Panel structure of concrete faced rockfill dam

Abstract

The utility model discloses a concrete faced rockfill dam panel structure, relates to the field of water conservancy and hydropower engineering, and aims at solving the problems of panel cracking and disengagement, through the design that a grouting pipe is pre-buried and a buckling groove is covered with geotextile, when a panel and a cushion layer are disengaged, grouting operation can be conveniently carried out, and the construction efficiency is improved. Therefore, tight contact between the top of the concrete panel constructed by stages and the bedding surface is guaranteed, the problems of crack aggravation, panel breakage and the like caused by void are reduced, and safe operation of a dam is guaranteed. Meanwhile, compared with a traditional mode that void detection is combined with drilling and grouting, free-air operation is avoided, the construction danger is reduced, the construction period is shortened, the construction cost is reduced, and the risk that the panel structure is damaged due to improper grouting pressure is also reduced.

Description

Technical Field

[0001] This utility model relates to the field of water conservancy and hydropower engineering, and in particular to a panel rockfill dam panel structure. Background Technology

[0002] Concrete-faced rockfill dams are the most common type of earth-rock dams and are currently widely used in water conservancy, hydropower, environmental protection, and energy storage projects. Concrete-faced rockfill dams are technologically mature, possessing strong adaptability to different geological conditions, mature construction techniques, and good seismic performance. They also offer advantages such as strong adaptability to dam deformation, full utilization of local materials, and overall cost savings.

[0003] Due to the varying deformation characteristics of concrete panels, extruded sidewalls, and dam fill, cracks inevitably appear in the concrete panels after construction. These cracks exacerbate dam leakage, and excessive cracking can compromise dam operational safety. To reduce panel cracking and considering panel pouring conditions, construction joints are typically incorporated into longer panels. For high dams, especially ultra-high concrete-faced rockfill dams, concrete panels are generally constructed in multiple phases to meet requirements for pre-settlement time and settlement rate, as well as temporary water retention or phased impoundment. Literature review and field investigations have revealed voids at the top of many concrete-faced rockfill dam panels. The primary cause of these voids is the continued deformation of the rockfill after panel pouring, leading to varying degrees of voids between the top of the phased panels and the underlying foundation layer (extruded sidewalls). These voids exacerbate crack formation and development during impoundment, and in severe cases, panel breakage results in significant leakage, impacting dam safety. Therefore, it is crucial to ensure proper contact between the phased concrete panels and the foundation layer. To ensure a tight seal between the top of the concrete panel and the subfloor during phased construction, a combination of void detection and drilling grouting is commonly used. While this method ensures the treatment effect, it also presents challenges such as high risk of working at height, long construction period, and high construction cost. Furthermore, due to the low borehole density, the grouting pressure needs to be increased to ensure the grout filling effect, which can easily lead to inappropriate grouting pressure, causing the panel to lift and damage the panel structure. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by providing a panel structure for rockfill dams. Through the design of pre-embedded grouting pipes and the use of geotextiles to cover the grooves, grouting operations can be conveniently carried out when there is a gap between the panel and the subbase. This ensures that the top of the concrete panel constructed in stages is in close contact with the subbase, reduces problems such as crack aggravation and panel breakage caused by gaps, and ensures the safe operation of the dam.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] A panel rockfill dam panel structure includes:

[0007] The cushion layer is inclinedly distributed on the slope of the rockfill dam. The cushion layer has grooves, and grouting pipes are arranged in the grooves. The opening of the groove is covered with geotextile, and the geotextile extends to the outside of the groove opening on both sides and is fixed to the cushion layer by anchor nails.

[0008] The panel is formed by laying concrete on the subbase. After the panel is cured, a void area is formed between the panel and the subbase. The groove passes through the mesh of the geotextile to connect the void area. One end of the grouting pipe protrudes out of the groove to connect to the external grouting equipment. The grouting pipe is used to inject grout into the groove and the void area.

[0009] Furthermore, the grooves are distributed along the inclined direction of the padding layer, and multiple grooves are arranged in sequence at intervals, with a grouting pipe arranged in each groove.

[0010] Furthermore, the panel is constructed in stages, with one end of the grouting pipe in the groove extending outside the groove covered by the corresponding stage panel.

[0011] Furthermore, a buckle is arranged in the buckle groove. The buckle is U-shaped, and the grouting pipe passes through the buckle. One open end of the buckle is fixed to the pad layer corresponding to the buckle groove to fix and constrain the grouting pipe.

[0012] Furthermore, multiple clips are installed in the groove and are spaced apart along the axial direction of the grouting pipe, so that the grouting pipe settles with the cushion layer.

[0013] Furthermore, the geotextile is in strip shape, arranged along the distribution direction of the groove, and extends to the top of the panel to be constructed in stages.

[0014] Furthermore, the surface of the geotextile away from the subbase is covered with a plastic film to prevent the emulsified asphalt from contacting the geotextile. The plastic film is removed after the emulsified asphalt is sprayed.

[0015] Furthermore, the geotextiles on both sides of the groove are fixed by anchors, with one end of the anchor inserted into the cushion layer.

[0016] Furthermore, the grouting pipe has grout outlet holes distributed on the segments located within the groove.

[0017] Furthermore, the grout outlet is provided in multiple locations, so that the segments of the grouting pipe located in the groove form a grouting flower pipe.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] To address the issues of panel cracks and voids, a design that incorporates pre-embedded grouting pipes and geotextile-covered grooves allows for convenient grouting when voids occur between the panel and the subbase. This ensures tight contact between the top of the concrete panel, constructed in stages, and the subbase, reducing problems such as crack aggravation and panel breakage caused by voids, thus guaranteeing the safe operation of the dam. Furthermore, compared to the traditional void detection combined with drilling and grouting method, this approach avoids working in open areas, reducing construction risks, shortening the construction period and costs, and also lowering the risk of damage to the panel structure due to improper grouting pressure.

[0020] The grouting grooves are distributed along the inclined direction of the foundation layer and arranged at multiple intervals. Each groove contains a grouting pipe, which can more comprehensively cover the areas where voids may occur between the panel and the foundation layer. During the phased construction of the panels, one end of the grouting pipe extends to the groove covering the corresponding phase of the panel, allowing for precise grouting of each phase of the panel and the foundation layer to ensure that each phase of the panel is in close contact with the foundation layer, further reducing cracking problems caused by voids and strengthening the guarantee for the safe operation of the dam.

[0021] The clips not only secure the grouting pipe and prevent it from shifting during construction, but also allow the grouting pipe to settle along with the subgrade. When the subgrade settles due to rockfill deformation, the grouting pipe can adapt to the changes synchronously, always maintaining effective communication with the voided area, ensuring the smooth progress of subsequent grouting operations, and avoiding insufficient or impossible grouting due to pipe displacement.

[0022] A plastic film is used to cover the surface of the geotextile away from the subbase. This prevents the emulsified asphalt from contacting the geotextile during spraying. The film is removed after spraying to protect the performance of the geotextile.

[0023] The grouting pipe has multiple grout outlets distributed on the segment inside the groove, forming a grouting flower pipe. This allows the grout to spread more evenly in the groove and void area, avoiding insufficient grouting in some areas due to concentrated grout outlets, and further improving the density and uniformity of the grouting. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the panel structure of the rockfill dam in an embodiment of this utility model;

[0025] Figure 2 This is a schematic diagram of the snap-fit ​​fixing of the grouting pipe in an embodiment of this utility model.

[0026] Labeling descriptions (in order of first appearance): 1. Subbase; 2. Grouting pipe; 3. Groove; 4. Geotextile; 5. Panel; 6. Top of phased panel; 7. Clip; 8. Anchor nail; 9. Plastic film. Detailed Implementation

[0027] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0028] like Figures 1-2 As shown, a panel rockfill dam panel structure includes a cushion layer 1, a grouting pipe 2, and a panel 5.

[0029] The foundation layer 1 is inclined and distributed on the slope of the rockfill dam, serving as the basic support structure for panel 5. It provides a stable bearing surface for panel 5, and its inclined distribution facilitates drainage and adapts to the dam's slope. It bears the weight of panel 5, evenly distributing the load to the dam foundation and reducing the impact of dam deformation on panel 5. This ensures the stability of panel 5, reducing the possibility of cracking due to uneven foundation settlement, and providing a fundamental guarantee for the overall structural stability of the rockfill dam.

[0030] A groove 3 is provided on the subbase 1 to accommodate the grouting pipe 2 and provide a channel for grouting, allowing the grout to flow to the void area between the panel 5 and the subbase 1. By creating the groove 3 on the subbase 1 and placing the grouting pipe 2 within it, when a void appears between the panel 5 and the subbase 1, the grouting pipe 2 delivers the grout to the void area through the groove 3 to fill it. This makes the grouting operation more targeted, improves the efficiency of the grout reaching the void area, effectively fills the void, and reduces cracks and leaks in the panel 5 caused by voids.

[0031] One end of the grouting pipe 2 protrudes outside the groove 3 to connect to external grouting equipment. The grouting pipe 2 is used to grout the groove 3 and the voided area. Connecting the external grouting equipment to the groove 3 and the voided area, the grouting pipe 2 delivers the grout to the areas requiring filling. One end of the grouting pipe 2 is connected to the external grouting equipment, while the other end is located inside the groove 3. During grouting, the grout, under pressure, flows through the grouting pipe 2 into the groove 3 and the voided area. This achieves precise grouting of the voided area. By adjusting the parameters of the external grouting equipment, the grout delivery volume and pressure can be controlled as needed, ensuring that the voided area is fully filled, strengthening the connection between the panel 5 and the cushion layer 1, and improving the dam's seepage prevention performance.

[0032] Geotextile 4 covers the opening of the groove 3 to prevent debris from entering the groove 3 and affecting the grouting effect, while allowing grout to enter the voided area through the mesh, thus guiding the grout. Covering the opening of the groove 3, the mesh size allows grout to pass through while blocking larger particles and debris, ensuring unobstructed grouting channels and grout purity, improving the quality and effect of grouting, enabling the grout to fill the voided area more evenly, and enhancing the adhesion between the panel 5 and the cushion layer 1.

[0033] The geotextile 4 extends beyond the opening of the groove 3 on both sides and is fixed to the cushion layer 1 by anchors 8. The anchors 8 keep the geotextile 4 in the correct position, preventing displacement or detachment during construction or operation. By fixing the extended portions of the geotextile 4 to the cushion layer 1 and anchoring them with the anchors 8, the geotextile 4 is tightly fitted to the opening of the groove 3. This ensures the stability of the geotextile 4, allowing it to continuously guide the grout, while also protecting the grouting pipe 2 and grouting channel within the groove 3, thus improving the overall reliability of the structure.

[0034] Panel 5, serving as the dam's seepage prevention structure, prevents reservoir water leakage while bearing water pressure and other loads. It is formed by being laid on the foundation layer 1 using concrete, together with the foundation layer 1, constituting the seepage prevention system. After panel 5 has cured, any voids that may form between it and the foundation layer 1 can be addressed through grouting. Panel 5, in conjunction with other structures, forms a complete seepage prevention system, effectively preventing water leakage, protecting the dam structure, and improving the dam's safety and durability.

[0035] The grooves 3 are distributed along the inclined direction of the foundation layer 1, and multiple grooves 3 are arranged alternately along the direction perpendicular to the inclined direction of the foundation layer 1, that is, arranged sequentially in the horizontal direction. Each groove 3 is equipped with a grouting pipe 2, which fully covers the area where voids may occur between the panel 5 and the foundation layer 1, so that the grouting pipe 2 can accurately correspond to potential voids, improving the targeting and effectiveness of grouting. According to the slope morphology of the rockfill dam, the grooves 3 are reasonably arranged along the inclined direction of the foundation layer 1. When voids occur between the panel 5 and the foundation layer 1 due to deformation, the grouting pipes 2 in each groove 3 can respond quickly and deliver grout to the corresponding void area.

[0036] The panel 5 is constructed in stages. One end of the grouting pipe 2 inside the groove 3 extends to the outside of the groove 3 covered by the corresponding stage panel 5. At the same time, the geotextile 4 covering the opening of the groove 3 can extend to the top of the stage panel 5, adapting to the characteristics of the staged construction of panel 5 and realizing independent and precise grouting treatment for the voids between each stage panel 5 and the subbase 1. After the staged construction of panel 5 is completed, for each stage panel 5 and subbase 1 void, the grouting equipment is connected through the grouting pipe 2 extending out of the groove 3 to grout the void area under the stage panel 5 individually.

[0037] A U-shaped clip 7 is arranged inside the groove 3. The grouting pipe 2 passes through the clip 7, and one open end of the clip 7 is fixed to the corresponding pad 1 in the groove 3 to fix and constrain the grouting pipe 2, stabilize its position, and prevent it from shifting due to external forces during construction, thus ensuring smooth grouting operations. This avoids grouting position deviations or grouting failures caused by displacement of the grouting pipe 2, ensuring that the grout can be accurately injected into the voided area, improving grouting quality and efficiency, and laying the foundation for a tight bond between the panel 5 and the pad 1.

[0038] Multiple clips 7 are installed in the groove 3 and are spaced apart along the axial direction of the grouting pipe 2, so that the grouting pipe 2 settles with the cushion layer 1, adapts to the deformation of the dam body during construction, and maintains connectivity with the void area. When the cushion layer 1 settles due to the deformation of the rockfill, the spaced clips 7 make the grouting pipe 2 move with the cushion layer 1, so that the grouting pipe 2 settles synchronously with the cushion layer 1, and always maintains an effective connection with the void area.

[0039] The geotextile 4 on both sides of the groove 3 is fixed by anchors 8. One end of the anchor 8 is inserted into the cushion layer 1 for stable fixation. The geotextile 4 is strip-shaped and arranged along the distribution direction of the groove 3, extending to the top 6 of the phased panel 5 under phased construction. This enhances the protection of the opening of the groove 3, prevents grout from overflowing during grouting, and provides continuous seepage protection for the phased panel 5. It prevents grout from overflowing from the edge of the groove 3 during grouting and plays a seepage prevention role at each stage of panel 5 construction, improving grouting efficiency, reducing grout waste, and ensuring that the voided areas are fully filled. At the same time, it enhances the seepage prevention performance between the cushion layer 1 and the panel 5, effectively preventing reservoir water leakage and improving the safety of the dam.

[0040] The surface of the geotextile 4 away from the cushion layer 1 is covered with a plastic film 9 to prevent the emulsified asphalt from contacting the geotextile 4. After the emulsified asphalt is sprayed, the plastic film 9 is removed to protect the performance of the geotextile 4, prevent the emulsified asphalt from damaging it, and ensure that the geotextile 4 can normally play its role in guiding the grout.

[0041] Before spraying emulsified asphalt, a plastic film 9 is first covered on the surface of geotextile 4. After the emulsified asphalt is sprayed, the film is removed so that the emulsified asphalt forms an impermeable layer on the surface of the cushion layer 1 without affecting the properties of geotextile 4.

[0042] The grouting pipe 2 has multiple grout outlet holes distributed on its segments within the groove 3. These holes form a grouting perforation pattern within the grouting pipe 2 segments, allowing the grout to spread evenly within the groove 3 and the voided areas. This improves the density and uniformity of the grouting, ensuring close contact between the panel 5 and the subbase 1. During grouting, the grout flows out simultaneously from multiple holes, spreading outwards under pressure to fill the voided areas.

[0043] In this embodiment, the grouting pipe 2 is a rigid PVC pipe made of PVC material, with an outer diameter of 50mm and a thickness of 2mm. A single grouting pipe 2 is 1.8m long and is bent into an approximate L-shape before implementation. Figure 1 As shown, the grouting pipe 2 is divided into two sections with the bend as the boundary. The lengths are 1.5m and 0.3m respectively, and the bend angle is 145 degrees. Before the grouting pipe 2 is pre-embedded, a through grout outlet hole with a diameter of 25mm should be drilled every 50cm on the grouting pipe 2, and the axes of adjacent grout outlet holes should be spatially perpendicular at 90°.

[0044] Geotextile 4 uses common geotextiles and geogrids, weighing 500g per square meter. Clips 7 are made of 6mm diameter plain round steel bars, each 1m long, cut and bent into U-shapes. Anchor nails 8 are round nails, 50mm long. Clip grooves 3 are 70mm x 70mm in size, 1.5m long, with a 3m spacing between adjacent grooves. The spacing of the round nails and the dimensions of geotextile 4 are arranged and cut as needed.

[0045] The specific embodiments of the utility model have been described in detail above, but they are only examples, and the utility model is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the utility model are also within the scope of the utility model. Therefore, all equivalent transformations, modifications, and improvements made without departing from the spirit and principles of the utility model should be covered within the scope of the utility model.

Claims

1. A face panel structure of a face panel rockfill dam, characterized by, include: The cushion layer is inclinedly distributed on the slope of the rockfill dam. The cushion layer has grooves, and grouting pipes are arranged in the grooves. The opening of the groove is covered with geotextile, and the geotextile extends to the outside of the groove opening on both sides and is fixed to the cushion layer by anchor nails. The panel is formed by laying concrete on the subbase. After the panel is cured, a void area is formed between the panel and the subbase. The groove passes through the mesh of the geotextile to connect the void area. One end of the grouting pipe protrudes out of the groove to connect to the external grouting equipment. The grouting pipe is used to inject grout into the groove and the void area.

2. The face panel structure of a face panelled rockfill dam according to claim 1, wherein, The grooves are distributed along the inclined direction of the cushion layer, and multiple grooves are arranged in sequence at intervals, with a grouting pipe arranged in each groove.

3. The panel rockfill dam panel structure as described in claim 2, characterized in that, The panel is constructed in stages, and one end of the grouting pipe in the groove extends to the outside of the groove covered by the corresponding stage panel.

4. The face panel structure of a face panelled rockfill dam according to claim 1, wherein, The groove is equipped with a U-shaped buckle. The grouting pipe passes through the buckle, and one open end of the buckle is fixed to the padding layer corresponding to the groove to fix and constrain the grouting pipe.

5. The face panel structure of a face panelled rockfill dam according to claim 4, wherein Multiple clips are installed in the groove and are spaced apart along the axial direction of the grouting pipe, so that the grouting pipe settles with the cushion layer.

6. The face panel structure of a face panelled rockfill dam according to claim 1, wherein, The geotextile is in strip shape, arranged along the distribution direction of the groove, and extends to the top of the panel to be constructed in stages.

7. The face panel structure of a face panelled rockfill dam according to claim 6, wherein The surface of the geotextile away from the subbase is covered with a plastic film to prevent the emulsified asphalt from contacting the geotextile. The plastic film is removed after the emulsified asphalt is sprayed.

8. The face panel structure of a face panelled rockfill dam according to claim 6 or 7, wherein, The geotextiles on both sides of the groove are fixed by anchors, with one end of the anchor inserted into the cushion layer.

9. The face panel structure of a face panelled rockfill dam according to claim 1, wherein, The grouting pipe has grout outlet holes distributed on the segments located within the groove.

10. The face panel structure of a face panelled rockfill dam according to claim 9, wherein, The grout outlet is provided in multiple locations, so that the grouting pipe segments located in the groove form a grouting flower pipe.

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