Construction method of composite flexible anti-seepage wall of embankment

Abstract

The present invention relates to the field of water conservancy project dams, and in particular to a construction method for a composite flexible anti-seepage wall for dams, comprising: step one, measurement and positioning; step two, equipment placement; step three, wall construction, forming a continuous cement-soil underground wall of equal thickness; step four, inserting an anti-seepage core plate; the anti-seepage core plate is composed of a main body, and a plurality of optical fiber bundles are distributed on the interior or outer surface of the main body. These optical fibers extend downward along the length of the main body and can monitor environmental changes of the main body and the surrounding underground continuous wall. For winding dams, a continuous and uniform composite flexible anti-seepage wall for dams can be formed, and the anti-erosion and anti-disturbance capabilities of the anti-seepage wall can be improved, and the anti-seepage durability can be improved. At the same time, the continuous wall can be monitored for leakage areas through the anti-seepage core plate, providing early warning for timely and effective preventive measures.

Description

Technical Field

[0001] The present invention relates to the field of water conservancy project dams, and in particular to a construction method of a composite flexible anti-seepage wall of a dam. Background Art

[0002] Earthen embankments are predominantly used for embankments along my country's major rivers and lakes. Strengthening embankment anti-seepage measures is crucial for their long-term stability. Traditional anti-seepage methods primarily rely on soil anti-seepage within the embankment, backfilling wells, and cement mixing piles. High-pressure jet grouting, geomembranes, and concrete formwork are also used. Frequent extreme weather events, such as continuous heavy rainfall and prolonged high water levels, pose serious risks to embankments, increasing the risk of serious dangers such as pipe bursts and dam failures caused by embankment leakage.

[0003] Existing embankments suffer from low compaction levels of their own soil and the backfill from the casing wells, as well as limited working space. These factors lead to insufficient durability of cement-mixed piles, while geomembranes and concrete panels suffer from offset settlement and joint failure. High-pressure jet grouting piles can easily damage the embankment structure. Furthermore, the embankment's complex and varied terrain and long length all contribute to the high cost and difficulty of reinforcing and anti-seepage projects.

[0004] The traditional mixing pile method, or SMW, often faces challenges such as uneven wall thickness and substandard strength under complex geological conditions. Cement-soil diaphragm walls, on the other hand, offer simple construction, uniform wall thickness, and low cost. However, due to the heavy construction equipment, large size, and high construction disturbance, traditional cement diaphragm walls are difficult to apply to general embankment anti-seepage treatment.

[0005] In this regard, Chinese invention patent publication number CN113356295A discloses a "continuous sawing device for underground deep narrow trenches." Through the coordination of a translating frame and a translating support frame, this device enables vertical and horizontal feeds for forming underground deep narrow trenches, efficiently and efficiently cutting and forming deep narrow trenches into wall-like structures as required. Chinese invention patent publication number CN116122370A discloses a "central wall forming TRD construction device." By securing the working device in the middle of the frame, the device reduces the construction space required by the work vehicle and is suitable for TRD construction of 6-8m embankments. The TRD method involves using a rotary chain saw to cut the soil layer and injecting a solidifying liquid, which is forcibly mixed with the in-situ soil to form a continuous cement wall. Steel sections can also be inserted into the wall to increase its rigidity and strength.

[0006] Despite advances in cement diaphragm wall construction technology, its limited durability and applicability remain. Particularly in winding embankments, diaphragm walls struggle to form an effective closed impermeable structure, making them difficult to meet the service life requirements of high-grade embankments.

[0007] The Chinese invention patent publication number is CN118110182A, which discloses "a method for constructing a retaining pile wall using a TRD method combined with sheet piles". The soil is cut and mixed in a channel-like manner using a TRD pile driver to form an underground cement soil continuous wall. Sheet piles are inserted into the continuous wall, and the plastic sheet piles of each sheet pile are connected as a whole through a mortise and tenon structure to form a retaining pile wall. By introducing a combination of plastic sheet piles and steel support piles, a water-stopping effect can be exerted to form an effective water-stopping curtain. In fact, this patent solution is mainly used in the enclosure of foundation pits. The land around the foundation pit can be leveled and compacted, and the enclosure is relatively wide, generally widened by TRD slots, between 100cm and 120cm. After slotting, steel sections are inserted below the bottom of the cement continuous wall to form support piles for the foundation pit, and the steel sections also form the support structure of the plastic sheet piles in the cement wall.

[0008] While the TRD method combined with sheet piles has achieved some success in excavation retaining, its effectiveness and stability in embankment and dam anti-seepage projects require further verification due to factors such as complex and variable embankment topography and widely varying soil qualities. Furthermore, the technology's economic viability, construction efficiency, and potential impact on the surrounding environment are all key considerations in embankment and dam anti-seepage applications. The application of retaining pile wall construction methods to embankment and dam anti-seepage projects has yet to be fully implemented and validated, presenting numerous technical challenges and operational adaptability issues.

[0009] Moreover, as a permanent anti-seepage dam, it is difficult to detect leakage-induced pipe bursts through effective monitoring methods, and it is difficult to assess or predict the risk of dam failure before a dangerous situation occurs, and to take timely and effective preventive measures. Summary of the Invention

[0010] In response to one or more problems existing in the existing dam anti-seepage, the present invention provides a construction method for a composite flexible anti-seepage wall of a dam. By using composite materials and advanced construction technology, the dam anti-seepage wall exhibits the flexibility required by the design and can flexibly adapt to various deformations and displacements of the dam, especially on winding embankments. It can form a continuous and uniform composite flexible anti-seepage wall, while significantly improving the anti-erosion and anti-disturbance capabilities of the anti-seepage wall and enhancing the anti-seepage durability. At the same time, the anti-seepage core plate is used to monitor whether there is a leakage area in the continuous wall, ensuring that the risk of dam collapse can be assessed or predicted before a dangerous situation occurs, and providing early warning for timely and effective preventive measures.

[0011] The purpose of the present invention is achieved through the following technical solutions:

[0012] The present invention provides a construction method for a composite flexible anti-seepage wall of a dam, comprising:

[0013] Step 1: Measure and locate. Mark the coordinates of the corner points of the center line of the cut-off wall at the top of the dam. Use the excavation mechanism to dig the working trench along the parallel trajectory of the center line of the cut-off wall.

[0014] Step 2: Equipment is in place and the construction machine equipment is transported to the top working position of the dam;

[0015] Step 3: Construction method wall, using a construction machine to cut along the working trench to the designed depth, and forcedly mix the original soil and solidifying liquid to form an underground continuous wall of equal thickness cement soil;

[0016] Step 4: Insert the anti-seepage core plate. After the construction reaches a working surface larger than the width of the anti-seepage core plate, insert the anti-seepage core plate in the middle of the cement soil underground continuous wall. Insert the bottom of the anti-seepage core plate to the designed depth. When multiple anti-seepage core plates are inserted, they are connected with adjacent anti-seepage core plates to form a composite flexible anti-seepage wall of the embankment.

[0017] The anti-seepage core board includes a main body, which includes a plate-shaped main board and wing plates arranged on both sides of the main board. The wing plates are provided with connection ends, including optical fibers and transceivers connected to the upper ends of the optical fibers. Several bundles of optical fibers are distributed inside and / or on the outer surface of the main body. The optical fibers extend downward along the length direction of the main body and are used to monitor changes in the environment of the main body and / or its surrounding underground continuous walls.

[0018] This invention embeds an anti-seepage core plate within a cement-soil underground continuous wall. The solidity of the cement wall further enhances the stability of the core plate, which in turn enhances the anti-seepage effectiveness of the cement wall, ensuring that it is less susceptible to deformation and failure during long-term use. By collecting optical fiber data on stress changes in the anti-seepage plate, as well as thermal radiation effects and vibration fluctuations in the water surrounding the plate, changes in the surrounding environment of the plate can be determined, and the presence of leakage points can be inferred. This allows the risk of dam failure to be assessed or predicted before a dangerous situation occurs, allowing timely and effective preventive measures to be taken.

[0019] Preferably, the surface of the main board is provided with a number of anchor rods extending along the length direction of the main board, the anchor rods include a main rod and a connecting part, the connecting part connects the main rod and the main board, the anchor rods are evenly staggered and distributed on both sides of the anti-seepage core board, after the anti-seepage core board is inserted into the underground continuous wall, the anchor rods are anchored and combined with the underground continuous wall.

[0020] In this invention, anchor rods reinforce the main structure and enhance the stability of the anti-seepage core. They can also be used independently without the support of H-beams, wooden piles, or other similar structures. Anchored into the underground cement continuous wall, the anchor rods form a secure connection with the surrounding ground. If the continuous wall deforms or leaks, the anchor rods act like antennae for optical fibers, amplifying signals of environmental changes.

[0021] Preferably, the cross-sectional width of the main rod is greater than the cross-sectional width of the connecting portion, or the diameter of the main rod is greater than twice the width of the connecting portion.

[0022] Preferably, an optical fiber is provided between the main rod and the main plate near the connection portion. The large cross-sectional area of ​​the main rod can form an effective anchoring effect, prevent the surrounding soil from being lost, improve the anti-seepage effect, and ensure that the anti-seepage core plate is more stable under complex geological conditions.

[0023] Preferably, the distance between the top of the anchor rod and the surface of the main plate is greater than the thickness of the main plate. The provision of the anchor rod can provide the main plate with a vertical bending resistance nearly twice the thickness of the main plate, while reducing overall resistance, facilitating the implantation of the anti-seepage core plate underground. At the same time, the main plate thickness should not be too large, so that the anti-seepage core plate has a certain degree of flexibility in the horizontal direction and has the ability to deform to adapt to complex geological environments.

[0024] Preferably, the connecting end includes a first connecting end and a second connecting end, the first connecting end includes a first end plate and a convex head, the second connecting end includes a second end plate and a concave head, and an optical fiber is arranged on the first end plate or the second end plate, or on the convex head or the concave head.

[0025] Preferably, in step 3, the thickness of the underground continuous wall is 30 cm to 45 cm;

[0026] In step 4, the inserted anti-seepage core plate has an overall thickness of 10 cm to 15 cm, and the anti-seepage core plate is entirely arranged in the middle of the width of the underground continuous wall.

[0027] In the present invention, the cement wall is 2-3 times the thickness of the anti-seepage plate, and the thickness of the cement wall is reasonably designed, which ensures the anti-seepage effect while avoiding unnecessary damage to the existing dam structure during construction.

[0028] Preferably, the width of the working trench is set to 0.5 to 0.7 m, and the depth needs to be more than 1.0 m.

[0029] Preferably, in step three, the cement content is adjusted according to the average cohesive strength of the soil layer, the cement content is controlled between 5% and 15%, and the cement soil strength is between 5% and 60% of the original soil layer strength.

[0030] Preferably, the vertical deviation of the insertion of the anti-seepage core plate is less than or equal to 1 / 300, and the first anti-seepage core plate is lifted and inserted into the cement soil slurry to keep it in the center position until the top of the anti-seepage core plate is 0.8m to 1m higher than the slurry; the second anti-seepage core plate is lifted, and the connecting ends of the two adjacent anti-seepage core plates are socketed and connected to each other, so that the two anti-seepage core plates are connected to each other until the top of the anti-seepage core plate is 0.8m to 1m higher than the slurry; then the first anti-seepage core plate is re-pressed until it is 0.2m higher than the slurry; when inserting the plate, ensure that the cement soil has not initially set. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the anti-seepage core plate structure from a top view;

[0032] Figure 2 Schematic diagram of the main structure of the anti-seepage core plate;

[0033] Figure 3 This is a schematic diagram of the narrow wall structure of the cut-off wall;

[0034] Figure 4 Schematic diagram of the wide wall structure of the cut-off wall;

[0035] Figure 5 This is a cross-sectional structural diagram of the cut-off wall on the embankment;

[0036] Figure 6 This is a top-down structural diagram of the cut-off wall on the embankment;

[0037] Figure 7 This is the process flow chart of TPD method.

[0038] In the figure: 1-main body, 2-main board, 3-wing board, 4-first connecting end, 41-first end plate, 42-convex head, 5-second connecting end, 51-second end plate, 52-concave head, 6-anchor rod, 61-main rod, 62-connecting part, 71-optical fiber, 72-transceiver, 10-cement wall, 20-river surface, 30-dam. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments should have elements such as specificity, operability, typicality, clarity, completeness, comparability, appropriateness, and flexibility to ensure that the innovation and practicality of the invention are fully demonstrated. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be understood as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referenced. Thus, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout the description of the present invention, unless otherwise specified, the term "plurality" refers to a quantity of two or more, and this definition is not subject to other limitations.

[0042] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; they may refer to direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances. Example

[0043] The present invention discloses a construction method for a composite flexible anti-seepage wall of an embankment, which is named Trench Cutting Plastic Pile-Mixing Deep Wall Method (TRD method is the full name of Trench Cutting Re-mixing Deep Wall Method, which adds a polymer anti-seepage plate to TRD). TPD method for short is developed on the basis of traditional TRD method to address the anti-seepage problem of existing embankments and intersecting buildings.

[0044] The core principle of the TPD method is to utilize the rotary motion of a chainsaw to precisely cut the soil layer to the designed depth. This is followed by a cross-cutting operation, followed by the injection of cutting and curing fluids, which are then thoroughly mixed with the in-situ soil. Finally, a continuous, nested anti-seepage core plate is inserted, creating a composite flexible anti-seepage wall with uniform thickness, continuity, and excellent anti-seepage performance.

[0045] like Figure 1 - Figure 2 As shown, the anti-seepage core plate includes a body 1, which includes a plate-shaped main plate 2 and wing plates 3 arranged on both sides of the main plate 2. One end of the wing plate 3 is connected to the main plate 2 and extends outward, and the other ends of the two wing plates 3 are respectively provided with connecting ends, which are respectively a first connecting end 4 and a second connecting end 5.

[0046] The first connecting end 4 includes a first end plate 41 and a convex head 42, and the second connecting end 5 includes a second end plate 51 and a concave head 52. The convex head 42 and the concave head 52 engage with each other to achieve sequential connection and tight fixation of the anti-seepage core plates.

[0047] The main plate 2 is provided with an anchor rod 6, which includes a main rod 61 and a connecting portion 62. The main rod 61 is generally cylindrical and extends parallel to the length of the main plate 2. The connecting portion 62 connects the main rod 61 and the main plate 2. The width of the connecting portion 62 is smaller than the diameter of the main rod 61 to ensure that the anchor rod 6 is firmly embedded.

[0048] When the optical fiber 71 is embedded in the body 1, its embedding method is flexible and diverse. It can be arranged along the preset groove inside the main board 2 or the wing plate 3, or it can be directly embedded during the molding process of the main board 2 or the wing plate 3. Doing so can ensure that the optical fiber 71 is tightly combined with the body 1, thereby improving the accuracy and stability of monitoring. The monitoring optical fiber selected by the sensor is a micro-fixed-point dense distributed strain sensing optical cable. By burying the optical fiber, that is, co-extruded into the anti-seepage core board, it is a dense strain sensing optical fiber that can monitor the stress condition of the board.

[0049] The production process for the anti-seepage core board involves creating channels in the extrusion die while the plastic-steel sheet is extruded, co-extruding the embedded optical fiber into the sheet pile. After forming, the sheet is fed into a shaping die where it is cooled by cold water, allowing the plastic-steel sheet to cool and set. The outer fiber layer requires an insulation layer and reinforcement layer to protect the internal fiber bundle. The fiber is then co-extruded and integrated with the sheet pile. The outer fiber layer is insulated and reinforced with materials such as aramid fiber, Teflon tubing, and metal tubing to enhance the strength and thermal insulation of the fiber bundle.

[0050] Composite flexible anti-seepage walls constructed using the TPD method offer advantages such as seamless joints, excellent water-stopping properties, high vertical precision, uniform texture, and a thin wall. The permeability coefficient is required to be k ≤ 1*10^-7 cm / s, and the wall's 28-day unconfined compressive strength is ≥ 0.3 MPa. TPD construction offers advantages such as high safety, high efficiency, low overall cost, wide geological applicability, and strong site adaptability.

[0051] Compared with the traditional TRD method anti-seepage wall, the composite flexible anti-seepage wall has a thin wall body, good embankment stability, good anti-seepage effect, strong anti-erosion ability and strong anti-disturbance ability.

[0052] (1) TPD process.

[0053] like Figure 7 As shown in the figure, the TPD process flow is described below with the main key steps.

[0054] 1. Measurement and positioning.

[0055] 1.1 Surveying and setting out. Before construction, accurately calculate the coordinates of the corner points of the centerline of the cut-off wall based on the design drawings and coordinate reference points. Use surveying instruments to set out and verify the coordinate data. Simultaneously, install protective piles. Notify relevant units to conduct a set-out and verification process.

[0056] The centerline of the cutoff wall is typically located at the centerline of the dam top, parallel to the dam axis and where stress is moderate. Measurements must be made with high precision, with an error strictly controlled within ±5mm to ensure accurate cutoff wall placement.

[0057] 1.2. Dig positioning trench.

[0058] Following the precise placement of the cutoff wall's centerline according to the TPD method's equipment weight requirements, a series of reinforcement measures, including the laying of steel plates, were implemented on the construction site to ensure the site could withstand the weight of the equipment and maintain stability during pile driver operation. An excavation mechanism was used to excavate a working trench parallel to the cutoff wall's centerline, with a width of approximately 0.6 meters and a depth exceeding 1.0 meters.

[0059] 2. The equipment is in place.

[0060] Put the host into position. Check the situation in all directions up, down, left and right before moving. If any obstacles are found, they should be removed in time. After the move, check the positioning and correct it in time. The host should be stable and flat.

[0061] The cutting chain saw is installed in place, and the cutting chain saw is lifted by a crane and connected to the main machine for installation.

[0062] 3. TPD method to build the wall.

[0063] First, determine the cement content and pre-mix the cement slurry based on the geological survey report; during construction, slightly adjust the cement content according to the distribution of different soil layers in each work section.

[0064] The cutting tool box is lowered and then cuts vertically to the designed depth. During the cutting process, the configuration and injection are controlled. The longitudinal groove is cut and the cutting agent slurry is injected into the bottom of the cutting box to cut the soil layer for a certain distance. Then, the excavation is withdrawn to the original position, and the solidifying slurry is injected. The composite soil is stirred and the solidifying liquid is forced to mix with the in-situ soil to form an underground continuous wall of equal thickness.

[0065] The cutting tool moves forward and reciprocates to carry out the construction of the next section of underground cement continuous wall.

[0066] Due to different soil layer distribution conditions, the average cohesion of the soil layer is calculated after mixing, and the cement content is adjusted according to the average cohesion of the soil layer. The cement content is controlled between 5% and 15%. The strength of cement soil should not be higher than 60% of the original soil layer strength. Generally, the strength of cement soil is between 5% and 60% of the original soil layer strength. The greater the difference in medium strength, the lower the anti-disturbance ability.

[0067] Adjust the aeration volume according to the cutting forward speed: increase the forward speed and increase the aeration volume to make the mixing amount of cement soil slurry the same at each moment.

[0068] The thickness of the cement-soil underground diaphragm wall is 30-45cm, which can be used for embankments with a minimum width of 3-4m. The excavation depth can reach 15-20m.

[0069] 4. Insert the anti-seepage core board.

[0070] After reaching a certain working surface, the high-strength anti-seepage core board will be inserted. The board needs to extend the working surface by 2 meters. The core board must remain vertical and be inserted vertically into the cement-soil mixing pile. The vertical deviation of the inserted core board should be less than or equal to 1 / 300, and the insertion time must be controlled within 3 hours after the completion of the mixing wall construction.

[0071] Lift the first anti-reverse seepage core board, insert it into the cement-soil slurry and keep it in the middle position until it is 1 meter above the slurry; lift the second anti-seepage core board, socket the connection ends of the two adjacent anti-seepage core boards, connect the two anti-seepage core boards to each other, and insert them into the slurry until they are 0.8 to 1 meter above the slurry; then re-press the first anti-seepage core board until it is 0.2m above the slurry, insert the first anti-seepage core board into the slurry, and construct the next anti-seepage core board in sequence. The first anti-seepage core board is pressed to a position of 0.8-1m to facilitate the socketing of the second anti-seepage core board. If it is too low, it will be difficult to socket it. Therefore, when the second anti-seepage core board is pressed to 0.8-1m, the first anti-seepage core board needs to be pressed down again until it is 0.2m above the slurry. Repeat this process for the third, fourth, and other anti-seepage core boards.

[0072] When inserting the panels, it is necessary to ensure that the cement soil has not yet initially set, and the panel insertion operation should be completed within 2 hours before the initial setting to avoid the vibration during the panel insertion process affecting the solidification of the cement soil around the completed panels.

[0073] The anti-seepage core plate was inserted into the diaphragm wall before it fully hardened, allowing for smooth insertion without the impact of complex geographical conditions. The core plate slotted smoothly into the bottom of the diaphragm wall without the need for additional piling support. Its strength alone ensured a tight fit within the diaphragm wall, forming a continuous, flexible wall structure.

[0074] 5. Pull out the cutting box.

[0075] After the construction is completed, the cutting box is pulled out in sections using the TPD host.

[0076] A construction method for composite flexible anti-seepage walls in dams is proposed. The narrow slot width allows for narrow embankments, facilitating construction. The impermeable core significantly enhances the area's anti-seepage capacity. Existing construction methods, such as vibratory pile driving, significantly disturb the site and prevent penetration into many soil layers. The unique characteristics of embankments preclude the use of water jet construction, which presents significant limitations.

[0077] like Figure 3 - Figure 4As shown, the anti-seepage core board has a wall thickness of 9mm, an overall width of 650mm, a length of 15m (adjustable according to engineering requirements), and a main board 2 of 402mm long. The width of the wing plate 3 projected onto the cross section perpendicular to the main board 2 is 120mm, and the length projected onto the surface of the main board 2 is 34mm. The wing plate 3 forms an angle A with the main board 2, tanA=120 / 34. The width of the connecting end is 90mm, parallel to the main board 2. The distance from the cross-sectional end of the anchor rod 6 to the side of the main board 2 is 11mm, the diameter of the main rod 61 is 9mm, and the width of the connecting end 62 is 4mm. The anchor rod 6 ensures that it can penetrate deep into the soil layer to form a firm support. The spacing between the anchor rods 6 is designed to be 80mm to 90mm, which can be slightly adjusted to ensure that the soil is evenly stressed and tightly connected to the cement soil underground continuous wall. Example

[0078] In this embodiment, optical fibers are arranged inside and on the surface of the anti-seepage core plate in Example 1.

[0079] Sensors are provided inside or on one side or both sides of the body 1 of the anti-seepage core board. The sensors are used to monitor the anti-seepage status in real time, and transmit data to a central processing system to analyze leakage risks.

[0080] The anchor rods 6 are evenly distributed on the surface of the main board 2, and their spacing remains consistent, thereby ensuring that the force on the entire structure reaches a balanced state. The anchor rods 6 are arranged on the surfaces of both sides of the main board 2 at the same time, and the anchor rods 6 on both sides are staggered to form a cross-support structure to enhance the overall tensile strength. The connection between the anchor rods 6 and the main board 2 is achieved by one-piece extrusion molding and other one-piece molding technologies. Through this design, not only the overall stability of the structure is improved, but also the service life of the anti-seepage system is extended. The precise monitoring and data analysis of the sensors enable the system to timely warn of potential leakage risks and ensure long-term safe operation. In addition, the wing panels 3 of the main body 1 are made of high-strength composite materials to enhance the deformation resistance, while requiring a certain degree of deformation flexibility, so that the wing panels 3 can bend moderately when subjected to external forces.

[0081] The sensor is a linear monitoring optical fiber 71. The optical fiber 71 is laid on the surface of the main board 2 and / or the wing board 3 through a preset path to ensure full coverage of the monitoring area.

[0082] The optical fiber 71 can be set at the same time inside and on the surface of the anti-seepage core board. The optical fiber 71 of the sensor is fixed on the surface of the main board 2, and the optical fiber can be selected as an active heating type stable vibration composite sensing optical cable. The optical fiber is an active heating type stable vibration composite sensing optical cable, and the main installation method is to stick it on the anti-seepage core board, and it needs to monitor the process of heat radiation and vibration being transmitted from one side to the other. Of course, it can also be pre-buried in the board. The optical fiber 71 is fixed between the anchor rod 6 and the main board 2. Specifically, the sensor is placed near the connection part 62 between the main rod 61 and the main board 2. Therefore, the sensor can be fixed on the main board 2 or the connection part 62, or fixed between the main rod 61 and the connection part 62, to ensure that the sensor is protected while being able to monitor the connection status of the main board 2, the anchor rod 6 and the surrounding environment, and to feedback data in real time to improve the stability and reliability of the anti-seepage system.

[0083] The anti-seepage core plate is used to install surface monitoring optical fibers. The fibers are deployed across the entire plate surface through methods such as secondary bonding with anchor rods. Carbon fiber cloth is impregnated with ethyl cyanoacrylate, covered with optical fiber cables, and fixed to the convex areas of the anchor rods on the anti-seepage core plate surface. Other polymer materials can also be used to wrap the optical fibers 71, with an additional steel wire outer layer.

[0084] When the anti-seepage core board is embedded in the formation, power is applied to the optical cable at the upper equipment, causing it to heat and vibrate. The heat radiation and vibration fluctuations in the water are detected, allowing calculation and analysis of possible leaks. While embedded in the formation, the anti-seepage core board effectively isolates the soil and groundwater on both sides while also conducting heat and vibration as a uniform medium. If a leak occurs, water flows through the channel formed by the anti-seepage core board, significantly changing the way heat and vibration are conducted, making it easier to identify the leak location.

[0085] The anti-seepage core plate body 1 itself serves as a structural support, eliminating the need for additional H-shaped steel or other foundation piles. Therefore, the provision of anchor rods 6 increases the structural strength of the body 1 and enhances the bond between the anti-seepage core plate and the surrounding soil, facilitating optical fiber detection of environmental changes surrounding the anti-seepage core plate. The smaller design of the wing plates 3 reduces the overall thickness of the anti-seepage wall, while also balancing rigidity and flexibility in the overall design of the anti-seepage core plate, adapting to complex geological conditions and ensuring long-term stable operation.

[0086] The flexible anti-seepage wall also includes a cement wall 10, which can be an underground continuous wall / cement continuous wall, etc. The cement continuous wall is tightly combined with the anti-seepage core board to form a double intelligent protection system.

[0087] Step 1: Following the precise placement of the cutoff wall's centerline according to the TRD method's equipment weight requirements, a series of reinforcement measures, including the laying of steel plates, were implemented on the construction site to ensure the site could withstand the weight of the equipment and maintain stability during pile driver operation. An excavator was used to excavate a working trench parallel to the cutoff wall's centerline, with a width of approximately 0.6 meters and a depth exceeding 1.0 meters.

[0088] Step 2: First, determine the cement content and pre-mix the cement slurry based on the geological survey report; during construction, adjust the cement content according to the distribution of different soil layers in each work section.

[0089] Inject excavation fluid into the bottom of the cutting box to pre-cut the soil layer for a certain distance, then withdraw the excavation to the original position, start solidifying the fluid to force it to mix and stir with the in-situ soil to form an equal-thick cement soil underground continuous wall.

[0090] Step 3: Insert high-strength anti-seepage core board.

[0091] After construction reaches a certain working surface, the high-strength anti-seepage core plate is inserted. The high-strength anti-seepage core plate must remain vertical and be inserted vertically into the cement-soil mixing pile. The vertical deviation of the inserted high-strength anti-seepage core plate must not exceed 1 / 300, and the insertion time must be controlled within 3 hours of the completion of the mixing wall construction.

[0092] The anti-seepage core board has multiple anchor rods added on the surface. Compared with the smooth surface of existing boards, it is more conducive to combining with the soil, concrete, cement soil and other media on both sides.

[0093] Flexible anti-seepage wall forming:

[0094] The thickness of the cement soil underground continuous wall is 350mm or 400mm, which is a reduced thickness compared to the traditional cement continuous wall which is about 1m thick. Setting up an anti-seepage wall on the embankment has less impact on the embankment itself.

[0095] After a large number of experimental verifications, the use of equal-thickness cement continuous walls with a thickness of 300mm to 450mm and anti-seepage core boards with a thickness of 90mm to 150mm can effectively achieve the anti-seepage function in the embankment, while having little impact on the embankment structure itself.

[0096] like Figure 3 , Figure 4 As shown, when the main board 2 is arranged close to the anti-seepage side, the thickness of the cement wall 10 is 350 mm; if the main board 2 is alternately arranged on the anti-seepage side or opposite thereto, the thickness of the cement wall 10 is 400 mm.

[0097] like Figure 5 , Figure 6As shown, in actual application, the flexible anti-seepage wall is constructed at the top center of the dam 30, located between the anti-seepage core plate 1 and the cement wall 10. This effectively covers the water level fluctuation range of the river surface 20 and prevents leakage. The dam 30 itself serves as the support for the flexible anti-seepage wall, and in the absence of water seepage, it can remain intact and prevent dam collapse.

[0098] The existing technology uses a single anti-seepage core plate, which causes excessive disturbance to the embankment during construction. The single TRD method requires heavy construction equipment and a wide slot, which causes great damage to the embankment and has poor anti-seepage effect. The SMW method has poor integrity and anti-seepage performance. To address the above problems, the TPD process for the construction of a composite flexible anti-seepage wall is realized by opening a narrow slot, mixing cement soil in situ, and inserting a single anti-seepage core plate.

[0099] For complex strata, the TPD method requires optimizing the cement slurry ratio to ensure wall uniformity and strength. This can also be achieved through optimization of the anti-seepage core board structure.

[0100] The present invention: 1. After the anti-seepage core board forms a wall within the soil layer, internal stress is generated. Fiber optics within the sheet pile sense compression and tension, which are received by a transceiver at the upper end and sent to a decoder at the upper end for decoding and analysis, forming a picture of stress changes within the soil during the operation of the anti-seepage core board. 2. The optical fibers on the outer surface of the anti-seepage core board compare their position with the optical fibers at the active end, performing stress analysis and monitoring relative movement. 3. The optical fibers on the outer surface of the anti-seepage core board are used for sound and temperature differential monitoring to analyze water seepage.

[0101] The present invention and its embodiments are described schematically above, and this description is not restrictive. The accompanying drawings illustrate only one embodiment of the method of the present invention and are not intended to be limiting. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, uninventively designs methods and embodiments similar to this technical solution, they shall fall within the scope of protection of the present invention.

Claims

1. A construction method for a composite flexible anti-seepage wall of a dam, characterized in that: include: Step 1: Measure and locate. Mark the coordinates of the corner points of the center line of the cut-off wall at the top of the dam. Use the excavation mechanism to dig the working trench along the parallel trajectory of the center line of the cut-off wall. Step 2: Equipment is in place and the construction machine equipment is transported to the top working position of the dam; Step 3: Construction method wall, using a construction machine to cut along the working trench to the designed depth, and forcedly mix the original soil and solidifying liquid to form an underground continuous wall of equal thickness cement soil; Step 4: Insert the anti-seepage core board. After the construction reaches the working surface larger than the width of the anti-seepage core board, insert the anti-seepage core board in the middle of the cement soil underground continuous wall. Insert the bottom of the anti-seepage core board to the designed depth. Insert multiple anti-seepage core boards and connect adjacent anti-seepage core boards in sequence to form a composite flexible anti-seepage wall of the embankment. The anti-seepage core plate comprises a body (1), the body (1) comprises a plate-shaped main board (2) and wing boards (3) arranged on both sides of the main board (2), the wing boards (3) being provided with connection ends; further comprising an optical fiber (71) and a transceiver (72), the transceiver (72) being connected to the upper end of the optical fiber (71); a plurality of optical fiber bundles (71) are distributed inside or / and on the outer surface of the body (1), the optical fibers (71) extending downward along the length direction of the body (1) and being used to monitor environmental changes of the body (1) or / and the surrounding underground continuous wall; The surface of the main plate (2) is provided with a plurality of anchor rods (6) extending along the length direction of the main plate (2), the anchor rods (6) comprising a main rod (61) and a connecting portion (62), the connecting portion (62) connecting the main rod (61) and the main plate (2), and after the anti-seepage core plate is inserted into the underground continuous wall, the anchor rods are anchored and combined with the underground continuous wall; The cross-sectional width of the main rod (61) is greater than the cross-sectional width of the connecting portion (62).

2. The construction method of a composite flexible anti-seepage wall of a dam according to claim 1, characterized in that: The anchor rods are evenly and staggeredly distributed on both sides of the anti-seepage core plate.

3. The construction method of a composite flexible anti-seepage wall of a dam according to claim 2, characterized in that: The diameter of the main rod (61) is greater than twice the width of the connecting portion (62).

4. The construction method of a composite flexible anti-seepage wall of a dam according to claim 2, characterized in that: It comprises an optical fiber (71) arranged between the main rod (61) and the main board (2) and close to the connecting portion (62).

5. The construction method of a composite flexible anti-seepage wall of a dam according to claim 4, characterized in that: The distance between the top end of the anchor rod (6) and the surface of the main board (2) is greater than the thickness of the main board (2).

6. The construction method of a composite flexible anti-seepage wall of a dam according to claim 1, characterized in that: The connecting end comprises a first connecting end (4) and a second connecting end (5), wherein the first connecting end (4) comprises a first end plate (41) and a male head (42), and the second connecting end (5) comprises a second end plate (51) and a female head (52), and an optical fiber (71) is provided on the first end plate (41) or the second end plate (51), or the optical fiber (71) is provided on the male head (42) or the female head (52).

7. A construction method for a composite flexible anti-seepage wall of a dam according to any one of claims 1 to 6, characterized in that: In step 3, the thickness of the underground diaphragm wall is 30cm to 45cm; In step 4, the inserted anti-seepage core plate has an overall thickness of 10 cm to 15 cm, and the anti-seepage core plate is entirely arranged in the middle of the width of the underground continuous wall.

8. The construction method of a composite flexible anti-seepage wall of a dam according to claim 7, characterized in that: The width of the working trench is set at 0.5 to 0.7 m, while the depth needs to exceed 1.0 m.

9. The construction method of a composite flexible anti-seepage wall of a dam according to claim 1, characterized in that: In step three, the cement content is adjusted according to the average bonding strength of the soil layer. The cement content is controlled between 5% and 15%, and the cement soil strength is between 5% and 60% of the original soil layer strength.

10. The construction method of a composite flexible anti-seepage wall of a dam according to claim 9, characterized in that: The vertical deviation of the insertion of the anti-seepage core plate is less than or equal to 1 / 300. Lift the first anti-seepage core plate and insert it into the cement-soil slurry and keep it in the center until the top of the anti-seepage core plate is 0.8m to 1m higher than the slurry; lift the second anti-seepage core plate and connect the connecting ends of the two adjacent anti-seepage core plates so that the two anti-seepage core plates are connected to each other until the top of the anti-seepage core plate is 0.8m to 1m higher than the slurry; then re-press the first anti-seepage core plate until it is 0.2m higher than the slurry; when inserting the plate, ensure that the cement soil has not initially set.

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