Rock-fill dam panel seam surface water stop structure and construction method

Abstract

The invention discloses a rock-fill dam panel seam surface water stop structure and a construction method, the rock-fill dam panel seam surface water stop structure comprises a first concrete panel and a second concrete panel, a structural seam is arranged between the first concrete panel and the second concrete panel, the structural seam is filled with plastic filler, the plastic filler is covered with a first water stop film, and the first water stop film is covered with a second water stop film. Water stop pieces are embedded in the first concrete face plate and the second concrete face plate respectively, one end of each water stop piece extends out of the face plate and is in lap joint with a second water stop film and a third water stop film, and the second water stop film and the upper surface of the water stop pieces form a whole through extrusion fusion. The third water stop film and the lower surface of the water stop piece are extruded and fused to form a whole, and the first water stop film, the second water stop film and the third water stop film are welded in a hot melting mode to form a whole. The sealing structure is good in stress performance, good in water stopping effect, good in sealing effect and high in safety performance.

Description

Technical Field

[0001] The present invention relates to a seepage prevention structure for hydraulic and hydropower engineering, and particularly to a surface water stop structure and construction method for the joints of the face slab of a rockfill dam. Background Art

[0002] In the existing reservoir construction using concrete face slab rockfill dams, generally, a water stop structure is set between the joints of the face slabs (structural joints between the face slabs) and the peripheral joints (structural joints between the face slab and the toe slab) for seepage prevention. And the connection part between the joints of the face slabs and the peripheral joints is the key part of seepage prevention and stress bearing. Once leakage occurs, it is inconvenient for operation and maintenance, and in severe cases, it will even endanger the safety of the dam. Therefore, the connection and sealing problem of the water stop structures for the joints of the face slabs and the peripheral joints must be solved.

[0003] The existing connection water stops for the joints of the face slabs and the peripheral joints of rockfill dams usually adopt two mutually independent anti-seepage water stop systems, namely the bottom copper water stop + surface water stop as shown in Chinese Patent CN118309018A. This method is widely used in the anti-seepage of water conservancy projects (such as reservoirs) and hydropower projects (face slab rockfill dams). At present, for the surface water stop, the cover sheet (usually made of rubber) is directly laid across the joint of the face slabs, and the two ends of the cover sheet are respectively fixed on the surfaces of the left and right face slabs of the joint of the face slabs, the face slabs on both sides of the peripheral joint and the toe slab. Then, the strip-shaped flat steel pressing strips with holes are respectively used to press the two side edges of the cover sheet, and the flat steel pressing strips are fixed on the concrete surface with bolts to form anchoring and fixing, so as to form a fixed seal. The surface water stop technology using physical anchoring type for connection and anchoring on the face slab or the toe slab has the following problems:

[0004] Pressing the cover sheet with strip-shaped flat steel pressing strips and fixing it on the concrete surface with bolts will, firstly, form damage to the concrete surface structure by continuously and intermittently opening holes on the edge surface of the concrete face slab, weaken the local strength of the concrete structure, and be unfavorable for the stress of the concrete structure; secondly, due to the relatively large size of the face slab in the slope direction, the stiffness of the strip-shaped flat steel pressing strip is relatively small, and the hole spacing on the flat steel pressing strip is usually 30 - 60 cm. When fixed with bolts, the flat steel pressing strip between the bolts will bulge upwards. It cannot tightly press the cover sheet, resulting in tight pressing at the bolt fixing position and the flat steel pressing strip bulging upwards more and more away from the bolt, and it is easy to have gap leakage; thirdly, affected by the flatness of the concrete face slab, the face slab will not be a flat surface and there will always be unevenness. It is impossible to seal by relying on the flat steel to press the cover sheet; fourthly, due to the action of the deformation of the dam body or water pressure on the concrete face slab, the concrete face slab will produce flexural deformation, and a phenomenon of void formation will occur between the flat steel pressing strip and the face slab surface. When the void is severe, even the bolts will be damaged, forming a direct leakage channel, and the surface water stop becomes ineffective; fifthly, the bolts fixed on the concrete surface by later drilling and the concrete between them are also leakage channels. Especially under high water pressure heads, it is very easy to form leakage around the holes and cannot achieve sealing.

[0005] In recent years, with the rapid development of hydropower development, especially the wide application of the construction of pumped-storage power stations, concrete face rockfill dams have been widely used. At the same time, due to the actual needs of the project, using this local material dam, namely the concrete face rockfill dam, has good adaptability and economy in pumped-storage power stations and becomes the preferred choice. However, the surface waterstop type between the joints of the face slab and the peripheral joints has poor connection and sealing effects, which is one of the main problems in the project. During the construction, especially during the operation process, waterstop failure often occurs and repairs are frequently required, which has an adverse impact on the project safety and operation. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a surface waterstop structure and construction method for the joints of the face slab of a rockfill dam with good mechanical properties, good waterstop effect, good sealing effect and high safety performance, aiming at the deficiencies of the current surface waterstop and anti-seepage structure for the joints between the face slabs and the peripheral joints of the rockfill dam.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A surface waterstop structure for the joints of the face slab of a rockfill dam includes a first concrete face slab and a second concrete face slab. There is a structural joint between the first concrete face slab and the second concrete face slab. The structural joint is filled with a plastic filler, and a first waterstop membrane is covered on the plastic filler. Its structural characteristics are as follows:

[0009] Waterstop sheets are respectively embedded in the first concrete face slab and the second concrete face slab. One end of the waterstop sheet extends out of the face slab and overlaps with a second waterstop membrane and a third waterstop membrane. The second waterstop membrane and the upper surface of the waterstop sheet are integrally formed by extrusion fusion, and the third waterstop membrane and the lower surface of the waterstop sheet are integrally formed by extrusion fusion. Moreover, the first waterstop membrane, the second waterstop membrane and the third waterstop membrane are integrally formed by hot melt welding.

[0010] It should be noted that the first concrete face slab and the second concrete face slab in this article can be the face slab or the toe slab of a rockfill dam. The structural joints involved in this article include the joints between the face slabs and the peripheral joints between the face slab and the toe slab.

[0011] Further, a number of connecting through holes are arranged at the end of the waterstop sheet that extends out of the face slab. The upper surface of the connecting through holes is covered with a second waterstop membrane, and the lower surface is covered with a third waterstop membrane. Moreover, the second waterstop membrane and the third waterstop membrane on the upper and lower surfaces of the connecting through holes and the second waterstop membrane and the third waterstop membrane outside the waterstop sheet are respectively integrally formed by hot melt welding.

[0012] Further, the overlapping length of the waterstop sheet with the second waterstop membrane and the third waterstop membrane is 10 - 20 cm.

[0013] Further, the water stop sheet includes a horizontal section, a vertical section, and a hook section that are connected in sequence, and the horizontal section, the vertical section, and the hook section are connected to form a right-angled hook shape, and the hook section extends out of the panel.

[0014] Further, a water stop rod is placed at the top of the structural joint.

[0015] Further, the water stop rod is made of PVC material.

[0016] Further, the diameter of the water stop rod is 3 - 5 cm.

[0017] Further, the water stop sheet is made of red copper.

[0018] Further, the plastic filler is filled into a bulging shape, and the plastic filler protrudes from the surfaces of the first concrete panel and the second concrete panel by a certain height.

[0019] Further, a V-shaped notch is formed at the top of the structural joint, a water stop rod is placed at the bottom of the V-shaped notch, and the plastic filler is filled in the V-shaped notch. The plastic filler is filled into a bulging shape and protrudes from the surfaces of the first concrete panel and the second concrete panel by a certain height.

[0020] Based on the same inventive concept, the present invention also provides a construction method for the surface water stop structure of the rockfill dam panel joint, which includes the following steps:

[0021] Before the pouring of the first concrete panel and the second concrete panel, the second water stop film is lapped on the upper surface of the extending panel end of the water stop sheet, the third water stop film is lapped on the lower surface of the extending panel end of the water stop sheet, and the upper surface of the extending panel end of the water stop sheet and the second water stop film are extruded and fused into a whole, the lower surface of the extending panel end of the water stop sheet and the third water stop film are extruded and fused into a whole, and the second water stop film and the third water stop film are formed into a whole by hot melt welding;

[0022] When the first concrete panel and the second concrete panel are poured, the water stop sheet is pre-embedded in the first concrete panel and the second concrete panel respectively, so that the lower end of the water stop sheet forms a whole with the concrete, and the extending panel end of the water stop sheet is exposed;

[0023] After the pouring of the first concrete panel and the second concrete panel is completed, first, a plastic filler with a certain modulus is filled at the top of the structural joint, then the first water stop film is used to cover the plastic filler on the structural joint, and the first water stop film and the second water stop film fused on the water stop sheet are formed into a whole by hot melt welding.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1) The present invention forms an integral sealed anti-seepage system by using a water stop sheet, a water stop film for water stop, and concrete panels (the first concrete panel and the second concrete panel), ensuring the surface water stop effect of the structural joint between the first concrete panel and the second concrete panel.

[0026] 2) The present invention pre-buries the water stop sheet in the concrete of the first concrete panel and the second concrete panel, enabling a completely sealed water stop effect around the water stop sheet. At the same time, the geomembrane is compounded on the water stop sheet by the blown film extrusion process to form a sealed whole, improving the water stop effect between the two.

[0027] 3) The present invention uses the first water stop film to cover the structural joint and thermally welds the first water stop film to the second water stop film reserved on the water stop sheet, replacing the bolt anchoring connection method used in the traditional method, thereby achieving a complete seal between the water stop sheet and the first water stop film, greatly improving the anti-seepage effect of the surface water stop and enhancing the safety of the dam. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of the present invention.

[0030] Figure 2 It is a schematic structural diagram of the water stop sheet.

[0031] Figure 3 It is a schematic diagram of the overlap of the water stop sheet and the second water stop film.

[0032] Figure 4 It is a schematic diagram of the overlap of the water stop sheet and the third water stop film.

[0033] Figure 5 It is a schematic diagram of the overlap state of the water stop sheet with the second and third water stop films.

[0034] In the figure: 1. The first concrete panel, 2. The structural joint, 3. The water stop bar, 4. The water stop sheet, 5. The second water stop film, 6. The third water stop film, 7. The plastic filler, 8. The first water stop film, 9. The connection through hole, 10. The second concrete panel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following further describes the present invention in conjunction with specific preferred embodiments, but does not limit the protection scope of the present invention thereby.

[0036] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Please refer to Figure 1 - Figure 5 An embodiment of the water stop structure for the joint surface of the rockfill dam panel of the present invention includes a first concrete panel 1 and a second concrete panel 10. There is a structural joint 2 between the first concrete panel 1 and the second concrete panel 10. Water stop sheets 4 are respectively embedded in the first concrete panel 1 and the second concrete panel 10. One end of the water stop sheet 4 extends out of the concrete panel and overlaps with a second water stop film 5 and a third water stop film 6. The second water stop film 5 and the upper surface of the water stop sheet 4 are integrally formed by extrusion fusion, and the third water stop film 6 and the lower surface of the water stop sheet 4 are integrally formed by extrusion fusion. The top of the structural joint 2 is filled with a plastic filler 7, and a first water stop film 8 is covered on the plastic filler 7. The first water stop film 8, the second water stop film 5, and the third water stop film 6 are integrally formed by hot melt welding.

[0039] To further improve the connection sealing performance between the water stop sheet 4 and the second water stop film 5 and the third water stop film 6, a number of connection through holes 9 are arranged at the end of the water stop sheet 4 extending out of the panel. The upper surface of the connection through holes 9 is covered with the second water stop film 5, and the lower surface is covered with the third water stop film 6. Moreover, the second water stop film 5 and the third water stop film 6 on the upper and lower surfaces of the connection through holes 9 and the second water stop film 5 and the third water stop film 6 outside the water stop sheet 4 are respectively integrally formed by hot melt welding. To ensure that the second water stop film 5 and the third water stop film 6 on the upper and lower surfaces of the water stop sheet 4 can be continuously integrally formed by hot melt connection, the number of connection through holes 9 is distributed in a plum blossom shape or an equilateral triangle shape.

[0040] The water stop 4 is preferably made of copper. The thickness of the water stop 4 is generally 0.8 - 1.2 mm. The thicknesses of the first water stop film 8, the second water stop film 5, and the third water stop film 6 are generally 0.8 - 2.0 mm. The overlapping lengths of the water stop 4 with the second water stop film 5 and the third water stop film 6 are 10 - 20 cm.

[0041] To ensure that the water stop 4 is firmly cast with the concrete panel (panel or toe slab), and at the same time prevent the seepage around the contact surface between the water stop 4 and the concrete under high water heads, as Figure 2 shown, the water stop 4 includes a horizontal section 41, a vertical section 42, and a hook section 43 that are connected in sequence, and the horizontal section 41, the vertical section 42, and the hook section 43 are connected to form a right-angled hook shape. The length of the horizontal section 41 can be selected as 5 - 10 cm according to needs, and the hook section 43 extends out of the concrete panel.

[0042] In this embodiment, the water stop film is preferably made of a geomembrane that can be used for hot melt connection, or a rubber film, or a composite TPO film and a TPO geomembrane.

[0043] The construction method of the surface water stop structure of the rockfill dam panel joint of the present invention specifically includes: before the pouring of the first concrete panel 1 and the second concrete panel 10, first, the overlapping part of the upper surface of the water stop 4 and the second water stop film 5 is subjected to extrusion compounding, and the overlapping part is fused to form a whole. Then, the lower surface of the water stop 4 and the third water stop film 6 are extruded and compounded into a whole. Then, at the position of the connection through hole 9 of the water stop 4, the second water stop film 5 and the third water stop film 6 are welded together by hot melt, so that the water stop 4 is tightly fixed with the second water stop film 5 and the third water stop film 6. Finally, the parts of the second water stop film 5 and the third water stop film 6 outside the water stop 4 are welded by hot melt to form a whole.

[0044] When the first concrete panel 1 and the second concrete panel 10 are poured, the water stop 4 is embedded in the first concrete panel 1 and the second concrete panel 10 respectively, so that the lower end of the water stop 4 forms a whole with the concrete, and the end of the water stop 4 extending out of the panel (hook section 43) is exposed.

[0045] After the pouring of the first concrete panel 1 and the second concrete panel 10 is completed, first place a PVC rod 3 on the top of the structural joint 2. The PVC rod 3 has a certain elastic modulus to prevent the plastic filler 7 from being pressed into the gap of the structural joint 2 under high water pressure. The diameter of the PVC rod 3 is generally 3 - 5 cm according to actual needs; then fill the "V"-shaped notch at the top of the structural joint 2 with a plastic filler 7 having a certain modulus. The plastic filler 7 is made into a bulge shape, protruding a certain height from the surfaces of the first concrete panel 1 and the second concrete panel 10 to prevent the plastic filler 7 from being squeezed and collapsed into the structural joint 2 under high water heads; finally, thermally weld the first water stop film 8 and the second water stop film 5 fused to the water stop piece 4 to form a sealed whole.

[0046] As described above, the above are only specific implementation schemes of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A rockfill dam panel seam surface water stop structure, comprising a first concrete panel and a second concrete panel, wherein a structural seam is provided between the first concrete panel and the second concrete panel, wherein the structural seam is filled with a plastic filler, and wherein the plastic filler is covered with a first water stop film, wherein: Waterstop plates are embedded in the first concrete panel and the second concrete panel respectively, one end of the waterstop plate extends out of the panel and overlaps the second waterstop membrane and the third waterstop membrane, the second waterstop membrane and the upper surface of the waterstop plate are fused together by extrusion to form a whole, the third waterstop membrane and the lower surface of the waterstop plate are fused together by extrusion to form a whole, and the first waterstop membrane, the second waterstop membrane and the third waterstop membrane are formed as a whole by hot melt welding.

2. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: The end of the water stop plate extending out of the panel is provided with a plurality of connecting through holes, the upper surface of the connecting through hole is covered with a second water stop film, and the lower surface is covered with a third water stop film, and the second water stop film and the third water stop film on the upper and lower surfaces of the connecting through hole and the second water stop film and the third water stop film outside the water stop plate are respectively hot-melt welded into a whole.

3. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: The overlapping length between the water-stop sheet and the second water-stop membrane and the third water-stop membrane is 10-20 cm.

4. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: The water stop plate comprises a horizontal section, a vertical section and a hook section which are connected in sequence, and the horizontal section, the vertical section and the hook section are connected to form a right-angle hook shape, and the hook section extends out of the panel.

5. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: A water stop rod is placed on the top of the structural joint.

6. The rockfill dam face plate seam surface water stop structure according to claim 5, characterized in that: The water stop rod is made of PVC material, and the diameter of the water stop rod is 3-5cm.

7. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: The water stop plate is made of red copper.

8. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: The plastic filler is filled into a bulge shape, and the plastic filler protrudes from the surfaces of the first concrete panel and the second concrete panel by a certain height.

9. The rockfill dam face plate seam surface water stop structure according to claim 1, characterized in that: A V-shaped notch is formed at the top of the structural joint, a water stop rod is placed at the bottom of the V-shaped notch, and the V-shaped notch is filled with the plastic filler. The plastic filler is filled into a bulge shape and protrudes a certain height from the surface of the first concrete panel and the second concrete panel.

10. A construction method for a rockfill dam face plate seam surface water stop structure according to any one of claims 1 to 9, characterized in that The following steps are involved: Before the first concrete panel and the second concrete panel are cast, the second water stop film is overlapped on the upper surface of the end of the water stop sheet extending out of the panel, and the third water stop film is overlapped on the lower surface of the end of the water stop sheet extending out of the panel, and the upper surface of the end of the water stop sheet extending out of the panel and the second water stop film are squeezed and fused to form a whole, and the lower surface of the end of the water stop sheet extending out of the panel and the third water stop film are squeezed and fused to form a whole, and the second water stop film and the third water stop film are formed into a whole by hot melt welding; When the first concrete panel and the second concrete panel are cast, the water stop plate is embedded in the first concrete panel and the second concrete panel respectively, so that the lower end of the water stop plate is integrated with the concrete, and the end of the water stop plate extending out of the panel is exposed; After the first concrete panel and the second concrete panel are cast, a plastic filler with a certain modulus is first filled on the top of the structural joint, and then the plastic filler on the structural joint is covered with a first water-stop membrane, and the first water-stop membrane and the second water-stop membrane fused on the water-stop plate are hot-melt welded to form a whole.

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