A single-pipe communication tower reinforcing device and method based on iron-based shape memory alloy self-prestress

Abstract

The application provides a single-pipe communication tower reinforcing device and method based on iron-based shape memory alloy self-prestress, which is used for reinforcing the iron tower and comprises a top positioning disc, a middle turning disc, a bottom ground anchor system, an excitation device, a plurality of iron-based shape memory alloy wires and a plurality of extruded anchor heads; the top positioning disc and the middle turning disc are respectively installed at the top and the middle of the iron tower, and the bottom ground anchor system is fixed on the ground at the bottom of the iron tower; the extruded anchor heads are used for being fixed at the two ends of the iron-based shape memory alloy wires, so as to connect the top positioning disc and the bottom ground anchor system, and the excitation device is used for electrifying the iron-based shape memory alloy wires. The application does not need to use large tensioning equipment, can effectively reduce the occupied site, has simple process and improves the construction efficiency. The application can generate large self-prestress in a short time, can greatly reduce the tower top displacement and improves the safety of the single-pipe communication tower.

Description

Technical Field

[0001] This invention relates to prestressed reinforcement of single-tube communication towers, belonging to the field of prestressed reinforcement technology in civil engineering, specifically a device and method for reinforcing single-tube communication towers based on self-prestressing of iron-based shape memory alloys. Background Technology

[0002] Communication towers are tower-shaped structures used to transmit radio wave signals. As important national defense and civilian equipment in my country, they have been widely used in mobile communications, broadcasting, television, and satellite communications. With the rapid development of 5G and the construction of a smart China, the requirements for communication equipment, including communication towers, are further increasing, necessitating the rapid construction of large-scale 5G base stations.

[0003] However, domestic land resources are limited, and space for building new 5G base stations is scarce. Adhering to the principles of cost reduction, efficiency improvement, and resource conservation, mounting new communication antennas on existing communication towers has become the most mainstream method. With the three major operators—China Mobile, China Telecom, and China Unicom—implementing a strategy of co-building and sharing communication towers, several new 5G antennas may need to be added to the same tower to meet communication demands. This leads to a significant increase in the self-weight of the communication tower and the wind load it experiences, even exceeding the original load-bearing capacity.

[0004] Single-tube communication towers are tall, wind-sensitive structures made of a single steel tube. They have low lateral stiffness and large top displacement under wind loads. Currently, many single-tube communication towers in my country have top displacements exceeding 100%, making the task of reinforcing single-tube communication towers an urgent matter.

[0005] However, the available space around a single-tube communication tower is usually small, the tower body often needs to carry a large number of communication devices, and reinforcement needs to avoid ladders and bottom maintenance holes. Therefore, when reinforcing a single-tube communication tower, a non-enclosed reinforcement method that occupies little space should be selected.

[0006] Novel iron-based shape memory alloys (Fe-SMA) are a class of smart metallic materials with shape memory effects. When their shape memory effect occurs, by constraining their deformation (e.g., anchoring them in concrete), restoring stress can be generated in the iron-based shape memory alloy. This restoring stress will generate prestress on the constrained body. Since the generation of prestress does not require on-site mechanical tensioning, but only requires temperature excitation, this technology is also figuratively called iron-based shape memory alloy self-prestressing technology.

[0007] The self-prestressed reinforcement technology based on iron-based shape memory alloys is simple to implement, has high space utilization, and provides good reinforcement results. It can be applied to reinforcement scenarios with limited space, such as reinforcing single-tube communication towers, and has broad development prospects. Summary of the Invention

[0008] To address the limitations of the existing technology, this invention provides a single-tube communication tower reinforcement device based on self-prestressed iron-based shape memory alloy (EMA) for reinforcing towers. The device includes a top positioning plate, a middle steering plate, a bottom ground anchor system, an excitation device, several EMA stranded wires, and several extrusion anchor heads. The top positioning plate and the middle steering plate are respectively installed at the top and middle of the tower, while the bottom ground anchor system is fixed to the ground at the bottom of the tower. Anchors are pressed against both ends of the EMA stranded wires to form extrusion anchor heads, thereby positioning the EMA stranded wires between the top positioning plate and the bottom ground anchor system. The excitation device is used to energize and excite the EMA stranded wires.

[0009] Furthermore, the iron-based shape memory alloy strands are arranged radially above the center steering wheel and perpendicular to the ground below the center steering wheel.

[0010] Furthermore, the top positioning plate includes a positioning ring, a first sleeve, and a first reinforcing rib; the first sleeve is used to fit the iron tower, the positioning ring is fixed on the upper side of the sleeve, and the first reinforcing rib is triangular, connecting the lower side of the positioning ring and the outer side of the first sleeve; the middle steering plate includes a steering ring, a second sleeve, and a second reinforcing rib; the second sleeve is used to fit the iron tower, the steering ring is fixed on the upper side of the sleeve, and the second reinforcing rib is triangular, connecting the lower side of the steering ring and the outer side of the second sleeve.

[0011] Furthermore, the top positioning plate is provided with a connecting gourd hole; the connecting gourd hole includes a large hole and a small hole that are connected. The diameter of the small hole is slightly larger than the diameter of the iron-based shape memory alloy stranded wire and smaller than the diameter of the extruded anchor head, and the diameter of the large hole is larger than the diameter of the extruded anchor head; the top surface of the positioning plate is a conical surface perpendicular to the direction of the radial iron-based shape memory alloy stranded wire.

[0012] Furthermore, the edge of the central steering wheel is provided with a steering channel, which is an open type of slot; the upper end of the steering channel is tangent to the direction of the radial iron-based shape memory alloy stranded wire, and the lower end is perpendicular to the ground.

[0013] Furthermore, the bottom anchor system includes an anchor plate, an anchor rod, and an anchor nut. The anchor plate has a positioning hole in the middle, the diameter of which is slightly larger than the diameter of the iron-based shape memory alloy stranded wire but smaller than the diameter of the extruded anchor head. The anchor plate has bolt holes around the positioning hole that correspond to the diameter of the anchor rod. The upper end of the anchor rod has threads that are compatible with the anchor nut.

[0014] Furthermore, it also includes wires, rheostats, switches, and stranded wire clamps; the wires, rheostats, switches, and excitation devices are connected to the circuit to control the heating and excitation process of the iron-based shape memory alloy stranded wire; the stranded wire clamp includes two stranded wire clamps with connecting holes on the clamps, and the stranded wire clamp is connected to both ends of the iron-based shape memory alloy stranded wire by bolts passing through the connecting holes.

[0015] This invention also provides a method for reinforcing a single-tube communication tower based on self-prestressing of iron-based shape memory alloy, used in the aforementioned reinforcement device, comprising the following steps:

[0016] S1. Install the top positioning plate, the middle steering wheel, and the bottom ground anchor system; fix both ends of the iron-based shape memory alloy stranded wire to the top positioning plate and the bottom ground anchor system by installing extruded anchor heads, while the iron-based shape memory alloy stranded wire passes around the middle steering wheel.

[0017] S2. Using an excitation device, energize a group of iron-based shape memory alloy stranded wires; after the temperature of the energized iron-based shape memory alloy stranded wires stabilizes, energize another group of unactivated iron-based shape memory alloy stranded wires; repeat until all iron-based shape memory alloy stranded wires are energized.

[0018] Furthermore, during the energization in S2, a set of iron-based shape memory alloy stranded wires consists of two iron-based shape memory alloy stranded wires symmetrical about the tower. The two ends of the two iron-based shape memory alloy stranded wires are respectively connected to the positive and negative terminals of the excitation device to form a parallel circuit for energization.

[0019] Furthermore, the reinforcement device also includes a rheostat; when energized, the temperature of the two iron-based shape memory alloy stranded wires is monitored, and the current in the parallel circuit branch is adjusted using the rheostat to control the heating rate of the stranded wires. When controlling the temperature of the two iron-based shape memory alloy stranded wires, if the tower has already tilted to one side, the temperature of the iron-based shape memory alloy stranded wire on the other side can be increased to generate asymmetric prestress, thereby correcting the tilt; if the tower has not tilted, the temperature of the two iron-based shape memory alloy stranded wires can be controlled to rise at the same rate.

[0020] This invention eliminates the need for large tensioning equipment, effectively reducing the required site area. Its simple process improves construction efficiency. Furthermore, it can generate significant prestress in a short time, greatly reducing tower top displacement, enhancing the safety of single-tube communication towers, and facilitating reinforcement.

[0021] This invention employs a radial arrangement of iron-based shape memory alloy stranded wires. By radiating the wires from the top and turning them in the middle, the impact on the communication tower body is reduced, thus avoiding any impact on functionality or aesthetics. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the reinforcement device of the present invention;

[0024] Figure 2 This is a schematic diagram of the top positioning disc of the present invention;

[0025] Figure 3 This is a schematic diagram of the steering wheel in the middle of the present invention;

[0026] Figure 4 This is a schematic diagram of the bottom anchor system of the present invention;

[0027] Figure 5 This is a schematic diagram of the excitation scheme in this invention;

[0028] Figure 6 This is a schematic diagram of another excitation scheme in this invention.

[0029] In the diagram: 1. Iron tower; 2. Iron-based shape memory alloy stranded wire; 3. Extruded anchor head; 4. Top positioning plate; 5. Middle steering wheel; 6. Bottom ground anchor system; 7. Wire; 8. Rheostat; 9. Excitation device; 10. Positioning ring; 11. First reinforcing rib; 12. First sleeve; 13. Large hole; 14. Small hole; 16. Steering ring; 17. Steering channel; 18. Stranded wire clamp; 19. Stranded wire clamp plate; 20. Ground anchor plate; 21. Ground anchor rod; 22. Ground anchor nut; 23. Switch; 24. Second reinforcing rib; 25. Second sleeve. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] See Figure 1 This embodiment is a single-tube communication tower reinforcement device used to reinforce tower 1. It includes a top positioning plate 4, a middle steering plate 5, a bottom ground anchor system 6, an excitation device 9, several iron-based shape memory alloy stranded wires 2 and extruded anchor heads 3.

[0033] The extrusion anchor 3 is used to fix the iron-based shape memory alloy stranded wire 2 at both ends. Through machine extrusion, the extrusion anchor undergoes plastic deformation, gripping the iron-based shape memory alloy stranded wire 2, facilitating installation on the top positioning plate 4 and the bottom ground anchor system 6. The excitation device 9 is used to energize the iron-based shape memory alloy stranded wire 2. It can be an excitation device 9 that directly provides DC power via a built-in battery, or it can be a device with a built-in AC-to-DC converter. The bottom ground anchor system 6 is located at the bottom of the tower 1 and is used to tighten the iron-based shape memory alloy stranded wire 2.

[0034] The tower 1 is usually narrow at the top and wide at the bottom. The inner contours of the top positioning plate 4 and the middle steering plate 5 are adapted to the outer contours of the corresponding positions of the tower 1. The top positioning plate 4 is sleeved on the upper part of the tower 1, and the middle steering plate 5 is sleeved on the middle part of the tower 1. If there are other shapes of tower 1, other types of connectors are needed to fix the top positioning plate 4 to the corresponding position of the tower 1.

[0035] See Figure 2 In this embodiment, the top positioning plate 4 includes a positioning ring 10, a first sleeve 12, and a first reinforcing rib 11. The first sleeve 12 is used to connect the iron tower 1. The positioning ring 10 is provided with a connecting gourd hole and is fixed to the upper side of the first sleeve 12. The first reinforcing rib 11 connects the lower side of the positioning ring 10 and the outer side of the first sleeve 12. For ease of installation, the top positioning plate 4 is divided into two parts along the axis, and the two parts are provided with bolt holes for connection by bolts. The connecting gourd hole includes a large hole 13 and a small hole 14 that are connected. The diameter of the small hole 14 is larger than the diameter of the iron-based shape memory alloy stranded wire 2 but smaller than the diameter of the extruded anchor head 3. The diameter of the large hole 13 is larger than the diameter of the extruded anchor head 3.

[0036] See Figure 3 In this embodiment, the central steering wheel 5 includes a steering ring 16, a second sleeve 25, and a second reinforcing rib 24. The second sleeve 25 is used to connect to the iron tower 1. The steering ring 16 is provided with a steering channel 17. The steering ring 16 is fixed to the upper side of the second sleeve 25. The second reinforcing rib 24 connects to the lower side of the positioning ring 10 and the outer side of the second sleeve 25. For ease of installation, the central steering wheel 5 is divided into two parts along the axis, and both parts are provided with bolt holes for connection by bolts. The steering channel 17 is an open, smooth channel. Its upper end is tangent to the direction of the radial iron-based shape memory alloy stranded wire 2, and its lower end is perpendicular to the ground. This allows the iron-based shape memory alloy stranded wire 2 to transition smoothly and be arranged radially above the central steering wheel 5, and perpendicular to the ground below the central steering wheel 5, reducing construction difficulty.

[0037] refer to Figure 4In this embodiment, the bottom anchor system 6 includes an anchor plate 20, an anchor rod 21, and an anchor nut 22. The anchor plate 20 has a positioning hole in the center, the diameter of which is slightly larger than the diameter of the iron-based shape memory alloy stranded wire 2 but smaller than the diameter of the extruded anchor head 3. Four bolt holes corresponding to the diameter of the anchor rod 21 are formed around the positioning hole. The upper end of the anchor rod 21 has a thread adapted to the anchor nut 22. Tightening the anchor nut 22 causes the anchor plate 20 to press down, thereby pre-tensioning the iron-based shape memory alloy stranded wire 2.

[0038] In this preferred embodiment, the device further includes a wire 7, a rheostat 8, a switch 23, and a stranded wire clamp 18. The wire 7, rheostat 8, switch 23, and excitation device 9 are connected to the circuit to control the heating and excitation process of the iron-based shape memory alloy stranded wire 2. The stranded wire clamp 18 includes two stranded wire plates 19 with connecting holes. Bolts are used to connect the stranded wire clamp 18 to both ends of the iron-based shape memory alloy stranded wire 2 through these connecting holes, allowing the wire 7 to be installed at both ends of the iron-based shape memory alloy stranded wire 2 during subsequent energization.

[0039] Example 2:

[0040] This embodiment is a reinforcement method used with the reinforcement device described in the above embodiment, and includes the following steps:

[0041] S1. Install the top positioning plate 4 and the middle steering plate 5; the top positioning plate 4 and the middle steering plate 5 are installed on the iron tower 1 according to the preset positions, and the top positioning plate 4 is preferably located about 500mm away from the equipment mounting area at the top of the tower.

[0042] This embodiment uses eight sets of iron-based shape memory alloy stranded wires 2 as an example for explanation. One end of the iron-based shape memory alloy stranded wire 2 is passed through the positioning hole on the ground anchor plate 20, and then extrusion anchor heads 3 are installed at both ends. The other end passes through the steering channel 17 of the middle steering wheel 5 and the large hole 13 of the gourd hole connecting the top positioning plate 4, and then is inserted into the small hole 14. Then, the bottom ground anchor system 6 is installed. The ground anchor rod 21 in the bottom ground anchor system 6 is inserted into the ground to a depth of not less than 1m to prevent the iron-based shape memory alloy stranded wire 2 from coming out. The ground anchor nut 22 is tightened to anchor and tension the iron-based shape memory alloy stranded wire 2.

[0043] S2. Using the excitation device 9, energize a group of iron-based shape memory alloy stranded wires 2. After the temperature of the energized iron-based shape memory alloy stranded wires 2 stabilizes, energize another group of unactivated iron-based shape memory alloy stranded wires 2; repeat until all iron-based shape memory alloy stranded wires 2 are energized, generating recovery stress, and completing the prestressing reinforcement of the iron tower 1.

[0044] In this preferred embodiment, during heating in S2, a set of iron-based shape memory alloy stranded wires 2 consists of two iron-based shape memory alloy stranded wires 2 symmetrical about the iron tower 1. Let one of the stranded wires be stranded wire No. 1, and the other stranded wires be stranded wires No. 2-8 in a clockwise direction. Then, stranded wire No. 1 and stranded wire No. 5 are used for excitation for the first time. The lower ends of the two iron-based shape memory alloy stranded wires 2 are connected to the positive pole of the excitation device 9 through stranded wire clamps 18 and wires 7, and the upper ends are connected to the negative pole in the same way to form a circuit for heating.

[0045] See Figure 5 In this preferred embodiment, if the tower is not tilted, during heating, the two switches 23 are connected to the A1 and B1 circuits respectively. A temperature monitoring device is used to monitor the temperature of the two stranded wires. When a temperature difference occurs between the two stranded wires, the switch 23 and the rheostat 8 are used to adjust the heating rate of the stranded wires. For example, when the temperature of the No. 1 iron-based shape memory alloy stranded wire 2 is higher, the switch 23 is turned to the A2 circuit, so that the rheostat 8 is connected to the circuit of the No. 1 iron-based shape memory alloy stranded wire 2, and the resistance of the rheostat 8 is adjusted to reduce the current and slow down the heating rate, so as to maintain the same temperature for the No. 1 iron-based shape memory alloy stranded wire 2 and the No. 5 iron-based shape memory alloy stranded wire 2.

[0046] See Figure 6 In other embodiments, a circuit containing two rheostats 8 can also be used. When heating, when the temperature of the No. 1 iron-based shape memory alloy stranded wire 2 is high, the resistance of the rheostat 8 in that branch is increased, so that the circuit resistance increases, the current decreases, and the heating rate decreases. Similarly, when the temperature of the No. 5 iron-based shape memory alloy stranded wire 2 is high, the resistance of the rheostat 8 in the corresponding branch is increased.

[0047] If the tower has already tilted to one side, the temperature of the other iron-based shape memory alloy stranded wire can be increased when controlling the temperature of the two iron-based shape memory alloy stranded wires to correct the tilt.

[0048] In other embodiments, two or more iron-based shape memory alloy stranded wires 2 can be electrically heated simultaneously, for example, three iron-based shape memory alloy stranded wires 2 spaced 120° apart, or four iron-based shape memory alloy stranded wires 2 spaced 90° apart.

[0049] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A single-tube communication tower reinforcement device based on iron-based shape memory alloy self-prestressing, used for reinforcing towers, characterized in that, It includes a top positioning plate, a middle steering plate, a bottom ground anchor system, an excitation device, several iron-based shape memory alloy stranded wires, and several extruded anchor heads; the top positioning plate and the middle steering plate are respectively installed at the top and middle of the tower, and the bottom ground anchor system is fixed to the ground at the bottom of the tower; the extruded anchor heads are used to fix the two ends of the iron-based shape memory alloy stranded wires, thereby connecting the top positioning plate and the bottom ground anchor system, and the excitation device is used to energize the iron-based shape memory alloy stranded wires; Iron-based shape memory alloy stranded wires can smoothly transition and are arranged radially above the center steering wheel, and are arranged perpendicular to the ground below the center steering wheel; The top positioning plate includes a positioning ring, a first sleeve, and a first reinforcing rib; the first sleeve is used to fit the iron tower, the positioning ring is fixed on the upper side of the first sleeve, and the first reinforcing rib connects the lower side of the positioning ring and the outer side of the first sleeve; the middle steering plate includes a steering ring, a second sleeve, and a second reinforcing rib; the second sleeve is used to fit the iron tower, the steering ring is fixed on the upper side of the second sleeve, and the second reinforcing rib connects the lower side of the steering ring and the outer side of the second sleeve. The top positioning plate is provided with a connecting gourd hole; the connecting gourd hole includes a large hole and a small hole that are connected. The diameter of the small hole is slightly larger than the diameter of the iron-based shape memory alloy stranded wire and smaller than the diameter of the extruded anchor head. The diameter of the large hole is larger than the diameter of the extruded anchor head. The top surface of the positioning plate is a conical surface perpendicular to the direction of the radial iron-based shape memory alloy stranded wire. The central steering wheel edge is provided with a steering channel, which is an open type of slot; the upper end of the steering channel is tangent to the direction of the radial iron-based shape memory alloy stranded wire, and the lower end is perpendicular to the ground.

2. The single-tube communication tower reinforcement device based on iron-based shape memory alloy self-prestressing as described in claim 1, characterized in that, The bottom anchor system includes an anchor plate, an anchor rod, and an anchor nut. The anchor plate has a positioning hole in the middle, the diameter of which is slightly larger than the diameter of the iron-based shape memory alloy stranded wire but smaller than the diameter of the extruded anchor head. The anchor plate has bolt holes around the positioning hole that correspond to the diameter of the anchor rod. The upper end of the anchor rod has threads that are compatible with the anchor nut.

3. The single-tube communication tower reinforcement device based on iron-based shape memory alloy self-prestressing as described in claim 1, characterized in that, It also includes wires, rheostats, switches, and stranded wire clamps; the wires, rheostats, switches, and excitation devices are connected to the circuit to control the process of heating and exciting the iron-based shape memory alloy stranded wire; the stranded wire clamps include two stranded wire clamps with connecting holes on the clamps, and the stranded wire clamps are connected to both ends of the iron-based shape memory alloy stranded wire by bolts passing through the connecting holes.

4. A method for reinforcing a single-tube communication tower based on self-prestressing of iron-based shape memory alloy, used in the reinforcement device as described in claim 1, characterized in that, Includes the following steps: S1. Install the top positioning plate, the middle steering wheel, and the bottom ground anchor system; fix both ends of the iron-based shape memory alloy stranded wire to the top positioning plate and the bottom ground anchor system by installing extruded anchor heads, while the iron-based shape memory alloy stranded wire passes around the middle steering wheel; S2. Using an excitation device, energize a group of iron-based shape memory alloy stranded wires; after the temperature of the energized iron-based shape memory alloy stranded wires stabilizes, energize another group of unactivated iron-based shape memory alloy stranded wires; repeat until all iron-based shape memory alloy stranded wires are energized.

5. The method for reinforcing a single-tube communication tower based on self-prestressing of iron-based shape memory alloy according to claim 4, characterized in that, When S2 is energized, a set of iron-based shape memory alloy stranded wires consists of two iron-based shape memory alloy stranded wires that are symmetrical about the tower. The two ends of the two iron-based shape memory alloy stranded wires are connected to the positive and negative terminals of the excitation device, respectively, to form a parallel circuit for energization.

6. The method for reinforcing a single-tube communication tower based on self-prestressing of iron-based shape memory alloy according to claim 5, characterized in that, The reinforcement device also includes a rheostat; when energized, the temperature of the two iron-based shape memory alloy stranded wires is monitored, and the current in the parallel circuit branch is adjusted by the rheostat to control the heating rate of the stranded wires.

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