Geomembrane inclined wall anti-seepage sand gravel dam structure

Abstract

The invention discloses a geomembrane inclined wall anti-seepage sand gravel dam structure which comprises a concrete base, a dam body and a dam crest with a wave wall, the concrete base is arranged at the upstream bottom of the dam body, the dam crest is arranged at the top of the dam body, a composite geomembrane is laid in the direction from a dam slope on the dam body to the dam crest, and the wave wall is arranged on the dam crest. The lower end of the composite geomembrane is connected with the concrete base in an anti-seepage mode, and the upper end of the composite geomembrane is anchored to a wave wall of the dam crest. The dam body composite geomembrane is connected with the concrete base and the wave wall of the dam crest, the upstream dam body is closed for seepage prevention, and the seepage prevention safety of the dam body is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of water conservancy engineering, and in particular relates to a geomembrane inclined wall anti-seepage gravel dam structure. Background Art

[0002] With the development of geosynthetics and the continuous improvement and maturity of design and construction technology systems, geomembranes have been widely used in water conservancy and anti-seepage projects due to their excellent anti-seepage properties, strong ability to adapt to foundation deformation, good tensile properties, convenient construction and low cost.

[0003] Gravel dam anti-seepage mainly consists of two parts: dam foundation and dam body anti-seepage. Foundation anti-seepage is generally achieved by setting a concrete base on the bedrock surface, and then consolidation grouting and curtain grouting on the base. Dam body anti-seepage mostly uses asphalt concrete, reinforced concrete panels, clay, geomembranes and other materials as core walls or inclined walls for anti-seepage. Asphalt concrete and reinforced concrete are rigid anti-seepage bodies, and copper water stops are set at the connection with the dam foundation anti-seepage body as the anti-seepage design of the joint. Clay core walls are generally made larger and wider foundations to play an anti-seepage role by increasing the seepage path. The above three anti-seepage technologies are mature and reliable and widely used, but they have disadvantages such as high engineering cost, large environmental impact, and complex construction process. As a new polymer material, geomembranes are thin, excellent in material properties, and low in price, and are gradually being widely used in reservoir dam projects. However, in actual practice, due to irregularities in design and construction, the connection between the geomembrane and the surrounding rigid buildings is not sealed, and the anti-seepage structure layer is not set up reasonably. This leads to water leakage in the dam body during operation, and in severe cases even threatens the safety of the dam body. Summary of the invention

[0004] The purpose of the present invention is to provide a geomembrane inclined wall anti-seepage gravel dam structure, which connects the dam body composite geomembrane with the concrete base and the wave-breaking wall on the dam top to seal the upstream dam body for anti-seepage and ensure the anti-seepage safety of the dam body.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A geomembrane inclined wall anti-seepage gravel dam structure comprises a concrete base, a dam body, and a dam crest with a wave-breaking wall. The concrete base is arranged at the upstream bottom of the dam body, the dam crest is arranged at the top of the dam body, a composite geomembrane is laid along the upstream dam slope of the dam body toward the dam crest, the lower end of the composite geomembrane is connected to the concrete base for anti-seepage, and the upper end of the composite geomembrane is anchored to the wave-breaking wall on the dam crest.

[0007] Preferably, the anti-seepage connection structure between the composite geomembrane and the concrete base is as follows: a bare geomembrane is sealingly connected to the side of the concrete base facing the dam body, and the bare geomembrane is welded to the lower end of the composite geomembrane of the dam body.

[0008] Preferably, two rows of bolts are embedded in the concrete base, and a steel plate is embedded in the lower row of bolts toward one side of the concrete base. A gripping rib is provided on the side of the steel plate facing the concrete base. KS anti-seepage primer, a first chloroprene rubber gasket, KS anti-seepage primer, and a bottom layer of smooth geomembrane are arranged in sequence from the inside to the outside on the anchoring surface of the concrete base. The bottom layer of smooth geomembrane is welded and connected to the composite geomembrane. KS anti-seepage primer and a first chloroprene rubber gasket are arranged in sequence on the outer surface of the bottom layer of smooth geomembrane from the inside to the outside. Galvanized channel steel, galvanized flat steel, and spring gasket are arranged in sequence from the inside to the outside on the outermost surface of the first chloroprene rubber gasket, and a nut is arranged on the outside of the spring gasket.

[0009] Preferably, a semicircular bulge is filled at the dam body with the bolt as the center, and the outermost layer of the semicircular bulge is wrapped with a light film geomembrane. The upper part of the outer light film geomembrane is anchored by the upper row of bolts, and the light film geomembrane is adhered to the surface of the concrete base. The lower part of the outer light film geomembrane is adhered to the bottom light film geomembrane by the KS anti-seepage primer, and the outer edges of both sides of the outer light film geomembrane are provided with edge sealing agents.

[0010] Preferably, a lower supporting layer is provided below the composite geomembrane, the lower supporting layer adopts a medium-coarse sand cushion layer, an upper protective layer is provided above the composite geomembrane, the upper protective layer adopts a mortar cushion layer, and a concrete slope protection is poured on the mortar cushion layer.

[0011] Preferably, the composite geomembrane of the dam body is laid along the upstream dam slope toward the dam top, and when it reaches the bottom elevation of the concrete cushion layer of the wave-breaking wall, it goes horizontally toward the dam body, and the end goes around behind the wave-breaking wall and is connected to the wave-breaking wall by nailing.

[0012] Preferably, a second chloroprene rubber gasket is provided between the wave-breaking wall and the composite geomembrane, a galvanized flat steel is provided on the composite geomembrane, and the nails are driven into the concrete to achieve nail anchoring of the composite geomembrane and the wave-breaking wall.

[0013] Preferably, consolidation grouting is provided below the concrete base, curtain grouting is provided below the consolidation grouting, and an excavated material cover weight is provided above the concrete base.

[0014] The beneficial effect of the present invention is that the composite geomembrane of the dam body is connected with the concrete foundation and the wave-breaking wall on the dam top, the upstream dam body is sealed to prevent seepage, and the safety of the dam body is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of the geomembrane inclined wall anti-seepage gravel dam of the present invention.

[0016] Figure 2It is a detailed view of the junction between the geomembrane inclined wall of the dam body and the anti-seepage of the dam foundation of the present invention.

[0017] Figure 3 It is a detailed diagram of the anchor connection structure between the composite geomembrane of the dam body and the concrete of the foundation according to the present invention.

[0018] Figure 4 It is a detailed view of the junction between the composite geomembrane of the dam body and the wave-breaking wall on the dam top of the present invention.

[0019] Figure 5 It is a detailed drawing of the nail anchoring structure of the dam body geomembrane and the dam top wave-breaking wall of the present invention.

[0020] In the figure: 1. Concrete base; 2. Consolidation grouting; 3. Curtain grouting; 4. Composite geomembrane; 5. Upstream dam slope; 6. Stainless steel railings; 7. Wave-breaking wall; 8. Dam top road; 9. Guardrails; 10. Medium-coarse sand cushion layer; 11. Mortar cushion layer; 12. Concrete slope protection; 13. Grab bars; 14. Bolts; 15. Steel plate; 16. KS anti-seepage primer; 17. First chloroprene rubber gasket; 18. Smooth film geomembrane; 19. Galvanized channel steel; 20. Galvanized flat steel; 21. Nuts; 21-1, spring gasket; 22, semicircular bulge; 23, edge sealing agent; 24, wave-breaking wall concrete cushion layer; 25, nails; 26, second chloroprene rubber gasket; 27, excavation material cover weight; 28, double seam welding. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0022] like Figures 1 to 5 As shown, a geomembrane inclined wall anti-seepage gravel dam structure includes a concrete base, a dam body, and a dam crest with a wave-breaking wall. A concrete base is arranged at the upstream bottom of the dam body, a dam crest is arranged on the top of the dam body, and a composite geomembrane 4 is laid along the upstream dam slope 5 of the dam body toward the dam crest. The lower end of the composite geomembrane 4 is anti-seepage connected to the concrete base, and the upper end of the composite geomembrane 4 is nailed and anchored to the wave-breaking wall 7 on the dam crest.

[0023] The side of the dam foundation concrete base 1 facing the dam body is sealed with a light film geomembrane 18, and the light film geomembrane 18 is welded to the lower end of the dam body composite geomembrane 4. The dam body composite geomembrane 4 is connected with the concrete base 1 and the wave-breaking wall 7 on the top of the dam to seal the upstream dam body from seepage and ensure the safety of the dam body from seepage. The specific steps are as follows:

[0024] Dam foundation anti-seepage:

[0025] The foundation surface of the concrete base 1 of the dam foundation is determined according to the height of the earth-rock dam. The high dam is excavated to the weakly weathered upper part, and the medium and low dams are excavated to the strongly weathered lower part. After the concrete is poured, the concrete base 1 is formed. The concrete base 1 is generally 5.0m long and 1.0m high. The consolidation grouting 2 is carried out below the concrete base 1, mainly to improve the integrity and strength of the bedrock at the bottom of the anti-seepage body. The drilling depth is 5.0~10.0m, and it is generally arranged in 2 rows with a hole spacing of 3.0~4.0m. After the consolidation grouting 2 is completed, the curtain grouting 3 is carried out. The drilling depth is determined according to factors such as the dam height, the level of the dam building, and the permeability of the bedrock. Generally, the minimum requirement is to go 5.0m below the 10Lu line, with a hole spacing of 1.5-3.0m. The leakage channel is blocked by filling cement slurry into the bedrock cracks, thereby forming an anti-seepage curtain. The curtain grouting 3 is connected to the concrete base 1 as a whole, and they jointly bear the anti-seepage function of the dam foundation.

[0026] Anti-seepage connection between geomembrane and concrete base 1:

[0027] The concrete base 1 is connected to the bare geomembrane 18 by bolts, and the bare geomembrane 18 is connected to the dam body composite geomembrane 4 by double seam welding 28 .

[0028] Before pouring the concrete of the concrete base 1, two rows of bolts 14 are pre-buried in the concrete base 1 according to the positioning. The bolts 14 have a specification of M10×250mm and a row spacing of 20cm. In order to ensure the flatness of the lower row core anchoring surface, the lower row of bolts 14 are pre-buried with a steel plate 15 facing the side of the concrete base. The steel plate 15 is welded with a gripping rib 13 facing the side of the concrete base, with a diameter of 10mm, so that the steel plate 15 is firmly combined with the concrete of the concrete base 1 to achieve an anchoring connection. After the concrete pouring of the concrete base 1 is completed, the anchoring component is first brushed with two coats of KS anti-seepage primer 16 on the anchoring surface of the concrete base 1. The KS anti-seepage primer 16 uses KS glue specially used for geomembranes. A layer of the first chloroprene rubber gasket 17 is laid on the anti-seepage primer 16. The thickness of the first chloroprene rubber gasket 17 is 10mm and the width is 25cm-30cm. Then, a layer of KS anti-seepage primer 16 is applied on the first chloroprene rubber gasket 17, and a bottom-layer smooth geomembrane 18 is laid and pasted on the KS anti-seepage primer 16. The bottom-layer smooth geomembrane 18 and the dam body composite geomembrane 4 are connected to form a closed whole by welding. A layer of KS anti-seepage primer 16 is applied on the outer surface of the bottom-layer smooth geomembrane 18, and then a layer of the first chloroprene rubber gasket 17 is laid on the outer surface of the KS anti-seepage primer 16. At this time, the smooth geomembrane 18 is connected to the concrete base 1, and the final bolt anchoring is required.

[0029] The lower row of anchors continues to lay out 10# galvanized channel steel 19, and the galvanized channel steel 19 is set on the surface of the outermost first chloroprene rubber gasket 17. The bolt 14 passes through the center of the galvanized channel steel 19, and a row of galvanized flat steels 20 are arranged on the surface of the galvanized channel steel 19 in sequence. The spring gasket 21-1 is arranged on the surface of the galvanized flat steel, and finally anchored through the outermost nut 21. The specification of the galvanized flat steel 20 is 40mm×3.0mm. In order to enhance the sealing and durability of the core anchor, a semicircular bulge 22 with a radius of about 10cm is filled at the dam body with the bolt 14 as the center. The semicircular bulge 22 uses SR plastic filling material, and the outermost layer of the semicircular bulge is wrapped with a light film geomembrane 18. The upper part of the outer smooth film geomembrane 18 is anchored by an upper row of bolts, and the outer smooth film geomembrane 18 is adhered to the concrete surface of the concrete base 1. The lower part of the outer smooth film geomembrane 18 is adhered to the bottom smooth film geomembrane 18 by a KS anti-seepage primer 16. The outer edges of both sides of the outer smooth film geomembrane 18 are treated with an edge sealing agent 23, and the edge sealing agent 23 is selected from polyurethane glue.

[0030] After the light film geomembrane 18 is bolted to the concrete base 1 and welded to the composite geomembrane 4 of the dam body, it is necessary to backfill the space between the slope and the tooth groove of the concrete base 1. In order to ensure that the light film geomembrane 18 is not punctured by sharp debris, a medium-coarse sand cushion layer 10 is filled under the light film geomembrane 18, and a mortar cushion layer 11 is laid on the light film geomembrane 18. The tooth groove slope is a 5 cm thick slope-fixing mortar. Keep it in a relaxed state during laying to avoid damage caused by high stress. After completion, the upper slope protection is constructed. After the slope protection is completed, the excavated material cover 27 on the concrete base 1 is backfilled for protection.

[0031] Dam body anti-seepage:

[0032] The dam shell material is filled at the bottom of the dam body, and an anti-seepage structure layer is set on the upstream slope 5 of the dam body. The anti-seepage structure layer is divided into a lower support layer, an anti-seepage layer and an upper protective layer from bottom to top. The specific steps are as follows:

[0033] A layer of composite geomembrane 4 is laid along the upstream dam slope 5 of the dam body toward the dam top, a lower support layer is arranged below the composite geomembrane 4 , and an upper protective layer is arranged above the composite geomembrane 4 .

[0034] Composite geomembrane 4 uses two cloths and one film. The film thickness is determined according to the project level, and the minimum is not less than 0.50mm. The film is made of polyethylene PE film. The geotextile is made of polyester filament spunbonded needle-punched non-woven geotextile with strong puncture resistance, and the specifications are generally 300g~500g / m 2 .

[0035] The lower support layer adopts a 20cm thick medium-coarse sand cushion layer 10, which mainly functions to even out the stress and discharge the water seepage under the membrane. To prevent the water seepage cushion layer from being damaged by frost heave, the mud content of the medium-coarse sand (particle size 0.075mm) is required to be less than 8.0%.

[0036] The upper protective layer is a 5cm thick M10.0 mortar cushion 11, on which a 20cm thick concrete slope protection 12 is poured. The concrete slope protection 12 is poured in blocks, and the block size is 3.0m×5.0m. The mortar cushion 11 is laid on the composite geomembrane 4 to avoid damage to the composite geomembrane 4 caused by personnel walking, equipment moving, template operation, etc. on the composite geomembrane 4 during construction. Secondly, the mortar cushion 11 is covered in time to prevent the impact of bad weather such as strong winds on the composite geomembrane 4 during construction.

[0037] The slope ratio of the concrete slope protection 12 is calculated based on the stability of the composite geomembrane 4 itself, and is generally 1:2.50~3.0.

[0038] Crest connection:

[0039] The composite geomembrane 4 of the dam body is laid along the upstream dam slope 5 toward the dam top, and when it reaches the bottom elevation of the wave-breaking wall concrete cushion layer 24, it goes horizontally toward the dam body, and the end goes around to the back of the wave-breaking wall 7, and is connected to the wave-breaking wall 7 by nails 25. The elevation of the anchor connection point should be higher than the highest static water level of the reservoir. A platform is set on the slope protection on the waterfront side in front of the wave-breaking wall 7. The platform width is 1.0m to 1.5m, and the slope ratio is 5% toward the reservoir to facilitate timely drainage. The platform is mainly used as a construction access road during construction and an inspection channel during operation. Stainless steel railings 6 are arranged on the free side of the upstream dam slope, and protective railings 9 are arranged on the free side of the downstream dam slope. A dam top road is built between the wave-breaking wall 7 and the protective railing 9.

[0040] Since the anchor point of wave-breaking wall 7 is higher than the highest water level of the reservoir, its main function is anchoring. The specific steps are as follows:

[0041] Through measurement and positioning, a second chloroprene rubber gasket 26 is laid along the anchor point of the wave-breaking wall 7. The second chloroprene rubber gasket 26 has a thickness of 10 mm and a width of 50 mm. The composite geomembrane 4 is arranged on the second chloroprene rubber gasket 26, and a layer of galvanized flat steel 20 is pressed on the composite geomembrane 4. The galvanized flat steel 20 has a specification of 40 mm×3.0 mm. After everything is completed, the nails 25 are shot into the concrete through special equipment to achieve the nail anchoring of the composite geomembrane 4 and the wave-breaking wall 7. The nail 25 is 42 mm long and the length shot into the concrete is not less than 30 mm.

[0042] After the nails 25 are anchored and connected to the wave-breaking wall 7, the dam shell material is filled behind the wave-breaking wall 7.

Claims

1. A geomembrane inclined wall anti-seepage gravel dam structure, characterized in that: It includes a concrete foundation, a dam body, and a dam crest with a wave-breaking wall. The concrete foundation is arranged at the upstream bottom of the dam body, the dam crest is arranged on the top of the dam body, and a composite geomembrane is laid along the upstream dam slope of the dam body toward the dam crest. The lower end of the composite geomembrane is connected to the concrete foundation for anti-seepage, and the upper end of the composite geomembrane is anchored to the wave-breaking wall on the dam crest.

2. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 1 is characterized in that: The anti-seepage connection structure between the composite geomembrane and the concrete base is as follows: the side of the concrete base facing the dam body is sealed with a bare geomembrane, and the bare geomembrane is welded to the lower end of the composite geomembrane of the dam body.

3. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 2 is characterized in that: Two rows of bolts are embedded in the concrete base, and a steel plate is embedded in the lower row of bolts toward one side of the concrete base. A gripping rib is arranged on the side of the steel plate facing the concrete base. KS anti-seepage primer, a first chloroprene rubber gasket, KS anti-seepage primer, and a bottom layer of smooth geomembrane are arranged in sequence from the inside to the outside on the anchoring surface of the concrete base. The bottom layer of smooth geomembrane is welded and connected to the composite geomembrane. KS anti-seepage primer and a first chloroprene rubber gasket are arranged in sequence on the outer surface of the bottom layer of smooth geomembrane from the inside to the outside. Galvanized channel steel, galvanized flat steel, and spring gasket are arranged in sequence from the inside to the outside on the outermost surface of the first chloroprene rubber gasket, and a nut is arranged on the outside of the spring gasket.

4. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 3 is characterized in that: A semicircular bulge is filled at the dam body with the bolt as the center, and the outermost layer of the semicircular bulge is wrapped with a light film geomembrane. The upper part of the outer light film geomembrane is anchored by the upper row of bolts, and the light film geomembrane is adhered to the surface of the concrete base. The lower part of the outer light film geomembrane is adhered to the bottom light film geomembrane by the KS anti-seepage primer, and the outer edges of both sides of the outer light film geomembrane are provided with edge sealing agents.

5. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 1 is characterized in that: A lower support layer is arranged below the composite geomembrane, and the lower support layer adopts a medium-coarse sand cushion layer. An upper protective layer is arranged above the composite geomembrane, and the upper protective layer adopts a mortar cushion layer. Concrete slope protection is poured on the mortar cushion layer.

6. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 1 is characterized in that: The composite geomembrane of the dam body is laid along the upstream dam slope toward the dam top, and when it reaches the bottom elevation of the concrete cushion layer of the wave-breaking wall, it goes horizontally toward the dam body, and the end goes around behind the wave-breaking wall and is connected to the wave-breaking wall by nailing.

7. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 6 is characterized in that: A second chloroprene rubber gasket is arranged between the wave-breaking wall and the composite geomembrane, a galvanized flat steel is arranged on the composite geomembrane, and the nails are inserted into the concrete to realize the nail anchoring of the composite geomembrane and the wave-breaking wall.

8. The geomembrane inclined wall anti-seepage gravel dam structure according to claim 1 is characterized in that: Consolidation grouting is arranged below the concrete base, curtain grouting is arranged below the consolidation grouting, and excavation material cover weight is arranged above the concrete base.

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