Connection structure between foundation gallery and cut-off wall of asphalt concrete core rockfill dam

Abstract

The present invention discloses a connection structure between the foundation gallery and the cutoff wall of an asphalt concrete core rockfill dam, relating to the technical field of water conservancy and hydropower engineering. The structure comprises an upstream rockfill area and a downstream rockfill area; a transition material, a filter material, a high-plasticity clay area, and a dam foundation cover layer are sequentially arranged between the upstream and downstream rockfill areas from top to bottom; a foundation gallery is located within the high-plasticity clay area; the foundation gallery is connected to the dam foundation concrete cutoff wall, which in turn is connected to the asphalt concrete core wall. The present invention provides safe and reliable anti-seepage protection, strong deformation adaptability, a simple design, and ease of construction, making it suitable for connecting the foundation gallery and the cutoff wall of an asphalt concrete core rockfill dam.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy and hydropower engineering, and more particularly to a connection structure between a foundation gallery and an anti-seepage wall of an asphalt concrete core wall rockfill dam. Background Art

[0002] As my country's water conservancy and hydropower development continues to advance, many major rivers where water resources development bases are located are facing deep cover layers, especially in my country's western regions, such as the main and tributary rivers of the Dadu River, the middle and upper reaches of the Jinsha River, and some rivers in Tibet and Xinjiang.

[0003] Entering the 21st century, my country's technology for utilizing overburden for dam construction has further advanced. A number of earth-rockfill dams over 100 meters high have been built on deep overburden. Simultaneously, a number of 200-meter-high earth-rockfill dams on deep overburden are under construction or design. For earth-rockfill dams built on deep overburden, the primary challenges facing foundation seepage control are stability and leakage losses. Vertical seepage control is a reliable and effective means of addressing these issues. Currently, the vast majority of earth-rockfill dams built on overburden employ vertical seepage control, or primarily utilize vertical seepage control as a seepage control measure.

[0004] Earth-rockfill dams constructed on overburden often employ vertical anti-seepage measures, such as cutoff walls or curtains connected below the cutoff walls. Many earth-rockfill dams 100-200 m high built on overburden typically employ a foundation corridor atop the wall to connect the cutoff body to the cutoff wall, a process known as a corridor-type connection. Currently, high earth-rockfill dams constructed on deep overburden generally utilize a direct connection between the foundation corridor and the cutoff wall, employing a rigid connection. Due to the high dam body and deep overburden, the stress characteristics of the foundation corridor and the cutoff wall are complex. Rigid connections often impose high calculated compressive and tensile stresses on the foundation corridor and cutoff wall, placing high demands on the structural design of the foundation corridor and cutoff wall, as well as the connection between them. This connection is a major weak point in dam foundation anti-seepage measures. Some existing projects have experienced cracking in the foundation corridor and resulting in water leakage, impacting the project's safe and stable operation.

[0005] Therefore, it is necessary to develop a connection structure between the foundation corridor and the cut-off wall of an asphalt concrete core rockfill dam. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and to provide a connection structure between the foundation gallery and the anti-seepage wall of an asphalt concrete core rockfill dam.

[0007] To achieve the above-mentioned object, the technical solution of the present invention is: a connection structure between the foundation corridor and the cut-off wall of an asphalt concrete core rockfill dam, characterized by comprising an upstream rockfill area and a downstream rockfill area; a transition material, a filter material, a high-plasticity clay area, and a dam foundation cover layer are sequentially arranged between the upstream rockfill area and the downstream rockfill area from top to bottom;

[0008] A foundation corridor is provided in the high-plasticity clay area; the lower end of the foundation corridor is connected to the dam foundation concrete anti-seepage wall located in the dam foundation cover layer through an inverted trapezoidal concrete connecting section, and the upper end of the foundation corridor is connected to the asphalt concrete core wall located in the transition material and filter material through an asphalt concrete core wall enlargement section;

[0009] The inverted trapezoidal concrete connecting section and the asphalt concrete core wall enlarged section are both located in a high plasticity clay area.

[0010] In the above technical solution, there is a structural joint between the foundation corridor and the inverted trapezoidal concrete connecting section, and the structural joint is filled with rubber pad spacer material.

[0011] In the above technical solution, the contact surface between the foundation gallery and the enlarged section of the asphalt concrete core wall is coated with asphalt mastic, and a first longitudinal copper water stop is continuously provided along the dam axis.

[0012] In the above technical solution, the structural joint has a second longitudinal copper waterstop on the side close to the upstream rockfill area and a third longitudinal copper waterstop on the side close to the downstream rockfill area. The second longitudinal copper waterstop and the third longitudinal copper waterstop are both continuously arranged along the axis direction of the foundation corridor.

[0013] In the above technical solution, the upper base width of the inverted trapezoidal concrete connecting section is the same as the bottom width of the foundation corridor, and the lower base width of the inverted trapezoidal concrete connecting section is the same as the thickness of the concrete anti-seepage wall.

[0014] In the above technical solution, the elastic modulus of the rubber pad spacer material is not greater than 2 MPa.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1) The anti-seepage system of the present invention is safe and reliable, has strong deformation adaptability, is simple in design and easy to construct, and can be applied to the connection between the foundation gallery and the anti-seepage wall of an asphalt concrete core rockfill dam.

[0017] 2) The present invention provides an inverted trapezoidal concrete connecting section between the foundation gallery and the concrete cut-off wall, provides a structural joint between the inverted trapezoidal concrete connecting section and the foundation gallery, and fills the joint with rubber pads, thereby reducing the overlying load transmitted to the concrete cut-off wall through the foundation gallery, reducing the stress concentration at the top of the concrete cut-off wall, and improving the stress condition of the concrete cut-off wall and the foundation gallery.

[0018] 3) The present invention provides a high-plasticity clay zone around the foundation gallery, the inverted trapezoidal concrete connecting section, and the asphalt concrete core wall enlargement section, thereby reducing the overlying load transmitted to the foundation gallery due to dam filling, and is beneficial to improving the stress condition of the concrete anti-seepage wall and the foundation gallery.

[0019] 4) The second longitudinal copper water stop and the third longitudinal copper water stop are arranged in the structural joint of the present invention, thereby enhancing the anti-seepage reliability of the structural joint.

[0020] 5) In the present invention, filter material and transition material are sequentially arranged between the high plasticity clay area and the upstream rockfill area and the downstream rockfill area to protect the high plasticity clay and prevent clay loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Among them, 1-upstream rockfill area, 2-downstream rockfill area, 31-transition material, 32-filter material, 33-high plasticity clay area, 34-dam foundation cover layer, 4-foundation corridor, 41-inverted trapezoidal concrete connecting section, 42-asphalt concrete core wall enlargement section, 421-first longitudinal copper waterstop, 43-structural joint, 431-rubber pad spacer material, 432-second longitudinal copper waterstop, 433-third longitudinal copper waterstop, 5-dam foundation concrete anti-seepage wall, 6-asphalt concrete core wall. DETAILED DESCRIPTION

[0023] The following detailed description of the embodiments of the present invention is given in conjunction with the accompanying drawings, which do not limit the present invention but are merely examples. The advantages of the present invention will become clearer and easier to understand through the description.

[0024] Referring to the accompanying drawings, the connection structure between the foundation gallery and the cutoff wall of an asphalt concrete core rockfill dam is characterized by comprising an upstream rockfill area 1 and a downstream rockfill area 2; a transition material 31, a filter material 32, a high-plasticity clay area 33, and a dam foundation cover layer 34 are sequentially arranged between the upstream rockfill area 1 and the downstream rockfill area 2, from top to bottom; and the filter material 32 and transition material 31 are sequentially arranged between the high-plasticity clay area 33 and the upstream rockfill area 1 and the downstream rockfill area 2 to protect the high-plasticity clay area 33 and prevent loss of the high-plasticity clay.

[0025] A foundation gallery 4 is provided within the high-plasticity clay zone 33. The lower end of the foundation gallery 4 is connected to a dam foundation concrete cutoff wall 5 within the dam foundation cover 34 via an inverted trapezoidal concrete connecting section 41. The upper end of the foundation gallery 4 is connected to an asphalt concrete core wall 6 within the transition material 31 and the filter material 32 via an asphalt concrete core wall enlargement section 42. The present invention provides safe and reliable anti-seepage protection, strong deformation adaptability, a simple design, and ease of construction. It is suitable for connecting foundation galleries and cutoff walls in asphalt concrete core wall rockfill dams.

[0026] The inverted trapezoidal concrete connecting section 41 and the asphalt concrete core wall enlarged section 42 are both located in the high plasticity clay zone 33; the high plasticity clay zone 33 is located around the foundation corridor 4, the inverted trapezoidal concrete connecting section 41 and the asphalt concrete core wall enlarged section 42, which reduces the overlying load transmitted to the foundation corridor 4 due to the dam body filling, and is conducive to improving the stress condition of the concrete anti-seepage wall 5 and the foundation corridor 4.

[0027] There is a structural joint 43 between the foundation corridor 4 and the inverted trapezoidal concrete connecting section 41, and the structural joint 43 is filled with rubber pad spacer material 431, which reduces the overlying load transmitted to the concrete anti-seepage wall 5 through the foundation corridor 4, reduces the stress concentration at the top of the concrete anti-seepage wall 5, and improves the stress conditions of the concrete anti-seepage wall 5 and the foundation corridor 4.

[0028] The contact surface between the foundation corridor 4 and the asphalt concrete core wall enlarged section 42 is coated with asphalt mastic, and a first longitudinal copper water stop 421 is continuously provided along the dam axis.

[0029] The structural joint 43 has a second longitudinal copper waterstop 432 on the side close to the upstream rockfill area 1 and a third longitudinal copper waterstop 433 on the side close to the downstream rockfill area 2. The second longitudinal copper waterstop 432 and the third longitudinal copper waterstop 433 are both continuously arranged along the axial direction of the foundation corridor 4. The second longitudinal copper waterstop 432 and the third longitudinal copper waterstop 433 enhance the anti-seepage reliability of the structural joint 43.

[0030] The upper base width of the inverted trapezoidal concrete connecting section 41 is the same as the bottom width of the foundation corridor 4 , and the lower base width of the inverted trapezoidal concrete connecting section 41 is the same as the thickness of the concrete anti-seepage wall 5 .

[0031] The elastic modulus of the rubber spacer material 431 is not greater than 2 MPa.

[0032] Other parts not described belong to the prior art.

Claims

1. The connection structure between the foundation gallery and the cut-off wall of the asphalt concrete core rockfill dam is characterized by: The invention comprises an upstream rockfill area (1) and a downstream rockfill area (2); a transition material (31), a filter material (32), a high plasticity clay area (33) and a dam foundation cover layer (34) are sequentially arranged between the upstream rockfill area (1) and the downstream rockfill area (2) from top to bottom; A foundation gallery (4) is provided in the high-plastic clay zone (33); the lower end of the foundation gallery (4) is connected to a dam foundation concrete anti-seepage wall (5) located in a dam foundation cover layer (34) via an inverted trapezoidal concrete connecting section (41); and the upper end of the foundation gallery (4) is connected to an asphalt concrete core wall (6) located in a transition material (31) and a filter material (32) via an asphalt concrete core wall enlargement section (42); The inverted trapezoidal concrete connecting section (41) and the asphalt concrete core wall enlarged section (42) are both located in the high plasticity clay zone (33); A structural joint (43) is provided between the foundation corridor (4) and the inverted trapezoidal concrete connecting section (41), and the structural joint (43) is filled with a rubber pad spacer material (431); The contact surface between the foundation corridor (4) and the asphalt concrete core wall enlarged section (42) is coated with asphalt mastic, and a first longitudinal copper water stop (421) is continuously provided along the dam axis direction; An inverted trapezoidal concrete connecting section is set between the foundation corridor and the concrete cut-off wall, and a structural joint is set between the inverted trapezoidal concrete connecting section and the foundation corridor, and filled with rubber pads. This reduces the overlying load transmitted to the concrete cut-off wall through the foundation corridor, reduces the stress concentration on the top of the concrete cut-off wall, and improves the stress condition of the concrete cut-off wall and the foundation corridor.

2. The connection structure between the foundation gallery and the cut-off wall of the asphalt concrete core rockfill dam according to claim 1, characterized in that: The structural joint (43) has a second longitudinal copper waterstop (432) on the side close to the upstream rockfill area (1), and has a third longitudinal copper waterstop (433) on the side close to the downstream rockfill area (2). The second longitudinal copper waterstop (432) and the third longitudinal copper waterstop (433) are both continuously arranged along the axial direction of the foundation corridor (4).

3. The connection structure between the foundation gallery and the cut-off wall of the asphalt concrete core rockfill dam according to claim 2, characterized in that: The upper base width of the inverted trapezoidal concrete connecting section (41) is the same as the bottom width of the foundation corridor (4), and the lower base width of the inverted trapezoidal concrete connecting section (41) is the same as the thickness of the concrete anti-seepage wall (5).

4. The connection structure between the foundation gallery and the cut-off wall of the asphalt concrete core rockfill dam according to claim 3, characterized in that: The elastic modulus of the rubber spacer material (431) is not greater than 2 MPa.

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