Fabricated super-toughness early-strength variable-stiffness temperature variation compensation bridge expansion joint device

Abstract

The utility model provides an assembly type super-toughness early-strength variable-stiffness temperature variation compensation bridge expansion joint device, and relates to the technical field of bridge expansion joints, the device comprises a plurality of expansion joint units, each unit comprises a high elastic body and a super-elastic inhaul cable which are assembled in a super-toughness concrete groove, and the high elastic body and a groove wall are connected through the stay cables; a pore channel penetrates through the high elastomer; the pre-tightening force ribs sequentially penetrate through the hole channels of the high-elasticity body to play a transverse connection role. Initial tension is applied to the inhaul cable; under the extreme temperature change condition, the inhaul cable stretches the high-elastic body towards the groove wall so as to restrain the high-elastic body from arching and prevent the high-elastic body from being disengaged from the groove wall. The adopted super-toughness early strength concrete groove wall has a tensile strain strengthening function and an elastic modulus between a beam body and a high elastic body, and the variable stiffness design reduces the damage of impact load to the expansion joint. And meanwhile, a stay wire type displacement sensor and a force measuring anchor head are arranged, collected telescopic displacement and axial force signals are uploaded to a cloud end through an intelligent monitoring module, and real-time monitoring of the state of the expansion joint device is achieved.

Description

Technical Field

[0001] This application relates to the field of bridge expansion joint technology, and in particular to a prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device. Background Technology

[0002] Bridge expansion joints are the core structure that ensures the free expansion and contraction of bridge structures under temperature changes, prestressed loads, and material contraction and expansion. Their performance directly affects driving safety, bridge durability, and maintenance costs. Traditional expansion joint devices (such as modular and comb-type) have significant drawbacks: First, installation relies on on-site welding or bolt fixing, which is complex and prone to sealing failure due to construction errors; second, the joint between rigid materials (such as structural steel) and concrete beams is prone to cracking due to impact stress, leading to vehicle bouncing, noise, and water leakage; third, vehicles are prone to slipping when passing at high speeds, especially in rainy or snowy weather, posing a greater safety hazard.

[0003] Furthermore, traditional expansion joint devices suffer from long on-site construction cycles and poor quality stability due to their inherent structural limitations. While some existing solutions utilize high-strength, high-toughness elastomers with self-recovering deformation capabilities to replace metal components, these elastomers typically require significant pre-stress during installation, leading to high construction difficulty and issues such as arching and slippage. Some structures also require the pre-embedding of complex anchoring steel bars and connectors at the bottom of the trench, increasing both construction volume and cost, and hindering the rapid opening of the bridge to traffic.

[0004] On the other hand, existing expansion joints generally rely on manual inspection, making it difficult to grasp key information such as changes in expansion and contraction, stress status, and integrity of the sealant in a timely manner. This makes it difficult to detect potential defects in the early stages, affecting operational safety and the efficiency of subsequent maintenance. Utility Model Content

[0005] To address the aforementioned issues, this invention provides a prefabricated, high-toughness, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device. Through modular design, pre-stress deformation control, pre-stress fastening, and nickel-titanium alloy hyperelastic constraints, it achieves efficient installation and long-term stable operation of the expansion joint device. Furthermore, an intelligent monitoring module is incorporated to monitor expansion displacement and cable stress, enabling real-time acquisition and remote monitoring and evaluation of the expansion joint's operational status, thereby improving maintenance and management efficiency.

[0006] This utility model provides a prefabricated, high-toughness, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device, the technical solution of which is:

[0007] A prefabricated, high-toughness, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device, comprising:

[0008] An expansion joint assembly includes multiple expansion joint units, each of which includes an elastomer and an elastic cable connected to each other. The multiple elastomers are assembled side by side along the transverse direction into a pre-set ultra-tough early-strength cement-based concrete groove at the beam end, and the elastic cable extends obliquely downward from the elastomer to connect with the groove wall of the pre-set ultra-tough early-strength cement-based concrete groove.

[0009] The elastic body is provided with a prestressed channel through it; and at least one of its surfaces is wavy to at least prevent the elastic body from arching upward when it undergoes compression deformation.

[0010] A prestressing device passes sequentially through the prestressed channel of each of the elastomers to tightly connect the plurality of the elastomers along the transverse bridge direction;

[0011] The elastic cable is subjected to an initial pre-tension stress to help maintain the fit between the elastic body and the preset ultra-tough early-strength cement-based concrete trough; the initial pre-tension strain of the elastic cable is 5%.

[0012] The elastic cable is made of a superelastic nickel-titanium alloy and is used for:

[0013] Under extreme heating conditions, the elastic cable constrains the elastic body downwards to prevent the elastic body from arching upwards; under extreme cooling conditions, the elastic cable stretches the elastic body towards the preset ultra-tough early-strength cement-based concrete trough to cause the elastic body to extend and fill the preset ultra-tough early-strength cement-based concrete trough; when switching from the extreme heating conditions or the extreme cooling conditions to normal temperature conditions, the elastic cable automatically returns to its initial state;

[0014] The intelligent monitoring module includes a wire-type displacement sensor located at the ring hinge position at the upper end of the elastic cable, used to collect the expansion and contraction displacement of the elastic body in the longitudinal direction of the bridge; and a force-measuring anchor head located at the ball hinge position at the lower end of the elastic cable, which can anchor the end of the elastic cable and simultaneously measure the axial force of the cable; both the wire-type displacement sensor and the force-measuring anchor head are electrically connected to the integrated monitoring terminal, used to send the monitoring data to the integrated monitoring terminal to realize real-time monitoring of the operating status of the expansion joint device.

[0015] As a preferred embodiment, multiple prestressed ducts are provided, and the multiple prestressed ducts are horizontally spaced; both the upper and lower surfaces of the elastic body are wavy; wherein,

[0016] Each of the prestressed ducts is correspondingly located below each crest arc segment in the corrugated upper surface;

[0017] The prestressing device includes multiple connecting rods and multiple bolts. Each connecting rod passes through each prestressing channel and is threadedly fastened by the bolts to the outer surfaces of two elastic bodies located at both ends in the transverse direction.

[0018] The elastic cable is provided in multiple parts, and the multiple elastic cables are symmetrical with respect to the central axis of the elastic body.

[0019] As one of the preferred embodiments, the inclined upper end of each elastic cable is connected to the connecting rod via a ring hinge, and the inclined lower end is connected to the groove wall via a ball hinge.

[0020] As one preferred embodiment, each expansion joint unit further includes:

[0021] A prestressed anchor plate is fixed to the outer surface of two elastic bodies located at both ends in a transverse direction, and each of the connecting rods is anchored to the prestressed anchor plate by the bolts.

[0022] A supporting steel plate is fixed to the lower surface of the elastomer by shear stud connectors to support the elastomer and prevent it from deflecting under vehicle loads.

[0023] As one preferred embodiment, the device further includes:

[0024] The height adjustment component is assembled onto the bottom wall of the preset ultra-tough early-strength cement-based concrete tank and abuts against the underside of the supporting steel plate.

[0025] A water-stopping device, including foam tape, is used to fill the expansion joint at the end of the beam.

[0026] As one preferred embodiment, the height adjustment component includes an ultra-tough early-strength cement-based concrete layer, the thickness of which is equal to the difference between the depth of the preset ultra-tough early-strength cement-based concrete groove and the target thickness of the elastomer, so that the wavy upper surface of the elastomer protrudes from the preset ultra-tough early-strength cement-based concrete groove; wherein the target thickness is the vertical distance between the trough of the wavy lower surface and the trough of the wavy upper surface of the elastomer.

[0027] As a preferred embodiment, each expansion joint unit further includes a limiting ring, which is fixed below the supporting steel plate; the limiting rings of multiple expansion joint units are anchored together by threaded steel bars.

[0028] As one of the preferred solutions, the corresponding surface of the wavy elastomer in the stress-free state is an elliptical curve, and the prestressed channel is elliptical; when the elastomer is assembled into the preset ultra-tough early-strength cement-based concrete trough and the temperature rises, the corresponding surface of the wavy elastomer gradually deforms into an arc curve, and the prestressed channel gradually deforms into a circle.

[0029] As one of the preferred options, the beam end includes two oppositely arranged ultra-tough early-strength cement-based concrete troughs, and a pre-set ultra-tough early-strength cement-based concrete trough and expansion joint are formed between the two ultra-tough early-strength cement-based concrete troughs from top to bottom.

[0030] Within the preset ultra-tough early-strength cement-based concrete trough, the elastic body, the supporting steel plate, and the ultra-tough early-strength cement-based concrete layer are arranged from top to bottom, with the limiting ring positioned below the supporting steel plate and between the ultra-tough early-strength cement-based concrete layers.

[0031] Both the ultra-tough early-strength cement-based concrete layer and the ultra-tough early-strength cement-based concrete trough are made of ultra-tough early-strength cement-based concrete. The ultra-tough early-strength cement-based concrete not only has a compressive strength of over 30 MPa after 2 hours, but also has a tensile strain strengthening capacity of over 5%. Furthermore, its elastic modulus is between that of a beam and an elastic body, which plays a role in variable stiffness. This significantly reduces the possibility of vehicle bounce caused by sudden stiffness changes and damage to the trough wall caused by impact loads, and also ensures rapid traffic opening within 4 hours.

[0032] Within the expansion joint, foam tape is filled in the area of ​​the expansion joint near the pre-set ultra-tough early-strength cement-based concrete groove;

[0033] The wavy extension direction of the elastic body located in the preset ultra-tough early-strength cement-based soil trench is parallel to the longitudinal direction of the bridge; and multiple shear nail connectors are evenly spaced along the transverse direction of the bridge.

[0034] As one of the preferred options, the elastomer is a polyurethane-based composite elastomer.

[0035] Compared with the prior art, this application has the following advantages:

[0036] This application provides a prefabricated ultra-tough early-strength variable stiffness temperature-compensating bridge expansion joint device. The device includes: an expansion joint assembly comprising multiple expansion joint units, each expansion joint unit including an interconnected elastic body and an elastic cable. The multiple elastic bodies are assembled side-by-side along the transverse direction into a pre-set ultra-tough early-strength cement-based concrete groove at the beam end, and the elastic cable extends obliquely downward from the elastic body to connect with the wall of the pre-set ultra-tough early-strength cement-based concrete groove; wherein, a prestressing channel is provided through the elastic body; and at least one side of its surface is wavy to at least prevent the elastic body from arching upward when it undergoes compressive deformation; a pre-tightening device passes sequentially through the prestressing channel of each elastic body to tighten the multiple elastic bodies. The bridge is tightly connected along the transverse direction; the elastic cable is subjected to an initial pre-tension stress to help maintain the fit between the elastomer and the pre-set ultra-tough early-strength cement-based concrete trough; the initial pre-tension strain of the elastic cable is 5%; and the elastic cable is made of nickel-titanium alloy and is used for: under extreme heating conditions, the elastic cable constrains the elastomer downward to prevent the elastomer from arching upward; under extreme cooling conditions, the elastic cable stretches the elastomer towards the pre-set ultra-tough early-strength cement-based concrete trough to cause the elastomer to extend and fill the pre-set ultra-tough early-strength cement-based concrete trough; and when switching from extreme heating or extreme cooling conditions to normal temperature conditions, the elastic cable automatically returns to its initial state.

[0037] By adopting the technical solution of this application, the corrugated design and pre-drilled channels under stress-free conditions enable controllable deformation during preloading, reducing installation difficulty and ensuring structural stability during service life. Factory prefabrication and rapid on-site assembly of modular units significantly shorten the construction cycle, while standardized production ensures consistent quality. Elastic nickel-titanium alloy cables provide active restraint, significantly enhancing the structure's adaptability and self-adjustment under extreme temperature conditions. The corrugated surface significantly increases tire contact friction during operation, especially reducing the risk of vehicle slippage in rain and snow, thus improving driving safety.

[0038] By setting up a wire-type displacement sensor and a force-measuring anchor head with both anchoring and force measurement functions, the expansion and contraction of the expansion joint components and the stress state of the cables can be obtained in real time. Remote monitoring can be achieved through a wireless transmission terminal, thereby improving the visibility of the expansion joint's operational status and the efficiency of maintenance management.

[0039] The trench walls are made of ultra-tough early-strength cement-based concrete, which not only has a compressive strength of over 30MPa after 2 hours, but also has an elastic modulus between that of a beam and an elastic body. This gives the expansion joint area the advantage of variable stiffness. In addition, its tensile strain strengthening capacity of up to 5% significantly reduces the probability of vehicle bumps and enhances the trench walls' resistance to impact damage, ensuring that traffic can be opened quickly within 4 hours. Attached Figure Description

[0040] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a structural diagram of the assembled ultra-tough early strength variable stiffness temperature compensation bridge expansion joint device provided in one embodiment of this application when it is assembled on a bridge.

[0042] Figure 2 This is an overall diagram of a prefabricated, high-toughness, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device provided in an embodiment of this application.

[0043] Figure 3 This is a state diagram of a highly elastic body provided in an embodiment of this application under stress-free conditions;

[0044] Figure 4 This is a diagram showing the state of a high-elasticity material provided in one embodiment of this application after it has been press-fitted into a pre-set ultra-tough early-strength cement-based concrete trough along the longitudinal bridge direction.

[0045] Figure 5 This is a schematic diagram illustrating the connection principle between expansion joint units according to an embodiment of this application;

[0046] Figure 6 This is a diagram showing the composition of the supporting steel plate, the limiting ring, and the shear stud connector provided in one embodiment of this application;

[0047] Figure 7 This is a three-dimensional structural diagram of a hyperelastic cable provided in an embodiment of this application.

[0048] Explanation of reference numerals in the attached figures:

[0049] 1. Ultra-tough, early-strength cement-based concrete trough; 2. Expansion joint assembly; 21. High-elasticity body; 22. Pre-tensioning device; 23. Prestressed anchor plate; 24. Supporting steel plate; 241. Shear stud connector; 25. Limiting ring; 26. Ultra-elastic cable; 27. Ball joint; 28. Ring joint; 29. ​​Prestressed duct; 3. Height adjustment assembly; 4. Water-stopping device; 5. Wire-type displacement sensor; 6. Force-measuring anchor head; 7. Integrated monitoring terminal. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] In this paper, the elastomer specifically refers to the high-elasticity material 21, which can be a polyurethane-based composite material with high mechanical strength, high toughness, and deformation self-recovery properties. The elastic cable specifically refers to the hyperelastic cable 26. The hyperelastic cable 26 is hyperelastic, with a nonlinear stress-strain curve. Under stress, it can undergo a reversible stress-induced phase transition, exhibits no residual deformation after unloading, and has extremely low hysteresis energy dissipation. During service, it generates elastic strain far greater than that of ordinary elastic materials, and can provide energy-dissipating support during cyclic deformation.

[0052] Reference Figure 1 and Figure 2 , Figure 1 This is a structural diagram of the assembled ultra-tough early strength variable stiffness temperature change compensation bridge expansion joint device shown in this utility model when it is assembled on a bridge. Figure 2 This is an overall diagram of a prefabricated, high-toughness, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device. Figure 1 and Figure 2 As shown, this utility model provides a prefabricated ultra-tough early strength variable stiffness temperature change compensation bridge expansion joint device. The device includes: an expansion joint assembly 2, which includes multiple expansion joint units. Each expansion joint unit includes a highly elastic body 21 and an ultra-elastic cable 26 connected to each other. The multiple highly elastic bodies 21 are assembled side by side along the transverse direction into a pre-set ultra-tough early strength cement-based concrete groove at the beam end, and the ultra-elastic cable 26 extends obliquely downward from the highly elastic body 21 to connect with the groove wall. Among them, a prestressed duct 29 is provided through the highly elastic body 21, and at least one side of its surface is wavy to at least prevent the highly elastic body 21 from arching upward when it undergoes compression deformation. The prestressing device 22 passes sequentially through the prestressed ducts 29 of each high elastic body 21 to tightly connect multiple high elastic bodies 21 side by side along the transverse bridge direction; wherein, the hyperelastic cable 26 is applied with an initial prestress to help maintain the fit between the high elastic body 21 and the preset ultra-tough early strength cement-based concrete trough; it is made of nickel-titanium alloy so that under extreme temperature change conditions, the hyperelastic cable 26 actively constrains the high elastic body 21 in the direction closer to the preset ultra-tough early strength cement-based concrete trough to suppress the upward arching of the high elastic body 21, or to promote the high elastic body 21 to extend to fill the preset ultra-tough early strength cement-based concrete trough.

[0053] The expansion joint assembly 2 is also equipped with an intelligent monitoring module. This module includes a wire-type displacement sensor 5 positioned at the upper ring hinge of the hyperelastic cable 26, and a force-measuring anchor head 6 positioned at the lower ball hinge of the hyperelastic cable 26. The wire-type displacement sensor 5 collects the longitudinal expansion and contraction displacement of the hyperelastic body 21, while the force-measuring anchor head 6 serves as an anchoring component at the end of the hyperelastic cable 26 and integrates a tension measurement unit to measure the axial force of the hyperelastic cable 26. Both the wire-type displacement sensor 5 and the force-measuring anchor head 6 are electrically connected to an integrated monitoring terminal 7 located near the bridge deck. The integrated monitoring terminal 7 collects and processes the displacement and axial force signals and wirelessly transmits them to an external receiving device or cloud server, enabling real-time monitoring and remote viewing of the expansion joint device's operating status.

[0054] Specifically, the expansion joint assembly 2 in this embodiment consists of multiple combinable expansion joint units, each of which can be an independent prefabricated module, thus facilitating factory production and rapid on-site assembly. During actual construction, multiple prepared high-elasticity bodies 21 are installed side-by-side in the pre-set ultra-tough early-strength cement-based concrete grooves reserved on both sides of the beam end according to the assembly sequence. Therefore, the number and combination of high-elasticity bodies 21 can be flexibly selected to adapt to the different sizes of pre-set ultra-tough early-strength cement-based concrete grooves reserved for various types of bridges.

[0055] It should be noted that the transverse direction of the bridge is usually the direction across the bridge, that is, from one side of the guardrail to the other. The longitudinal direction, perpendicular to this, is the direction of the main span of the bridge, that is, along the direction of traffic. In actual construction, long, narrow grooves for installing expansion joint devices are usually pre-reserved in the bridge deck pavement or beam end structure. These grooves typically span the entire lane; therefore, the length of the pre-prepared ultra-tough, early-strength cement-based concrete groove can be understood as the transverse direction, and the width as the longitudinal direction.

[0056] The specific structure of the expansion joint device will be explained below, taking the direction of the beam end as a reference.

[0057] In some embodiments, multiple high-elasticity bodies 21 are arranged side-by-side in the transverse direction of the bridge, and the total length of the installed high-elasticity bodies 21 is the same as the length of the preset ultra-tough early-strength cement-based concrete trough, which is suitable for common ordinary highway bridges, urban viaducts, steel box girder bridges, and other bridges. In some embodiments, multiple high-elasticity bodies 21 are arranged side-by-side in the transverse direction of the bridge and also in the longitudinal direction of the bridge, and the total length of the transversely installed high-elasticity bodies 21 is the same as the length of the preset ultra-tough early-strength cement-based concrete trough, and the total width is the same as the width of the preset ultra-tough early-strength cement-based concrete trough, so as to adapt to the larger size of the preset ultra-tough early-strength cement-based concrete trough.

[0058] Preferably, the width of each high-elasticity body 21 is designed to be slightly larger than the width of the preset ultra-tough early-strength cement-based concrete groove, and the height is adapted to the depth of the preset ultra-tough early-strength cement-based concrete groove. Simultaneously, multiple high-elasticity bodies 21 are arranged laterally side-by-side within the preset ultra-tough early-strength cement-based concrete groove, facilitating embedding and compression within the groove. Therefore, multiple high-elasticity bodies 21 can be prefabricated in the factory using standardized modules, and on-site pre-installation of the expansion joint device can be completed simply by sequentially inserting them laterally, improving assembly efficiency.

[0059] In this embodiment, a prestressed channel 29 is formed through the highly elastic body 21, and at least one side surface is wavy. The highly elastic body 21 has high elasticity, requiring significant force to be pressed into the pre-set ultra-tough early-strength cement-based concrete groove, and is prone to slippage. The wavy design and prestressed channel 29 of the highly elastic body 21 allow for controllable deformation during pre-stressing, reducing installation difficulty and ensuring structural stability during service life. During installation, applying a small amount of pre-pressure or even no pre-pressure is sufficient to place the highly elastic body 21 into the pre-set ultra-tough early-strength cement-based concrete groove. With the help of the ultra-elastic cable 26, the highly elastic body 21 fits tightly against the beam end.

[0060] In this embodiment, multiple prestressed ducts 29 can be provided, and they transversely penetrate the high-elasticity body 21. A wavy surface can be provided on the upper and / or lower surface of the high-elasticity body 21, while the left and right surfaces of the high-elasticity body 21 are planar. When the high-elasticity body 21 is installed in a pre-set ultra-tough early-strength cement-based concrete trough, the left and right side walls of the high-elasticity body 21 are in close contact with the side walls of the pre-set ultra-tough early-strength cement-based concrete trough. The wavy shape can be sinusoidal, circular, trapezoidal, etc. The design of the prestressed ducts 29 or the wavy line can adjust the longitudinal compressive stiffness of the bridge, facilitating the embedding of the high-elasticity body 21 within the pre-set ultra-tough early-strength cement-based concrete trough.

[0061] In addition, the surface of the high elastomer 21 is designed with a wave shape, which can reduce the risk of it arching when it is compressed by a vehicle.

[0062] Preferably, at least the upper surface of the high elastomer 21 is designed to be wavy. The wavy surface can significantly increase the friction of the tire contact surface during operation, especially in rainy and snowy weather, reducing the risk of vehicle slippage and improving driving safety.

[0063] Of course, in other embodiments, the prestressed ducts 29 can be slots formed in the high elastic body 21, and can be dispersed, arrayed, or staggered in the high elastic body 21. The prestressed ducts 29 can be straight or curved, etc.

[0064] In some embodiments, the number of prestressed ducts 29 may be greater than the number of pretensioning devices 22. Some or all of the prestressed ducts 29 penetrate laterally or penetrate the high elastic body 21 in a direction inclined to the lateral direction. In this case, the prestressed ducts 29 that penetrate laterally serve as pretensioning installation ducts for installing the pretensioning devices 22.

[0065] After placing multiple high-elasticity bodies 21 into a pre-set ultra-tough early-strength cement-based concrete trough, a pre-tightening device 22 can be used to achieve a tight connection between the multiple high-elasticity bodies 21. By applying pre-tightening force, the multiple expansion joint units are tightly fitted together, completely eliminating installation gaps and preventing displacement gaps under load, thereby maintaining the overall integrity of the assembly and improving sealing and load-bearing stability. In this embodiment, the pre-tightening device 22 passes through a pre-tightening installation channel to connect the assembled units into one unit. Therefore, the pre-stressed channel 29 serves as the installation channel for the pre-tightening device 22, providing it with precise guidance.

[0066] Another significant advancement in this embodiment lies in the design of the hyperelastic cable 26. The hyperelastic cable 26 exhibits hyperelasticity, with a non-linear stress-strain curve. Under stress, it undergoes a reversible stress-induced phase transition, exhibits no residual deformation after unloading, and generates elastic strain far exceeding that of ordinary elastic materials during service, providing energy-dissipating support during cyclic deformation. In this embodiment, the hyperelastic cable 26 is subjected to an initial pre-tension stress and obliquely connected between the wall of a pre-designed ultra-tough, early-strength cement-based concrete trough and the highly elastic body 21.

[0067] Initially, the highly elastic body 21 is in contact with the beam end. Further restraint is provided by the hyperelastic cable 26, which has been initially prestressed, maintaining the contact between the highly elastic body 21 and the pre-set ultra-tough early-strength cement-based concrete groove, ensuring long-term adhesion and a more reliable seal. The hyperelastic cable 26 is further designed to be made of nickel-titanium alloy. Under extreme temperature changes, when the initial prestress is insufficient to maintain the contact between the highly elastic body 21 and the pre-set ultra-tough early-strength cement-based concrete groove, it can further elongate to suppress arching of the elastic body or insufficient filling, thereby maintaining the good working condition of the expansion joint assembly 2.

[0068] Based on this, this embodiment integrates a force-measuring anchor head 6 with the ball joint 27 at the lower end of the hyperelastic cable 26. This allows for real-time measurement of the axial force change of each hyperelastic cable 26 while simultaneously securing it, reflecting the cable preload maintenance and additional stress caused by temperature changes. Monitoring data can determine whether the cables are slack, have abnormal anchorage, or are at risk of overload under extreme conditions, providing a quantitative basis for maintenance decisions.

[0069] Specifically, under extreme temperature conditions, the walls of the two sides of the tank expand thermally, causing the width of the pre-set ultra-tough early-strength cement-based concrete tank to tend to narrow. This compresses the high-elasticity body 21 within the tank, causing it to arch upwards and create gaps or partial separation from the tank. As the high-elasticity body 21 arches upwards, the ultra-elastic cable 26 provides active downward restraint, pulling it downwards towards the pre-set ultra-tough early-strength cement-based concrete tank. This helps to suppress the upward arching of the elastomer under extreme high-temperature conditions, improving the overall stability and adaptability of the structure. Under extreme cooling conditions, the walls of the two sides contract, causing the width of the pre-set ultra-tough early-strength cement-based concrete tank to tend to widen. The expansion range exceeds the extension range of the high-elasticity body 21 during its own elastic deformation. When the high-elasticity body 21 can no longer extend, it cannot completely fill the pre-set ultra-tough early-strength cement-based concrete tank, resulting in gaps. Since the two ends of the cable are fixed to the trench wall and the high-elasticity body 21 respectively, the hyperelastic cable 26 provides tensile constraint, stretching the high-elasticity body 21 towards the trench wall of the preset ultra-tough early-strength cement-based concrete trench. This allows the high-elasticity body 21 to refill the gap between itself and the preset ultra-tough early-strength cement-based concrete trench at extremely low temperatures. Because the nickel-titanium alloy cable possesses hyperelasticity and hysteretic energy dissipation properties throughout the cycle, its extra elongation can automatically return to its initial state without residual deformation when the environment returns to normal temperature conditions. This provides energy dissipation support during cyclic deformation, achieving automatic temperature change compensation and enhancing the overall toughness of the device.

[0070] On the other hand, the wire-type displacement sensor 5, located between the ring hinge 28 at the upper end of the high-elasticity body 21 and the super-elastic cable 26, is reliably connected to the high-elasticity body 21 or the pre-tensioning device 22 through its wire end. It generates displacement synchronously with the longitudinal expansion and contraction of the high-elasticity body 21, and the internal winding mechanism of the sensor converts this expansion and contraction into an electrical signal. This allows for continuous acquisition of the actual expansion and contraction, residual deformation, and temperature-displacement response relationship of the expansion joint device during its service life, used to verify the rationality of the designed pre-stressing amount and to determine if there are abnormal gaps in the joint filler. The output signals of the wire-type displacement sensor 5 and the force-measuring anchor head 6 are uniformly connected to a data acquisition, demodulation, and transmission device located near the bridge deck. This device has a built-in data acquisition module, signal conditioning module, and wireless communication module, which can filter, amplify, and encode the raw sensor signals and upload them in real time to a cloud server or roadside receiving terminal via wireless communication methods (such as cellular networks, Wi-Fi, or LoRa). Users can remotely view the expansion and contraction displacement of the expansion joint, the tension of the cables, and their evolution curves over time and temperature via computer or mobile terminal, enabling online monitoring, evaluation, and early warning of the expansion joint's operating status.

[0071] Thus, this embodiment utilizes nickel-titanium alloy cables with applied initial pre-tension stress to achieve an integrated design of pre-stress deformation control and temperature change compensation functions. Its structure is simple, the construction and installation steps are simple, and it significantly improves construction efficiency and reliability.

[0072] It is worth mentioning that, because the highly elastic body 21 tends to arch upwards under extreme temperature conditions, the hyperelastic cable 26 is designed to extend downwards at an angle, with its extended end fixed to the channel wall of the bridge. This creates a downward component force at both ends of the highly elastic body 21, effectively suppressing the arching phenomenon. If it were angled upwards, it would be difficult to prevent bulging under extreme temperature increases or load changes. In some embodiments, the hyperelastic cable 26 can also extend horizontally, with the tension direction parallel to the longitudinal direction of the bridge.

[0073] In summary, the high elasticity body 21 of this utility model embodiment has at least the following advantages:

[0074] (1) The wave-shaped design and reserved holes under stress-free conditions reduce the difficulty of installation and ensure the structural stability during service.

[0075] (2) The factory prefabrication and rapid on-site assembly of modular units greatly shorten the construction cycle, while standardized production ensures consistent quality.

[0076] (3) The nickel-titanium alloy superelastic cable 26 achieves active limiting constraint, which significantly enhances the adaptability and self-adjustment ability of the structure under extreme temperature change conditions.

[0077] (4) The wavy surface can significantly increase the friction of the tire contact surface during operation, especially in rainy and snowy weather, reducing the risk of vehicle slippage and improving driving safety.

[0078] (5) By setting wire-type displacement sensors 5 and force-measuring anchors 6 at both ends of the super-elastic cable 26, and in conjunction with data acquisition and wireless transmission terminals, the expansion displacement of the expansion joint component 2 and the cable force information can be obtained in real time, providing data support for the monitoring of the expansion joint's operating status and maintenance decisions.

[0079] As a further explanation of this embodiment, the preload of the high elasticity 21 should not be less than the maximum expansion amount of the expansion joint calculated from the bridge linear expansion coefficient, the groove wall length and the ambient temperature difference, as shown in formula (1):

[0080] (1)

[0081] in, This represents the longitudinal deformation of one side of the tank wall, in mm. The coefficient of linear expansion of the bridge is expressed in mm / °C. This represents the length of one side of the tank wall, in meters (m). The structural temperature during elastomer installation, in °C; The minimum effective temperature for bridges as specified in the regulations is expressed in °C.

[0082] To ensure a balance between the overall constraint effect and material utilization, the design of the hyperelastic cable 26 should comprehensively consider installation constraints, structural function, and material properties. After determining the geometric distance between the two anchor points, the free length of the cable is shown in formula (2):

[0083] (2)

[0084] in, The free length of the cable is expressed in mm. The cable installation length is in mm; The initial tensile strain of the cable is expressed in mm / mm.

[0085] Furthermore, the prestress applied during the installation of the hyperelastic cable 26 should be determined comprehensively based on the bridge's coefficient of linear expansion, the compressive stiffness of the elastic body, the preload, and the maximum temperature range. The initial prestress of the hyperelastic cable 26 is shown in formula (3):

[0086] (3)

[0087] in, The cable preload is expressed in kN. This refers to the elastic modulus of the cable, expressed in MPa. The cross-sectional area of ​​the cable is in mm². 2 .

[0088] Furthermore, the horizontal component of the cable preload should meet the tensile strength requirements of the elastomer for filling the gap at extreme low temperatures, as shown in formula (4):

[0089] (4)

[0090] in, The angle between the cable and the horizontal line, in degrees; The minimum tensile force required to extend an elastomer, measured in kN, depends on the elastomer modulus, effective cross-section, and the required extension length under extreme conditions.

[0091] Under the premise of meeting the above mechanical requirements, the initial prestress of the hyperelastic cable 26 is designed to minimize the amount of material used.

[0092] In addition, to ensure hysteretic energy dissipation performance, the initial pretension strain of the cable should be controlled within a reasonable range, while maintaining extended redundancy and safety reserves for more extreme environments, so as to achieve a balance between performance and economy.

[0093] Preferably, considering that the ultimate tensile strain of nickel-titanium alloy is 8% to 10%, the initial tensile strain of the cable should be designed to be 4% to 6%, preferably 5%. Therefore, the initial pre-tension strain of the hyperelastic cable 26 is designed to be 5%. This strain range can provide sufficient initial pre-tension stress to assist in compressing the high elastic body 21 to make it fit tightly, while providing additional elongation allowance caused by extreme temperature changes, avoiding the material from entering the plastic deformation zone, and realizing dynamic compensation during thermal expansion and contraction.

[0094] The shape of the wavy upper and lower surfaces of the high-elasticity body 21 and the shape of the preload mounting channel can be determined by the amount of preload deformation. As a further improvement to this embodiment, such as… Figure 3 and Figure 4 , Figure 3 The diagram shows the state of the highly elastic body 21 of this invention in a stress-free state; Figure 4 The diagram shows the state of the high-elasticity body 21 after it has been press-fitted into a pre-set ultra-tough early-strength cement-based concrete trough along the longitudinal direction of the bridge. The upper and lower surfaces of the wavy high-elasticity body 21 are elliptical curves in the stress-free state, and the prestressing installation channels are also elliptical. This design significantly reduces the compressive stiffness of the high-elasticity body 21 along the longitudinal direction of the bridge, facilitating its adaptation to the dimensions of the pre-set ultra-tough early-strength cement-based concrete trough after pre-stressing deformation. When the high-elasticity body 21 is assembled into the pre-set ultra-tough early-strength cement-based concrete trough, the upper and lower surfaces of the wavy high-elasticity body 21 deform into arc-shaped curves, and the prestressing channels 29 simultaneously deform into circles, achieving a tight fit between the elastomer and the pre-set ultra-tough early-strength cement-based concrete trough.

[0095] Of course, in some embodiments, the wavy line curve can be designed as a rectangular curve, and the prestressing duct 29 can be designed as a rectangle. Preferably, it is designed as an ellipse, which allows the prestressing duct 29 to become circular after installation, while also facilitating the passage of the prestressing device 22. The prestressing device 22 can be a circular metal rod with threads at both ends.

[0096] As mentioned above, the number of prestressing channels 29 can be greater than the number of pre-tensioning devices 22. Preferably, the number of prestressing channels 29 corresponds one-to-one with the number of pre-tensioning devices 22, with all prestressing channels 29 transversely penetrating the high elasticity body 21 as pre-tensioning installation channels, and multiple prestressing channels 29 are arranged horizontally at intervals. The upper and lower surfaces of the high elasticity body 21 are both wavy; each prestressing channel 29 is correspondingly located below each crest arc segment in the wavy upper surface; the pre-tensioning device 22 includes multiple connecting rods and multiple bolts, each connecting rod correspondingly protruding from each prestressing channel 29 and being threadedly fastened to the surface of the high elasticity body 21 arranged side by side by bolt threads; multiple superelastic cables 26 are provided, and the multiple superelastic cables 26 are symmetrical with respect to the central axis of the high elasticity body 21.

[0097] In this embodiment, the horizontally and longitudinally spaced distribution of multiple prestressed ducts 29 can uniformly distribute the prestressing force across the entire width of the highly elastic body 21. The wavy upper and lower surfaces are symmetrical, with each prestressed duct 29 positioned below each crest of the wavy upper surface and above each trough of the wavy lower surface. The area enclosed by the upper and lower surfaces is thicker than other areas, allowing for a more rational spatial arrangement of the prestressed ducts 29 and a more significant reduction in longitudinal compressive stiffness.

[0098] In some embodiments, the wavy upper surface and the wavy lower surface are parallel.

[0099] In some embodiments, the arc width of the crest segment of the wavy upper surface is greater than the arc width of the trough segment.

[0100] In some embodiments, the crests of the wavy upper surface and the troughs of the wavy lower surface are staggered.

[0101] In some embodiments, a plurality of prestressed channels 29 are arranged in an array within the highly elastic body 21.

[0102] More specifically, such as Figure 5 The diagram shows the connection principle between the expansion joint units. Connecting rods and bolts tightly press multiple highly elastic bodies 21 together in the transverse direction, ensuring the integrity of the overall structure. Preferably, prestressed anchor plates 23 are fixed on both sides of the corrugated highly elastic body 21, and threaded steel rods are inserted into the pre-tension mounting holes of adjacent highly elastic bodies 21. Bolts are installed at both ends of the steel rods and anchored to the prestressed anchor plates 23.

[0103] Then, symmetrically arranging multiple hyperelastic cables 26 can ensure that the high elastic body 21 is subjected to uniform stress under extreme temperature change conditions, avoiding asymmetrical deformation of the structure caused by unilateral stress. Specifically, four hyperelastic cables 26 can be set on both longitudinal sides of the transverse end faces of the high elastic body 21, and two transversely parallel high elastic bodies 21 share two hyperelastic cables 26 on the contact surface.

[0104] Preferably, the prestressed duct 29 is closer to the wavy upper surface than the wavy lower surface. The inclined lower end of the hyperelastic cable 26 is fixed to the lower surface of the groove wall near the high elastic body 21, and the inclined upper end is fixed to the pre-tightening device 22 on the bottom wall of the groove away from the preset hyper-toughness early strength cement-based concrete groove.

[0105] In optional embodiments, the hyperelastic cable 26 can be connected to the high elastic body 21 or the sidewall of the trench by means of groove, perforation, or adhesive. In optional embodiments, the hyperelastic cable 26 can also be arranged inside the high elastic body 21. Preferably, the hyperelastic cable 26 is connected to the outer wall surface of the high elastic body 21 where it is not in contact with the trench wall of the preset hyper-toughness early-strength cement-based concrete trench, so as to avoid installation interference between the high elastic body 21 and the preset hyper-toughness early-strength cement-based concrete trench. At the same time, the connection point is set on the outer wall surface, so that the cable can be installed and tensioned from the outside, improving the ease of assembly. More preferably, the hyperelastic cable 26 is connected to the pre-tensioning device 22 on the high elastic body 21 and the sidewall of the preset hyper-toughness early-strength cement-based concrete trench, respectively. After the high elastic body 21 is pre-installed independently, the pre-tensioning device 22 and the hyperelastic cable 26 can be installed. There is sufficient space for installation operation, which facilitates efficient on-site construction.

[0106] In the preferred example provided in this embodiment, such as Figure 7 The diagram shows the three-dimensional structure of the hyperelastic cable 26, in conjunction with reference. Figure 2 Each hyperelastic cable 26 has its inclined upper end connected to the connecting rod via a ring hinge 28, and its inclined lower end connected to the sidewall of the groove via a ball hinge 27, which is used to form an active limiting constraint.

[0107] Furthermore, such as Figure 6 As shown, Figure 6 This diagram illustrates the assembly of the supporting steel plate 24, the limiting ring 25, and the shear stud connector 241 according to an embodiment of the present invention. Each expansion joint unit further includes a supporting steel plate 24, which is fixed to the lower surface of the high elastic body 21 via the shear stud connector 241. In this embodiment, the supporting steel plate 24 is fixedly connected to the corrugated high elastic body 21 via the shear stud connector 241. The supporting steel plate 24 supports the high elastic body 21 and is positioned directly below the high elastic body 21, preventing the high elastic body 21 from deflecting under vehicle load when it is compressed by a vehicle.

[0108] Furthermore, the supporting steel plate 24, serving as an intermediate structural member between the highly elastic body 21 and the beam end, can also be used to transfer vehicle loads to the channel wall. The shear stud connectors 241 connecting the supporting steel plate 24 include, but are not limited to, reinforcing bar connectors, structural steel connectors, and stud connectors.

[0109] A height adjustment component 3 can be installed below the supporting steel plate 24. The height adjustment component 3 is a concrete layer formed by pouring ultra-tough early-strength concrete onto the bottom wall of the tank. It transfers the vehicle load sequentially from the high-elasticity body 21 to the supporting steel plate 24, the height adjustment component 3, and the tank wall, ensuring uniform load distribution. In some designs, the length of the supporting steel plate 24 can be the same as the length of the high-elasticity body 21, while its width is smaller than that of the high-elasticity body 21, and it is located in the middle region of the high-elasticity body 21.

[0110] Both the ultra-tough early-strength cement-based concrete layer and the ultra-tough early-strength cement-based concrete tank 1 are made of ultra-tough early-strength cement-based concrete. The ultra-tough early-strength cement-based concrete not only has a compressive strength of over 30 MPa after 2 hours, but also has a tensile strain strengthening capacity of over 5%. Furthermore, its elastic modulus is between that of the beam and the high-elasticity body 21, which plays a role in variable stiffness. This significantly reduces the possibility of vehicle bouncing caused by sudden stiffness changes and damage to the tank wall caused by impact loads, and also ensures that traffic can be opened quickly within 4 hours.

[0111] The thickness of the ultra-tough early-strength cement-based concrete layer is determined based on the difference between the depth of the preset ultra-tough early-strength cement-based concrete groove formed by the ultra-tough early-strength cement-based concrete groove 1 and the thickness of the wavy high-elasticity body 21, to meet the adaptation requirements of different bridge deck elevations. In a preferred embodiment, the thickness of the ultra-tough early-strength cement-based concrete layer is equal to the difference between the depth of the preset ultra-tough early-strength cement-based concrete groove and the target thickness of the high-elasticity body 21, so that the wavy upper surface of the high-elasticity body 21 protrudes beyond the preset ultra-tough early-strength cement-based concrete groove; wherein the target thickness is the vertical distance between the trough of the wavy lower surface and the trough of the wavy upper surface of the high-elasticity body 21. In this embodiment, the ultra-tough early-strength cement-based concrete layer fills the remaining space after the high-elasticity body 21 is installed in the preset ultra-tough early-strength cement-based concrete groove, and the crest arc of the wavy upper surface of the high-elasticity body 21 just extends beyond the preset ultra-tough early-strength cement-based concrete groove, so that the vehicle can be buffered by friction from the wavy upper surface during high-speed driving, reducing the risk of vehicle slippage.

[0112] When a supporting steel plate 24 is provided, the target thickness is the vertical distance from the trough of the wavy lower surface of the high elastic body 21 to the lower surface of the steel plate.

[0113] Furthermore, a limiting ring 25 is set below the midpoint of the supporting steel plate 24, and the limiting ring 25 is located between the concrete layers. The limiting rings 25 of each expansion joint unit are connected and anchored through threaded steel bars to limit the deviation of the expansion joint assembly 2 in the longitudinal direction of the bridge, thereby further ensuring the structural stability.

[0114] A further improvement of this utility model is the provision of a water-stopping device 4, which consists of a soft foam strip filled at the bottom of the gap between the two sides of the bridge channel wall to form a flexible sealing layer, effectively preventing sewage and debris from entering.

[0115] In addition, an intelligent monitoring module is installed on the expansion joint assembly 2. The intelligent monitoring module includes a wire-type displacement sensor 5 located near the annular hinge 28 at the upper end of the hyperelastic cable 26, and a force-measuring anchor head 6 located at the ball hinge 27 at the lower end of the hyperelastic cable 26. The force-measuring anchor head 6 is an integrated component, serving both as an anchoring unit at the cable end and as a built-in force sensing element for collecting the axial force signal of the hyperelastic cable 26. The wire-type displacement sensor 5 is used to collect the expansion and contraction displacement of the highly elastic body 21 in the longitudinal direction of the bridge. These sensing signals are collected and encoded by a data acquisition and wireless transmission unit located near the bridge deck, and then wirelessly transmitted to a roadside server or cloud monitoring platform. This enables real-time monitoring and remote diagnosis of the deformation state of the expansion joint device and the stress state of the cable, facilitating performance evaluation and early warning maintenance during the operation and maintenance phase.

[0116] Correspondingly, when the expansion joint device provided by this utility model is installed on a bridge, the bridge includes two opposing ultra-tough early-strength cement-based concrete troughs 1. A pre-set ultra-tough early-strength cement-based concrete trough and an expansion joint are formed between the two ultra-tough early-strength cement-based concrete troughs 1, arranged from top to bottom and interconnected. The expansion joint corresponds to the middle area of ​​the pre-set ultra-tough early-strength cement-based concrete trough. Inside the pre-set ultra-tough early-strength cement-based concrete trough, a high-elasticity body 21, a supporting steel plate 24, and ultra-tough early-strength cement-based concrete are arranged from top to bottom. In the soil layer, the limiting ring 25 is positioned below the supporting steel plate 24 and between the ultra-tough early-strength cement-based concrete layers. Within the expansion joint, foam tape fills the area near the pre-set ultra-tough early-strength cement-based concrete groove. The wavy extension direction of the high-elasticity body 21 within the pre-set ultra-tough early-strength cement-based concrete groove on the groove wall is parallel to the longitudinal direction of the bridge to enhance vehicle friction in the driving direction. The parallel direction of multiple high-elasticity bodies 21 is parallel to the transverse direction of the bridge. Multiple shear stud connectors 241 are evenly spaced along the transverse direction of the bridge. Furthermore, the expansion joint assembly 2 is equipped with an intelligent monitoring module, which uses a wire-type displacement sensor 5 and a force-measuring anchor head 6 to monitor in real time the expansion and contraction displacement of the high-elasticity body 21 in the longitudinal direction of the bridge and the axial force on the ultra-elastic cable 26. The collected signals are processed by terminal encoding near the bridge deck and then wirelessly transmitted to a cloud monitoring platform for real-time status perception of the expansion joint device, preload health assessment, and performance warning under temperature change conditions.

[0117] In summary, the expansion joint device provided by this utility model mainly consists of two ultra-tough, early-strength cement-based concrete troughs 1, a wavy expansion joint assembly 2, a height adjustment assembly 3, and a water-stopping device 4. The ends of the two ultra-tough, early-strength cement-based concrete troughs 1 are pre-set with ultra-tough, early-strength cement-based concrete grooves. The height adjustment assembly 3 is installed within the grooves to adjust the installation height of the expansion joint assembly 2, ensuring its surface is aligned with the bridge deck elevation. The wavy expansion joint assembly 2 is composed of multiple expansion joint units. Each expansion joint unit includes a wavy, highly elastic body 21, prestressed ducts 29, a prestressed anchor plate 23, a supporting steel plate 24 with shear stud connectors 241, and a nickel-titanium alloy cable with applied prestress. The wavy, highly elastic body 21 is placed within the pre-set ultra-tough, early-strength cement-based concrete trough. After applying prestress, the nickel-titanium alloy cable is obliquely hinged between the trough wall and the steel rod in the prestressed installation duct. Furthermore, the device integrates an intelligent monitoring module for monitoring expansion displacement and cable stress state.

[0118] In this way, the modular expansion joint units eliminate gaps through prestressed fastening of steel bars and anchor plates, ensuring a tight connection of the overall structure. Nickel-titanium alloy cables, with initial prestress applied, provide active restraint, applying downward limiting or tensile compensation when extreme temperature changes cause the elastomer to arch upwards or insufficient caulking occurs. They can further elongate when prestress is insufficient to maintain the device in normal operating condition without residual deformation. The corrugated surface design increases tire friction during operation, effectively preventing slippage. Furthermore, the intelligent monitoring module can record expansion joint deformation and cable stress evolution in real time, enabling remote monitoring, anomaly warnings, and maintenance guidance. Compared to traditional solutions, this device significantly improves construction efficiency and quality consistency through its prefabricated design, eliminating the need for complex on-site processes. The combination of active restraint and intelligent monitoring significantly reduces maintenance costs and driving risks.

[0119] This embodiment takes the setting of two expansion joint units, the bridge including two sides of ultra-tough early-strength cement-based concrete troughs 1, and the ends of the two sides of ultra-tough early-strength cement-based concrete troughs 1 having preset ultra-tough early-strength cement-based concrete troughs as an example, and proposes a specific prefabricated variable stiffness temperature-compensated bridge expansion joint device.

[0120] The expansion joint device includes an expansion joint component 2, a height adjustment component 3, and a water-stopping device 4. The height adjustment component 3 is poured into the bottom of a pre-cast ultra-tough, early-strength cement-based concrete trough. The water-stopping device 4, composed of soft foam strips, fills the expansion joint between the two ultra-tough, early-strength cement-based concrete trough bodies 1. The pre-cast ultra-tough, early-strength cement-based concrete trough has a width of 200mm, a depth of 150mm, and a beam linear expansion coefficient of 1e. -2 mm / °C.

[0121] Please refer to it again. Figure 2Each expansion joint unit includes a wave-shaped high elastic body 21, a pre-tensioning device 22, a supporting steel plate 24 with shear stud connectors 241, and an obliquely arranged super-elastic cable 26, wherein the prestressed anchor plate 23 is only arranged at both ends of the expansion joint device.

[0122] The wavy high-elasticity material 21 is a polyurethane-based composite high-elasticity material with an elastic modulus of 150 MPa and a compression set of no more than 5% (according to ASTM D395 standard). The two side walls have a span of 30 m, with a minimum effective temperature of -3℃ and a maximum effective temperature of 34℃. When the expansion joint assembly 2 is installed, the structural temperature of the wall is 25℃. Therefore, one side of the wall shrinks by 8.4 mm at the minimum effective temperature, which is the minimum preload of the wavy high-elasticity material 21.

[0123] Taking into account the channel width, installation compression space, and the maximum expansion and contraction of the bridge, the preload of the corrugated high elastic body 21 is designed to be 10mm. Under stress-free conditions, its longitudinal, vertical, and transverse lengths are 210mm, 120mm, and 300mm, respectively. The upper and lower surfaces are elliptical curves with a preset peak height of 15mm and a longitudinal wavelength of 40mm.

[0124] The prestressed duct 29 is designed to be elliptical, with a minor axis of 20mm and a major axis of 22mm. During installation, the high-elasticity body 21 is compressed to the groove size by applying longitudinal bridge preload, deforming into an arc-shaped upper and lower surface. The duct also deforms into a circle to ensure close contact with the pre-set ultra-tough early-strength cement-based concrete groove and to achieve preload control.

[0125] A steel rod with threads at both ends is inserted into the prestressed channel 29 of the adjacent high elastic body 21. Bolts are installed at both ends of the steel rod and anchored to the prestressed anchor plate 23. By applying pre-tightening force, the modules are tightly fitted together, and the gaps are completely eliminated.

[0126] The supporting steel plate 24 is 8mm thick and made of Q345B low-alloy steel, with a galvanized surface to improve corrosion resistance. Shear stud connectors 241 are uniformly welded to the bottom of the supporting steel plate 24. Each shear stud has a diameter of 12mm and a height of 16mm, arranged in an array at 250mm intervals, and embedded in the bottom of the high-elasticity body 21 to ensure effective transfer of vehicle load to the channel wall. A limit ring 25 with an outer diameter of 21mm and an inner diameter of 15mm is welded below the midpoint of the supporting steel plate 24 to limit the longitudinal displacement of the expansion joint assembly 2, with a designed allowable displacement of ±70mm. Adjacent limit rings 25 are anchored together by threaded steel bars, further enhancing the overall stability and anti-displacement capability of the assembly.

[0127] The expansion joint unit is equipped with diagonally arranged nickel-titanium alloy cables. The cables are made of nickel-titanium alloy with an elastic modulus of 40 GPa, an installation length of 80 mm, and a maximum allowable strain range of 8%~10%. During installation, one end of the hyperelastic cable 26 is connected to the trench wall via a ball joint 27, and the other end is connected to the pre-tensioning device 22 via a ring joint 28. The trench wall's structural history shows an extreme low temperature of -20℃, at which point the shrinkage of one side of the trench wall reaches 13.5 mm, exceeding the maximum preload of the hyperelastic body 21 by 3.5 mm. Therefore, the cables need to provide a 90 kN tension to extend the hyperelastic body 21 to the trench wall. Considering the cable's hysteretic energy dissipation performance, active restraint performance requirements, safety margin, and material cost, the initial pre-tension strain of the nickel-titanium alloy cable is designed to be 5%, and the cable cross-sectional diameter is 6 mm.

[0128] The height adjustment component 3 is made of high-toughness concrete with a compressive strength ≥50MPa. Its thickness is the difference between the groove depth and the actual height of the high elastic body 21 after compression. In this embodiment, it is taken as 65mm to ensure that the upper surface of the expansion joint component 2 is consistent with the elevation of the bridge road surface and the flatness error is ≤±1mm.

[0129] A wire-type displacement sensor 5 is installed at the ring hinge 28 at the upper end of each hyperelastic cable 26 to measure the expansion and contraction of the hyperelastic body 21 along the longitudinal direction of the bridge in real time. A force-measuring anchor head 6 is installed at the ball hinge 27 at the lower end of the hyperelastic cable 26. The force-measuring anchor head 6 has dual functions of cable end anchoring and axial force monitoring, and is used to obtain the stress changes of the cable in real time. The displacement and force signals are conditioned, encoded and transmitted by a data acquisition and wireless transmission terminal near the bridge deck, and uploaded to the cloud monitoring platform via Wi-Fi communication to realize online monitoring of the daily deformation, temperature response and preload evolution of the expansion joint. The intelligent monitoring module can generate real-time warnings. If abnormal attenuation of cable preload, expansion and contraction exceeding the threshold or insufficient temperature compensation is detected, it can automatically remind maintenance personnel to check, thereby significantly improving the safety, maintainability and service reliability of the device.

[0130] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A prefabricated, high-toughness, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device, characterized in that, The device includes: An expansion joint assembly includes multiple expansion joint units, each of which includes an elastomer and an elastic cable connected to each other. The multiple elastomers are assembled side by side along the transverse direction into a pre-set ultra-tough early-strength cement-based concrete groove at the beam end, and the elastic cable extends obliquely downward from the elastomer to connect with the groove wall of the pre-set ultra-tough early-strength cement-based concrete groove. The elastic body is provided with a prestressed channel through it; and at least one of its surfaces is wavy to at least prevent the elastic body from arching upwards when it undergoes compression deformation. A prestressing device passes sequentially through the prestressed channel of each of the elastomers to tightly connect the plurality of the elastomers along the transverse bridge direction; The elastic cable is subjected to an initial pre-tension stress to help maintain the fit between the elastic body and the preset ultra-tough early-strength cement-based concrete trough; the initial pre-tension strain of the elastic cable is 5%. The elastic cable is made of nickel-titanium alloy and is used for: Under extreme heating conditions, the elastic cable constrains the elastic body downwards to suppress the elastic body from arching upwards; under extreme cooling conditions, the elastic cable stretches the elastic body towards the preset ultra-tough early-strength cement-based concrete trough to cause the elastic body to extend and fill the preset ultra-tough early-strength cement-based concrete trough; when switching from the extreme heating conditions or the extreme cooling conditions to normal temperature conditions, the elastic cable automatically returns to its initial state.

2. The prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to claim 1, characterized in that, The corresponding surface of the wavy elastomer in the stress-free state is an elliptical curve, and the prestressed channel is elliptical; when the elastomer is assembled into the preset ultra-tough early-strength cement-based concrete trough and the ambient temperature rises, the corresponding surface of the wavy elastomer gradually deforms into an arc curve, and the prestressed channel gradually deforms into a circle.

3. The prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to claim 1, characterized in that, Multiple prestressing channels are provided, and the multiple prestressing channels are arranged horizontally at intervals; both the upper and lower surfaces of the elastic body are wavy; wherein, Each of the prestressed ducts is correspondingly located below each crest arc segment in the corrugated upper surface; The prestressing device includes multiple connecting rods and multiple bolts. Each connecting rod passes through each prestressing channel and is threadedly fastened by the bolts to the outer surfaces of two elastic bodies located at both ends in the transverse direction. The elastic cable is provided in multiple parts, and the multiple elastic cables are symmetrical with respect to the central axis of the elastic body.

4. The prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to claim 3, characterized in that, The inclined upper end of each elastic cable is connected to the connecting rod via a ring hinge, and the inclined lower end is connected to the groove wall via a ball hinge.

5. A prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to claim 3, characterized in that, Each of the expansion joint units also includes: A prestressed anchor plate is fixed to the outer surface of two elastic bodies located at both ends in a transverse direction, and each of the connecting rods is anchored to the prestressed anchor plate by the bolts. The supporting steel plate is fixed to the lower surface of the elastic body by shear stud connectors.

6. A prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to claim 5, characterized in that, The device further includes: The height adjustment component is assembled onto the bottom wall of the preset ultra-tough early-strength cement-based concrete tank and abuts against the underside of the supporting steel plate. A water-stopping device, including foam tape, is used to fill the expansion joint at the end of the beam.

7. A prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to claim 6, characterized in that, The height adjustment component includes an ultra-tough early-strength cement-based concrete layer, the thickness of which is equal to the difference between the depth of the preset ultra-tough early-strength cement-based concrete groove and the target thickness of the elastomer, so that the wavy upper surface of the elastomer protrudes from the preset ultra-tough early-strength cement-based concrete groove; wherein the target thickness is the vertical distance between the trough of the wavy lower surface and the trough of the wavy upper surface of the elastomer.

8. A prefabricated ultra-tough early-strength variable stiffness temperature-compensating bridge expansion joint device according to claim 5, characterized in that, Each of the expansion joint units also includes a limiting ring, which is fixed below the supporting steel plate; the limiting rings of multiple expansion joint units are anchored together by threaded steel bars.

9. A prefabricated ultra-tough early strength variable stiffness temperature-compensating bridge expansion joint device according to any one of claims 1-8, characterized in that, The beam end includes two oppositely arranged ultra-tough early-strength cement-based concrete troughs, and a pre-set ultra-tough early-strength cement-based concrete trough and an expansion joint are formed between the two ultra-tough early-strength cement-based concrete troughs from top to bottom. Within the preset ultra-tough early-strength cement-based concrete trough, the elastic body, the supporting steel plate, and the ultra-tough early-strength cement-based concrete layer are arranged from top to bottom, with the limiting ring positioned below the supporting steel plate and between the ultra-tough early-strength cement-based concrete layers. Both the ultra-tough early-strength cement-based concrete layer and the ultra-tough early-strength cement-based concrete tank are made of ultra-tough early-strength cement-based concrete. Within the expansion joint, foam tape is filled in the area of ​​the expansion joint near the pre-set ultra-tough early-strength cement-based concrete groove; The wavy extension direction of the elastic body located in the preset ultra-tough early strength cement-based concrete trough is parallel to the longitudinal direction of the bridge.

10. A prefabricated, ultra-tough, early-strength, variable-stiffness, temperature-compensating bridge expansion joint device according to claim 9, characterized in that, The elastomer is a polyurethane-based composite elastomer.

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