of the wall are sequentially carried out; a certain protective layer and a cushion material area on the downstream side of the toe board are chiseled away, an asphaltic sand cushion is backfilled, a convex circular bulge is formed after backfilling, and the asphaltic sand cushion is backfilled between the outer side edge of the wave wall and the protective layer; geotechnical cloth is laid on the protective layer of the upstream water retaining dam face, and the joints where the toe boards, the wave wall and the filling body are connected and the preset positions of the filling body are arranged to be in an outwards-protruding bulge shape in the mode that multiple layers of geotechnical cloth strips are additionally laid for heightening; spraying a first layer of polyurea to cover the surface of the geotechnical cloth; spraying a plurality of layers of polyurea impermeable layers, and arranging tire base cloth; and a polyurea thickening layer is arranged at a preset bulge-shaped part.

Description

Technical Field

[0001] This application relates to the technical field of rockfill dam engineering, and particularly to a construction method for a rockfill dam with a polyurea anti-seepage membrane. Background Art

[0002] Polyurea has excellent anti-seepage, impact resistance, and ductility, and is convenient for construction. However, there is no engineering practice in using it for the surface anti-seepage of rockfill dams. The main problem is that there is an excellent bonding performance between polyurea and the protective layer on the surface of the rockfill. During the operation of the dam, deformation occurs, resulting in cracking of the protective layer. The clamping effect formed by the effective bonding between polyurea and the protective layer will greatly reduce the deformation adaptability of the polyurea anti-seepage layer. Summary of the Invention

[0003] This application provides a construction method for a rockfill dam with a polyurea anti-seepage membrane. The rockfill dam with a polyurea anti-seepage membrane constructed by this construction method can effectively overcome the problems of applying polyurea to the surface anti-seepage of a concrete face rockfill dam.

[0004] The construction method for a rockfill dam with a polyurea anti-seepage membrane provided by this application includes the following steps: 1) Excavate the foundation of the rockfill dam body, pour the toe slab, fill the rockfill dam body, construct the foundation anti-seepage treatment, and fill behind the wave wall and the wall in sequence. The foundation anti-seepage treatment includes laying a bedding layer and a polyurea anti-seepage layer. The bedding layer includes a transition material area, a cushion material area, and a protective layer laid in sequence. When laying the polyurea anti-seepage structure, lay a geotextile as an isolation layer between the protective layer and the polyurea anti-seepage layer. The geotextile and the polyurea anti-seepage layer form a polyurea anti-seepage structure;

[0005] 2) Chisel off the protective layer and the cushion material area within 50 cm on the downstream side of the toe slab to a depth of not less than 20 cm, and backfill with an asphalt sand cushion. After backfilling, form a convex circular bulge. Backfill the asphalt sand cushion between the outer edge of the wave wall and the protective layer;

[0006] 3) Lay a geotextile on the protective layer of the upstream water-retaining dam face. At the joint positions where the toe slab, the wave wall, and the filling body are connected, and at the preset positions of the filling body, set them into a convex bulge shape by laying multiple layers of geotextile strips to raise the height;

[0007] 4) Spray the first layer of polyurea to cover the surface of the geotextile. After spraying, ensure that the geotextile is not exposed;

[0008] 5) Spray the polyurea anti-seepage layer in multiple layers and set up a base fabric. The total thickness reaches 3 - 5 mm, and the base fabric is 1 - 2 layers;

[0009] 6) Set a polyurea thickening layer at the preset bulge-shaped position. The polyurea thickening layer includes 1 - 2 mm thick polyurea and one layer of base fabric.

[0010] In addition, the construction method of the polyurea impermeable membrane rockfill dam provided by this application also has the following additional technical features:

[0011] In an alternative solution, in step 1), when filling the rockfill dam body, according to the filling height, slope trimming is carried out every 15m height difference, and roller-compacted mortar is laid to form the protective layer. When the extrusion side wall or the form-turning slope fixation construction process is adopted for the slope, the construction of the protective layer is carried out synchronously with the filling.

[0012] In an alternative solution, in the polyurea impermeable membrane rockfill dam after construction, a first deformation bulge is provided at the joint between the polyurea impermeable structure and the toe slab, a second deformation bulge is provided at the joint between the polyurea impermeable structure and the wave wall, and a plurality of third deformation bulges are arranged at intervals on the polyurea impermeable structure. The third deformation bulges extend in the upstream and downstream directions and connect the first deformation bulge and the second deformation bulge.

[0013] In an alternative solution, in the polyurea impermeable membrane rockfill dam after construction, the first deformation bulge includes an asphalt sand cushion layer and a polyurea thickened layer. The asphalt sand cushion layer at the first deformation bulge protrudes outward from the polyurea impermeable structure to form an arc surface, and the polyurea thickened layer is laid on the surface of the asphalt sand cushion layer.

[0014] In an alternative solution, in the polyurea impermeable membrane rockfill dam after construction, the wave wall is arranged on the cushion material area. The second deformation bulge includes an asphalt sand cushion layer and a polyurea thickened layer, and the polyurea thickened layer is laid on the surface of the asphalt sand cushion layer.

[0015] In an alternative solution, in the polyurea impermeable membrane rockfill dam after construction, the third deformation bulge includes a polyurea thickened layer; the polyurea thickened layer includes a geotextile and a polyurea impermeable layer. The thickness of the geotextile laid at the polyurea thickened layer is greater than the thickness of the geotextile laid on the polyurea impermeable structure, and the thickness difference between the two geotextiles is not less than 5cm.

[0016] In an alternative solution, in the polyurea impermeable membrane rockfill dam after construction, the thickness of the polyurea impermeable layer laid at the polyurea thickened layer is greater than the thickness of the polyurea impermeable layer laid on the polyurea impermeable structure, and the thickness difference between the two polyurea impermeable layers is 1 - 2mm; in the polyurea thickened layer, the thickening range of the polyurea impermeable layer is greater than the thickening range of the geotextile, and the range difference between the two is not less than 20cm.

[0017] In an alternative solution, in the polyurea impervious membrane rockfill dam after construction, the rockfill dam body includes a rockfill drainage layer area and a secondary rockfill area. The rockfill drainage layer area and the secondary rockfill area are arranged along the upstream and downstream directions, and the cross-section of the rockfill dam body is trapezoidal; the connection method of the polyurea impervious structure with the toe slab and the wave wall is adhesive connection; the bottom foundation of the toe slab is subjected to anti-seepage treatment, and the anti-seepage treatment includes consolidated grouting and curtain grouting, or the bottom foundation is a soil foundation, and the anti-seepage treatment is carried out by using an impervious wall.

[0018] The beneficial effects of the present application are as follows:

[0019] The construction method of the polyurea impervious membrane rockfill dam in the present application utilizes the isolation effect of the geotextile to eliminate the strong bonding between the polyurea impervious layer and the lower protective layer, and gives full play to the excellent impervious performance and deformation performance of the polyurea impervious layer, solving the problem of the application of polyurea in the surface imperviousness of the rockfill dam. Compared with the reinforced concrete face rockfill dam and the asphalt concrete face rockfill dam, the impervious structure has better adaptability to the deformation of the dam, and the dam filling materials have a wider range of adaptability.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic plan view of the polyurea impervious membrane rockfill dam provided by the present application;

[0022] Figure 2 is Figure 1 a schematic cross-sectional view of the polyurea impervious membrane rockfill dam in

[0023] Figure 3 is a schematic connection view of the polyurea impervious structure and the toe slab at the joint part provided by the present application;

[0024] Figure 4 is a schematic connection view of the polyurea impervious structure and the wave wall at the joint part provided by the present application;

[0025] Figure 5 is a schematic connection view of the polyurea impervious structure at the third deformation bulge position provided by the present application.

[0026] Reference numerals: rockfill dam body 1, toe slab 2, wave wall 3, transition material area 4, cushion material area 5, protective layer 6, polyurea impervious structure 7, polyurea impervious layer 8, geotextile 9, first deformation bulge 10, second deformation bulge 11, third deformation bulge 12, asphalt sand cushion 13, polyurea thickened layer 14, rockfill drainage layer area 15, secondary rockfill area 16, bottom foundation 17.

[0027] The accompanying drawings here are incorporated into and form a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application. Detailed Embodiments

[0028] To better understand the technical solutions of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0029] It should be clear that the described embodiments are only a part rather than all of the embodiments of this application. All other technical solutions obtained by those of ordinary skill in the art based on the embodiments in this application without any creative efforts fall within the scope of protection of this application.

[0030] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms "a", "the" and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise.

[0031] It should be understood that the term " / and" used herein is only a description of the associated relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0032] It should be noted that the orientation terms such as "upper", "lower", "left", and "right" described in the embodiments of this application are described from the angles shown in the accompanying drawings and should not be construed as a limitation on the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0033] Such as Figures 1-5As shown in the figure, in the first aspect of the embodiment of the present application, a polyurea impervious membrane rockfill dam is provided. The polyurea impervious membrane rockfill dam mainly includes a rockfill dam body 1, a bedding layer, and a polyurea impervious structure 7. Among them, the rockfill dam body 1 has an upstream water retaining dam surface and a downstream dam surface. A toe slab 2 is provided at the bottom of the upstream water retaining dam surface, and a wave wall 3 is provided on one side of the top of the upstream water retaining dam surface; the bedding layer includes a transition material area 4, a cushion material area 5, and a protective layer 6 laid on the upstream water retaining dam surface in sequence. The protective layer 6 includes structures such as roller-compacted mortar, extruded side walls, or formwork overturning slope protection; the polyurea impervious structure 7 is laid on the surface of the protective layer 6, and one side of the polyurea impervious structure 7 is directly or indirectly connected to the toe slab 2, and the other side is directly or indirectly connected to the wave wall 3. The polyurea impervious structure 7 includes a polyurea impervious layer 8 and a geotextile 9. The geotextile 9 is laid as an isolation layer between the protective layer 6 and the polyurea impervious layer 8. By setting the geotextile 9, the separation between the polyurea impervious layer 8 and the protective layer 6 can be effectively realized, avoiding the polyurea from bonding to the protective layer 6. When cracks occur in the protective layer 6, the polyurea impervious layer 8 can expand and contract relatively freely.

[0034] In the polyurea impervious membrane rockfill dam and construction method of this embodiment, by using the isolation effect of the geotextile 9, the strong bonding between the polyurea impervious layer 8 and the lower protective layer 6 is eliminated, and the excellent impervious performance and deformation performance of the polyurea impervious layer 8 are fully exerted, solving the problem of the application of polyurea in the surface imperviousness of the rockfill dam. Compared with the reinforced concrete face rockfill dam and the asphalt concrete face rockfill dam, the impervious structure has better adaptability to the deformation of the dam, and the dam filling materials have a wider range of adaptability.

[0035] In addition, the polyurea impervious layer 8 has good impact resistance, so it can effectively resist the damage of external forces during operation and ensure the operation safety. Compared with the geomembrane impervious membrane rockfill dam with the same excellent deformation adaptability, the surface protection structure can be simplified. The polyurea impervious layer 8 has excellent constructability, less investment in labor costs, fast construction speed, and convenient operation and repair in the later stage. Whether it is a local pothole or a large-scale damage, after simple surface treatment, it can be directly sprayed or painted, and water can be stored or put into normal operation on the day of completing the construction.

[0036] As Figure 1 shown, in a specific embodiment, a first deformation bulge 10 is provided at the joint part of the polyurea impervious structure 7 and the toe slab 2, a second deformation bulge 11 is provided at the joint part of the polyurea impervious structure 7 and the wave wall 3, and a plurality of third deformation bulges 12 are arranged at intervals on the polyurea impervious structure 7. The interval between two adjacent third deformation bulges 12 can be 10 - 20m, and the third deformation bulges 12 extend along the upstream and downstream directions and connect the first deformation bulge 10 and the second deformation bulge 11.

[0037] As Figures 3-5As shown, in a specific embodiment, the third deformed bulge 12 includes a polyurea thickening layer 14; the polyurea thickening layer 14 includes a geotextile 9 and a polyurea anti-seepage layer 8. The thickness of the geotextile 9 laid at the polyurea thickening layer 14 is greater than that of the geotextile 9 laid at the polyurea anti-seepage structure 7, and the thickness difference of the geotextile 9 between the two is not less than 5 cm. The thickness of the polyurea anti-seepage layer 8 laid at the polyurea thickening layer 14 is greater than that of the polyurea anti-seepage layer 8 laid at the polyurea anti-seepage structure 7, and the thickness difference of the polyurea anti-seepage layer 8 between the two is 1 - 2 mm; in the polyurea thickening layer 14, the thickening range of the polyurea anti-seepage layer 8 is greater than that of the geotextile 9, and the range difference between the two is not less than 20 cm.

[0038] As Figure 3 shown, in a specific embodiment, the first deformed bulge 10 includes an asphalt sand cushion layer 13 and a polyurea thickening layer 14. The asphalt sand cushion layer 13 at the first deformed bulge 10 protrudes outward from the polyurea anti-seepage structure 7 to form an arc surface, and the polyurea thickening layer 14 is laid on the surface of the asphalt sand cushion layer 13. Specifically, during construction, the protective layer 6 and the cushion layer at the pre-site of the peripheral joint of the toe slab 2 can be first excavated, and the asphalt sand cushion layer 13 is used for filling to form the protruding first deformed bulge 10. Geotextiles 9 are laid on both sides of the first deformed bulge 10 to increase the size of the bulge. The structural sharp corners at the parts covered by the polyurea anti-seepage layer 8 inside the toe slab 2 are set to be arc-shaped. The laying range of the geotextile 9 on the asphalt sand cushion layer 13 is 10 cm on each side of the asphalt sand cushion layer 13, and the thickness is not less than 5 cm.

[0039] As Figure 2 and Figure 4 shown, in a specific embodiment, the wave wall 3 is arranged on the cushion material area 5 to avoid increasing the risk of cracking at the top of the protective layer 6 due to inconsistent deformation performance between the protective layer 6 and the cushion material area 5. The second deformed bulge 11 includes an asphalt sand cushion layer 13 and a polyurea thickening layer 14, and the polyurea thickening layer 14 is laid on the surface of the asphalt sand cushion layer 13. Specifically, after filling and smoothing the protective layer 6 and the wave wall 3 with the asphalt sand cushion layer 13, geotextiles 9 are laid to form a protruding bulge. The structural sharp corners at the parts covered by the polyurea anti-seepage layer 8 outside the wave wall 3 are set to be arc-shaped. In the second deformed bulge 11 preset at the horizontal joint of the wave wall 3, the laying range of the geotextile 9 extends 10 cm beyond the range of the asphalt sand cushion layer 13, and the thickness is not less than 5 cm.

[0040] As Figures 1-2As shown, in a specific embodiment, the rockfill dam body 1 includes a rockfill drainage layer area 15 and a secondary rockfill area 16. The rockfill drainage layer area 15 and the secondary rockfill area 16 are arranged along the upstream and downstream directions, and the cross-section of the rockfill dam body 1 is trapezoidal. In addition, the connection method of the polyurea anti-seepage structure 7 with the toe slab 2 and the wave wall 3 is adhesive connection; the bottom foundation 17 of the toe slab 2 is subjected to anti-seepage treatment, and the anti-seepage treatment includes consolidated grouting and curtain grouting. When the bottom foundation 17 is a soil foundation, the anti-seepage treatment is carried out by using a cut-off wall for anti-seepage treatment.

[0041] As Figures 1-5 shown, the second aspect of the embodiment of the present application provides a construction method of a polyurea anti-seepage membrane rockfill dam for constructing the polyurea anti-seepage membrane rockfill dam in the first aspect. The construction method specifically includes the following steps:

[0042] 1) Excavate the foundation of the rockfill dam body 1, pour the toe slab 2, fill the rockfill dam body 1, construct the foundation anti-seepage treatment, and construct the wave wall 3 and the backfill behind the wall in sequence;

[0043] When filling the rockfill dam body 1, according to the filling height, the slope surface is trimmed every 15 m height difference, and the rolled mortar is laid to form a protective layer 6. When the extrusion side wall or the form turnover slope fixing construction process is adopted for the slope surface, the construction of the protective layer 6 is carried out synchronously with the filling.

[0044] 2) Chisel off the protective layer 6 and the cushion material area 5 within 50 cm on the downstream side of the toe slab 2, with a depth of not less than 20 cm, and backfill with asphalt sand cushion 13. After backfilling, an outward convex circular bulge is formed, and the asphalt sand cushion 13 is backfilled between the outer edge of the wave wall 3 and the protective layer 6.

[0045] 3) Lay a geotextile 9 on the protective layer 6 of the upstream water retaining dam surface, and at the joint part where the toe slab 2, the wave wall 3 are connected with the filling body, and at the preset position of the filling body, an outward convex bulge is set by the way of laying multiple layers of geotextile 9 strips to pad up.

[0046] 4) Spray the first layer of polyurea to cover the surface of the geotextile 9. After spraying, it is necessary to ensure that the geotextile 9 is not exposed white.

[0047] 5) Spray the polyurea anti-seepage layer 8 in multiple layers and set the base fabric. The total thickness reaches 3 - 5 mm, and the base fabric is 1 - 2 layers.

[0048] 6) Set a polyurea thickening layer 14 at the preset bulging part. The polyurea thickening layer 14 includes 1 - 2 mm thick polyurea and one layer of base fabric. In this step and step 5), the polyurea anti-seepage layer 8 can be constructed by using the scraping process.

[0049] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A construction method for a rockfill dam with a polyurea anti-seepage membrane, which is used for the construction of a rockfill dam with a polyurea anti-seepage membrane, and is characterized in that, The construction method includes the following steps: 1) Excavate the foundation of the rockfill dam body, pour the toe slab, fill the rockfill dam body, construct the foundation anti-seepage treatment, and fill behind the wave wall and the wall in sequence. The foundation anti-seepage treatment includes laying a bedding layer and a polyurea anti-seepage layer. The bedding layer includes a transition material area, a cushion material area, and a protective layer laid in sequence. When laying the polyurea anti-seepage structure, a geotextile is laid as an isolation layer between the protective layer and the polyurea anti-seepage layer. The geotextile and the polyurea anti-seepage layer form the polyurea anti-seepage structure; 2) Chisel off the protective layer and the cushion material area within 50 cm on the downstream side of the toe slab, with a depth of not less than 20 cm, and backfill with an asphalt sand cushion layer. After backfilling, a convex circular bulge is formed. The asphalt sand cushion layer is backfilled between the outer edge of the wave wall and the protective layer; 3) Lay a geotextile on the protective layer of the upstream water-retaining dam surface. At the joint parts where the toe slab, the wave wall are connected to the filling body, and at the preset positions of the filling body, an outward convex bulge shape is set by laying multiple layers of geotextile strips to raise the height; 4) Spray the first layer of polyurea to cover the surface of the geotextile. After spraying, it is necessary to ensure that the geotextile is not exposed; 5) Spray the polyurea anti-seepage layer in multiple layers and set up a base fabric. The total thickness reaches 3 - 5 mm, and the base fabric is 1 - 2 layers; 6) Set up a polyurea thickening layer at the preset bulge-shaped parts. The polyurea thickening layer includes 1 - 2 mm thick polyurea and one layer of base fabric.

2. The construction method of the polyurea impervious membrane rockfill dam according to claim 1, characterized in that, In step 1), when filling the rockfill dam body, according to the filling height, the slope surface is trimmed every 15 m height difference, and the roller-compacted mortar is laid to form the protective layer. When the slope surface adopts the construction technology of extrusion side wall or turnover form for slope fixation, the construction of the protective layer is carried out synchronously with the filling.

3. The construction method of the polyurea impervious membrane rockfill dam according to claim 1 or 2, characterized in that, In the polyurea anti-seepage membrane rockfill dam after construction, a first deformation bulge is set at the joint part between the polyurea anti-seepage structure and the toe slab, a second deformation bulge is set at the joint part between the polyurea anti-seepage structure and the wave wall, and multiple third deformation bulges are arranged at intervals on the polyurea anti-seepage structure. The third deformation bulges extend in the upstream and downstream directions and connect the first deformation bulge and the second deformation bulge.

4. The construction method of the polyurea impervious membrane rockfill dam according to claim 3, characterized in that, In the polyurea anti-seepage membrane rockfill dam after construction, the first deformation bulge includes an asphalt sand cushion layer and a polyurea thickening layer. The asphalt sand cushion layer at the first deformation bulge protrudes outward from the polyurea anti-seepage structure to form an arc surface, and the polyurea thickening layer is laid on the surface of the asphalt sand cushion layer.

5. The construction method of the polyurea impervious membrane rockfill dam according to claim 3, characterized in that In the polyurea anti-seepage membrane rockfill dam after construction, the wave wall is set on the cushion material area. The second deformation bulge includes an asphalt sand cushion layer and a polyurea thickening layer, and the polyurea thickening layer is laid on the surface of the asphalt sand cushion layer.

6. The construction method of the polyurea impervious membrane rockfill dam according to claim 4 or 5, characterized in that In the polyurea anti-seepage membrane rockfill dam after construction, the third deformation bulge includes a polyurea thickening layer; the polyurea thickening layer includes a geotextile and a polyurea anti-seepage layer. The thickness of the geotextile laid at the polyurea thickening layer is greater than the thickness of the geotextile laid in the polyurea anti-seepage structure, and the thickness difference between the two geotextiles is not less than 5 cm.

7. The construction method of the polyurea impermeable membrane rockfill dam according to claim 6, characterized in that, In the constructed polyurea impermeable membrane rockfill dam, the thickness of the polyurea impermeable layer laid at the polyurea thickened layer is greater than that of the polyurea impermeable layer laid in the polyurea impermeable structure, and the thickness difference of the polyurea impermeable layer between the two is 1 - 2 mm; in the polyurea thickened layer, the thickening range of the polyurea impermeable layer is greater than that of the geotextile, and the range difference between the two is not less than 20 cm.

8. The construction method of the polyurea impervious membrane rockfill dam according to any one of claims 1-2 or 4-5 or 6, characterized in that, In the constructed polyurea impermeable membrane rockfill dam, the rockfill dam body includes a rockfill drainage layer area and a secondary rockfill area. The rockfill drainage layer area and the secondary rockfill area are arranged along the upstream and downstream directions, and the cross-section of the rockfill dam body is trapezoidal; the connection method of the polyurea impermeable structure with the toe slab and the wave wall is adhesive connection; the bottom foundation of the toe slab is subjected to anti-seepage treatment, and the anti-seepage treatment includes consolidated grouting and curtain grouting, or the bottom foundation is a soil foundation, and the anti-seepage treatment is carried out by using an impermeable wall for anti-seepage treatment.

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