Surface barrier structure for dam termite prevention and implementation method

Abstract

The invention relates to a surface barrier structure for dam termite prevention and an implementation method. A dam comprises a dam body, a protection slope, drainage prisms and infiltration lines. The surface barrier structure comprises an anti-termite layer which is arranged between a protection slope and a dam body and comprises a liquid-doped soil layer and a water-resisting layer from outside to inside; the water conveying system comprises a water conveying main pipe and water conveying branch pipes, the water conveying branch pipes are arranged at different elevations of the liquid-doped soil layer, the upper end of the water conveying main pipe is used for inputting doped liquid, and the lower end of the water conveying main pipe is connected with the water conveying branch pipes at different elevations; by pre-burying the water conveying pipeline, the process of increasing the salt (chemical) content of soil can be extended to the time after the dam body is completed, construction is easy and convenient, the influence on dam body construction is small, the construction period is shortened, the construction quality of the barrier structure is guaranteed, and the construction cost is reduced; the salt (pesticide) content of soil can be monitored in real time in the operation and maintenance period, salt (pesticide) water conveying is carried out according to actual conditions, the protection effect of the barrier structure is ensured, and maintenance is convenient; the water-resisting layer in the anti-termite layer is made of clay, combination of soil layers is facilitated, and stability of the dam slope is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of termite control in dams for water conservancy and hydropower projects, and particularly relates to a surface barrier structure and an implementation method for termite prevention in dams. Background Art

[0002] Soil-dwelling termites are one of the important threats to the safety of dams. They excavate ant galleries inside the dams, changing the soil structure of the dams, thereby affecting the stability and safety of the dams. The existence of termite nests may cause dangers such as seepage and piping in the dams, and in severe cases, it may even lead to dam break accidents.

[0003] In order to effectively control soil-dwelling termites, the salt soil or medicated soil barrier technology has emerged. This technology forms a barrier with ant-preventive effect by incorporating a certain amount of salt or medicine (hereinafter referred to as the incorporated liquid) into specific areas of the dam. The barrier structure can change the soil environment, making it impossible for termites to survive and reproduce in it, thereby achieving the purpose of termite control. However, there are certain drawbacks in the traditional dam barrier setting. Firstly, the incorporated liquid barrier needs to be implemented by spreading salt, spraying salt water or medicine on the soil surface of the dam body above the phreatic line. The implementation process requires a large amount of capital, manpower and material resources, with high construction costs and a greater impact on the project duration. Secondly, the dam barrier structure has high requirements for construction quality. If the implementation quality control is not good, it may affect the protection effect. Finally, the later maintenance of the barrier structure requires regular inspections. When problems occur, professional equipment is needed for repair, and the repair is difficult. If necessary, the soil salt content needs to be increased or the medicine needs to be re-sprayed to ensure its protection effect, with high maintenance difficulty and costs. Therefore, it is necessary to propose a surface barrier structure for dams that is simple to construct, cost-saving, time-saving and easy to maintain later.

[0004] Based on this, this case is proposed. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a surface barrier structure for termite prevention in dams, which has the advantages of simple construction, safety and reliability, low cost, time-saving, easy quality control and convenient later maintenance.

[0006] In order to achieve the above purpose, the technical solution of the present invention is as follows:

[0007] A surface barrier structure for termite prevention in dams, the dam includes a dam body, a slope protection, an anti-seepage layer, a drainage prism and a phreatic line. The slope protection includes an upstream slope protection and a downstream slope protection respectively arranged on both sides of the dam body. The anti-seepage layer and the phreatic line are located inside the dam body, and the drainage prism is arranged at the toe of the dam below the downstream slope protection of the dam body;

[0008] The surface barrier structure includes:

[0009] An ant-proof layer is provided between the slope protection and the dam body. From the outside to the inside, it includes a liquid-mixed soil layer and a water-proof layer. The liquid-mixed soil layer is arranged above the phreatic line, with a longitudinal length extending from the upstream slope protection through the dam top, downstream slope protection to the drainage prism. The water-proof layer is arranged above the phreatic line, with a longitudinal length extending from the dam top to the toe of the downstream slope protection.

[0010] A water conveyance system includes a main water conveyance pipe and a plurality of branch water conveyance pipes. There are several branch water conveyance pipes, which are arranged at different elevations in the liquid-mixed soil layer. A number of liquid outlet holes are opened on the pipe wall. The upper end of the main water conveyance pipe is used to input the mixed liquid, and it is connected to the branch water conveyance pipes at different elevations. A main pipe maintenance valve and a main pipe control valve are provided along the main water conveyance pipe, and a branch pipe control valve is provided at the end of the branch water conveyance pipe on the connection side with the main water conveyance pipe.

[0011] Furthermore, the ant-proof layer includes a number of monitoring devices arranged in the liquid-mixed soil layer for monitoring the concentration of the mixed liquid in the liquid-mixed soil layer.

[0012] Furthermore, the water-proof layer is made of clay material.

[0013] Furthermore, a geotextile and steel wire are provided outside the branch water conveyance pipe. The steel wire is wound on the surface of the geotextile to firmly wrap the branch water conveyance pipe.

[0014] Furthermore, a reserved pressurization pipe is provided on the main water conveyance pipe.

[0015] Furthermore, the branch water conveyance pipes between adjacent different elevations are connected; and / or the branch water conveyance pipes on the upstream slope protection side are connected to the branch water conveyance pipes at the dam top.

[0016] Furthermore, valve chambers are provided at the locations of the main pipe maintenance valve, reserved pressurization pipe, main pipe control valve and branch pipe control valve. The valve chambers are made of finished stainless steel material, and an openable cover plate is provided at the top. The valve chambers are hidden below the ground surface.

[0017] Furthermore, the water supply system includes a submersible pump, a water supply pipe, a mixer and a storage tank. The storage tank is arranged at the highest position of the dam and is connected to the upper end of the main water conveyance pipe. The storage tank is used to store the mixed liquid. The submersible pump is arranged on the upstream slope protection and is used to convey the water in the reservoir into the storage tank through the water supply pipe. The mixer is used to promote the uniform mixing of the mixed liquid in the storage tank;

[0018] and / or the water supply system uses a movable liquid storage vehicle, and the liquid storage vehicle is used to store the mixed liquid and can be connected to the main water conveyance pipe.

[0019] Furthermore, the storage tank is made of cast-in-place concrete or a finished stainless steel box body. An openable cover plate is provided at the top of the box body, and a ladder or step is provided inside and outside the box.

[0020] The second object of the present invention is to provide a method for implementing the surface barrier structure for preventing termites on the dam, comprising the following steps:

[0021] S1. During the dam construction period, hidden devices shall be embedded in the dam body, including but not limited to water delivery system and anti-termite layer; during the dam construction period, external devices shall be constructed simultaneously, including but not limited to water supply system;

[0022] S2. After the dam is completed, the doped liquid is promptly delivered to the doped soil layer through the water supply system and the water delivery system until the concentration of the doped liquid in the doped soil layer reaches the termite control requirement;

[0023] S3. During the operation period, the concentration of the doped liquid in the doped soil layer is regularly monitored by monitoring equipment. When the concentration of the doped liquid in the doped soil layer is lower than the termite control requirement, the water supply system and the water delivery system are turned on, and the main control valve and the branch control valve are adjusted to open and close, so as to carry out targeted doped liquid delivery to the defective doped soil layer.

[0024] The advantages of the present invention are:

[0025] 1) Simple construction, time-saving and easy quality control: By setting a salt (medicine) soil layer (i.e., a liquid-doped soil layer, which can be called a salt soil layer when the doped liquid is salt, and a medicinal soil layer when the doped liquid is medicinal) and a water-blocking layer on the surface of the earth-rock dam, and pre-burying a water pipeline in the salt (medicine) soil layer, and burying water supply equipment upstream of the earth-rock dam and on the mountain side, the process of increasing the salt (medicine) content of the salt (medicine) soil layer can be extended to after the completion of the dam body. The overall construction is simple, with little impact on the main construction of the dam, saving construction time, and in the later process of passing salt (medicine) water, the soil salt (medicine) content index can be strictly controlled by monitoring equipment, thereby ensuring the construction quality of the salt (medicine) soil barrier;

[0026] 2) Low construction cost: The water supply system and water delivery system included in this scheme are low in cost. The process of increasing the salt (medicine) content of the salt (medicine) soil layer is delayed until the dam body is completed. The salt (medicine) water can flow to the salt (medicine) soil layer by gravity. Compared with the traditional situation where the salt (medicine) soil barrier is implemented simultaneously with the main body of the dam, it greatly reduces labor and machinery costs and reduces construction costs;

[0027] 3) Convenient maintenance in the later stage: During the operation and maintenance period of the reservoir, the salt (drug) content of the salt (drug) soil layer is monitored in real time through monitoring equipment. For defective parts where the salt (drug) content of the soil is significantly reduced, the water supply system and the water delivery system can be started, and the salt (drug) water can be transported to the defective salt (drug) soil layer in a targeted manner by adjusting the opening and closing of the control valve, thereby increasing the salt (drug) content of the soil in the defective parts and ensuring the protective effect of the salt (drug) soil barrier. The overall maintenance is convenient, no secondary excavation and repair are required, and the impact on the dam body is small;

[0028] 4) Safe and reliable: The water - proof layer in the ant - prevention layer described in this solution uses clay material with low water permeability, and the implementation range is above the phreatic line, which does not affect the anti - seepage principle of "upper cut - off and lower drainage" of the earth - rock dam, and also ensures the stability of the contact surfaces between the water - proof layer and the adjacent salt (medicine) soil layer and the dam body, avoiding slope instability caused by the formation of unfavorable structural planes. Brief Description of the Drawings

[0029] Figure 1 is the plan layout schematic diagram of the surface barrier structure for preventing termites in the dam in Embodiment 1;

[0030] Figure 2 is Figure 1 the A - A sectional view schematic diagram of;

[0031] Figure 3 is Figure 1 detail drawing A of;

[0032] Figure 4 is Figure 2 detail drawing B of;

[0033] Figure 5 is Figure 3 the B - B sectional view schematic diagram of;

[0034] Figure 6 is Figure 5 detail drawing C of;

[0035] Label Description:

[0036] 1. Dam; 11. Upstream slope protection; 12. Downstream slope protection; 13. Dam crest; 14. Dam body; 15. Anti - seepage layer; 16. Drainage prism; 17. Phreatic line;

[0037] 2. Water supply system; 21. Submersible pump; 22. Water supply pipe; 23. Water storage tank; 24. Mixer; 25. Incorporation liquid;

[0038] 3. Water conveyance system; 31. Main water conveyance pipe; 32. Water conveyance branch pipe; 32a. Permeable water - spraying pipe; 32b. Geotextile; 32c. Steel wire; 33. Main pipe maintenance valve; 34. Main pipe control valve; 35. Reserved pressurized pipe; 36. Branch pipe control valve; 37. Valve chamber;

[0039] 4. Ant - prevention layer; 41. Liquid - incorporated soil layer; 42. Water - proof layer; 43. Monitoring equipment. Detailed Implementation Modes

[0040] The present invention will be further described in detail below in conjunction with embodiments. It should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. in the text are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0041] Embodiment 1

[0042] As Figures 1 to 6 shown, this embodiment proposes a surface barrier structure for preventing termites in dikes, which has the advantages of simple construction, safety and reliability, low cost, saving construction period, easy quality control, and convenient later maintenance. The surface barrier structure is arranged on the dike 1 and includes a water supply system 2, a water conveyance system 3, and an anti-termite layer 4.

[0043] As Figure 2 shown, the dike 1 has the same structure as the existing dike structure that adopts the anti-seepage principle of "upper interception and lower drainage", including a slope protection, a dam body 14, an anti-seepage layer 15, a drainage prism 16, and a phreatic line 17. The slope protection includes an upstream slope protection 11 and a downstream slope protection 12 respectively arranged on both sides of the dam body 14. The anti-seepage layer 15 and the phreatic line 17 are located inside the dam body, and the drainage prism 16 is arranged at the toe of the dam under the downstream slope protection 12 of the dam body 14. Among them, the phreatic line 17 is the intersection line of the free water surface formed by water seeping from the upstream face of the earth dam (or earth embankment) through the dam body to the downstream and the cross-section of the dam body.

[0044] As Figure 1 and Figure 3 shown, the water supply system 2 includes a submersible pump 21, a water supply pipe 22, a water storage tank 23, a mixer 24, and an admixture liquid 25. The water storage tank 23 is arranged on the dam crest 13, and the submersible pump 21 is arranged on the upstream slope protection 11 of the dike 1, which can transport the water in the reservoir to the water storage tank 23 through the water supply pipe 22. The water storage tank 23 is connected to the water conveyance system 3 on the side of the dike 1 to transport the admixture liquid 25 in the tank to the anti-termite layer 4. A mixer 24 is arranged in the water storage tank 23 to promote better fusion of the admixture liquid 25 (such as the mixture of salt and water, or the mixture of medicine and water). Of course, the mixer 24 can also be an external manual handheld type, so as to reduce the setting of mechanical and related power distribution equipment in the tank. Taking brine as an example, the water in the water storage tank 23 needs to be pumped into the tank by the submersible pump 21 first, and then after adding salt, the mixer 24 in the water storage tank 23 is started to promote better fusion of the brine. The water supply pipe 22 can be buried underground along one side of the earth-rock dam 1 to the water storage tank 23.

[0045] The ant-proof layer 4 is arranged between the slope protection and the dam body 14, and includes a liquid-mixed soil layer 41, a water-proof layer 42 and a monitoring device 43. Among them, the water-proof layer 42 is arranged between the dam body 14 and the liquid-mixed soil layer 41, and the liquid-mixed soil layer 41 is arranged between the water-proof layer 42 and the slope protection.

[0046] As Figure 2 shown, the liquid-mixed soil layer 41 is arranged above the phreatic line 17, and its longitudinal length extends from the upstream slope protection 11 through the dam crest 13, the downstream slope protection 12 to the drainage prism 16. The water-proof layer 42 is arranged deeper in the dam body 14 and is closely attached to the liquid-mixed soil layer 41. The water-proof layer 42 can prevent the infiltrated liquid 25 seeping out of the water delivery branch pipe 32 from flowing to other soil layers deep in the dam body 14. At the same time, in order not to affect the anti-seepage principle of "intercepting at the top and draining at the bottom" of the dam 1, the water-proof layer 42 is arranged above the phreatic line, and its longitudinal length range is smaller than that of the liquid-mixed soil layer 41, from the dam crest 13 to the downstream slope protection 12 near the dam toe. The monitoring device 43 is used to monitor the concentration of the infiltrated liquid in the liquid-mixed soil layer 41, so as to better control the concentration index of the soil infiltrated liquid, so as to achieve a good termite protection effect.

[0047] Preferably, the water-proof layer 42 can be made of clay material with a lower permeability to ensure the stability of the contact surfaces between the water-proof layer 42, the liquid-mixed soil layer 41 and the dam body 14, so as to prevent the formation of adverse structural surfaces from causing slope instability. At the same time, the monitoring device 43 can be an embedded device and is arranged in a relatively soft soil layer with green plants on the surface, or other plug-in devices can be used to monitor the soil salt content during the operation and maintenance period.

[0048] The submersible pump 21, the mixer 24 and the embedded monitoring device 43 should all be provided with power distribution for the operation of the equipment.

[0049] The water delivery system 3 includes a water delivery main pipe 31, water delivery branch pipes 32, a main pipe maintenance valve 33, a main pipe control valve 34, a reserved pressurized pipe 35, a branch pipe control valve 36 and a valve chamber 37. There are multiple water delivery branch pipes 32, which are arranged at different elevations of the liquid-mixed soil layer 41. The water delivery main pipe 31 is connected to the storage water tank 23 at the top and is connected to the water delivery branch pipes 32 at different elevations at the bottom. A main pipe maintenance valve 33, a reserved pressurized pipe 35 and a main pipe control valve 34 are arranged along the water delivery main pipe 31. The branch pipe control valve 36 of the water delivery branch pipe 32 is arranged at the end of the side connected to the water delivery main pipe 31. Valve chambers 37 should be provided at the locations of the main pipe maintenance valve 33, the reserved pressurized pipe 35, the main pipe control valve 34 and the branch pipe control valve 36, so as to hide the valves or reserved pipelines below the ground surface without affecting the normal operation and maintenance and aesthetics of the project. Since the valve chamber 37 has a small volume, it can be made of finished stainless steel material for easy construction. At the same time, a cover plate is provided on the top of the valve chamber 37 for opening and closing operations.

[0050] As Figure 6As shown in the figure, the water delivery branch pipe 32 is constructed as a water seepage and flower pipe 32a, with a geotextile 32b and a steel wire 32c arranged outside. The steel wire 32c is wound around the surface of the geotextile 32b, firmly wrapping the geotextile 32b around the water seepage and flower pipe 32a. The water seepage and flower pipe 32a can ensure that the admixture liquid 25 seeps into the admixture soil layer 41, and the geotextile 32b can prevent the soil particles in the admixture soil layer 41 from entering the water seepage and flower pipe 32 and causing blockage.

[0051] Through the above design, the admixture liquid 25 in the water storage tank 23 can flow by gravity to the water delivery main pipe 31 and the water delivery branch pipe 32, or an external device can be used to pressurize the admixture liquid 25 to the water delivery main pipe 31 and the water delivery branch pipe 32 through the reserved pressurization pipe 35.

[0052] Preferably, the water storage tank 23 can be made of cast-in-place concrete or a finished stainless steel box body. A cover plate is provided on the top of the box body for opening and closing operations. Ladders or steps can be provided inside and outside the box for manual operation and maintenance. The joints of the water supply pipe 22, the water delivery main pipe 31 and the water storage tank 23 should be well treated to prevent water leakage of the admixture liquid 25. At the bifurcation of the water delivery main pipe 31 and the connection between the water delivery main pipe 31 and the water delivery branch pipe 32, a tee joint should be used for connection and anti-seepage treatment to prevent water leakage of the admixture liquid 25.

[0053] At the same time, the water delivery branch pipe 32 can be connected between adjacent different elevations, and the number of branch pipe control valves 36 can be adjusted accordingly to achieve flexible control of the admixture soil layer 41 in a larger range and make the implementation operation more convenient. On the upstream slope protection 11 side of the dam, since it is inconvenient to implement the control valve, a small number of water delivery branch pipes 32 here can be connected to the water delivery branch pipes 32 at the dam crest 13. In addition, the water delivery main pipe 31 and the water delivery branch pipe 32 can be made of PE pipes to enable the pipes to adapt to the deformation caused by soil settlement.

[0054] During the layout, equipment such as the water delivery branch pipe 32 and the branch pipe control valve 36 that have cross-construction with the dam 1 should be pre-embedded during the construction of the dam 1. Equipment such as the water supply system 2 that has no cross-construction with the dam 1 can be constructed after the completion of the dam 1. The process of conveying the admixture liquid 25 into the admixture soil layer 41 can also be implemented after the completion of the dam body 14, thereby reducing the impact on the main construction of the dam 1, saving the construction period, and during the later process of passing the admixture liquid 25, the soil admixture liquid concentration index can be strictly controlled through the monitoring equipment 43, ensuring the construction quality of the admixture soil layer 41.

[0055] This embodiment also proposes an implementation method of a surface barrier structure based on the above termite prevention. By pre-burying a water conveyance pipeline in the liquid admixture layer 41 on the surface of the dam 1, the process of increasing the concentration of the admixture in the liquid admixture layer 41 can be extended until after the completion of the main dam construction, with little impact on the construction of the main dam body, saving the construction period and reducing the construction cost. At the same time, during the operation and maintenance period of the reservoir, the concentration of the admixture in the defective part can be specifically increased to ensure the protection effect of the barrier structure, without the need for secondary excavation and repair, with little impact on the dam body, and ensuring the safety and stability of the dam body. The implementation method includes the following steps:

[0056] S1. During the construction period of the dam 1, concealment devices such as a main water conveyance pipe 31, a branch water conveyance pipe 32, a main pipe maintenance valve 33, a main pipe control valve 34, a reserved pressurized pipe 35, a branch pipe control valve 36, and a detection device 43 are pre-buried in the dam body;

[0057] During the construction period of the dam 1, external devices such as the water supply system 2 are synchronously implemented in a timely manner;

[0058] S3. After the completion of the dam 1, the admixture 25 is promptly conveyed to the liquid admixture layer 41 through the water supply system 2 and the water conveyance system 3 until the concentration of the admixture in the liquid admixture layer 41 reaches the termite prevention requirements;

[0059] S4. During the operation period, regularly monitor the concentration of the admixture in the liquid admixture layer 41 according to the monitoring device 43. When the concentration of the admixture in the liquid admixture layer is lower than the termite prevention requirements, turn on the water supply system 2 and the water conveyance system 3, and through adjusting the opening and closing of the pipe control valve 34 and the branch pipe control valve 36, specifically convey the admixture to the defective liquid admixture layer 41, thereby increasing the concentration of the admixture in the defective part and ensuring the protection effect of the barrier.

[0060] Embodiment 2

[0061] The principle of this embodiment is basically similar to that of Embodiment 1. The difference is that the water supply system 2 in this embodiment uses a movable liquid storage vehicle, while the submersible pump 21, the water supply pipe 22, the water storage tank 23, and the mixer 24 in Embodiment 1 are not provided. The liquid storage vehicle is used to store the admixture. When replenishment is required, the movable vehicle filled with brine or liquid medicine is driven near the dam crest, and the brine or liquid medicine is conveyed to the ant-proof layer 4 through the connected main water conveyance pipe 31.

[0062] Embodiment 3

[0063] The principle of this embodiment is basically similar to that of Embodiment 1. The difference lies in that the water supply system 2 of this embodiment further includes a movable liquid storage vehicle for storing the admixture liquid. When the water storage tank 23 is unavailable but liquid replenishment is required (such as during operation and maintenance), a vehicle filled with brine or liquid medicine is driven near the dam crest. It can be connected to the water conveyance main pipe 31 through the reserved pressurization pipe 35, or the connection between the water conveyance main pipe 31 and the water storage tank 23 is first disconnected, and then the output end of the vehicle is connected to the water conveyance main pipe 31, and finally the brine or liquid medicine is conveyed to the ant-proof layer 4.

[0064] The above embodiments are only used to explain the concept of the present invention, rather than limiting the protection scope of the rights of the present invention. Any non-substantive modification made to the present invention using this concept shall fall within the protection scope of the present invention.

Claims

1. A surface barrier structure for preventing termites from entering a dam, the dam comprising a dam body, a slope protection, an impermeable layer, a drainage prism and an infiltration line, the slope protection comprising an upstream slope protection and a downstream slope protection respectively arranged on both sides of the dam body, the impermeable layer and the infiltration line are located in the dam body, and the drainage prism is arranged at the dam toe below the downstream slope protection of the dam body; It is characterized in that Surface barrier structures include: The anti-termite layer is arranged between the slope protection and the dam body, and includes a liquid-mixed soil layer and a waterproof layer from the outside to the inside. The liquid-mixed soil layer is arranged above the infiltration line, and its longitudinal length is from the upstream slope protection through the top of the dam body, the downstream slope protection to the drainage prism. The waterproof layer is arranged above the infiltration line, and its longitudinal length is from the top of the dam body to the foot of the downstream slope protection. The water delivery system comprises a water delivery main pipe and a water delivery branch pipe. There are several water delivery branch pipes arranged at different elevations of the liquid-doped soil layer. Several liquid outlet holes are provided on the pipe wall. The upper end of the water delivery main pipe is used to input the doped liquid, and the lower end is connected to the water delivery branch pipes at different elevations. A main pipe inspection valve and a main pipe control valve are provided along the water delivery main pipe, and a branch pipe control valve is provided at the end of the water delivery branch pipe on the side where it is connected to the water delivery main pipe.

2. A surface barrier structure for preventing termites from entering a dam as claimed in claim 1, characterized in that: The anti-termite layer includes a plurality of monitoring devices arranged in the liquid-doped soil layer, which are used to monitor the concentration of the liquid doped in the liquid-doped soil layer.

3. A surface barrier structure for preventing termites from entering a dam as claimed in claim 1, characterized in that: The waterproof layer is made of clay.

4. A surface barrier structure for preventing termites from entering a dam as claimed in claim 1, characterized in that: The water delivery branch pipe is provided with a geotextile and a steel wire outside, and the steel wire is wound around the surface of the geotextile, so that the geotextile firmly wraps the water delivery branch pipe.

5. The surface barrier structure for preventing termites from entering a dam as claimed in claim 1, characterized in that: A reserved pressure pipe is arranged on the water delivery main pipe.

6. The surface barrier structure for preventing termites from entering a dam as claimed in claim 1, characterized in that: The water delivery branches between adjacent different elevations are connected; and / or the water delivery branch located on the upstream slope protection side is connected to the water delivery branch at the top of the dam body.

7. A surface barrier structure for preventing termites from entering a dam as claimed in claim 5, characterized in that: Valve chambers are arranged at the locations of the main inspection valve, the reserved pressurized pipe, the main control valve and the branch control valve. The valve chambers are made of finished stainless steel and have an openable and closable cover plate at the top. The valve chambers are hidden below the ground surface.

8. The surface barrier structure for preventing termites from entering a dam as claimed in claim 1, characterized in that: The water supply system includes a submersible pump, a water supply pipe, a mixer and a water storage tank. The water storage tank is arranged at the highest position of the dam body and is connected to the upper end of the water supply pipe. The water storage tank is used to store the mixed liquid. The submersible pump is arranged on the upstream slope protection and is used to transport the water in the reservoir to the water storage tank through the water supply pipe. The mixer is used to promote the uniform mixing of the mixed liquid in the water storage tank. And / or the water supply system adopts a movable liquid storage vehicle, which is used to store the mixed liquid and can be connected to the water supply main pipe.

9. A surface barrier structure for preventing termites from entering a dam as claimed in claim 8, characterized in that: The water storage tank adopts cast-in-place concrete or finished stainless steel box body, the top of the box body is provided with an openable and closable cover plate, and ladders or steps are provided inside and outside the box.

10. A method for implementing the surface barrier structure for preventing termites on dams based on claims 1 to 9, characterized in that: The following steps are involved: S1. During the dam construction period, hidden devices shall be embedded in the dam body, including but not limited to water delivery system and anti-termite layer; during the dam construction period, external devices shall be constructed simultaneously, including but not limited to water supply system; S2. After the dam is completed, the doped liquid is promptly delivered to the doped soil layer through the water supply system and the water delivery system until the concentration of the doped liquid in the doped soil layer reaches the termite control requirement; S3. During the operation period, the concentration of the doped liquid in the doped soil layer is regularly monitored by monitoring equipment. When the concentration of the doped liquid in the doped soil layer is lower than the termite control requirement, the water supply system and the water delivery system are turned on, and the main control valve and the branch control valve are adjusted to open and close, so as to carry out targeted doped liquid delivery to the defective doped soil layer.

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