Double - line flexible anchoring structure of geomembrane of core wall of dam body and foundation concrete structure

Abstract

The present invention relates to a double - defense flexible anchoring structure for a geomembrane of a dam core wall and a foundation concrete structure. The object of the present invention is a double - defense flexible anchoring structure for a geomembrane of a dam core wall and a foundation concrete structure, which is used to fix the geomembrane in the dam to the underlying foundation concrete. The technical solution of the present invention is as follows: an anchoring groove is provided on the top surface of the foundation concrete. The anchoring groove is divided into a plastic deformation zone filled with plastic filler on the upstream side and an anchoring mechanism on the downstream side. The geomembrane passes through the plastic deformation zone and is fixed in the downstream side of the plastic deformation zone by the anchoring mechanism. The present invention is applicable to projects that use geomembranes as the anti - seepage core wall in the middle of the dam.

Description

Technical Field

[0001] The present invention relates to a double - defense flexible anchoring structure for the geomembrane of the core wall of a dam and the foundation concrete structure, which is applicable to projects using geomembrane as the anti - seepage core wall in the middle of the dam. Background Art

[0002] Placing the geomembrane in the middle of the dam to form a rock - fill dam with a geomembrane core wall can effectively isolate ultraviolet rays, extend the service life of the geomembrane, and at the same time avoid external damages such as rolling stones and organisms during the operation of the geomembrane. However, research results show that during the operation of the geomembrane core wall at the anchoring part with the concrete structure at the bottom, large tensile stresses will be generated, resulting in damage to the connection part. The main reason is that after impounding water, the anti - seepage body moves downstream under the thrust of the water load, generating a dislocation displacement at the anchoring part. Affected by the "clamping effect", the geomembrane undergoes large local stretching deformation, leading to the concentration of tensile stress. Local tensile stress concentration may cause problems such as tearing damage of the geomembrane or anchoring failure. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: in view of the above - mentioned problems, to provide a double - defense flexible anchoring structure for the geomembrane of the core wall of a dam and the foundation concrete structure with a reliable anti - seepage effect and capable of effectively releasing deformation, so as to ensure the safe and stable operation of the rock - fill dam with a geomembrane core wall under various adverse working conditions and conditions such as high water head and soft dam - filling materials.

[0004] The technical solution adopted by the present invention is: a double - defense flexible anchoring structure for the geomembrane of the core wall of a dam and the foundation concrete structure, which is used to fix the geomembrane in the dam to the underlying foundation concrete. It is characterized in that: an anchoring groove is provided on the top surface of the foundation concrete. The anchoring groove is divided into a plastic deformation zone filled with plastic filler on the upstream side and an anchoring mechanism on the downstream side. The geomembrane passes through the plastic deformation zone and is fixed in the downstream side of the plastic deformation zone through the anchoring mechanism.

[0005] The anchoring mechanism includes a bottom glue, a plastic filler, a rubber cover sheet, and a plastic filler arranged in sequence on the bottom surface of the anchoring groove. The core - wall geomembrane is laid on the plastic filler, and a rubber cover sheet is laid on the core - wall geomembrane and is pressed tightly by an angle steel in cooperation with bolts and nuts.

[0006] Secondary concrete is poured in the anchoring groove and presses on the anchoring mechanism.

[0007] The secondary concrete is connected to the foundation concrete through anchor bars.

[0008] Geotextile and a fine sand layer are sequentially laid on the surface of the secondary concrete and the plastic deformation zone.

[0009] The plastic deformation zone includes a base glue and a plastic filler sequentially disposed on the bottom surface and the upstream side wall of the anchorage groove. The plastic filler forms a semi-circular plastic filler bulge near the anchorage mechanism, and the surface of the plastic filler is attached to the geomembrane, and the upper part of the geomembrane is filled with the plastic filler.

[0010] In the plastic deformation zone, the downstream side of the plastic filler filled above the geomembrane remains upright and the bottom is arc-shaped.

[0011] The cross-section of the anchorage groove is a trapezoid with a larger upper part and a smaller lower part, and the top corners on the upstream side are in the shape of an arc or an elliptical arc.

[0012] A dam, characterized in that it has a foundation concrete, a dam body with a geomembrane inside, and a double-line flexible anchorage structure for the geomembrane of the dam body core wall and the foundation concrete structure.

[0013] A construction method for a double-line flexible anchorage structure of the geomembrane of the dam body core wall and the foundation concrete structure, characterized in that:

[0014] Construct the foundation concrete, reserve the anchorage groove, and preset anchor bars on the downstream side wall of the groove.

[0015] After cleaning and drying the anchorage groove, apply the base glue along the downstream side of the bottom surface of the anchorage groove, and sequentially lay the plastic filler, rubber cover sheet, plastic filler, the geomembrane and the rubber cover sheet. Angle steel is pressed on the rubber cover sheet and tightened with bolts and nuts to form an anchorage mechanism.

[0016] After cleaning and drying the upstream side part of the anchorage groove, apply the base glue on the bottom and upstream side wall of the upstream side of the anchorage groove, and lay the plastic filler. The plastic filler forms a semi-circular plastic filler bulge near the anchorage mechanism, and attach the geomembrane along the surface of the plastic filler.

[0017] The upper part of the geomembrane in the upstream side part of the anchorage groove is filled with the plastic filler. The downstream side of the plastic filler remains upright and the bottom is arc-shaped.

[0018] After the plastic filler is filled on the upstream side of the anchorage groove, a cavity is formed on the downstream side, and secondary concrete is poured in the cavity to press the anchorage mechanism.

[0019] A layer of geotextile and a fine sand layer are sequentially laid on the surfaces of the plastic filler filled on the upstream side of the anchorage groove and the secondary concrete poured on the downstream side, and the dam body is filled according to the dam cross-section design on the upper part.

[0020] The beneficial effect of the present invention is that: the present invention utilizes the plastic filler to form a plastic deformation zone between the anchorage mechanism and the dam rockfill. Since the plastic deformation zone is on the upstream side of the anchorage structure, when the geomembrane core wall of the dam deflects downstream after impounding water, the deformation of the plastic deformation zone on the downstream side of the geomembrane can effectively eliminate the generation of the tensile stress of the geomembrane and improve the operation safety of the geomembrane core wall.

[0021] In the present invention, secondary concrete is poured on the upper part of the anchoring mechanism, and a semi-circular plastic filler bulge is reserved upstream of the anchoring mechanism. When large deformation occurs at the edge of the anchoring mechanism under the most unfavorable conditions, the deformation direction of the geomembrane is adjusted from the horizontal deformation of the traditional anchoring structure to the vertical upward deformation. Since the gravity resistance of the dam body is much greater than the horizontal resistance, the deformation of the mechanically anchored part can be effectively controlled. At the same time, the reserved bulge provides sufficient deformation space, effectively reducing the "clamping effect" of the traditional anchoring structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the overall structure diagram of the dam for the embodiment.

[0023] Figure 2 It is the structural schematic diagram of the anchorage groove part for the embodiment.

[0024] 1. Dam foundation; 2. Foundation concrete; 3. Geomembrane; 4. Dam body; 5-1. Bolt; 5-2. Angle steel; 5-3. Nut; 5-4. Plastic filler; 5-5. Rubber cover sheet; 5-6. Secondary concrete; 5-7. Geotextile; 5-8. Fine sand layer; 5-9. Anchor bar. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] This embodiment is a double-line flexible anchoring structure for the geomembrane of the core wall of the dam body and the foundation concrete structure, which is used to fix the geomembrane in the dam body to the underlying foundation concrete.

[0026] In this example, an anchorage groove is provided on the top surface of the foundation concrete. The anchorage groove is divided into an upstream area and a downstream area. A plastic deformation area is provided in the upstream area of the anchorage groove, and an anchoring mechanism is provided in the downstream area of the anchorage groove. The geomembrane in the dam body passes through the plastic deformation area and is fixed in the anchorage groove through the anchoring mechanism.

[0027] In order to reduce the influence of the anchorage groove on the overall performance of the foundation concrete structure, the anchorage groove is arranged at a position where the thickness of the foundation concrete structure is relatively thick. The anchorage groove has a trapezoidal cross-section that is larger at the top and smaller at the bottom, and the top corners on the upstream side are rounded or elliptical arcs to avoid sharp corners.

[0028] In this embodiment, the anchoring mechanism includes angle steel (or flat steel), bolts and nuts, etc. One to two bottom adhesives, a layer of plastic filler, a layer of rubber cover sheet, a layer of plastic filler, the geomembrane extending from the dam body, and a layer of rubber cover sheet are sequentially laid on the bottom surface of the downstream area of the anchorage groove. The angle steel is pressed on the rubber cover sheet, and the angle steel is fixed to the bottom surface of the anchorage groove through bolts and nuts. By pressing the angle steel tightly, the rubber cover sheet and plastic filler between the geomembrane and the foundation concrete are in a compressed state.

[0029] In this example, the plastic deformation zone includes the bottom surface and the upstream side wall of the upstream area of the anchorage groove, where 1 - 2 coats of primer are applied, a layer of plastic filler is laid, and a semi-circular plastic filler bulge is formed near the bolt anchorage. A geomembrane extending from the dam body is applied along the surface of the plastic filler. In the upstream area of the anchorage groove and above the geomembrane, plastic filler is stuffed. The downstream side of the stuffed plastic filler remains vertical, and the bottom is arc-shaped. The closest distance between the stuffed plastic filler and the anchoring mechanism is controlled within 5 - 10 cm.

[0030] In this embodiment, the primer and plastic filler in the upstream area of the anchorage groove are connected to the primer and plastic filler in the downstream area of the anchorage groove without leaving a blank in the middle.

[0031] In this embodiment, after stuffing plastic filler in the upstream area of the anchorage groove, a cavity is formed above the anchoring mechanism in the downstream area of the anchorage groove, and secondary concrete is poured in the cavity to press on the anchoring mechanism. To strengthen the connection strength between the secondary concrete and the extruded concrete, when pouring the foundation concrete, anchor bars are preset at the position of the downstream side wall of the anchorage groove, and the anchor bars can connect the secondary concrete and the foundation concrete.

[0032] In this embodiment, a layer of geotextile and a fine sand layer are sequentially laid on the top surface of the foundation concrete corresponding to the anchorage groove, and the upper part is filled with the dam body according to the dam section design. The geotextile and the fine sand layer cover the plastic filler in the upstream area of the anchorage groove and the surface of the secondary concrete in the downstream area. The geotextile and the fine sand layer mainly play a protective role, preventing the extrusion damage of the plastic filler caused by the compaction of the coarse-grained soil of the dam body and the loss of the plastic filler under the water pressure during the permanent operation.

[0033] In this embodiment, a double-defense flexible anchoring structure for the geomembrane of the dam core wall and the foundation concrete structure is as follows:

[0034] Construct the foundation concrete on the dam foundation, and reserve an anchorage groove on the top surface. Cast-in-place anchor bars are preset on the downstream side wall of the groove. When the bolts in the anchoring mechanism are cast-in-place anchored, cast-in-place bolts are preset according to the design line and spacing;

[0035] Clean the debris in the groove, and deal with the defects such as pits and sharp corners in the groove that may damage the geomembrane and the uneven parts along the anchoring structure that affect the anti-seepage effect of the anchoring structure; when the bolts in the anchoring mechanism are anchored with post-anchoring agent after drilling, drill holes and embed bolts according to the design line and spacing;

[0036] After cleaning and drying the anchorage groove, apply 1 - 2 coats of primer along the downstream area of the anchorage groove, and sequentially lay a layer of plastic filler, a layer of rubber cover sheet, a layer of plastic filler, a geomembrane extending from the dam body, a layer of rubber cover sheet, press on the angle steel, and install nuts to fasten;

[0037] After cleaning and drying the upstream part of the anchorage groove, apply 1 - 2 layers of primer on the bottom and upstream side wall of the upstream area of the anchorage groove, lay a layer of plastic filler, and form a semi-circular plastic filler bulge near the bolt anchorage. Affix the geomembrane extending from the dam body along the surface of the plastic filler.

[0038] In the upstream area of the anchorage groove, fill plastic filler above the geomembrane. The downstream side of the filled plastic filler remains vertical, and the bottom is arc-shaped. The closest distance between the filling area and the anchoring mechanism is controlled within 5 - 10 cm.

[0039] After filling plastic filler in the upstream area of the anchorage groove, form a cavity above the anchoring mechanism in the downstream area of the anchorage groove, and pour secondary concrete in the cavity to cover the anchoring mechanism.

[0040] Lay a layer of geotextile and a fine sand layer in sequence on the surface of the plastic filler filled in the upstream area of the anchorage groove and the secondary concrete in the downstream area, and fill the dam body according to the dam section design in the upper part.

Claims

1. A double - line flexible anchoring structure for the geomembrane of the core wall of a dam and the foundation concrete structure, which is used to fix the geomembrane in the dam to the underlying foundation concrete. It is characterized in that: An anchorage groove is provided on the top surface of the base concrete. The anchorage groove is divided into a plastic deformation zone filled with plastic filler on the upstream side and an anchoring mechanism on the downstream side. The geomembrane passes through the plastic deformation zone and is fixed in the downstream side of the plastic deformation zone by the anchoring mechanism; Secondary concrete is poured in the anchorage groove to cover the anchoring mechanism; A geotextile and a fine sand layer are sequentially laid on the surfaces of the secondary concrete and the plastic deformation zone; The plastic deformation zone includes a bottom glue and a plastic filler sequentially arranged on the bottom surface and the upstream side wall of the anchorage groove. The plastic filler forms a semi-circular plastic filler bulge near the anchoring mechanism. The geomembrane is attached to the surface of the plastic filler, and the upper part of the geomembrane is filled with plastic filler.

2. The double-defense flexible anchoring structure of the geomembrane of the core wall of the dam and the foundation concrete structure according to claim 1, wherein: The anchoring mechanism includes a bottom glue, a plastic filler, a rubber cover sheet, and a plastic filler sequentially arranged on the bottom surface of the anchorage groove. The core wall geomembrane is laid on the plastic filler, and a rubber cover sheet is laid on the core wall geomembrane and is pressed tightly by an angle steel in cooperation with bolts and nuts.

3. The double-line flexible anchoring structure of the geomembrane of the core wall of the dam and the foundation concrete structure according to claim 1, characterized in that: The secondary concrete is connected to the base concrete through anchor bars.

4. The double - line flexible anchoring structure of the geomembrane of the core wall of the dam body and the foundation concrete structure according to claim 1, characterized in that: In the plastic deformation zone, the downstream side of the plastic filler filled in the upper part of the geomembrane remains upright, and the bottom is arc-shaped.

5. The double - line flexible anchoring structure of the geomembrane of the core wall of the dam and the foundation concrete structure according to claim 1, characterized in that: The cross-section of the anchorage groove is a trapezoid with a larger upper part and a smaller lower part, and the top corners on the upstream side are in a circular arc or an elliptical arc.

6. A dam, characterized in that: A double-defense flexible anchoring structure of a dam body with a base concrete, a dam body with a geomembrane inside, and the core wall geomembrane of the dam body and the base concrete structure as claimed in any one of claims 1 to 5.

7. A construction method of a double-defense flexible anchoring structure of a core wall geomembrane of a dam body and a base concrete structure as claimed in any one of claims 1 to 5, characterized in that: Construct the base concrete, reserve the anchorage groove, and preset anchor bars on the downstream side wall of the groove; After cleaning and drying the anchorage groove, apply a bottom glue along the downstream side of the bottom surface of the anchorage groove, and sequentially lay a plastic filler, a rubber cover sheet, a plastic filler, the geomembrane and a rubber cover sheet. Press an angle steel on the rubber cover sheet and cooperate with bolts and nuts to achieve tight pressing to form an anchoring mechanism; After cleaning and drying the upstream side part in the anchorage groove, apply a bottom glue to the bottom and the upstream side wall of the upstream side of the anchorage groove, and lay a plastic filler. The plastic filler forms a semi-circular plastic filler bulge near the anchoring mechanism, and the geomembrane is attached to the surface of the plastic filler; The upper part of the geomembrane in the upstream side part of the anchorage groove is filled with plastic filler. The downstream side of the plastic filler remains upright, and the bottom is arc-shaped; In the downstream side of the anchorage groove, a cavity formed after the plastic filler is filled in the upstream side is filled with secondary concrete to cover the anchoring mechanism; A geotextile and a fine sand layer are sequentially laid on the surfaces of the plastic filler filled in the upstream side of the anchorage groove and the secondary concrete poured in the downstream side, and the upper part is filled with a dam body according to the design of the dam section.

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