Dam body structure of earth-rock cofferdam back slope type seepage prevention dam and construction method thereof

Abstract

The present application relates to the field of anti-seepage dam construction, and discloses a dam body structure of a soil-rock cofferdam back slope type anti-seepage dam and a construction method thereof, which comprises a foundation, a dam body is arranged on the upper side of the foundation, a drainage cavity is formed in the dam body, an installation plate is fixedly connected to the inner wall of the drainage cavity, a plurality of drainage cylinders are rotatably connected to the installation plate, a driving mechanism matched with the drainage cylinders is arranged in the drainage cavity, a connecting pipe is arranged on the inner wall of the drainage cavity, a plurality of rotary joints are arranged on the connecting pipe, the drainage cylinders are rotatably connected to the inner wall of the rotary joints, and drainage pipes are fixedly connected to the two ends of the connecting pipe, and flow valves are arranged on the drainage pipes. In the present application, the driving mechanism is arranged to drive the drainage cylinders to rotate and drain water, and the adjustable flow valves can actively and quickly drain the water accumulated around the dam body, effectively reduce the water pressure around the dam body, reduce the lateral pressure borne by the dam body, and improve the stability of the dam body.

Description

Dam structure and construction method of earth-rock cofferdam back slope seepage prevention dam Technical Field

[0001] This invention relates to the field of seepage control dam construction, and more particularly to the dam structure and construction method of earth-rock cofferdam back slope seepage control dam. Background Technology

[0002] In the field of water conservancy engineering, the seepage prevention structure of reservoir dam is the core element to ensure the stability and safe operation of the dam. Its importance is self-evident. Most of the seepage prevention structures currently in use follow the traditional water conservancy design ideas and build a preliminary drainage framework. They are mainly used to remove water accumulated inside the dam in a timely manner and effectively alleviate the seepage pressure of water on the dam.

[0003] In existing technologies, some earth-rock cofferdams and seepage prevention dams have the following defects: the drainage system is mostly a passive structure, lacking an active drainage mechanism, making it difficult to accurately adjust the drainage volume according to water level changes, which leads to water accumulation around the dam body and the potential for water pressure hazards; the seepage prevention system often uses a single material or a simple composite structure, and when the dam body deforms, the seepage prevention layer is prone to cracks and does not have self-repairing ability, resulting in a high risk of leakage. Summary of the Invention

[0004] To overcome the above deficiencies, this invention provides the dam structure and construction method of an earth-rock cofferdam back slope seepage prevention dam, aiming to improve the problems of drainage system lacking active drainage mechanism, seepage prevention layer being prone to cracking and lacking self-repair capability, resulting in a high risk of leakage, and solves the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a dam structure of an earth-rock cofferdam with a back slope for seepage prevention, including a foundation, a dam body installed on the upper side of the foundation, a drainage cavity opened inside the dam body, an installation plate fixedly connected to the inner wall of the drainage cavity, multiple drainage cylinders rotatably fitted on the installation plate, a driving mechanism cooperating with the drainage cylinders being provided inside the drainage cavity, a connecting pipe installed on the inner wall of the drainage cavity, multiple rotary joints installed on the connecting pipe, the drainage cylinders rotatably fitted on the inner wall of the rotary joints, drainage pipes fixedly connected to both ends of the connecting pipe, and flow valves installed on the drainage pipes;

[0006] A flexible seepage-proof layer is provided on the side wall of the dam body, and a rigid seepage-proof layer parallel to the flexible seepage-proof layer is provided on the inner wall of the dam body. A self-healing interlayer is provided at the interlayer between the flexible seepage-proof layer and the rigid seepage-proof layer.

[0007] As a further description of the above technical solution:

[0008] The drive mechanism includes a waterproof motor fixedly connected to one side of the inner wall of the drainage chamber. A worm gear is fixedly connected to the output end of the waterproof motor. Multiple bearings are rotatably fitted on the upper side of the inner wall of the drainage chamber, and worm wheels are mounted on the bearings.

[0009] As a further description of the above technical solution:

[0010] One end of the worm gear is rotatably fitted to one side of the inner wall of the drainage cavity, the worm gear meshes with the worm wheel, and the lower end of the bearing is fixedly connected to the upper end of the drainage cylinder.

[0011] As a further description of the above technical solution:

[0012] A sand discharge pipe is fixedly connected to one side of the drainage chamber. A control valve is installed at one end of the sand discharge pipe, and the other end of the sand discharge pipe extends to the inner wall of the drainage chamber.

[0013] As a further description of the above technical solution:

[0014] A wave-breaking wall is fixedly connected to the upper side of the dam body, and the bottom of the inner wall of the drainage cavity is funnel-shaped.

[0015] As a further description of the above technical solution:

[0016] The dam body has two symmetrically arranged filter layers inside, and an impermeable membrane is provided on the opposite side of the two filter layers.

[0017] As a further description of the above technical solution:

[0018] The flexible impermeable layer is a rubber asphalt composite material with a thickness of 0.5~2.0mm, and the rigid impermeable layer is a plastic concrete impermeable wall with a permeability coefficient ≤1×10⁻ 7 cm / s, the self-healing interlayer is a superabsorbent polymer resin layer, the volume expansion rate after contact with water is ≥200%, the rigid anti-seepage layer is pre-embedded with fiber optic sensors, the top of the dam body is equipped with a data acquisition instrument, the fiber optic sensors are connected to the data acquisition instrument, and the fiber optic sensors are laid at intervals of 0.5~1.0m.

[0019] The construction method for the dam body structure of an earth-rock cofferdam with a back slope seepage barrier, including the aforementioned dam body structure, is as follows:

[0020] S1: An optical fiber sensor is pre-embedded in the rigid seepage barrier layer. The optical fiber sensor works in conjunction with an external data acquisition instrument to set alarm thresholds and monitor seepage points in real time. When external water seeps into the dam, it will pass through the three layers of seepage prevention: the flexible seepage barrier layer, the self-healing interlayer, and the rigid seepage barrier layer. When the water reaches the rigid seepage barrier layer, the optical fiber sensor will monitor the water flow changes in real time. The data acquisition instrument receives the optical fiber signal, demodulates it into data, and alarms, thereby achieving the monitoring function.

[0021] S2: The water flowing into the drainage chamber carries silt. When the silt accumulates to a certain extent and needs to be cleaned, the control valve at one end of the silt discharge pipe is opened. Because the bottom of the inner wall of the drainage chamber is funnel-shaped, the silt will converge to the bottom under the action of gravity and be discharged from the dam body along the silt discharge pipe. This effectively avoids the accumulation of silt in the drainage chamber, prevents blockage of the drainage system, and ensures the continuous and stable drainage function. The two symmetrically set reverse filter layers inside the dam body play a key filtering role. When external water flow attempts to penetrate the dam body, the reverse filter layer can block soil particles from entering the dam body with the water flow, allowing only clean water to pass through. This prevents the internal structure of the dam body from being damaged by soil loss. At the same time, the impermeable membrane located on the opposite side of the two reverse filter layers further prevents water flow from penetrating, forming a double seepage protection, which greatly enhances the seepage prevention performance of the dam body, ensures the stability of the dam body structure, and reduces the risk of leakage.

[0022] S3: When there is accumulated water around the dam that needs to be drained, the waterproof motor is started. The waterproof motor drives the worm to rotate. Since the worm meshes with the worm wheel, the rotation of the worm is converted into the rotation of the worm wheel. The worm wheel is fixedly connected to the upper end of the drainage cylinder through the bearing, so that the drainage cylinder rotates on the inner wall of the rotary joint. The external accumulated water enters the drainage cylinder through the drainage chamber, then gathers through the connecting pipe, and finally is discharged from the dam through the drainage pipes at both ends. During this process, the flow valve adjusts the drainage volume according to the actual drainage needs, precisely controls the drainage speed, and ensures that the water level around the dam is maintained within a safe range. When the drainage cylinder rotates, under the action of centrifugal force, the mud and sand adhering to the surface of the drainage cylinder are thrown off, avoiding clogging the water inlet holes on the surface of the drainage cylinder.

[0023] The present invention has the following beneficial effects:

[0024] 1. In this invention, by setting up a drainage chamber, drainage cylinder, and driving mechanism inside the dam body, the active drainage of water around the dam body can be achieved. The flow valve can accurately adjust the drainage volume to maintain a safe water level. The rotary joint ensures that the drainage cylinder can rotate flexibly while maintaining a seal, preventing water leakage and making the entire drainage process smooth and efficient. This effectively reduces the water pressure around the dam body, reduces the lateral pressure on the dam body, and improves the stability of the dam body. The funnel-shaped design at the bottom of the inner wall of the drainage chamber, combined with the sand discharge pipe, facilitates the discharge of sediment and prevents blockage of the drainage system. The dual setting of the filter layer and the impermeable membrane effectively blocks the infiltration of soil particles and ensures the stability of the dam structure. The flexible impermeable layer and the rigid impermeable layer, together with the self-healing interlayer, form a three-layer impermeable system. The flexible impermeable layer adapts to the deformation of the dam body, the rigid impermeable layer has a low permeability coefficient, and the self-healing interlayer has a water expansion rate of ≥200%, which can automatically fill cracks. The synergistic effect of the three significantly improves the impermeability performance.

[0025] 2. In this invention, the waterproof motor in the drive mechanism drives the drainage cylinder to rotate through the meshing transmission of a worm gear and a worm wheel. The rotary joint ensures both flexible rotation of the drainage cylinder and maintains a seal, preventing leakage and making the entire drainage process smooth and efficient. The centrifugal force of the rotating drainage cylinder can throw off surface mud and sand, preventing blockage of the inlet hole and improving drainage efficiency. The sand discharge pipe and control valve facilitate the regular cleaning of accumulated mud and sand in the drainage chamber, and the funnel-shaped bottom design ensures long-term unobstructed drainage. The wave wall can weaken the impact of waves on the dam body and enhance the dam's resistance to wind and waves. The symmetrically arranged reverse filter layer and impermeable membrane inside the dam body form a double impermeable barrier, further preventing water infiltration and preventing soil loss inside the dam body. The fiber optic sensor embedded in the rigid impermeable layer is connected to the data acquisition instrument on the top of the dam to monitor the leakage point in real time. The fiber optic signal demodulation enables accurate alarm, improving the intelligence and reliability of dam leakage monitoring. At the same time, the fiber optic sensor embedded in the rigid impermeable layer, together with the data acquisition instrument, can monitor the leakage point in real time and alarm, ensuring the long-term stability and effectiveness of the impermeable system. Attached Figure Description

[0026] Figure 1 is a perspective view of the dam structure and construction method of the earth-rock cofferdam back slope seepage prevention dam proposed in this invention.

[0027] Figure 2 is a schematic diagram of the dam structure and construction method of the earth-rock cofferdam back slope seepage prevention dam proposed in this invention.

[0028] Figure 3 is a schematic diagram of the waterproof motor structure of the back slope seepage prevention dam of the earth-rock cofferdam proposed in this invention and its construction method.

[0029] Figure 4 is a schematic diagram of the wave wall structure of the back slope seepage prevention dam of the earth-rock cofferdam proposed in this invention and its construction method.

[0030] Figure 5 is a schematic diagram of the rigid anti-seepage layer structure of the dam body structure and construction method of the earth-rock cofferdam back slope anti-seepage dam proposed in this invention.

[0031] Legend:

[0032] 1. Foundation; 2. Dam body; 3. Drainage chamber; 4. Mounting plate; 5. Drainage cylinder; 6. Drive mechanism; 61. Waterproof motor; 62. Worm gear; 63. Bearing; 64. Worm wheel; 7. Connecting pipe; 8. Rotary joint; 9. Drainage pipe; 10. Flow valve; 11. Sand discharge pipe; 12. Control valve; 13. Wave wall; 14. Filter layer; 15. Geomembrane; 16. Flexible geomembrane; 17. Self-healing interlayer; 18. Rigid geomembrane; 19. Data acquisition instrument; 20. Fiber optic sensor. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] Please refer to Figures 1-5 for the dam structure of the earth-rock cofferdam backslope seepage-proof dam. The dam structure includes a foundation 1, a dam body 2 installed on the upper side of the foundation 1, a drainage chamber 3 inside the dam body 2, an installation plate 4 fixedly connected to the inner wall of the drainage chamber 3, multiple drainage cylinders 5 rotatably fitted on the installation plate 4, a drive mechanism 6 cooperating with the drainage cylinders 5 inside the drainage chamber 3, a connecting pipe 7 installed on the connecting pipe 7, multiple rotary joints 8 installed on the connecting pipe 7, drainage pipes 9 fixedly connected to both ends of the connecting pipe 7, a flow valve 10 installed on the drainage pipe 9, a flexible seepage-proof layer 16 on the side wall of the dam body 2, a rigid seepage-proof layer 18 parallel to the flexible seepage-proof layer 16 on the inner wall of the dam body 2, a self-healing interlayer 17 at the interlayer between the flexible seepage-proof layer 16 and the rigid seepage-proof layer 18, and the drainage cylinders 5 rotatably fitted on the inner wall of the rotary joints 8. A sand discharge pipe 11 is fixedly connected to one side of the drainage chamber 3. A control valve 12 is installed at one end of the sand discharge pipe 11, and the other end of the sand discharge pipe 11 extends to the inner wall of the drainage chamber 3. A wave wall 13 is fixedly connected to the upper side of the dam body 2. The bottom of the inner wall of the drainage chamber 3 is funnel-shaped. Two reverse filter layers 14 are symmetrically arranged inside the dam body 2. An anti-seepage membrane 15 is arranged on the opposite side of the two reverse filter layers 14. The flexible anti-seepage layer 16 is a rubber asphalt composite material, which adapts to the deformation of the dam body and has a thickness of 0.5~2.0mm. The rigid anti-seepage layer 18 is a plastic concrete anti-seepage wall, which provides structural support and has a permeability coefficient ≤1×10⁻ 7cm / s, the self-healing interlayer 17 is a superabsorbent polymer resin layer, which realizes automatic filling of cracks and drainage pressure reduction. The volume expansion rate after encountering water is ≥200%. The rigid seepage prevention layer 18 has a fiber optic sensor 20 embedded inside. The top of the dam body 2 is equipped with a data acquisition instrument 19. The fiber optic sensor 20 is connected to the data acquisition instrument 19. The fiber optic sensor 20 is laid at a spacing of 0.5~1.0m.

[0036] Implementation process: A flexible seepage barrier layer 16 is installed on the side wall of dam body 2, and a rigid seepage barrier layer 18 parallel to the flexible seepage barrier layer 16 is installed on the inner wall of dam body 2. A self-healing interlayer 17 is installed at the interlayer between the flexible seepage barrier layer 16 and the rigid seepage barrier layer 18. The flexible seepage barrier layer 16 is a rubber asphalt composite material, which adapts to dam deformation and has a thickness of 0.5~2.0mm. The rigid seepage barrier layer 18 is a plastic concrete seepage barrier wall, which provides structural support and has a permeability coefficient ≤1×10⁻ 7 The self-healing interlayer 17 is a superabsorbent polymer layer, which automatically fills cracks and reduces pressure through drainage. Its volume expansion rate after contact with water is ≥200%. A fiber optic sensor 20 is pre-embedded within the rigid impermeable layer 18. The fiber optic sensor 20 works in conjunction with an external data acquisition instrument 19 to set alarm thresholds and monitor leakage points in real time. When external water seeps into the dam body 2, it passes through the three layers of impermeability: the flexible impermeable layer 16, the self-healing interlayer 17, and the rigid impermeable layer 18. When the water reaches the rigid impermeable layer 18, the fiber optic sensor 20 monitors the water flow changes in real time. The data acquisition instrument 19 receives the fiber optic signal, demodulates it into data, and triggers an alarm, thus achieving the monitoring function. Over time, the water flowing into the drainage chamber 3 may carry sediment. When the sediment accumulates to a certain extent and needs to be cleaned, the sediment discharge pipe is opened. The control valve 12 at one end of 11, because the bottom of the inner wall of the drainage chamber 3 is funnel-shaped, the silt will gather to the bottom under the action of gravity and be discharged from the dam body 2 along the sand discharge pipe 11, effectively avoiding the accumulation of silt in the drainage chamber 3, preventing blockage of the drainage system, and ensuring the continuous and stable drainage function. The two reverse filter layers 14 symmetrically arranged inside the dam body 2 play a key filtering role. When the external water flow attempts to penetrate the dam body 2, the reverse filter layer 14 can block soil particles from entering the interior of the dam body 2 with the water flow, allowing only clean water to pass through, preventing the internal structure of the dam body 2 from being damaged by soil loss. At the same time, the impermeable membrane 15 located on the opposite side of the two reverse filter layers 14 further prevents water flow penetration, forming a double seepage protection, which greatly enhances the seepage prevention performance of the dam body 2, ensures the structural stability of the dam body 2, and reduces the risk of leakage.

[0037] Benefits of implementation: By setting up drainage chambers, drainage cylinders, and drive mechanisms inside the dam body, active drainage of water accumulated around the dam body can be achieved. The flow valve can precisely adjust the drainage volume to maintain a safe water level, effectively reducing water pressure around the dam body, alleviating the lateral pressure on the dam body, and improving the stability of the dam body. The flexible seepage barrier layer and the rigid seepage barrier layer, together with the self-healing interlayer, form a three-layer seepage prevention system. The flexible seepage barrier layer adapts to dam deformation, the rigid seepage barrier layer has a low permeability coefficient, and the self-healing interlayer has a water expansion rate of ≥200%, which can automatically fill cracks. The synergistic effect of the three significantly improves the seepage prevention performance. The funnel-shaped design at the bottom of the drainage chamber inner wall, combined with the sand discharge pipe, facilitates the discharge of sediment and prevents blockage of the drainage system. The dual setting of the filter layer and the seepage membrane effectively blocks the infiltration of soil particles, ensuring the stability of the dam structure. At the same time, the fiber optic sensor and data acquisition instrument pre-embedded in the rigid seepage barrier layer can monitor the seepage points in real time and alarm, ensuring the long-term stability and effectiveness of the seepage prevention system.

[0038] Example 2

[0039] The drive mechanism 6 includes a waterproof motor 61 fixedly connected to one side of the inner wall of the drainage chamber 3. A worm gear 62 is fixedly connected to the output end of the waterproof motor 61. Multiple bearings 63 are rotatably fitted on the upper side of the inner wall of the drainage chamber 3. A worm wheel 64 is mounted on the bearing 63. One end of the worm gear 62 is rotatably fitted to one side of the inner wall of the drainage chamber 3. The worm gear 62 meshes with the worm wheel 64. The lower end of the bearing 63 is fixedly connected to the upper end of the drainage cylinder 5.

[0040] Implementation process: When there is water accumulation around the dam body 2 that needs to be drained, the waterproof motor 61 is started. The waterproof motor 61 drives the worm gear 62 to rotate. Since the worm gear 62 meshes with the worm wheel 64, the rotation of the worm gear 62 is converted into the rotation of the worm wheel 64. The worm wheel 64 is fixedly connected to the upper end of the drainage cylinder 5 through the bearing 63, so that the drainage cylinder 5 rotates on the inner wall of the rotary joint 8. The external water accumulation can enter the drainage chamber 3 through the drainage cylinder 5, then converge through the connecting pipe 7, and finally be discharged from the dam body 2 through the drainage pipes 9 at both ends. During this process, the flow valve 10 can adjust the drainage volume according to the actual drainage needs, accurately control the drainage speed, and ensure that the water level around the dam body 2 is maintained within a safe range. When the drainage cylinder 5 rotates, under the action of centrifugal force, the mud and sand adhering to the surface of the drainage cylinder 5 are thrown off, avoiding clogging the water inlet holes on the surface of the drainage cylinder 5.

[0041] Benefits of implementation: The waterproof motor in the drive mechanism drives the drainage cylinder to rotate through the meshing of the worm gear and worm wheel. The rotary joint ensures both flexible rotation of the drainage cylinder and maintains a seal, preventing leakage and making the entire drainage process smooth and efficient. The centrifugal force of the rotating drainage cylinder can throw off surface silt, preventing blockage of the inlet hole and improving drainage efficiency. The installation of the sand discharge pipe and control valve facilitates the regular cleaning of silt accumulated in the drainage chamber, and the funnel-shaped bottom design ensures long-term unobstructed drainage. The wave wall can weaken the impact of waves on the dam body and enhance the dam's resistance to wind and waves. The symmetrically arranged reverse filter layer and seepage prevention membrane inside the dam body form a double seepage barrier, further preventing water infiltration and preventing soil loss inside the dam body.

[0042] Working principle: A flexible seepage barrier layer 16 is installed on the side wall of dam body 2, and a rigid seepage barrier layer 18 parallel to the flexible seepage barrier layer 16 is installed on the inner wall of dam body 2. A self-healing interlayer 17 is installed between the flexible seepage barrier layer 16 and the rigid seepage barrier layer 18. The flexible seepage barrier layer 16 is a rubber asphalt composite material, which adapts to the deformation of the dam body, and has a thickness of 0.5~2.0mm. The rigid seepage barrier layer 18 is a plastic concrete seepage barrier wall, which provides structural support, and its permeability coefficient is ≤1×10⁻ 7The self-healing interlayer 17 is a superabsorbent polymer layer, which automatically fills cracks and reduces pressure during drainage. Its volume expansion rate after contact with water is ≥200%. A fiber optic sensor 20 is embedded within the rigid impermeable layer 18. The fiber optic sensor 20 works in conjunction with an external data acquisition instrument 19 to set alarm thresholds and monitor leakage points in real time. When external water seeps into the dam body 2, it passes through the three layers of impermeability: the flexible impermeable layer 16, the self-healing interlayer 17, and the rigid impermeable layer 18. When the water reaches the rigid impermeable layer 18, the fiber optic sensor 20 monitors the water flow changes in real time. The data acquisition instrument 19 receives the fiber optic signal, demodulates it into data, and triggers an alarm, thus achieving the monitoring function. Over time, the water flowing into the drainage chamber 3 may carry sediment. When the sediment accumulates to a certain level and needs to be cleaned, the control valve 12 at one end of the sand discharge pipe 11 is opened. Because the bottom of the inner wall of the drainage chamber 3 is funnel-shaped, the sediment will converge towards the bottom under gravity. The sediment is discharged through the sand discharge pipe 11 into the dam body 2, effectively preventing sediment from accumulating in the drainage chamber 3, preventing blockage of the drainage system, and ensuring the continuous and stable drainage function. The two symmetrically arranged reverse filter layers 14 inside the dam body 2 play a key filtering role. When external water flow attempts to penetrate the dam body 2, the reverse filter layer 14 can block soil particles from entering the interior of the dam body 2 with the water flow, allowing only clean water to pass through, preventing the internal structure of the dam body 2 from being damaged by soil loss. At the same time, the impermeable membrane 15 located on the opposite side of the two reverse filter layers 14 further prevents water flow penetration, forming a double seepage protection, which greatly enhances the seepage prevention performance of the dam body 2, ensures the structural stability of the dam body 2, and reduces the risk of leakage. The design of the sand discharge pipe 11 and the bottom of the funnel-shaped drainage chamber 3 solves the problem of sediment accumulation from the root. Regular cleaning of sediment can ensure that the drainage system is unobstructed for a long time. The double-layer seepage barrier can not only effectively prevent leakage of the dam body 2, but also reduce the waste of water resources.

[0043] When water accumulates around dam 2 and needs to be drained, the waterproof motor 61 is activated. The waterproof motor 61 drives the worm gear 62 to rotate. Since the worm gear 62 meshes with the worm wheel 64, the rotational motion of the worm gear 62 is converted into the rotation of the worm wheel 64. The worm wheel 64 is fixedly connected to the upper end of the drainage cylinder 5 through the bearing 63, causing the drainage cylinder 5 to rotate on the inner wall of the rotary joint 8. External water can enter the drainage chamber 3 through the drainage cylinder 5, then converge through the connecting pipe 7, and finally be discharged from dam 2 through the drainage pipes 9 at both ends. During this process, the flow valve 10 can adjust the drainage volume according to the actual drainage needs, precisely control the drainage speed, and ensure that the water level around dam 2 is maintained within a safe range. When the drainage cylinder 5 rotates, under the action of centrifugal force... This allows the mud and sand adhering to the surface of the drainage cylinder 5 to be thrown off, preventing blockage of the water inlet holes on the surface of the drainage cylinder 5. The setting of the rotary joint 8 not only ensures that the drainage cylinder 5 can rotate flexibly, but also maintains the sealed connection between the connecting pipe 7 and the drainage cylinder 5 to prevent water leakage, making the entire drainage process smooth and efficient. By setting the drive mechanism 6, the drainage cylinder 5 is driven to rotate and drain water. With the help of the adjustable flow valve, the water accumulated around the dam body can be quickly and accurately discharged, effectively reducing the water pressure around the dam body 2, reducing the lateral pressure on the dam body 2, and improving the stability of the dam body 2. When the drainage cylinder 5 rotates, it achieves self-cleaning under the action of centrifugal force, avoiding blockage of the water inlet holes on the drainage cylinder 5, improving drainage efficiency, and preventing the water pressure inside the dam body 2 from increasing.

[0044] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The dam structure of an earth-rock cofferdam with a back slope for seepage prevention, including the foundation (1), is characterized by: A dam body (2) is installed on the upper side of the foundation (1). A drainage cavity (3) is provided inside the dam body (2). An installation plate (4) is fixedly connected to the inner wall of the drainage cavity (3). Multiple drainage cylinders (5) are rotatably fitted on the installation plate (4). A drive mechanism (6) that cooperates with the drainage cylinders (5) is provided inside the drainage cavity (3). A connecting pipe (7) is installed on the inner wall of the drainage cavity (3). Multiple rotary joints (8) are installed on the connecting pipe (7). The drainage cylinders (5) are rotatably fitted on the inner wall of the rotary joints (8). Drainage pipes (9) are fixedly connected to both ends of the connecting pipe (7). A flow valve (10) is installed on the drainage pipe (9). A flexible seepage-proof layer (16) is provided on the side wall of the dam body (2). A rigid seepage-proof layer (18) parallel to the flexible seepage-proof layer (16) is provided on the inner wall of the dam body (2). The flexible seepage-proof layer (16) and the rigid seepage-proof layer (18) are connected. A self-healing interlayer (17) is provided at the interlayer; the drive mechanism (6) includes a waterproof motor (61) fixedly connected to one side of the inner wall of the drainage cavity (3), the output end of the waterproof motor (61) is fixedly connected to a worm (62), the upper side of the inner wall of the drainage cavity (3) is rotatably fitted with multiple bearings (63), and a worm wheel (64) is installed on the bearing (63); one end of the worm (62) is rotatably fitted to one side of the inner wall of the drainage cavity (3), the worm (62) meshes with the worm wheel (64), the lower end of the bearing (63) is fixedly connected to the upper end of the drainage cylinder (5); a sand discharge pipe (11) is fixedly connected to one side of the drainage cavity (3), one end of the sand discharge pipe (11) is equipped with a control valve (12), and the other end of the sand discharge pipe (11) extends to the inner wall of the drainage cavity (3); a wave wall (13) is fixedly connected to the upper side of the dam body (2), and the bottom of the inner wall of the drainage cavity (3) is funnel-shaped.

2. The dam structure of the earth-rock cofferdam backslope seepage-proof dam according to claim 1, characterized in that: The dam body (2) has two symmetrically arranged filter layers (14) inside, and a seepage-proof membrane (15) is provided on the opposite side of the two filter layers (14).

3. The dam structure of the earth-rock cofferdam backslope seepage-proof dam according to claim 1, characterized in that: The flexible impermeable layer (16) is a rubber asphalt composite material with a thickness of 0.5~2.0mm, and the rigid impermeable layer (18) is a plastic concrete impermeable wall with a permeability coefficient ≤1×10⁻ 7 cm / s, the self-healing interlayer (17) is a polymer water-absorbing resin layer, and its volume expansion rate after encountering water is ≥200%. The rigid seepage prevention layer (18) is pre-embedded with an optical fiber sensor (20). The top of the dam body (2) is equipped with a data acquisition instrument (19). The optical fiber sensor (20) is connected to the data acquisition instrument (19). The optical fiber sensor (20) is laid out at a spacing of 0.5~1.0m.

4. A construction method for the dam body structure of an earth-rock cofferdam with a back slope for seepage prevention, comprising the dam body structure of the earth-rock cofferdam with a back slope for seepage prevention as described in any one of claims 1 to 3, characterized in that: The specific operating steps are as follows: S1: An optical fiber sensor is pre-embedded in the rigid seepage barrier layer. The optical fiber sensor works in conjunction with an external data acquisition instrument to set alarm thresholds and monitor seepage points in real time. When external water seeps into the dam, it passes through the three layers of seepage prevention: the flexible seepage barrier layer, the self-healing interlayer, and the rigid seepage barrier layer. When the water reaches the rigid seepage barrier layer, the optical fiber sensor will monitor the water flow changes in real time. The data acquisition instrument receives the optical fiber signal, demodulates it into data, and triggers an alarm to achieve the monitoring function. S2: The water flowing into the drainage chamber carries sediment. When the sediment accumulates to a certain extent and needs to be cleaned, the control valve at one end of the sand discharge pipe is opened. Because the bottom of the inner wall of the drainage chamber is funnel-shaped, the sediment will converge to the bottom under gravity and be discharged from the dam through the sand discharge pipe, effectively preventing sediment from accumulating in the drainage chamber, preventing blockage of the drainage system, and ensuring the continuous and stable drainage function. The two symmetrically arranged reverse filter layers inside the dam play a key filtering role. When external water attempts to penetrate the dam, the reverse filter layers can prevent soil particles from entering the dam with the water flow. Internally, only clean water is allowed to pass through to prevent damage to the internal structure of the dam due to soil erosion. At the same time, the impermeable membrane located on the opposite side of the two filter layers further prevents water seepage, forming a double seepage protection, which greatly enhances the seepage prevention performance of the dam, ensures the stability of the dam structure, and reduces the risk of leakage. S3: When there is water accumulation around the dam that needs to be drained, the waterproof motor is started. The waterproof motor drives the worm to rotate. Since the worm and worm wheel are meshed, the rotation of the worm is converted into the rotation of the worm wheel. The worm wheel is fixedly connected to the upper end of the drainage cylinder through the bearing, so that the drainage cylinder rotates on the inner wall of the rotary joint. The external water accumulation enters the drainage cylinder through the drainage chamber, then gathers through the connecting pipe, and finally is discharged from the dam through the drainage pipes at both ends. During this process, the flow valve adjusts the drainage volume according to the actual drainage needs, precisely controls the drainage speed, and ensures that the water level around the dam is maintained within a safe range. When the drainage cylinder rotates, under the action of centrifugal force, the mud and sand adhering to the surface of the drainage cylinder are thrown off, avoiding clogging of the water inlet holes on the surface of the drainage cylinder.

Images