Spiral anchor and FRP intelligent anchor rod composite foundation structure and manufacturing method

Abstract

The invention belongs to the technical field of power transmission line foundation engineering, and particularly relates to a spiral anchor and FRP intelligent anchor rod composite foundation structure and a manufacturing method. The structure comprises a spiral anchor, an FRP intelligent anchor rod and a connecting sleeve, the FRP intelligent anchor rod is divided into an upper-section anchor rod and a lower-section anchor rod, and FBG optical fibers are arranged on the upper-section anchor rod and the lower-section anchor rod for real-time monitoring. The spiral anchor is suitable for a soft soil layer, the FRP intelligent anchor rod is suitable for a hard rock layer, and high-strength anchoring is achieved through grouting. The connecting sleeve is connected with the spiral anchor and the FRP anchor rod through threads, and the connecting force and durability are enhanced. The manufacturing method comprises the working procedures of screwing the spiral anchor in soil, drilling holes in rock, grouting the anchor rod, monitoring the optical fiber and the like, large-area excavation is not needed, efficiency is improved, and environmental damage is reduced. The structure has the advantages of light weight, high strength, corrosion resistance, real-time stress deformation monitoring and the like, and is suitable for power transmission line infrastructure construction of complex soil-rock composite strata.

Description

Technical Field

[0001] The present invention belongs to the technical field of power transmission line foundation engineering, and in particular relates to a composite foundation structure of a spiral anchor and an FRP intelligent anchor rod and a manufacturing method thereof. Background Art

[0002] The stability and construction efficiency of tower foundations not only determine the long-term operational safety of transmission lines but also play a key role in the project's economic viability and sustainability. With the continued expansion of transmission line construction and the increasing complexity of geological conditions, the industry's demand for foundation construction is shifting from traditional, resource-intensive methods to intelligent, green solutions. Promoting optimized foundation design, reducing concrete usage, and incorporating intelligent construction techniques to improve efficiency and precision not only accelerates project progress but also ensures safety and controllability during the construction process through real-time monitoring and data management. This has become a new trend in the development of transmission line infrastructure.

[0003] In the construction of transmission line tower foundations, soil-rock composite strata are a typical and complex geological condition, characterized by soft upper soil and hard, dense lower rock. Traditional composite foundation structures primarily include short pile-anchor composite foundations and excavation-anchor composite foundations. While these technologies have some applicability, they require extensive excavation, which increases construction difficulty, results in large amounts of earthwork to be transported, and prolongs construction time, resulting in high costs and low efficiency. These technologies have demonstrated significant limitations in actual projects, making them unsuitable for areas with complex terrain. When retrofitting transmission lines in cities, it is crucial to avoid large-scale excavation that would disrupt surrounding buildings and infrastructure. Furthermore, in coastal areas, where soils are often highly acidic or humid, traditional reinforced concrete foundations are susceptible to corrosion, shortening their service life. Furthermore, dynamic monitoring of foundation stress, deformation, and health during construction and maintenance is difficult, posing safety risks. Summary of the Invention

[0004] The purpose of the present invention is to provide a composite foundation structure of spiral anchors and FRP smart anchor rods and a manufacturing method thereof, so as to solve the problems of uncertain stress state of the foundation structure and low construction efficiency during tower foundation construction in soil-rock composite strata.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a composite foundation structure of a spiral anchor and an FRP smart anchor rod, comprising a spiral anchor, an FRP smart anchor rod and a connecting sleeve; the FRP smart anchor rod comprises an upper anchor rod and a lower anchor rod connected to each other; wherein, both the upper anchor rod and the lower anchor rod are provided with FBG optical fibers, and the upper anchor rod is arranged in the connecting sleeve; the connecting sleeve is arranged in the spiral anchor and is respectively connected to the upper anchor rod and the spiral anchor.

[0006] As an optional solution of the present invention, the spiral anchor is provided with an internal thread, the connecting sleeve is provided with an internal thread and an external thread, and the upper anchor rod is provided with an external thread; the upper anchor rod is threadedly connected to the connecting sleeve, and the connecting sleeve is threadedly connected to the spiral anchor.

[0007] As an optional solution of the present invention, the lower anchor rod includes a lower anchor core, the surface of the lower anchor core is provided with a spiral groove, and part of the FBG optical fiber is provided in the spiral groove; an anchor core groove wrapping layer is provided outside the lower anchor core; and a carbon fiber wrapping layer is provided outside the anchor core groove wrapping layer.

[0008] As an optional solution of the present invention, the upper anchor rod includes an upper anchor core, a glass fiber layer is provided on the outside of the upper anchor core, and a carbon fiber cloth layer is provided on the outside of the glass fiber layer; part of the FBG optical fiber is arranged along the surface of the upper anchor core and is located between the glass fiber layer and the upper anchor core; the surface of the carbon fiber cloth layer is provided with threads.

[0009] In a second aspect, the present invention provides a method for manufacturing a composite foundation structure of a spiral anchor and an FRP smart anchor rod, comprising the following steps: S1. Screw the spiral anchor into the soil layer to the designed depth; S2, drilling the rock formation downward along the spiral anchor to obtain a hole of designed diameter and depth; S3. Insert the FRP smart anchor rod into the hole from the inner spiral anchor, so that the upper anchor rod is located outside the hole and the lower anchor rod is located inside the hole; a casing installation space is formed between the upper anchor rod and the spiral anchor; S4, grouting and filling the hole; S5. Place the connecting sleeve in the sleeve installation space, and lead the FBG optical fiber on the FRP smart anchor out of the composite foundation structure.

[0010] As an optional solution of the present invention, in step S2, the diameter of the hole is 1.2 to 1.5 times the diameter of the spiral anchor; the depth of the hole is greater than the length of the FRP smart anchor by 5 cm to 10 cm.

[0011] As an optional solution of the present invention, in step S1, the designed depth is the depth of the intersection of the soil layer and the rock layer.

[0012] The third aspect of the present invention provides a method for manufacturing an FRP smart anchor rod, comprising manufacturing an upper anchor rod and a lower anchor rod; Fabrication of the lower anchor rod: a spiral groove is prepared on the surface of the lower anchor core, and an FBG optical fiber is installed inside the spiral groove; a carbon fiber reinforced composite material is impregnated with a thermosetting resin and then filled into the anchor core groove to form an anchor core groove wrapping layer; a carbon fiber wrapping layer is formed outside the anchor core groove wrapping layer to obtain the lower anchor rod; wherein the FBG optical fiber is led out from the upper part of the lower anchor rod; Preparation of the upper anchor rod: the FBG optical fiber is led out from the upper part of the lower anchor rod and fixed to the surface of the upper anchor core, and then impregnated with epoxy resin; a glass fiber layer is wrapped around the upper anchor core, and the glass fiber layer also wraps the FBG optical fiber on the surface of the upper anchor core, and then impregnated with epoxy resin again; a carbon fiber cloth layer is made outside the glass fiber layer, and a thread pattern is pressed on the surface of the carbon fiber cloth layer to obtain the upper anchor rod; wherein, the FBG optical fiber is led out from the upper part of the upper anchor rod.

[0013] As an optional solution of the present invention, the thickness of the carbon fiber wrapping layer is 2 cm to 3 cm.

[0014] As an optional solution of the present invention, the lower anchor core is made of basalt fiber and glass fiber; the upper anchor core is made of basalt fiber.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: For complex soil-rock composite formations, this invention provides a composite foundation structure of spiral anchors and FRP smart anchor rods. The upper spiral anchor is suitable for soft soil layers, achieving efficient mechanical locking through twisting. The lower FRP smart rock anchor rod is suitable for hard rock layers, achieving high-strength anchoring through grouting. Based on the construction concept of "twisting in the soil and drilling in the rock," intelligent mechanical operation is used during construction, eliminating the need for large-scale excavation or complex concrete pouring, significantly shortening the construction period.

[0016] Spiral anchors and FRP smart anchors are suitable for soil and rock layers respectively, achieving full ground coverage.

[0017] The inner wall of the spiral anchor is pre-threaded to enhance the connection strength and durability. The mechanical locking of the thread further improves the connection strength between the rock bolt and the spiral anchor, effectively preventing slippage under load.

[0018] The spiral anchor achieves stable anchoring in soft soil layers through the mechanical locking structure of prefabricated threads.

[0019] The FRP smart anchor rod adopts a multi-layer composite material design. It is not only lightweight, high-strength and corrosion-resistant, but also embedded with FBG fiber optic sensing technology, which can monitor key parameters such as force, deformation and temperature in real time.

[0020] The connecting sleeve adopts double thread design to ensure a firm connection between the spiral anchor and the FRP anchor rod.

[0021] During construction, the system's production method includes processes such as screwing in the soil, drilling into the rock, anchor grouting, and fiber optic monitoring. This eliminates the need for extensive excavation, significantly improving efficiency and minimizing environmental damage. Its modular design is suitable for mass and standardized construction, improving on-site efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 This is a structural schematic diagram of a composite foundation structure of a spiral anchor and FRP smart anchor rod according to an embodiment of the present invention; Figure 2 This is a schematic structural diagram of a connecting sleeve in an embodiment of the present invention; Figure 3 Schematic diagram of the structure of the FRP smart anchor in an embodiment of the present invention; Figure 4 Schematic diagram of the connection between the FBG optical fiber and the optical fiber demodulator in an embodiment of the present invention; Figure 5 This is a construction drawing of a method for manufacturing a composite foundation structure of a spiral anchor and FRP smart anchor rod according to an embodiment of the present invention; Among them: 1. spiral anchor; 11. anchor plate; 2. FRP smart anchor; 21. upper anchor; 22. lower anchor; 3. connecting sleeve; 4. FBG optical fiber; 5. hole; 6. optical fiber demodulator. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0024] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Example 1 This invention addresses the construction needs of complex soil-rock composite formations by leveraging the superior performance of FRP (fiber-reinforced plastic) to create an intelligent, efficient, and green engineering solution. By combining FRP smart anchors with spiral anchors, this invention achieves a highly efficient "screwing in soil, drilling in rock" process during construction. This eliminates the need for extensive excavation, significantly reduces damage to the surface environment, and significantly reduces concrete usage and carbon emissions, demonstrating exceptional environmental performance. The anchors incorporate FBG (fiber Bragg grating) sensing technology, enabling real-time monitoring of the foundation's stress state, deformation, and temperature changes. This provides accurate data support for construction and maintenance, comprehensively improving construction quality and safety. Combining intelligent monitoring, superior material performance, and green environmental protection concepts, this invention offers an intelligent, efficient, and sustainable solution for transmission line infrastructure construction.

[0028] like Figures 1 to 3As shown, a composite foundation structure of a spiral anchor and an FRP smart anchor comprises a spiral anchor 1, an FRP smart anchor 2 and a connecting sleeve 3; the FRP smart anchor 2 comprises an upper anchor 21 and a lower anchor 22 connected to each other; wherein, both the upper anchor 21 and the lower anchor 22 are provided with FBG optical fibers, and the upper anchor 21 is provided in the connecting sleeve 3; the connecting sleeve 3 is provided in the spiral anchor 1 and is connected to the upper anchor 21 and the spiral anchor 1 respectively.

[0029] Specifically, the spiral anchor 1 is provided with an internal thread, the connecting sleeve 3 is provided with an internal thread and an external thread, and the upper anchor rod 21 is provided with an external thread; the upper anchor rod 21 is threadedly connected to the connecting sleeve 3, and the connecting sleeve 3 is threadedly connected to the spiral anchor 1.

[0030] Specifically, the lower anchor rod 22 includes a lower anchor core, the surface of the lower anchor core is provided with a spiral groove, and part of the FBG optical fiber is provided in the spiral groove; an anchor core groove wrapping layer is provided outside the lower anchor core; and a carbon fiber wrapping layer is provided outside the anchor core groove wrapping layer.

[0031] Specifically, the upper anchor rod 21 includes an upper anchor core, a glass fiber layer is provided on the outside of the upper anchor core, and a carbon fiber cloth layer is provided on the outside of the glass fiber layer; part of the FBG optical fiber is arranged along the surface of the upper anchor core and is located between the glass fiber layer and the upper anchor core; the surface of the carbon fiber cloth layer is provided with threads.

[0032] As an example of the above solution, the spiral anchor 1 is made of an anchor plate welded on the surface of a hollow anchor pipe, and the inner wall is prefabricated with concave threads; it is suitable for soft soil layers and can achieve efficient mechanical locking by screwing.

[0033] As an example of the aforementioned solution, FRP Smart Anchor 2 uses fiber-reinforced plastic (FRP) as its primary material and employs a segmented, multi-layer composite design. FRP (fiber-reinforced plastic) smart anchors are lightweight, high-strength, corrosion-resistant, and non-conductive, significantly extending the lifespan of foundations and are particularly suitable for use in acidic soils or hot and humid environments.

[0034] Specifically, the FRP smart anchor 2 consists of two sections, the lower section 22, which includes a cylindrical lower anchor core made of basalt fiber and glass fiber. Its surface is prefabricated with a spiral groove for embedding an FBG optical fiber. A carbon fiber-reinforced composite material impregnated with thermosetting resin is then filled into the anchor core groove, forming a wrapping layer. The wrapping layer, with a thickness of 2 to 3 cm, enhances the tensile and compressive properties of the anchor. The FBG optical fiber in the lower section 22 is routed from the upper section and then fed into the upper section 21.

[0035] The upper anchor bolt 21 utilizes a multi-layer composite material design, with an inner layer reinforced with basalt fiber, a secondary layer of glass fiber, and an outer layer of carbon fiber cloth. This ensures corrosion resistance and enhances external strength. The FBG fiber 4 is placed on the inner surface of the upper anchor bolt 21 and wrapped with a thin layer of glass fiber. The fiber material is impregnated layer by layer with epoxy resin to ensure resin penetration. The carbon fiber cloth is then evenly applied to the outermost layer and compacted using a metal mold to create a threaded appearance. The inner surface of the metal mold is engraved with the anchor bolt thread pattern.

[0036] Specifically, the FBG optical fiber 4 is mounted on the surface of the basalt fiber and fixed with a high-performance adhesive. The FBG optical fiber 4 is arranged for axial and shear stress monitoring and calibration of temperature compensation light.

[0037] FRP anchor rods are integrated with fiber optic sensors and distributed fiber optic sensing technology to monitor the stress, temperature and health of the anchor rods in real time, thus achieving real-time perception and monitoring of the entire foundation construction process and operation and maintenance cycle.

[0038] Specifically, the outer surface of the connecting sleeve 3 is prefabricated with a convex thread, and the inner cavity is prefabricated with a concave thread, which is used to connect the spiral anchor and the FRP smart anchor rod.

[0039] As an example, the connecting sleeve 3 is a steel sleeve, and the outer surface and inner cavity of the steel sleeve are prefabricated with male threads and female threads respectively. The female threads of the inner cavity match the male threads of the upper anchor rod 21, and the male threads on the outside of the steel sleeve match the female threads inside the anchor pipe of the spiral anchor 1.

[0040] The composite foundation structure of spiral anchors and FRP smart anchor rods provided in this solution is installed and manufactured as follows: Equipped with equipment required for construction, including: spiral anchor screwing machine, rock drilling equipment, fiber optic demodulator, etc.

[0041] Use mechanical screwing equipment to screw the spiral anchor 1 into the soil layer to the designed depth, and use drilling equipment to drill a hole 5 of the designed diameter and depth in the rock layer. The diameter of the hole 5 is slightly larger than the anchor rod diameter, usually 1.2 to 1.5 times, and the hole depth is 5 to 10 cm greater than the anchor rod length.

[0042] The FRP smart anchor rod is inserted into the hole 5 so that the convex thread of the upper anchor rod 21 is exposed outside the hole 5, and grouting is performed in the hole of the lower anchor rod 22 to fill the gap around the rock hole and enhance the anchoring strength.

[0043] The connecting sleeve 3 is screwed between the spiral anchor 1 and the FRP smart anchor 2, and is securely connected to the spiral anchor 1 and the FRP smart anchor 2 through threads. Optionally, an anti-corrosion material is applied to the connection of the connecting sleeve 3 to enhance durability.

[0044] Connect the lead-out end of the FBG fiber 4 to the fiber demodulator 6. Check the stability of the fiber signal transmission to ensure smooth data acquisition and calibrate the temperature compensation fiber to correct temperature interference in stress monitoring.

[0045] like Figure 4 As shown, in this solution, the FBG fiber is connected to a fiber optic interrogator. The fiber optic interrogator is used to provide optical signal input, detect the optical signal reflected or transmitted by the FBG, and convert it into an electrical signal for further processing and analysis. In this way, the FBG fiber can measure various physical quantities, such as strain and temperature. Therefore, in this solution, the FBG fiber is used to monitor axial stress, shear stress, and temperature compensation. Specifically, the signal output by the fiber optic interrogator is transmitted to the monitoring software platform via a data transmission module for data processing and analysis, allowing real-time monitoring of the stress distribution of the anchor body along the depth direction.

[0046] The above solution combines spiral anchors and FRP smart anchor rods, significantly improving the efficiency and adaptability of foundation construction under complex soil-rock composite strata.

[0047] In summary, this solution has the following advantages: 1. Improved construction efficiency: The highly efficient "screwing in soil, drilling in rock" construction process eliminates the need for large-scale excavation and concrete pouring, significantly shortening the construction period. Compared with traditional methods, on-site construction time is reduced by 30%-50%, and the utilization rate of construction equipment is increased by approximately 20%. Mechanized operation and modular design further reduce manual errors, improve construction accuracy by 25%, and save 15%-20% in project costs.

[0048] 2. Enhanced foundation performance: FRP smart anchor rods have the advantages of being lightweight, high-strength, and corrosion-resistant. Their tensile strength is approximately 50% higher than that of traditional steel bars, and their durability in hot, humid or acidic soil environments is increased by 3-5 times. Fiber optic sensing technology allows real-time monitoring of the stress, deformation, and other parameters of the foundation structure, which can detect hidden dangers at an early stage and avoid accidents caused by foundation instability. It is expected to reduce maintenance and reinforcement costs by approximately 40%-60%.

[0049] 3. Significant environmental benefits: By reducing the use of concrete and earth excavation, the carbon emissions of the construction process of this invention are reduced by approximately 20%-35%; the recyclability and non-conductive properties of FRP materials avoid long-term damage to the environment; in addition, the modular design reduces the energy consumption of transportation and construction equipment, and the overall construction energy consumption is reduced by approximately 15%-25%, further achieving the goal of green construction.

[0050] The composite foundation structure of spiral anchors and FRP smart anchors provided by this solution can be applied to the following scenarios: 1) Transmission line tower infrastructure construction in mountainous areas In mountainous environments, due to the undulating terrain and complex geology, tower foundation construction faces the challenge of coexisting soft soil and hard rock. By utilizing this solution's composite foundation structure, spiral anchors quickly stabilize the upper soft soil layer, while FRP smart anchors penetrate deeply into the underlying rock layer for efficient anchoring. Furthermore, an integrated fiber-optic sensing system (FBG) provides real-time monitoring of the foundation's stress state during extreme conditions such as earthquakes and landslides, ensuring the long-term operation of transmission lines in mountainous areas. Compared to traditional excavation and concrete pouring methods, this approach reduces the construction area and equipment transportation difficulties, significantly improving construction efficiency.

[0051] 2) High-durability infrastructure in coastal areas Soil in coastal areas is often highly acidic or humid, and traditional reinforced concrete foundations are susceptible to corrosion, shortening their service life. The corrosion resistance and non-conductivity of the FRP smart anchors in this invention are particularly suitable for such environments. Combined with the locking function of the helical anchor, this structure maintains high efficiency and stability in soft coastal soils. Furthermore, the intelligent monitoring system can sense the stress and temperature changes of the anchors in real time, providing reliable data support for long-term operation and maintenance in high-humidity environments.

[0052] 3) Urban power transmission line reconstruction project When renovating power transmission lines in cities, construction must avoid disturbing surrounding buildings and infrastructure. This solution's composite foundation structure, constructed using a "screwing in the soil and drilling in the rock" method, avoids large-scale excavation and noise pollution, making it suitable for rapid construction in urban environments. Furthermore, the lightweight and high-strength FRP smart anchors facilitate equipment transportation and installation. The intelligent monitoring system can also be connected to the city's smart grid platform, enabling remote monitoring and optimizing the operation and maintenance efficiency of urban power transmission lines.

[0053] This invention introduces FRP (fiber reinforced composite material) smart anchor rods into spiral anchor and anchor rod foundation structures for the first time, and embeds FBG (fiber Bragg grating) optical fibers into the anchor rods, thereby improving the mechanical properties of the anchor rods and realizing real-time monitoring of the stress, strain and deformation of the composite foundation structure, thus possessing intelligent characteristics.

[0054] The lower anchor rod features a spiral groove and anchor core groove wrapping layer, with FBG optical fibers embedded in the grooves and a carbon fiber outer layer wrapped around them, enhancing the rod's shear and tensile strength and protecting the optical fibers. The upper anchor rod is wrapped with a glass fiber layer and a carbon fiber cloth layer, with threads pressed into the carbon fiber cloth surface, further improving its tight connection with the connecting sleeve and overall shear resistance.

[0055] The design of the connecting sleeve tightly integrates the spiral anchor and the FRP smart anchor, forming an integrated composite foundation structure. The inner threads of the sleeve tightly engage with the threads on the upper anchor, ensuring efficient force transfer between the upper anchor and the connecting sleeve. This ensures uniform force distribution throughout the anchor, avoiding the stress concentration and unstable connection that can occur with traditional connection methods.

[0056] The connecting sleeve has both mechanical connection and stress transmission functions in structure; Mechanical connection function: The upper and lower anchor rods are quickly spliced ​​together through the connecting sleeve, which simplifies the construction and installation process and improves construction efficiency.

[0057] Stress transfer function: The connecting sleeve transmits the tension, shear force and bending moment of the upper and lower anchor rods to the spiral anchor rod without loss through a tight threaded connection, thereby enhancing the mechanical properties of the overall foundation structure.

[0058] The thread structure and dimensions of the connecting sleeve can be standardized based on actual needs, enabling rapid docking with anchor bolts of varying sizes and enhancing adaptability. During construction, anchor bolt connections can be completed simply by screwing, eliminating the need for additional welding or complex operations, significantly improving construction convenience and efficiency. The connecting sleeve is designed to withstand the pullout forces of conventional geological conditions while also adapting to complex environments such as strong earthquakes and high pressure, extending its applicability to a wider range of applications.

[0059] Example 2 like Figure 5 As shown, this solution provides a method for manufacturing a composite foundation structure of a spiral anchor and an FRP smart anchor rod, comprising the following steps: S1. Screw the spiral anchor 1 into the soil layer to the designed depth; S2, drilling the rock formation downward along the spiral anchor 1 to obtain a hole 5 of the designed diameter and depth; S3. Insert the FRP smart anchor rod 2 from the inner spiral anchor 1 into the hole 5, so that the upper anchor rod 21 is located outside the hole 5 and the lower anchor rod 22 is located inside the hole 5; a casing installation space is formed between the upper anchor rod 21 and the spiral anchor 1; S4, grouting and filling into the hole 5; S5. Place the connecting sleeve 3 in the sleeve installation space, and lead the FBG optical fiber on the FRP smart anchor 2 out of the composite foundation structure.

[0060] Optionally, in step S2, the diameter of the hole 5 is 1.2 to 1.5 times the diameter of the spiral anchor 1; the depth of the hole 5 is greater than the length of the FRP smart anchor 2 by 5 cm to 10 cm.

[0061] Optionally, in step S1, the designed depth is the depth at which the soil layer and the rock layer intersect.

[0062] In a more preferred solution, a method for manufacturing a composite foundation structure of a spiral anchor and an FRP smart anchor includes the following steps: S100, screw anchor screw positioning; The spiral anchor 1 is screwed into the soil layer using a spiral anchor screwing machine according to the design depth requirement. Specifically, the spiral anchor 1 is selected to the depth where the predetermined soil layer and rock layer intersect to maximize its anchoring effect.

[0063] The design depth can be determined based on the geological survey report, allowing the spiral anchor to penetrate the soft soil layer and firmly rest on the harder rock layer, providing a stable support point for the subsequent FRP smart anchor.

[0064] S200, rock drilling operation; A rock drilling device is used to drill a hole 5 in the rock formation along the screwed-in spiral anchor 1 to form a hole 5 of a designed diameter and depth.

[0065] The diameter of the hole 5 is set to 1.2 to 1.5 times the diameter of the spiral anchor 1 so that the FRP smart anchor 2 can be inserted smoothly and leave enough space for grouting.

[0066] The depth of the hole 5 needs to be 5 cm to 10 cm greater than the total length of the FRP smart anchor 2 so that the anchor can be fully embedded in the rock formation and provide sufficient anchoring depth.

[0067] S300, FRP smart anchor insertion and preparation; The FRP smart anchor rod 2 is inserted into the drilled hole 5 from above the spiral anchor 1 , so that the upper anchor rod 21 is located outside the hole 5 and the lower anchor rod 22 is located inside the hole 5 .

[0068] At the same time, sufficient casing installation space is formed between the upper anchor rod 21 and the spiral anchor 1 to facilitate the subsequent installation of the connecting casing 3.

[0069] S400, grouting filling and curing; Grouting is performed into the hole 5 to fully fill the gap between the anchor rod and the hole wall to enhance the anchoring effect.

[0070] During the grouting process, control the grouting pressure to avoid unnecessary damage to the anchor rod or the surrounding strata. After the grouting is completed, wait for the grouting material to completely solidify so that the anchor rod and the rock formation are tightly bonded.

[0071] S500, connecting sleeve installation and FBG fiber lead-out; The connecting sleeve 3 is placed in the sleeve installation space and threadedly connected to the spiral anchor 1 and the FRP smart anchor rod 2 respectively to ensure a stable and reliable connection.

[0072] At the same time, the FBG optical fiber is led out from the composite foundation structure and connected to a fiber optic demodulator to monitor the stress state and temperature changes of the anchor rod in real time.

[0073] In an optional solution, an anti-corrosion material is coated on the connection of the connecting sleeve 3 to enhance its durability and prevent connection failure due to corrosion.

[0074] In an optional solution, the hole 5 is cleaned and pre-treated before grouting to improve the adhesion between the grouting material and the hole wall.

[0075] Example 3 This solution provides a method for manufacturing an FRP smart anchor rod, which includes manufacturing an upper anchor rod 21 and a lower anchor rod 22; Specifically, the production of the lower anchor rod 22 includes: preparing a spiral groove on the surface of the lower anchor core, installing the FBG optical fiber inside the spiral groove; impregnating the carbon fiber reinforced composite material with a thermosetting resin and filling it into the anchor core groove to form an anchor core groove wrapping layer; and forming a carbon fiber wrapping layer outside the anchor core groove wrapping layer to obtain the lower anchor rod 22; wherein the FBG optical fiber is led out from the upper part of the lower anchor rod 22; Specifically, the production of the upper anchor rod 21 includes: leading the FBG optical fiber from the upper part of the lower anchor rod 22 and fixing it to the surface of the upper anchor core, and then impregnating it with epoxy resin; wrapping a glass fiber layer on the outer side of the upper anchor core, and the glass fiber layer also wraps the FBG optical fiber on the surface of the upper anchor core, and then impregnating it with epoxy resin again; making a carbon fiber cloth layer outside the glass fiber layer, and pressing a thread pattern on the surface of the carbon fiber cloth layer to obtain the upper anchor rod 21; wherein, the FBG optical fiber is led out from the upper part of the upper anchor rod 21.

[0076] Optionally, the thickness of the carbon fiber wrapping layer is 2 cm to 3 cm.

[0077] Optionally, the lower anchor core is made of basalt fiber and glass fiber; the upper anchor core is made of basalt fiber.

[0078] In a more specific solution, a method for manufacturing an FRP smart anchor is also provided, which covers the manufacturing process of the upper anchor 21 and the lower anchor 22. The specific steps are as follows: 1) Fabrication of the lower anchor rod 22 Basalt fiber and glass fiber are used as the primary reinforcement materials for the lower anchor core. A spiral groove is created on the surface of the lower anchor core to serve as the embedding channel for the FBG fiber. The FBG fiber is installed within the spiral groove, and the fiber's lead-out end is marked and protected for subsequent integration with the monitoring system. A carbon fiber-reinforced composite material is impregnated with a thermosetting resin, allowing the resin to fully penetrate the composite material. The impregnated composite material is then filled into the anchor core groove to form an anchor core groove wrapping layer, enhancing the tensile and compressive properties of the anchor rod. A second carbon fiber wrapping layer is applied outside the anchor core groove wrapping layer to further enhance the strength and durability of the anchor rod.

[0079] 2) Fabrication of upper anchor rod 21 Basalt fiber is selected as the primary material for the upper anchor core, which is manufactured through a mold forming or pultrusion process. The FBG optical fiber extending from the lower anchor rod 22 is fixed to the surface of the upper anchor core and securely bonded using a high-performance adhesive. The upper anchor core is then impregnated with epoxy resin to initially solidify the connection between the optical fiber and the anchor core. A fiberglass layer is wrapped around the upper anchor core, simultaneously enveloping the FBG optical fiber on the upper anchor core surface. After the fiberglass layer is wrapped, the upper anchor core is impregnated with epoxy resin again to further solidify the connection between the fiberglass layer and the upper anchor core. A carbon fiber cloth layer is applied over the fiberglass layer to enhance the anchor rod's external strength and corrosion resistance. A metal mold is used to compact and extrude a threaded pattern on the surface of the carbon fiber cloth layer to increase the strength and stability of the connection between the anchor rod and the connecting sleeve. The FBG optical fiber is extended from the upper portion of the upper anchor rod 21, and a protective sleeve or connector is provided at the lead-out end.

[0080] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0081] It is understood from common technical knowledge that the present invention may be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the embodiments disclosed above are, in all respects, merely illustrative and not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are intended to be encompassed by the present invention.

Claims

1. A composite foundation structure of a spiral anchor and FRP smart anchor, characterized in that: It comprises a spiral anchor (1), an FRP smart anchor rod (2) and a connecting sleeve (3); The FRP smart anchor rod (2) comprises an upper anchor rod (21) and a lower anchor rod (22) which are connected to each other; wherein the upper anchor rod (21) and the lower anchor rod (22) are both provided with FBG optical fibers, and the upper anchor rod (21) is arranged in the connecting sleeve (3); the connecting sleeve (3) is arranged in the spiral anchor (1) and is respectively connected to the upper anchor rod (21) and the spiral anchor (1).

2. The spiral anchor and FRP smart anchor composite foundation structure according to claim 1 is characterized in that: The spiral anchor (1) is provided with an internal thread, the connecting sleeve (3) is provided with an internal thread and an external thread, and the upper anchor rod (21) is provided with an external thread; the upper anchor rod (21) is threadedly connected in the connecting sleeve (3), and the connecting sleeve (3) is threadedly connected in the spiral anchor (1).

3. The spiral anchor and FRP smart anchor composite foundation structure according to claim 1, characterized in that: The lower anchor rod (22) comprises a lower anchor core, a surface of the lower anchor core is provided with a spiral groove, and part of the FBG optical fiber is provided in the spiral groove; an anchor core groove wrapping layer is provided outside the lower anchor core; and a carbon fiber wrapping layer is provided outside the anchor core groove wrapping layer.

4. The spiral anchor and FRP smart anchor composite foundation structure according to claim 1, characterized in that: The upper anchor rod (21) comprises an upper anchor core, a glass fiber layer is arranged outside the upper anchor core, and a carbon fiber cloth layer is arranged outside the glass fiber layer; the portion of the FBG optical fiber is arranged along the surface of the upper anchor core and is located between the glass fiber layer and the upper anchor core; and a thread is arranged on the surface of the carbon fiber cloth layer.

5. A method for manufacturing a composite foundation structure of a spiral anchor and FRP smart anchor, characterized in that: The steps include: S1. Screw the screw anchor (1) into the soil layer to the designed depth; S2, drilling a hole into the rock formation downward along the spiral anchor (1) to obtain a hole (5) of designed diameter and depth; S3, inserting the FRP smart anchor rod (2) from the inner spiral anchor (1) into the hole (5), so that the upper anchor rod (21) is located outside the hole (5) and the lower anchor rod (22) is located inside the hole (5); a casing installation space is formed between the upper anchor rod (21) and the spiral anchor (1); S4, injecting grout into the hole (5); S5. Place the connecting sleeve (3) in the sleeve installation space, and lead the FBG optical fiber arranged on the FRP smart anchor rod (2) out of the composite foundation structure.

6. The method according to claim 5, characterized in that: In step S2, the diameter of the hole (5) is 1.2 to 1.5 times the diameter of the spiral anchor (1); the depth of the hole (5) is greater than the length of the FRP smart anchor (2) by 5 cm to 10 cm.

7. The manufacturing method according to claim 5, characterized in that: In step S1, the designed depth is the depth where the soil layer and the rock layer intersect.

8. A method for manufacturing an FRP smart anchor, characterized in that: The method comprises the production of an upper anchor rod (21) and a lower anchor rod (22); The production of the lower anchor rod (22) includes: preparing a spiral groove on the surface of the lower anchor core, installing the FBG optical fiber inside the spiral groove; impregnating the carbon fiber reinforced composite material with a thermosetting resin and filling it into the anchor core groove to form an anchor core groove wrapping layer; producing a carbon fiber wrapping layer outside the anchor core groove wrapping layer to obtain the lower anchor rod (22); wherein the FBG optical fiber is led out from the upper part of the lower anchor rod (22); The upper anchor rod (21) is manufactured by: the FBG optical fiber is led out from the upper part of the lower anchor rod (22) and fixed to the surface of the upper anchor core, and then impregnated with epoxy resin; a glass fiber layer is wrapped outside the upper anchor core, and the glass fiber layer simultaneously wraps the FBG optical fiber on the surface of the upper anchor core, and then impregnated with epoxy resin again; a carbon fiber cloth layer is manufactured outside the glass fiber layer, and a thread pattern is pressed on the surface of the carbon fiber cloth layer to obtain the upper anchor rod (21); wherein the FBG optical fiber is led out from the upper part of the upper anchor rod (21).

9. The manufacturing method according to claim 8, characterized in that: The thickness of the carbon fiber wrapping layer is 2 cm to 3 cm.

10. The method according to claim 8, characterized in that The lower anchor core is made of basalt fiber and glass fiber; the upper anchor core is made of basalt fiber.

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