Anti-seepage structure system for concrete dam on covering layer foundation

Abstract

The application discloses an anti-seepage structure system, in particular to an anti-seepage structure system for a concrete dam on a covering layer foundation, and belongs to the technical field of water conservancy and hydropower engineering structure design and manufacturing. The application provides an anti-seepage structure system for a concrete dam on a covering layer foundation, which can be widely applied to various permanent anti-seepage wall constructions and has a small construction scene. The anti-seepage structure system comprises a concrete dam body and an anti-seepage structure, and further comprises an elastic buffering anti-seepage connecting structure; the anti-seepage structure in the covering layer is connected with the concrete dam body on the covering layer through the elastic buffering anti-seepage connecting structure to form an integral whole.

Description

Technical Field

[0001] This invention relates to a seepage prevention structure system, and more particularly to a seepage prevention structure system for concrete dams on overburden foundations, belonging to the field of design and manufacturing technology of hydraulic and hydropower engineering structures. Background Technology

[0002] When constructing dams on overburden layers, cutoff walls are typically used as the foundation seepage prevention solution. These walls are usually formed by excavating trenches and casting in place with concrete. However, the construction of cast-in-place concrete cutoff walls is difficult, time-consuming, and expensive. High-pressure jet grouting is also an effective cutoff wall formation method, currently generally used in temporary projects such as earth-rock cofferdams, and is also commonly used in reservoir reinforcement. Researching how to use high-pressure jet grouting cutoff walls for permanent seepage prevention of concrete dam foundations is a meaningful endeavor, providing a new option for permanent seepage prevention of concrete dams. Patent application number 202110623293.9 provides an effective solution, and its application in a project in Nepal has yielded good results. However, during implementation, the technical solution of this patent is relatively complex to construct, and excessive tensile stress can easily be generated at the joint structure of the cutoff wall, which limits the practical application scenarios of this technology, such as limitations on dam height and foundation deformation. Therefore, there is an urgent need to study more solutions to ensure that high-pressure jet grouting can still be used to form permanent anti-seepage walls for concrete dams on the overburden layer under conditions of greater foundation deformation, so as to make the application of high-pressure jet grouting to form anti-seepage walls more widespread in permanent projects. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a seepage prevention structure system for concrete dams on overburden foundations that is less restricted in construction scenarios and can be widely applied to the construction of various permanent seepage prevention walls.

[0004] The technical solution adopted to solve the above-mentioned technical problems is: a seepage prevention structure system for concrete dams on overburden foundations, including a concrete dam body and a seepage prevention structure. The seepage prevention structure system also includes an elastic buffer seepage prevention connection structure. The seepage prevention structure located in the overburden is connected to the concrete dam body on the overburden as a whole through the elastic buffer seepage prevention connection structure.

[0005] Furthermore, the seepage prevention structure is a seepage prevention wall embedded in the overburden layer directly below the concrete dam body, and the lower end of the elastic buffer seepage prevention connection structure is flexibly connected to the seepage prevention wall.

[0006] The preferred embodiment of the above scheme is that the anti-seepage wall is a high-pressure jet grouting anti-seepage wall or a high-pressure rotary jet grouting pile body arranged sequentially along the length of the concrete dam body.

[0007] Furthermore, the concrete dam body includes a bottom layer of cast-in-place material and a cast-in-place dam structure arranged sequentially upwards along the height direction, with the upper end of the elastic buffer seepage prevention connection structure being flexibly seepage-proofly connected to the bottom layer of cast-in-place material.

[0008] The preferred embodiment of the above scheme is that the elastic buffer seepage prevention connection structure includes a lower flexible seepage prevention connector, an elastic buffer seepage prevention system, and an upper flexible seepage prevention connector. The upper end of the elastic buffer seepage prevention system is flexibly connected to the bottom cast-in-place body through the upper flexible seepage prevention connector, and the lower end of the elastic buffer seepage prevention system is flexibly connected to the seepage prevention wall through the lower flexible seepage prevention connector.

[0009] Furthermore, the elastic buffer seepage prevention system includes a composite waterstop and a flexible backfill protection structure. The upper end of the composite waterstop embedded in the flexible backfill protection structure along the length direction is connected to the bottom layer of the cast-in-place flexible seepage prevention body through an upper flexible seepage prevention connector. The lower end of the composite waterstop embedded in the flexible backfill protection structure along the length direction is connected to the seepage prevention wall through a lower flexible seepage prevention connector.

[0010] The preferred embodiment of the above scheme is that the flexible backfill protection structure is a soft clay protective layer filled between the bottom layer of the cast-in-place body and the top surface of the anti-seepage wall, and the composite waterstop is embedded in the soft clay protective layer along the length direction.

[0011] Furthermore, the composite waterstop is a copper sheet with rubber sheets on both the front and back sides, and the copper sheet embedded in the backfill soft clay protective layer is arranged in a curved shape along the height direction.

[0012] The preferred embodiment of the above scheme is that the lower flexible seepage prevention connector includes a lower backfill resin material protective body and fixing bolts. A lower filling groove with a trapezoidal cross-section is provided on the top surface of the seepage prevention wall. The lower end of the copper sheet extending along the length of the dam body is fixed to the seepage prevention wall in the lower filling groove by fixing bolts. The lower backfill resin material protective body is filled in the lower filling groove.

[0013] Furthermore, the upper flexible seepage-proof connector includes an upper backfill resin material protective body and fixing bolts. An upper filling groove with an inverted trapezoidal cross-section is provided at the bottom of the bottom layer of the dam body. The upper end of the copper sheet extending along the length of the dam body is fixed to the bottom layer of the dam body outside the top of the upper filling groove by fixing bolts. The upper backfill resin material protective body is filled in the upper filling groove.

[0014] The beneficial effects of this invention are as follows: The technical solution provided in this application is based on the existing concrete dam body and seepage prevention structure. By adding an elastic buffer seepage prevention connection structure, a new seepage prevention structure system for the concrete dam is formed. The seepage prevention structure located within the overburden layer is connected to the concrete dam body, which is seated on the overburden layer, as a whole through the elastic buffer seepage prevention connection structure. Thus, since the seepage prevention structure located within the overburden layer and the concrete dam body seated on the overburden layer are connected by the elastic buffer seepage prevention connection structure, the technical problems of complex construction caused by hard connections in the prior art, and the tendency for excessive tensile stress to occur and cause damage at the joint of the seepage prevention wall, are effectively solved. Furthermore, since this application uses an elastic buffer seepage prevention connection structure, the problem of limited construction scenarios can be significantly reduced. Therefore, the technical solution of this application can be widely applied to the construction of various types of concrete dams with permanent seepage prevention walls on overburden foundations. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of the anti-seepage structure system of the concrete dam on the overburden foundation of the present invention.

[0016] The markings in the diagram are as follows: 1. Pouring dam structure; 2. Seepage prevention structure; 3. Covering layer; 4. Bottom pouring body; 5. Flexible backfill protection structure; 6. Rubber sheet; 7. Copper sheet; 8. Lower backfill resin material protection body; 9. Fixing bolt; 10. Lower filling groove; 11. Upper backfill resin material protection body; 12. Upper filling groove. Detailed Implementation

[0017] like Figure 1The diagram illustrates a seepage-proof structural system for concrete dams on overburden foundations, provided by this invention. This system is applicable to various permanent cutoff wall constructions with limited construction scenarios. The seepage-proof structural system includes a concrete dam body and a seepage-proof structure 2. It also includes an elastic buffer seepage-proof connection structure. The seepage-proof structure 2, located within the overburden layer 3, is integrally connected to the concrete dam body, which is mounted on the overburden layer 3, through the elastic buffer seepage-proof connection structure. The technical solution provided in this application is based on existing concrete dam bodies and seepage-proof structures. By adding an elastic buffer seepage-proof connection structure, a new seepage-proof structural system for concrete dams is constructed, and the seepage-proof structure within the overburden layer is integrally connected to the concrete dam body, which is mounted on the overburden layer, through the elastic buffer seepage-proof connection structure. Thus, since the seepage prevention structure located within the overburden layer and the concrete dam body seated on the overburden layer are connected by an elastic buffer seepage prevention connection structure, the technical problems caused by hard connections in the prior art, such as construction complexity and the tendency to generate excessive tensile stress at the joint of the seepage prevention wall, which can lead to damage, are effectively solved. Furthermore, since the application adopts an elastic buffer seepage prevention connection structure, the problem of limited construction scenarios can be significantly reduced, thereby enabling the technical solution of this application to be widely applied to the construction of concrete dams on overburden foundations containing permanent seepage prevention walls.

[0018] Accordingly, considering the existing technology, as described above, in order to maximize the applicability of the technical solution of this application to the construction of concrete dams on various types of overburden layers, the seepage prevention structure 2 described in this application is a seepage prevention wall embedded in the overburden layer 3 directly below the concrete dam body, and the lower end of the elastic buffer seepage prevention connection structure is flexibly connected to the seepage prevention wall. The seepage prevention wall can be a high-pressure jet grouting wall, or it can be a high-pressure rotary jet grouting pile arranged sequentially along the length of the concrete dam body; and the concrete dam body includes a bottom casting 4 and a cast dam structure 1, with the upper end of the elastic buffer seepage prevention connection structure flexibly connected to the bottom casting 4.

[0019] Furthermore, as a key improvement to the technical solution of this application, the elastic buffer seepage prevention connection structure includes a lower flexible seepage prevention connector, an elastic buffer seepage prevention system, and an upper flexible seepage prevention connector. The upper end of the elastic buffer seepage prevention system is flexibly connected to the bottom cast-in-place body 4 via the upper flexible seepage prevention connector, and the lower end of the elastic buffer seepage prevention system is flexibly connected to the seepage prevention wall via the lower flexible seepage prevention connector. More specifically, the elastic buffer seepage prevention system of this application includes a composite waterstop and a flexible backfill protection structure 5. The upper end of the composite waterstop, embedded in the flexible backfill protection structure 5 along its length, is flexibly connected to the bottom cast-in-place body 4 via the upper flexible seepage prevention connector, and the lower end is flexibly connected to the seepage prevention wall via the lower flexible seepage prevention connector. In this case, the flexible backfill protection structure 5 is preferably a soft clay protective layer filled between the bottom cast-in-place body and the top surface of the seepage prevention wall, and the composite waterstop is embedded in the soft clay protective layer along its length. The composite waterstop is preferably a copper sheet 7 with rubber sheets 6 laminated on both the front and back sides. The copper sheet 7, embedded in the backfill soft clay protective layer, is arranged in a curved shape along the height direction to improve the composite waterstop's adaptability to dam deformation. The lower flexible seepage prevention connector includes a lower backfill resin material protective body 8 and fixing bolts 9. A lower filling groove 10 with a trapezoidal cross-section is provided on the top surface of the seepage prevention wall. The lower end of the copper sheet 7 extending along the length of the dam is fixed to the seepage prevention wall in the lower filling groove 10 by fixing bolts 9. The lower backfill resin material protective body 8 fills the lower filling groove 10. The upper flexible seepage prevention connector includes an upper backfill resin material protective body 11 and fixing bolts 9. An upper filling groove 12 with an inverted trapezoidal cross-section is provided at the bottom of the bottom layer of the cast-in-place slab 4. The upper end of the copper sheet 7 extending along the length of the dam is fixed to the bottom layer of the cast-in-place slab 4 outside the top of the upper filling groove 12 by fixing bolts 9. The upper backfill resin material protective body 11 fills the upper filling groove 12.

[0020] The technical solution of this application will be further described below through specific embodiments:

[0021] 1) The high-pressure jet grouting cutoff wall is not directly connected to the concrete dam, and there is a certain distance between them. This can prevent the self-weight stress of the dam from being directly transferred to the high-pressure jet grouting cutoff wall, and prevent damage to the top of the high-pressure jet grouting wall due to excessive stress.

[0022] 2) Using a composite waterstop with a certain degree of curvature to connect the concrete dam and the high-pressure jet grouting anti-seepage wall has the main advantage that the curved composite waterstop can adapt to the uneven deformation between the gravity dam and the high-pressure jet grouting anti-seepage body in the overburden foundation. At the same time, it can effectively form a closed anti-seepage structure between the dam body and the anti-seepage body.

[0023] Example 1

[0024] A trapezoidal groove is pre-excavated at the top of the high-pressure jet grouting anti-seepage wall. The composite waterstop is fixed to the bottom of the trapezoidal groove with bolts. The fixed end of the waterstop is backfilled with resin material in the trapezoidal groove to protect it. The other end of the waterstop is connected to the dam body. The connection method is as follows: during the pouring of the first layer of concrete of the dam body, an inverted trapezoidal groove is reserved. The composite waterstop passes through the reserved groove and bends the waterstop to the top surface of the first layer of concrete and is fixed with bolts. The reserved inverted trapezoidal groove is backfilled with resin material. The second concrete is poured directly on the fixed composite waterstop.

[0025] The curved waterstop between the dam and the seepage prevention body is backfilled with soft clay within a certain range upstream and downstream to protect the composite waterstop.

Claims

1. A seepage-proof structural system for concrete dams on overburden foundations, comprising a concrete dam body and a seepage-proof structure (2), characterized in that: The aforementioned seepage prevention structure system also includes an elastic buffer seepage prevention connection structure. The seepage prevention structure (2) is arranged in the cover layer (3). The seepage prevention structure (2) is a seepage prevention wall embedded in the cover layer (3) directly below the concrete dam body. The concrete dam body is seated on the cover layer (3). The seepage prevention structure (2) is connected to the concrete dam body as a whole through the elastic buffer seepage prevention connection structure. The concrete dam body consists of a bottom layer of cast-in-place material (4) arranged sequentially upwards along the height direction and a cast-in-place dam structure (1). The upper end of the elastic buffer seepage prevention connection structure is flexibly seeped into the bottom layer of cast-in-place material (4). The elastic buffer seepage prevention connection structure includes a lower flexible seepage prevention connector, an elastic buffer seepage prevention system, and an upper flexible seepage prevention connector. The upper end of the elastic buffer seepage prevention system is flexibly connected to the bottom cast-in-place body (4) through the upper flexible seepage prevention connector, and the lower end of the elastic buffer seepage prevention system is flexibly connected to the seepage prevention wall through the lower flexible seepage prevention connector. The elastic buffer seepage prevention system includes a composite waterstop and a flexible backfill protection structure (5). The composite waterstop is a copper sheet (7) with rubber sheets (6) on both the front and back sides. The copper sheet (7) embedded in the flexible backfill protection structure (5) is arranged in a curved shape along the height direction. The lower flexible seepage prevention connector includes a lower backfill resin material protective body (8) and a fixing bolt (9). A lower filling groove (10) with a trapezoidal cross-section is provided on the top surface of the seepage prevention wall. The lower end of the copper sheet (7) extending along the length of the dam body is fixed to the seepage prevention wall in the lower filling groove (10) by the fixing bolt (9). The lower backfill resin material protective body (8) is filled in the lower filling groove (10).

2. The seepage prevention structure system for concrete dams on overburden foundations according to claim 1, characterized in that: The cutoff wall is either a high-pressure jet grouting cutoff wall or a high-pressure rotary jet grouting pile arranged sequentially along the length of the concrete dam body.

3. The seepage prevention structure system for concrete dams on overburden foundations according to claim 1 or 2, characterized in that: The upper end of the composite waterstop embedded in the flexible backfill protection structure (5) along the length direction is connected to the bottom pouring body (4) through the upper flexible anti-seepage connector, and the lower end of the composite waterstop embedded in the flexible backfill protection structure (5) along the length direction is connected to the anti-seepage wall through the lower flexible anti-seepage connector.

4. The seepage prevention structure system for concrete dams on overburden foundations according to claim 3, characterized in that: The flexible backfill protection structure (5) is a soft clay protective layer filled between the bottom casting body and the top surface of the anti-seepage wall, and the composite waterstop is embedded in the soft clay protective layer along the length direction.

5. The seepage prevention structure system for concrete dams on overburden foundations according to claim 1, characterized in that: The upper flexible seepage prevention connector includes an upper backfill resin material protective body (11) and a fixing bolt (9). An upper filling groove (12) with an inverted trapezoidal cross-section is provided at the bottom of the bottom layer of the dam body (4). The upper end of the copper sheet (7) extending along the length of the dam body is fixed to the bottom layer of the dam body (4) outside the top of the upper filling groove (12) by the fixing bolt (9). The upper backfill resin material protective body (11) is filled in the upper filling groove (12).

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