Reservoir basin geomembrane and concrete toe board composite anti-seepage connecting structure and safety monitoring method

Abstract

The invention provides a reservoir basin geomembrane and concrete toe board composite anti-seepage connecting structure and a safety monitoring method. The reservoir basin geomembrane and concrete toe board composite anti-seepage connecting structure comprises a concrete toe board, a GM-GCL composite anti-seepage connecting structure, a reservoir basin geomembrane and a special rolling area. Osmometers are arranged between the corrugated geomembrane and the GCL and below the GCL, and a safety monitoring meter is arranged at the position where the geomembrane is horizontally laid. The corrugated GM-GCL composite anti-seepage connecting structure is formed by the geomembrane and the GCL geosynthetic clay liner which are arranged in a corrugated mode, self-adaptive deformation is generated under the action of overlying water pressure by means of the telescopic characteristic of the corrugated GM-GCL composite anti-seepage connecting structure, and therefore the differential settlement difference between a concrete toe board and a reservoir basin foundation is coordinated, and the anti-seepage effect is achieved. Meanwhile, a special rolling area is arranged to improve the supporting capacity of the silty-fine sand filler and the transition layer below the composite anti-seepage connection structure, the problem that local connection of the anti-seepage geomembrane is damaged due to deformation discordance is effectively solved, and a leakage and deformation monitoring method of the corrugated GM-GCL composite anti-seepage connection structure is established; technical support is provided for concrete toe board and geomembrane anti-seepage connection design and a safety monitoring method in pumped storage power station reservoir engineering.

Description

Technical Field

[0001] The invention relates to the field of water conservancy and hydropower engineering, and in particular to a composite anti-seepage connection structure of a reservoir basin geomembrane and a concrete toe plate and a safety monitoring method. Background Art

[0002] The leakage problem of pumped storage power station reservoir directly affects the economic benefits of the power station. Severe leakage will cause local seepage damage and affect the anti-seepage safety of the reservoir. In response to the leakage problem of the reservoir basin, the anti-seepage type of the pumped storage power station reservoir basically adopts the vertical anti-seepage type and the surface anti-seepage type. When the hydrogeological conditions in the reservoir area are poor, the groundwater level is deep, and the sealing is poor, it is difficult to adopt vertical anti-seepage, and the surface anti-seepage type is preferred. The geomembrane anti-seepage of the entire reservoir basin is the most commonly used surface anti-seepage type.

[0003] When the geomembrane of the whole reservoir basin is used for anti-seepage, in order to form a complete reservoir dam anti-seepage system, the geomembrane of the reservoir basin needs to be connected to the concrete toe plate of the dam. Due to the uncoordinated deformation of the connection area between the rigid concrete and the flexible geomembrane, the connection between the concrete toe plate and the geomembrane of the reservoir basin is prone to become a weak point in anti-seepage. Under the action of the overlying water pressure, uneven settlement will occur between the concrete toe plate and the reservoir foundation, and a large settlement difference will occur at the connection between the geomembrane and the concrete toe plate, causing the geomembrane to be partially tensile and damaged. Once the geomembrane is damaged, it will form defective leakage, affecting the power generation efficiency of the power station and endangering the safety of the reservoir.

[0004] In the prior art, when the periphery of the geomembrane of the reservoir basin is connected to the concrete toe plate of the panel dam, measures such as setting a Z-shaped expansion joint or reserving superelevation are generally adopted. For the Z-shaped expansion joint, under the action of the reservoir water pressure, the Z-shaped geomembrane is not easy to stretch after being pressed tightly, and the ideal expansion effect cannot be achieved. In addition, stress concentration is easily generated at the bending part, which accelerates its aging and damage; for overfill measures such as reserved superelevation, the overfill is usually a single-layer geomembrane for anti-seepage. Under the conditions of reservoir water storage and discharge cycles, the geomembrane at the overfill and the superfill below it are frequently deformed, and the fine particles on the top of the superfill are easy to flow downward, resulting in direct contact between the single-layer geomembrane at the overfill and larger particles, resulting in top-breaking or puncturing, forming local defect leakage. In addition, in the existing design scheme for connecting the geomembrane of the reservoir basin with the concrete toe plate, there is a lack of leakage and deformation monitoring of the connection structure, and the operating status of the connection structure during the change of reservoir water level is unknown. Summary of the invention

[0005] The main purpose of the present invention is to provide a composite anti-seepage connection structure of a reservoir basin geomembrane and a concrete toe plate and a safety monitoring method to solve the problems in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: comprising a concrete toe plate and a reservoir geomembrane, the concrete toe plate is located below the concrete panel 12 of the panel rockfill dam, and a geomembrane fastener is pre-embedded at its end, the reservoir geomembrane is laid on the reservoir bottom cushion layer, and the reservoir geomembrane is a corrugated geomembrane near the concrete toe plate, thereby forming a GM-GCL composite anti-seepage connection structure, a GCL bentonite waterproof pad is provided below the corrugated geomembrane, and the end of the corrugated geomembrane is connected and fixed to the geomembrane fastener through a T-shaped lock structure; A special rolling area is provided between the reservoir bottom transition layer and the dam cushion layer, which is located below the GM-GCL composite anti-seepage connection structure; A number of first piezometers are installed between the corrugated geomembrane and the GCL bentonite waterproofing pad, and a number of second piezometers are installed under the GCL bentonite waterproofing pad. According to the changes in the osmotic pressure values ​​of the piezometers in each area, the anti-seepage safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir is monitored in real time.

[0007] Preferably, a safety monitoring meter is provided on the geomembrane horizontally laid near the GM-GCL composite anti-seepage connection structure, and the safety monitoring meter is a displacement meter and a level meter; The safety monitoring instrument monitors the vertical displacement and inclination changes of the reservoir basin geomembrane, and monitors the deformation safety of the GM-GCL composite anti-seepage connection structure in real time during the operation of the reservoir.

[0008] Preferably, there is fine sand filler underneath the GM-GCL composite anti-seepage connection structure, and the corrugated geomembrane and the GCL bentonite waterproofing pad deform synergistically under the reservoir water pressure, and fit tightly with the fine sand filler during the deformation process.

[0009] Preferably, the special rolling area uses materials with a larger deformation modulus and a high rolling standard to improve the supporting capacity of the fine sand filler and transition layer below the GM-GCL composite anti-seepage connection structure.

[0010] Preferably, a water-swellable waterstop strip is provided between the T-shaped locking structure and the geomembrane fastener, and plastic concrete is cast on the outer side thereof.

[0011] Preferably, the osmotic pressure value and the corresponding position of the piezometer are monitored in real time by a remote computer, an alarm is issued when a sudden increase in the monitored osmotic pressure value occurs, and the defect leakage range is automatically determined by the distribution of abnormal osmotic pressure changes at each osmotic pressure point.

[0012] Preferably, the displacement meter and level meter of the safety monitoring meter have monitoring value accuracies of 0.001m and 0.1° respectively, and both can transmit real-time monitoring data to a remote computer.

[0013] Real-time monitoring of the anti-seepage safety of the GM-GCL composite anti-seepage connection structure during reservoir operation, including the following situations: The monitored seepage pressures of both the first piezometer and the second piezometer are 0, indicating that the GM-GCL composite anti-seepage connection structure is intact and there are no defect leaks. The monitored seepage pressure of the first piezometer suddenly rises, while the monitored seepage pressure of the second piezometer is 0, or the seepage pressure value is small and stable, indicating that there are local minor defects in the geomembrane. After the GCL bentonite waterproof pad under the defect swells when encountering water, it plays a role in restricting defect leakage, and the anti-seepage safety of the GM-GCL composite anti-seepage connection structure is still relatively good. The monitored seepage pressures of both the first piezometer and the second piezometer suddenly rise, indicating that there are local major defects in the geomembrane. The GCL bentonite waterproof pad can no longer play a role in restricting defect leakage, and the GM-GCL composite anti-seepage connection structure is locally ineffective. According to the position of the piezometer where the seepage pressure suddenly rises, determine the defect leakage position in time and carry out repair treatment.

[0014] During the operation of the reservoir, the deformation safety of the GM-GCL composite anti-seepage connection structure is monitored in real time, including the following situations: The vertical displacement of the safety monitoring instrument is within the range of △h, and the inclination angle of the level is within the range of △θ, indicating that when the corrugated GM-GCL composite anti-seepage connection structure adapts to the uneven settlement between the concrete toe slab of the dam and the nearby reservoir basin foundation, its own deformation is within the safe range. If one of the vertical displacement ≤ △h and the inclination angle ≤ △θ of the safety monitoring instrument does not meet the requirements, it indicates that there are problems of excessive deformation or local damage in the corrugated GM-GCL composite anti-seepage connection structure, and it is necessary to carry out maintenance in time.

[0015] The design parameters of the GM-GCL composite anti-seepage connection structure include the length L and the corrugation heights h1~h5, which are determined according to the following steps: S1. Establishment of the finite element model of the dam and reservoir: According to the existing layout of each partition of the dam body and the reservoir bottom, establish a finite element calculation model including the concrete toe slab of the face slab dam, the face slab, the dam cushion layer, the transition layer, the rockfill area, as well as the reservoir bottom cushion layer and the reservoir bottom backfill area. The geomembrane of the reservoir basin and the special compaction area are not considered in the model. S2. Input of material parameters for each partition: According to the test results of the dam construction materials and rock and soil mechanics in the reservoir area, input the calculation parameters of the cushion material, transition material, rockfill material, reservoir bottom backfill material, as well as the face slab and concrete toe slab. S3. Application of water head conditions: Apply the water head conditions H 1 and the water head condition H 2 ; S4. Obtaining the finite element calculation results: Respectively obtain the maximum vertical deformation values d 1 and d 2 of the reservoir basin foundation near the concrete toe slab under the water head condition H 1 and the water head condition H 2 ; S5. Calculate the corrugation height h of the corrugated geomembrane by the following formula 1 ~h 5 :

[0016]

[0017] Where: k d is the vertical deformation safety factor, taking 1.5 - 2.0; S6. Calculate the length L of the corrugated geomembrane by the following formula:

[0018] Where: △l is the reserved length, taking 0.5 m - 1.0 m.

[0019] The present invention provides a composite anti-seepage connection structure and a safety monitoring method for the geomembrane of the reservoir basin and the concrete toe slab, and the beneficial effects are as follows: 1. The present invention adopts a corrugated GM-GCL composite anti-seepage connection structure composed of a corrugated geomembrane and a GCL bentonite waterproof blanket. Utilizing its telescopic characteristics, it generates self-adaptive deformation under the action of the overlying water pressure, thereby coordinating the uneven settlement difference between the concrete toe slab and the reservoir basin foundation. At the same time, a special compaction area is set to improve the supporting capacity of the fine sand filler and the transition layer under the composite anti-seepage connection structure, effectively solving the problem of local damage of the anti-seepage geomembrane caused by inconsistent deformation.

[0020] 2. The present invention adopts a composite anti-seepage connection structure combining a geomembrane and a GCL bentonite waterproof blanket. Utilizing the water-swelling and leakage-limiting characteristics of the GCL bentonite waterproof blanket, when the upper geomembrane is damaged, it fully exerts its role in restricting the leakage of reservoir water, enhancing the anti-seepage safety at the connection between the geomembrane of the reservoir basin and the concrete toe slab.

[0021] 3. The present invention takes measures for seepage pressure, displacement and inclination monitoring, and conducts safety monitoring on the connection structure between the geomembrane of the reservoir basin and the concrete toe slab from two aspects of leakage and deformation, obtains the operating state of the corrugated GM-GCL composite anti-seepage connection structure in real time during the operation of the reservoir, and can judge the defect leakage position according to the abnormal seepage pressure value and the corresponding piezometer position, ensuring the safe operation of the corrugated GM-GCL composite anti-seepage connection structure during the change of the reservoir water level.

[0022] 4. The present invention considers the cyclic water load under normal operating conditions of the reservoir and the maximum water load under flood conditions, and reasonably determines the design parameters of the corrugated GM-GCL composite anti-seepage connection structure, ensuring that the anti-seepage connection structure can meet the operation requirements of the reservoir. Description of the Drawings

[0023] The following further describes the present invention in conjunction with the drawings and embodiments: Figure 1 It is a schematic diagram of the composite anti-seepage connection structure of the reservoir basin geomembrane and the concrete toe plate of the present invention; Figure 2 This is a schematic diagram of the design parameters of the corrugated geomembrane structure of the present invention; Figure 3 It is a schematic diagram of the finite element calculation results of the vertical deformation of the dam and reservoir basin foundation of the present invention; Figure 4 It is a schematic diagram of the connection between the geomembrane fastener and the T-shaped lock structure of the present invention; In the figure: reservoir basin geomembrane 1; corrugated geomembrane 101; horizontally laid geomembrane 102; GCL bentonite waterproofing pad 2; T-shaped lock structure 3; geomembrane fastener 4; plastic concrete 5; fine sand filler 6; first piezometer 701; second piezometer 702; safety monitoring meter 8; reservoir bottom cushion 9; special rolling area 10; concrete toe plate 11; panel 12; dam cushion 13; transition layer 14; reservoir bottom backfill area 15; rockfill area 16; water-swelling waterstop 17. DETAILED DESCRIPTION

[0024] Example 1 like Figures 1 to 4 As shown, the composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate includes a concrete toe plate 11 and a reservoir geomembrane 1. The concrete toe plate 11 is located below the concrete panel 12 of the panel rockfill dam, and a geomembrane fastener 4 is pre-buried at its end. The reservoir geomembrane 1 is laid on the reservoir bottom cushion 9. The reservoir geomembrane 1 is close to the concrete toe plate 11 in the area of ​​the concrete toe plate 11, thereby forming a GM-GCL composite anti-seepage connection structure. A GCL bentonite waterproof pad 2 is provided below the corrugated geomembrane 101, and the end of the corrugated geomembrane 101 is connected and fixed to the geomembrane fastener 4 through a T-shaped locking structure 3; A special rolling area 10 is provided between the reservoir bottom transition layer 14 and the dam cushion layer 13, which is located below the GM-GCL composite anti-seepage connection structure; A plurality of first piezometers 701 are provided between the corrugated geomembrane 101 and the GCL bentonite waterproofing pad 2, and a plurality of second piezometers 702 are provided below the GCL bentonite waterproofing pad 2. The anti-seepage safety of the GM-GCL composite anti-seepage connection structure is monitored in real time during the operation of the reservoir according to the changes in the osmotic pressure values ​​of the piezometers in each area.

[0025] A corrugated geomembrane and a GCL bentonite waterproof pad 2 are used to form a corrugated GM-GCL composite anti-seepage connection structure. The expansion and contraction characteristics of the geomembrane are utilized to produce adaptive deformation under the action of the overlying water pressure, thereby coordinating the uneven settlement difference between the concrete toe plate 11 and the reservoir basin foundation. At the same time, a special rolling area 10 is set to improve the supporting capacity of the fine sand filler 6 and the transition layer 14 under the composite anti-seepage connection structure, effectively solving the problem of local damage to the anti-seepage geomembrane caused by uncoordinated deformation.

[0026] By utilizing the water-expanding and water-limiting properties of the GCL bentonite waterproof pad 2, when the upper geomembrane is damaged, it can fully exert its limiting effect on reservoir water leakage, thereby enhancing the anti-seepage safety of the connection between the reservoir basin geomembrane 1 and the concrete toe plate 11.

[0027] Preferably, a safety monitoring meter 8 is provided on the geomembrane 102 horizontally laid near the GM-GCL composite anti-seepage connection structure, and the safety monitoring meter 8 is a displacement meter and a level meter; The vertical displacement and inclination changes of the reservoir basin geomembrane 1 are monitored by the safety monitoring device 8, and the deformation safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir is monitored in real time.

[0028] Measures for monitoring seepage pressure, displacement and inclination are adopted to monitor the connection structure between the reservoir basin geomembrane 1 and the concrete toe plate 11 in terms of leakage and deformation, so as to obtain the operating status of the corrugated GM-GCL composite anti-seepage connection structure in real time during the operation of the reservoir. The defective leakage position can be determined according to the abnormal seepage pressure value and the corresponding piezometer position, thus ensuring the safe operation of the corrugated GM-GCL composite anti-seepage connection structure during the change of reservoir water level.

[0029] Preferably, there is fine sand filler 6 below the GM-GCL composite anti-seepage connection structure, and the corrugated geomembrane 101 and the GCL bentonite waterproofing pad 2 deform synergistically under the reservoir water pressure, and fit tightly with the fine sand filler 6 during the deformation process.

[0030] Preferably, the special rolling area 10 uses a material with a large deformation modulus and a high rolling standard to improve the supporting capacity of the fine sand filler 6 and the transition layer 14 below the GM-GCL composite anti-seepage connection structure.

[0031] In this embodiment, the filling material used in the special rolling area 10 is preferably a strongly rolled and weakly weathered rockfill material with a porosity of less than 12%, a maximum particle size of 450 mm, a mass fraction of particles less than 5 mm of no more than 18%, a maximum compaction force of more than 10 tons, and vibration rolling for no less than 16 times.

[0032] The head condition H1 is a constant head, and the head value is the reservoir verification flood level; the head condition H2 is a circulating head load, and the peak value of the circulating water load is the normal water level of the reservoir, and the valley value is the dead water level of the reservoir. The single cycle period is 1 day, and the number of cycles is n.

[0033] Preferably, Figure 1 , 2 As shown in 4, a water-swellable waterstop strip 17 is provided between the T-shaped locking structure 3 and the geomembrane fastener 4, and plastic concrete 5 is cast on the outer side thereof.

[0034] Preferably, the osmotic pressure value and the corresponding position of the osmometer are monitored in real time by a remote computer. When the monitored osmotic pressure value suddenly rises, an alarm is issued, and the range of defective leakage is automatically determined by the distribution of abnormal change values of the osmotic pressure at each osmotic pressure point.

[0035] Preferably, the monitoring value accuracies of the displacement meter and the level meter of the safety monitor 8 are 0.001 m and 0.1°, respectively, and both can transmit real-time monitoring data to a remote computer.

[0036] Embodiment 2 Combined with Embodiment 1, the usage method of the composite anti-seepage connection structure of the geomembrane of the reservoir basin and the concrete toe slab is further described: The anti-seepage safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir is monitored in real time, including the following situations: The monitored osmotic pressure values of the first osmometer 701 and the second osmometer 702 are both 0, indicating that the GM-GCL composite anti-seepage connection structure is intact and there is no defective leakage. The monitored osmotic pressure value of the first osmometer 701 suddenly rises, the monitored osmotic pressure value of the second osmometer 702 is 0, or the osmotic pressure value is small and the change is stable, indicating that there are local small defects in the geomembrane. After the GCL bentonite waterproof pad 2 below the defect swells when encountering water, it plays a role in restricting defective leakage, and the anti-seepage safety of the GM-GCL composite anti-seepage connection structure is still good. The monitored osmotic pressure values of the first osmometer 701 and the second osmometer 702 both suddenly rise, indicating that there are local large defects in the geomembrane, and the GCL bentonite waterproof pad 2 can no longer play a role in restricting defective leakage, and the GM-GCL composite anti-seepage connection structure is locally ineffective; According to the position of the osmometer with a sudden rise in the osmotic pressure value, the defective leakage position is determined in time and repaired.

[0037] The deformation safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir is monitored in real time, including the following situations: The vertical displacement of the safety monitor 8 is within the range of △h, and the inclination angle of the level meter is within the range of △θ, indicating that when the corrugated GM-GCL composite anti-seepage connection structure adapts to the uneven settlement between the concrete toe slab 11 and the nearby reservoir basin foundation, its own deformation is within the safe range. If one of the vertical displacement ≤ △h and the inclination angle ≤ △θ of the safety monitor 8 does not meet the requirements, it indicates that there are problems of excessive deformation or local damage in the corrugated GM-GCL composite anti-seepage connection structure, and it needs to be repaired in time.

[0038] The design parameters of the GM-GCL composite anti-seepage connection structure include the length L and each corrugation height h 1 ~h 5 , which are determined according to the following steps: S1. Establishment of finite element model of reservoir and dam: According to the existing dam body and the layout of each partition of the reservoir bottom, a finite element calculation model including the concrete toe plate 11, the face plate 12, the dam cushion layer 13, the transition layer 14, the rockfill area 16, the reservoir bottom cushion layer 9, and the reservoir bottom backfill area 15 is established. The reservoir basin geomembrane 1 and the special rolling area 10 are not considered in the model; S2. Input of material parameters for each zone: According to the damming materials and rock and soil mechanical test results in the reservoir area, input the calculation parameters of cushion material, transition material, rockfill material and reservoir bottom backfill, as well as the face plate 12 and concrete toe plate 11; S3. Applying head conditions: Apply head conditions H to the reservoir. 1 and head condition H 2 ; S4. Obtaining finite element calculation results: Get the water head conditions H 1 and head condition H 2 The maximum vertical deformation value d of the reservoir foundation near the concrete toe plate 11 1 and d 2 ; S5. Calculate the corrugation height h of the corrugated geomembrane by the following formula 1 ~h 5 :

[0039]

[0040] Where: k d is the safety factor of vertical deformation, which is 1.5~2.0; S6. Calculate the length L of the corrugated geomembrane by the following formula:

[0041] Among them: △l is the reserved length, which can be 0.5m~1.0m.

[0042] Head condition H 1 is a constant head, and the head value is the reservoir verification flood level; the head condition H 2 is the circulating water head load, the peak value of the circulating water load is the normal water level of the reservoir, the valley value is the dead water level of the reservoir, the single cycle period is 1 day, and the number of cycles is n.

[0043] Taking into account the circulating water load under normal reservoir operation and the maximum water load under flood conditions, the design parameters of the corrugated GM-GCL composite anti-seepage connection structure were reasonably determined to ensure that the anti-seepage connection structure can meet the reservoir operation requirements.

[0044] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. The composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate is characterized by: The invention comprises a concrete toe plate (11) and a reservoir geomembrane (1), wherein the concrete toe plate (11) is located below a concrete panel 12 of a panel rockfill dam, and a geomembrane fastener (4) is pre-buried at the end of the concrete toe plate (11). The reservoir geomembrane (1) is laid on a reservoir bottom cushion (9), and the reservoir geomembrane (1) is provided with a corrugated geomembrane (101) in an area close to the concrete toe plate (11), thereby forming a GM-GCL composite anti-seepage connection structure. A GCL bentonite waterproof pad (2) is provided below the corrugated geomembrane (101), and the end of the corrugated geomembrane (101) is connected and fixed to the geomembrane fastener (4) via a T-shaped locking structure (3); A special rolling area (10) is provided between the reservoir bottom transition layer (14) and the dam cushion layer (13), and is located below the GM-GCL composite anti-seepage connection structure; A plurality of first piezometers (701) are arranged between the corrugated geomembrane (101) and the GCL bentonite waterproof pad (2), and a plurality of second piezometers (702) are arranged below the GCL bentonite waterproof pad (2). The anti-seepage safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir is monitored in real time according to changes in the osmotic pressure values ​​of the piezometers in each area.

2. According to claim 1, the composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate is characterized by: A safety monitoring meter (8) is provided on the geomembrane (102) horizontally laid near the GM-GCL composite anti-seepage connection structure. The safety monitoring meter (8) is a displacement meter and a level meter. The vertical displacement and inclination of the reservoir basin geomembrane (1) are monitored by a safety monitoring meter (8), and the deformation safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir is monitored in real time.

3. The composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate according to claim 1 is characterized by: Below the M-GCL composite anti-seepage connection structure is a fine sand filler (6). The corrugated geomembrane (101) and the GCL bentonite waterproofing pad (2) deform synergistically under the reservoir water pressure, and fit tightly with the fine sand filler (6) during the deformation process.

4. The composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate according to claim 1 is characterized by: The special compaction area (10) uses materials with a large deformation modulus and a high compaction standard to improve the support capacity of the fine sand filler (6) and the transition layer (14) below the GM-GCL composite anti-seepage connection structure.

5. According to claim 1, the composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate is characterized by: A water-swellable water stop strip (17) is provided between the T-shaped lock structure (3) and the geomembrane fastener (4), and plastic concrete (5) is cast on the outer side of the water stop strip.

6. The composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate according to claim 1 is characterized by: The osmotic pressure value and corresponding position of the piezometer are monitored in real time by a remote computer. When the monitored osmotic pressure value suddenly rises, an alarm is issued, and the defect leakage range is automatically determined by the distribution of abnormal osmotic pressure changes at each osmotic pressure point.

7. The composite anti-seepage connection structure of reservoir geomembrane and concrete toe plate according to claim 2 is characterized by: The displacement meter and level meter monitoring values ​​of the safety monitoring meter (8) have an accuracy of 0.001m and 0.1° respectively, and both can transmit real-time monitoring data to a remote computer.

8. The safety monitoring method of the composite anti-seepage connection structure of the reservoir basin geomembrane and the concrete toe plate according to claims 1 to 7, wherein the method is: real-time monitoring of the anti-seepage safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir, including the following situations: The monitored osmotic pressure values ​​of the first osmometer (701) and the second osmometer (702) are both 0, indicating that the GM-GCL composite anti-seepage connection structure is intact and there is no defect leakage; The osmotic pressure value monitored by the first piezometer (701) rises suddenly, while the osmotic pressure value monitored by the second piezometer (702) is 0, or the osmotic pressure value is small and changes steadily, indicating that a small local defect has occurred in the geomembrane, and the GCL bentonite waterproof pad (2) below the defect has expanded in water and has played a role in limiting the leakage of the defect, and the anti-seepage safety of the GM-GCL composite anti-seepage connection structure is still good; The monitored osmotic pressure values ​​of the first piezometer (701) and the second piezometer (702) both suddenly increased, indicating that a large local defect appeared in the geomembrane, the GCL bentonite waterproofing pad (2) could no longer play the role of limiting the leakage of the defect, and the GM-GCL composite anti-seepage connection structure had failed locally. Based on the position of the piezometer with the sudden increase in osmotic pressure value, the defect leakage position was promptly determined and repaired.

9. The safety monitoring method of the composite anti-seepage connection structure of the reservoir basin geomembrane and the concrete toe plate according to claim 8, wherein the method is: real-time monitoring of the deformation safety of the GM-GCL composite anti-seepage connection structure during the operation of the reservoir, including the following situations: The vertical displacement of the safety monitoring meter (8) is within the range of △h, and the inclination angle of the level meter is within the range of △θ, indicating that the self-deformation of the corrugated GM-GCL composite anti-seepage connection structure is within the safety range when there is uneven settlement between the adaptive concrete toe plate (11) and the nearby reservoir basin foundation; If one of the vertical displacement ≤△h and the inclination angle ≤△θ of the safety monitoring meter (8) is not satisfied, it indicates that the corrugated GM-GCL composite anti-seepage connection structure has excessive deformation or local damage, and needs to be repaired in time.

10. The safety monitoring method of the composite anti-seepage connection structure of the reservoir basin geomembrane and the concrete toe plate according to claim 9, wherein the design parameters of the GM-GCL composite anti-seepage connection structure include the length L and the heights of each corrugation h1-h5, which are determined according to the following steps: S1. Establishment of finite element model of reservoir and dam: Based on the existing dam body and the layout of the reservoir bottom, a finite element calculation model is established, including the concrete toe plate (11), the face plate (12), the dam cushion (13), the transition layer (14), the rockfill area (16), the reservoir bottom cushion (9), and the reservoir bottom backfill area (15). The reservoir basin geomembrane (1) and the special rolling area (10) are not considered in the model. S2. Input of material parameters for each zone: Based on the damming materials and rock and soil mechanical test results in the reservoir area, input the calculation parameters of cushion material, transition material, rockfill material and reservoir bottom backfill, as well as the face plate (12) and concrete toe plate (11); S3, applying hydraulic head conditions: applying hydraulic head conditions H1 and H2 to the reservoir respectively; S4. Obtaining finite element calculation results: obtaining the maximum vertical deformation values ​​d1 and d2 of the reservoir basin foundation near the concrete toe plate (11) under the water head condition H1 and the water head condition H2 respectively; S5. Calculate the corrugation height h1~h5 of the corrugated geomembrane by the following formula: in: k d is the safety factor of vertical deformation, which is 1.5~2.0; S6. Calculate the length L of the corrugated geomembrane by the following formula: Among them: △l is the reserved length, which can be 0.5m~1.0m.

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