A test device and method for the overall tension performance of steel strand anchor groups

Abstract

This invention relates to a device and method for testing the overall tensioning performance of steel strand group anchors, comprising: a tensioning table, a tensioning loading assembly, a force transmission assembly, and a testing assembly. A testing channel is opened on the surface of the tensioning table, and the group anchor specimen is placed on one side of it. The tensioning loading assembly includes a first anchor beam, a second anchor beam, and first and second jacks arranged vertically. A pressure sensor is installed between the jacks and the second anchor beam, and the second anchor beam has a lifting ring. The force transmission assembly consists of multiple threaded rods connected to each steel strand, which pass through each component sequentially and are fixed to the second anchor beam. The testing assembly includes a measuring plate connected to the threaded rods and symmetrically arranged dual displacement gauges. This invention achieves large-tonnage overall synchronous tensioning through the combination of dual anchor beams and dual jacks. The pressure sensor and dual displacement gauges enable high-precision synchronous testing of tension force and slippage, simplifying the installation process. The overall structure is stable and the testing accuracy is high, providing reliable data support for group anchor performance evaluation and meeting the requirements for large-tonnage group anchor tensioning testing.

Description

Technical Field

[0001] This invention relates to the field of prestressed engineering testing technology, and in particular to a test device and method for the overall tension performance of a steel strand anchor group. Background Technology

[0002] In the construction industry, the prestressed precast monolithic structural system can effectively improve the load-bearing capacity of components, reduce structural deformation, and improve crack resistance. It is further adapted to the application requirements of large-scale buildings such as multi-story logistics warehouses and large-span industrial plants, which demand large spans, heavy loads, and high integrity, and is gradually becoming the mainstream structural system for such buildings. Currently, the beam-column connection of this structural system mainly adopts the steel strand bending group anchorage connection method.

[0003] The anchoring performance, synergistic stress-bearing performance, and slip deformation characteristics of steel strand group anchors directly affect the effective transfer of prestress, the stress state at the ends of components, and the overall safety of the structure. In order to accurately grasp its actual stress mechanism and working performance, conducting group anchor overall tensioning tests that closely approximate actual engineering conditions is a key foundation for related technical research and engineering applications.

[0004] In the existing technology, most common tensioning test devices are designed for single steel bars, single steel strands, or small-tonnage anchors. They cannot meet the overall synchronous tensioning test requirements of large-tonnage steel strand group anchors. It is difficult to achieve synchronous loading and accurate performance testing of multiple steel strands under the premise of simulating the stress state of real engineering projects, and cannot provide reliable test data support for the performance evaluation of steel strand group anchors. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of existing tensioning test devices, which are mostly designed for single steel bars, steel strands or small-tonnage anchors, and cannot be adapted to the overall synchronous tensioning test of large-tonnage steel strand group anchors. They are difficult to achieve synchronous loading and accurate performance testing, and cannot provide reliable data support for their performance evaluation.

[0006] To address the aforementioned technical problems, this invention provides a testing device for the overall tension performance of steel strand group anchors, used for testing the overall tension performance of group anchor specimens, comprising: A tensioning table is provided with a test channel on its surface. The group anchor specimen is placed on one side of the tensioning table, and the group anchor specimen contains multiple steel strands. The tensioning loading assembly includes a first anchor beam, a second anchor beam, a first jack, and a second jack. The first and second anchor beams are located on the side of the tensioning table away from the group anchor specimen. The first anchor beam is located close to the tensioning table. The first and second jacks are located between the first and second anchor beams. The first jack is located on top of the second jack. One end of both the first and second jacks abuts against the first anchor beam. A pressure sensor is installed between the other end of the first and second jacks and the second anchor beam. A lifting ring is installed on the second anchor beam. The force transmission component includes multiple threaded rods, one end of which is connected to the steel strand, and the other end of which passes through the test channel, the first anchor beam, and the second anchor beam in sequence, and the threaded rod is connected to the second anchor beam. The test assembly includes a measuring plate and a pair of displacement gauges. The measuring plate is connected to the threaded rod, and the pair of displacement gauges are symmetrically arranged on both sides of the test channel, with the measuring ends of the displacement gauges facing the measuring plate.

[0007] In one embodiment of the present invention, a pair of pads are provided between the group anchor specimen and the tensioning table, and the pair of pads are symmetrically arranged on both sides of the test channel.

[0008] In one embodiment of the present invention, a first inclined surface is provided on the side of the tensioning table that is in contact with the pad block, and a second inclined surface that cooperates with the first inclined surface is provided on the surface of the pad block.

[0009] In one embodiment of the present invention, the surface of the first anchor beam is provided with a plurality of first through holes that cooperate with the threaded rod, and the surface of the second anchor beam is provided with a plurality of second through holes that cooperate with the threaded rod. The inner diameters of the first through holes and the second through holes are equal, and the inner diameters of the first through holes and the second through holes are larger than the diameter of the threaded rod.

[0010] In one embodiment of the present invention, the tensioning loading assembly further includes a support frame disposed between the first anchor beam and the second anchor beam, the first jack and the second jack being disposed on the support frame, and a plurality of threaded rods passing through the support frame and disposed between the first jack and the second jack.

[0011] In one embodiment of the present invention, the force transmission component further includes a connector and a threaded anchor. The connector is disposed between the threaded rod and the steel strand, and the threaded anchor is disposed at the end of the threaded rod away from the steel strand. The threaded anchor is sleeved on the threaded rod and abuts against the second anchor beam.

[0012] In one embodiment of the present invention, the test assembly further includes a fixing plate, a magnetic base, and a connecting rod. The fixing plate is disposed on the tensioning table, the magnetic base cooperates with the fixing plate, and the two ends of the connecting rod are respectively connected to the displacement gauge and the magnetic base.

[0013] In one embodiment of the present invention, a verticality measuring ruler is provided on one side of the second anchor beam.

[0014] A method for testing the overall tension performance of a steel strand group anchor, using the aforementioned testing equipment, further includes the following steps: S1. Hoist the anchor group test specimen with the anchor inherent steel strand and place it on the tensioning platform, so that the anchor group test specimen is close to the tensioning platform; S2. Connect one end of multiple threaded rods to multiple steel strands one by one, so that the threaded rods pass through the test channel of the tensioning table, the first anchor beam and the second anchor beam in sequence, fix the threaded rods to the second anchor beam, and lift the second anchor beam off the ground at the same time. S3. Fix the measuring plate on multiple threaded rods, install a pair of displacement gauges symmetrically on both sides of the test channel, make the measuring end of the displacement gauge face the measuring plate, and zero the displacement gauge; S4. Control the first and second jacks to apply tension force in a coordinated manner, and collect tension force data synchronously through the pressure sensor and relative slip data synchronously through the displacement acquisition device until the predetermined test conditions are reached or the group anchor specimen is damaged, thus completing the test.

[0015] In one embodiment of the present invention, in step S4, the average value of the displacement values ​​measured by the two displacement gauges is taken as the relative slip of the group anchor specimen.

[0016] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: This invention discloses a testing device and method for the overall tension performance of steel strand group anchors. Through a synergistic loading structure of double anchor beams and double jacks, it achieves synchronous tensioning of large-tonnage steel strands. Simultaneously, corresponding force transmission components ensure synchronous force distribution across all steel strands, avoiding the problems of uneven force distribution and eccentric loading in existing technologies. The combination of pressure sensors and symmetrically arranged dual displacement gauges enables high-precision synchronous testing of tension force and slippage, eliminating the defects of existing technologies such as interference from structural deformation and large measurement errors. It also simplifies the installation process of large-tonnage loading components. The overall structure exhibits clear force distribution, stable loading, and high testing accuracy, providing reliable experimental data support for evaluating the working performance of steel strand group anchors and effectively meeting the testing requirements for the overall tension performance of large-tonnage steel strand group anchors. Attached Figure Description

[0017] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Schematic diagram of the installation position of the middle group anchor specimen; Figure 3 for Figure 2 Schematic diagram of the intermediate tensioning table; Figure 4 for Figure 1 Schematic diagram of the structure of the tension loading component; Figure 5 for Figure 1 Schematic diagram of the force transmission component; Figure 6 for Figure 2 A schematic diagram of the structure of the test component; Explanation of reference numerals in the accompanying drawings: 1. Tensioning table; 2. Tensioning loading assembly; 3. Force transmission assembly; 4. Test assembly; 5. Group anchor specimen; 6. Pad block; 11. Test channel; 12. First inclined plane; 21. First anchor beam; 22. Second anchor beam; 23. First jack; 24. Second jack; 25. Pressure sensor; 26. Support frame; 31. Threaded rod; 32. Connector; 33. Threaded anchor; 41. Measuring plate; 42. Displacement gauge; 43. Fixing plate; 44. Magnetic base; 45. Connecting rod; 51. Steel strand; 61. Second inclined plane; 211. First through hole; 221. Lifting ring; 222. Verticality measuring ruler; 223. Second through hole. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0019] Reference Figures 1-6 As shown, this invention discloses a testing device for the overall tension performance of a group anchor of steel strands, used for testing the overall tension force of the group anchor specimen 5, including: Tensioning table 1, the surface of which is provided with a test channel 11, the group anchor specimen 5 is placed on one side of the tensioning table 1, and the group anchor specimen 5 has multiple steel strands 51 anchored inside. The tensioning loading assembly 2 includes a first anchor beam 21, a second anchor beam 22, a first jack 23, and a second jack 24. The first anchor beam 21 and the second anchor beam 22 are located on the side of the tensioning table 1 away from the group anchor specimen 5. The first anchor beam 21 is located close to the tensioning table 1. The first jack 23 and the second jack 24 are located between the first anchor beam 21 and the second anchor beam 22. The first jack 23 is located on top of the second jack 24. One end of the first jack 23 and the second jack 24 abuts against the first anchor beam 21, and the other end abuts against the second anchor beam 22 through pressure sensors 25. Pressure sensors 25 are provided between the first jack 23 and the second jack 24 and the second anchor beam 22. A lifting ring 221 is provided on the second anchor beam 22. The force transmission component 3 includes multiple threaded rods 31. One end of each threaded rod 31 is connected to the steel strand 51, and the other end of each threaded rod 31 passes through the test channel 11, the first anchor beam 21, and the second anchor beam 22 in sequence. The threaded rod 31 is also connected to the second anchor beam 22. Test component 4 includes a measuring plate 41 and a pair of displacement gauges 42. The measuring plate 41 is connected to the threaded rod 31. The pair of displacement gauges 42 are symmetrically arranged on both sides of the test channel 11, and the measuring end of the displacement gauge 42 faces the measuring plate 41.

[0020] In the above structure, a tensioning loading structure with double anchor beams and double jacks is adopted to separate the reaction force bearing and loading traction functions. The first anchor beam 21 is mainly used to form a loading reaction force support, while the second anchor beam 22 is mainly used to collect and transfer the tension load. This avoids the problem of excessive deformation and insufficient bearing capacity caused by a single anchor beam bearing tensile and compressive combined stresses simultaneously. It can adapt to the overall tensioning requirements of a group of anchors of large-tonnage steel strands 51 weighing hundreds of tons. The first jack 23 and the second jack 24 are arranged vertically and horizontally to load in coordination, which can provide a larger total tension force. At the same time, it ensures that the second anchor beam 22 is subjected to uniform force during the loading process, avoiding uneven force on the upper and lower rows of steel strands 51 due to loading eccentricity. This effectively ensures the tensioning synchronization of all steel strands 51 and truly restores the actual stress state of the project. The pressure sensor 25 is directly installed between the jack and the second anchor beam 22. Positioned along the force transmission path, the pressure sensor 25 can directly acquire the load signal at the loading end and serve as the test basis for the overall tension load of the anchor group. It is unaffected by the deformation of the first anchor beam 21 or the tensioning table 1 itself, significantly improving the accuracy of the tension force test and ensuring the reliability of the test data. The force transmission component 3 adopts a structure where multiple threaded rods 31 are connected one-to-one with the steel strands 51, forming an independent and synchronous force transmission path. This ensures that all steel strands 51 are stressed simultaneously, solving the problem of asynchronous stress distribution among multiple steel strands 51 in existing technologies, and accurately simulating the overall stress characteristics of the anchor group in engineering. Test component 4 adopts a structure with a measuring plate 41 connected to a threaded rod 31 and a pair of displacement gauges 42 symmetrically arranged. In actual operation, the measuring plate 41 is fixed on the uppermost threaded rod and moves synchronously with the steel strand 51, accurately reflecting the overall slippage of the steel strand 51. The symmetrical arrangement of the two displacement gauges 42 effectively eliminates the systematic error caused by the tilt of the measuring plate 41, further improving the accuracy of slippage testing and providing reliable data support for the evaluation of the anchorage performance of the group anchor. A lifting ring 221 is set on the second anchor beam 22, which facilitates the hoisting and positioning of the second anchor beam 22 and the adjustment of its posture using external lifting equipment. The second anchor beam 22 can be lifted and suspended in the air, avoiding friction interference between the second anchor beam 22 and the ground during loading. This simplifies the installation process of the large-tonnage loading component, improves the convenience of the test operation, and reduces the difficulty of the test installation.

[0021] This invention achieves large-tonnage overall synchronous tensioning through a synergistic loading structure of double anchor beams and double jacks. Simultaneously, the one-to-one force transmission components 3 ensure synchronous force distribution across all steel strands 51, avoiding the problems of uneven force distribution and eccentric loading in existing technologies. The cooperation of pressure sensors 25 and symmetrically arranged dual displacement gauges 42 enables high-precision synchronous testing of tension force and slippage, eliminating the defects of existing technologies where test data is affected by structural deformation and has large measurement errors. It also simplifies the installation process of large-tonnage loading components. The overall structure exhibits clear force distribution, stable loading, and high testing accuracy, providing reliable experimental data support for evaluating the working performance of the steel strand group anchors and effectively meeting the testing requirements for the overall tensioning performance of large-tonnage steel strand group anchors.

[0022] Furthermore, a pair of pads 6 are provided between the group anchor specimen 5 and the tensioning table 1, and the pair of pads 6 are symmetrically arranged on both sides of the test channel 11; a first inclined surface 12 is provided on the side of the tensioning table 1 that is in contact with the pads 6, and a second inclined surface 61 that cooperates with the first inclined surface 12 is provided on the surface of the pads 6.

[0023] Specifically, the pad 6 serves as an intermediate support component between the anchor group specimen 5 and the tensioning table 1. It provides a stable support foundation for the anchor group specimen 5, isolates the specimen from direct contact with the tensioning table 1, and reserves operating space for adjusting the installation posture of the anchor group specimen 5. The first inclined surface 12 of the tensioning table 1 is the bearing surface. One side of the second inclined surface 61 of the pad 6 is in contact with the first inclined surface 12, and the vertical surface of the pad 6 is in contact with the anchor group specimen 5. The tensioning end of the steel strand 51 of the anchor group specimen 5 faces the test channel. The tensioning table 1 adopts a sloping structure that is wider at the bottom and narrower at the top, which significantly improves the structural stability and anti-overturning ability of the tensioning table 1 itself, and can safely withstand the huge horizontal reaction force generated by large-tonnage tensioning. The first inclined surface 12 and the second inclined surface 61 form a tightly fitted surface contact force transmission system, which can evenly diffuse the concentrated reaction force transmitted by the anchor group specimen 5 into the overall structure of the tensioning table 1, effectively avoiding cracking of the tensioning table 1 or breakage of the pad 6 caused by local stress concentration.

[0024] Furthermore, the surface of the first anchor beam 21 is provided with a plurality of first through holes 211 that cooperate with the threaded rod 31, and the surface of the second anchor beam 22 is provided with a plurality of second through holes 223 that cooperate with the threaded rod 31. The inner diameter of the first through hole 211 and the inner diameter of the second through hole 223 are equal, and the inner diameter of the first through hole 211 and the inner diameter of the second through hole 223 are larger than the diameter of the threaded rod 31.

[0025] Specifically, the first through hole 211 and the second through hole 223 provide precise guide channels for the threaded rods 31, constraining their spatial position and ensuring that all threaded rods 31 are arranged along the same axial direction. Structurally, this avoids the problem of uneven stress on the steel strand 51 caused by eccentric force on the threaded rods 31. The equal inner diameters of the first through hole 211 and the second through hole 223 ensure consistent guidance of the threaded rods 31 by the double anchor beams, preventing bending deformation of the threaded rods 31 due to differences in hole diameter. The larger inner diameters of the first through hole 211 and the second through hole 223 provide sufficient space for the lifting and attitude adjustment of the second anchor beam 22, preventing radial compression forces on the threaded rods 31 during lifting due to swaying or tilting of the second anchor beam 22. This prevents bending deformation of the threaded rods 31, ensuring that all threaded rods 31 are always subjected to axial force, eliminating the interference of radial force on the actual tension of the steel strand 51, and ensuring the accuracy of the test results.

[0026] Furthermore, the tensioning loading assembly 2 also includes a support frame 26, which is disposed between the first anchor beam 21 and the second anchor beam 22. The first jack 23 and the second jack 24 are disposed on the support frame, and multiple threaded rods 31 pass through the support frame 26 and are disposed between the first jack 23 and the second jack 24.

[0027] Specifically, by setting a support frame 26 between the first anchor beam 21 and the second anchor beam 22, and between the first jack 23 and the second jack 24, stable support and precise positioning can be provided for the vertically arranged first jack 23 and second jack 24. This effectively prevents the jacks from sagging or shifting due to their own weight, ensures the coaxiality and relative position accuracy of the two jacks, and ensures that the two ends of the jacks maintain a uniform and tight contact with the first anchor beam 21 and the second anchor beam 22. This avoids the jacks from tilting or shifting during loading, thereby ensuring the uniformity and synchronization of force when the two jacks are loaded together.

[0028] Furthermore, the force transmission component 3 also includes a connector 32 and a threaded anchor 33. The connector 32 is disposed between the threaded rod 31 and the steel strand 51, and the threaded anchor 33 is disposed at the end of the threaded rod 31 away from the steel strand 51. The threaded anchor 33 is sleeved on the threaded rod 31 and abuts against the second anchor beam 22. Simultaneously, the threaded rods 31 are concentrated in the central stress area between the two jacks, allowing the tension load applied by the jacks to be evenly transmitted to each threaded rod 31 through the second anchor beam 22. This avoids localized load concentration and ensures uniform stress on all steel strands 51, significantly improving the stability of tension loading and the accuracy of test results structurally.

[0029] Furthermore, the test assembly 4 also includes a fixing plate 43, a magnetic base 44, and a connecting rod 45. The fixing plate 43 is disposed on the tensioning table 1, the magnetic base 44 cooperates with the fixing plate 43, and the two ends of the connecting rod 45 are respectively connected to the displacement gauge 42 and the magnetic base 44.

[0030] Specifically, the fixing plate 43 is fixed to the tensioning table 1 as a stable reference for displacement measurement. The magnetic attraction between the magnetic base 44 and the fixing plate 43 enables the quick assembly and disassembly of the displacement gauge 42 and flexible position adjustment without the need for additional drilling or bolt tightening, greatly simplifying the installation and debugging process of the displacement gauge 42. At the same time, the displacement gauge 42 and the magnetic base 44 are connected by the connecting rod 45, which allows for flexible adjustment of the installation height and angle of the displacement gauge 42. This ensures that the probe of the displacement gauge 42 can be accurately aligned and stably abut against the measuring plate 41, effectively avoiding measurement errors caused by loose installation or positional deviation of the displacement gauge 42. From the aspects of reference stability and adjustment convenience, the accuracy of the slippage test of the steel strand 51 and the efficiency of the test operation are guaranteed.

[0031] Furthermore, a verticality measuring ruler 222 is provided on one side of the second anchor beam 22.

[0032] Specifically, the verticality measuring ruler 222 can provide an intuitive and accurate verticality measurement benchmark for adjusting the installation posture of the second anchor beam 22. After the second anchor beam 22 is lifted and suspended by the lifting ring 221, its posture can be monitored in real time by the verticality measuring ruler 222 and the adjustment can be completed quickly to ensure that the second anchor beam 22 always remains vertical, thus avoiding the loading eccentricity problem caused by the tilt of the second anchor beam 22 from the root.

[0033] A method for testing the overall tension performance of a steel strand group anchor, using the aforementioned testing equipment, further includes the following steps: S1. Hoist the anchor group specimen 5 of the anchor inherent steel strand 51 and place it on the tensioning table 1, so that the anchor group specimen 5 is close to the tensioning table 1. S2. Connect one end of multiple threaded rods 31 to multiple steel strands 51 one by one, so that the threaded rods 31 pass through the test channel 11 of the tensioning table 1, the first anchor beam 21 and the second anchor beam 22 in sequence, fix the threaded rods 31 to the second anchor beam 22, and at the same time lift the second anchor beam 22 off the ground. S3. Fix the measuring plate 41 on multiple threaded rods 31, install a pair of displacement gauges 42 symmetrically on both sides of the test channel 11, so that the measuring end of the displacement gauge 42 faces the measuring plate 41, and zero the displacement gauge 42. S4. Control the first jack 23 and the second jack 24 to apply tension force in a coordinated manner, and collect tension force data synchronously through the pressure sensor 25. Collect relative slip data synchronously through the displacement acquisition device. The average value of the displacement values ​​measured by the two displacement gauges 42 is used as the relative slip of the group anchor specimen 5 until the predetermined test conditions are reached or the group anchor specimen 5 is damaged, and the test is completed.

[0034] Step S1 is the placement step of the group anchor specimen 5. Specifically, the group anchor specimen 5 is hoisted and placed on the tensioning table 1. A pair of pads 6 are placed on the first inclined surface 12 of the tensioning table 1. The second inclined surface 61 of the pads 6 is attached to the first inclined surface 12, and the group anchor specimen 5 is placed close to the other side of the pads 6.

[0035] Step S2 involves connecting the group anchor specimen 5 to the force transmission assembly 3. Specifically, the threaded rod 31 passes sequentially through the test channel 11 of the tensioning table 1, the first anchor beam 21, and the second anchor beam 22. Then, the tensioning end of each steel strand 51 is connected to the corresponding connector 32, and each connector 32 is then connected to the corresponding threaded rod 31. After the connection is completed, the threaded rod 31 is fixed using the threaded anchor 33. When lifting the second anchor beam 22, the lifting ring 221 is used in conjunction with an external lifting device to lift the second anchor beam 22 to a predetermined position, placing it in a suspended state. Then, the installation posture of the second anchor beam 22 is adjusted using a verticality measuring ruler 222 to keep the second anchor beam 22 vertical.

[0036] Step S3 is the installation step of test component 4. Specifically, during the actual installation process, two fixing plates 43 are steel plates embedded in the tensioning table 1. The measuring plate 41 with a slot is vertically fixed to the uppermost threaded rod 31, and the measuring plate 41 is positioned within the test channel 11. Then, two displacement gauges 42 are installed on the two fixing plates 43 using two magnetic bases 44, and the positions of the displacement gauges 42 are adjusted so that the probes of the two displacement gauges 42 are in stable contact with the two sides of the measuring plate 41. After installation, the displacement gauges 42 are connected to the matching displacement acquisition equipment, and the pressure sensor 25 is connected to the load acquisition equipment. Simultaneously, the two displacement gauges 42 are zeroed to facilitate real-time acquisition of slip displacement data during the overall tensioning process of the steel strand 51. After confirming that the data collected at each measuring point is stable, continuous, and without obvious abnormalities, the loading stage begins.

[0037] Step S4 employs a graded loading method to test the tension performance of the steel strand 51. Specifically, before the formal test, a pre-loading is performed to check the reliability of the connections of each component and whether each testing unit can function properly. After the pre-loading is completed and the system is confirmed to be working properly, the formal loading begins. During the formal loading, the first jack 23 and the second jack 24 work together to apply the overall tension load to the steel strand 51. A graded loading method is used during the loading process: in the initial stage, the load is applied in small increments; when the load reaches a certain level, the single-level loading amplitude is appropriately increased; when the slippage of the steel strand 51 increases significantly or the specimen is close to failure, the single-level loading amplitude is reduced to improve the accuracy of the test data in the near-failure stage. After each level of load is applied, it is maintained for a certain period of time until the load and the readings at each measuring point are basically stable before the next level of loading is applied.

[0038] Throughout the loading process, the pressure sensor 25 collects tension load data in real time, the two displacement gauges 42 collect displacement change data of the measuring plate 41 in real time, and the static strain test and analysis system synchronously collects strain data of each steel strand 51 resistance strain gauge. During the test, since the two displacement gauges 42 are symmetrically arranged on both sides of the measuring plate 41, taking the average value can reduce the influence of the measuring plate 41 deflection, local tilt, or unilateral contact error on the slip measurement results. Specifically, the average displacement measured by the two displacement gauges 42 is taken as the slip amount during the overall tensioning process of the steel strand 51, and the slip amount is synchronously recorded with the tension load and strain data of the steel strand 51 at the corresponding moment. Through the above method, the load-slip relationship and strain response law during the overall tensioning process of the steel strand 51 anchor group can be obtained.

[0039] As a preferred embodiment of the present invention, the overall tension performance testing equipment for steel strand group anchors can also be used to test the tension strain of steel strands. Adding resistance strain gauges further improves the accuracy of the test results based on the data from the resistance strain gauges. The specific operating steps are as follows: In step S3, several steel strands 51 are selected, and resistance strain gauges are pasted onto the surface of the outer steel wire near the tensioning end. Before pasting, the surface of the steel strands 51 is ground, cleaned, and degreased to improve the bonding quality between the strain gauges and the surface of the steel strands 51. After pasting, the strain gauges and lead wires are insulated and protected to prevent the strain gauges from falling off or the signal from being interfered with during the test. The leads of each resistance strain gauge are uniformly led out and connected to the matching static strain test and analysis system to achieve synchronous testing of three types of test signals: load, displacement, and strain. Similarly, during the entire loading process, the static strain test and analysis system synchronously collects the strain data of the resistance strain gauges of each steel strand 51.

[0040] In summary, this invention introduces a testing device and method for the overall tension performance of a group of steel strand anchors. Through a collaborative loading structure using double anchor beams and double jacks, large-tonnage overall synchronous tensioning is achieved. Simultaneously, the one-to-one force transmission components 3 ensure synchronous force application to all steel strands 51, avoiding the problems of uneven force distribution and eccentric loading in existing technologies. The cooperation of pressure sensors 25 and symmetrically arranged dual displacement gauges 42 enables high-precision synchronous testing of tension force and slippage, eliminating the defects of existing technologies where test data is affected by structural deformation and measurement errors are large. It also simplifies the installation process of large-tonnage loading components. The overall structure exhibits clear force distribution, stable loading, and high testing accuracy, providing reliable experimental data support for evaluating the working performance of the group of steel strand anchors 51, effectively meeting the testing requirements for the overall tension performance of large-tonnage steel strand anchor groups 51.

[0041] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A testing device for the overall tension performance of a group of steel strand anchors, used for testing the overall tension performance of group anchor specimens, characterized in that, include: A tensioning table is provided with a test channel on its surface. The group anchor specimen is placed on one side of the tensioning table, and the group anchor specimen contains multiple steel strands. The tensioning loading assembly includes a first anchor beam, a second anchor beam, a first jack, and a second jack. The first and second anchor beams are located on the side of the tensioning table away from the group anchor specimen. The first anchor beam is located close to the tensioning table. The first and second jacks are located between the first and second anchor beams. The first jack is located on top of the second jack. One end of both the first and second jacks abuts against the first anchor beam. A pressure sensor is installed between the other end of the first and second jacks and the second anchor beam. A lifting ring is installed on the second anchor beam. The force transmission component includes multiple threaded rods, one end of which is connected to the steel strand, and the other end of which passes through the test channel, the first anchor beam, and the second anchor beam in sequence, and the threaded rod is connected to the second anchor beam. The test assembly includes a measuring plate and a pair of displacement gauges. The measuring plate is connected to the threaded rod, and the pair of displacement gauges are symmetrically arranged on both sides of the test channel, with the measuring ends of the displacement gauges facing the measuring plate.

2. The overall tension performance testing equipment for steel strand group anchors according to claim 1, characterized in that: A pair of pads are provided between the anchor group specimen and the tensioning table, and the pair of pads are symmetrically arranged on both sides of the test channel.

3. The overall tension performance testing equipment for steel strand group anchors according to claim 2, characterized in that: The tensioning table has a first inclined surface on the side that is in contact with the pad, and the surface of the pad has a second inclined surface that cooperates with the first inclined surface.

4. The overall tension performance testing equipment for steel strand group anchors according to claim 1, characterized in that: The surface of the first anchor beam has a plurality of first through holes that mate with the threaded rod, and the surface of the second anchor beam has a plurality of second through holes that mate with the threaded rod. The inner diameters of the first through holes and the second through holes are equal, and the inner diameters of the first through holes and the second through holes are larger than the diameter of the threaded rod.

5. The overall tension performance testing equipment for steel strand group anchors according to claim 1, characterized in that: The tensioning loading assembly also includes a support frame, which is disposed between the first anchor beam and the second anchor beam. The first jack and the second jack are disposed on the support frame, and multiple threaded rods pass through the support frame and are disposed between the first jack and the second jack.

6. The overall tension performance testing equipment for steel strand group anchors according to claim 1, characterized in that: The force transmission component also includes a connector and a threaded anchor. The connector is disposed between the threaded rod and the steel strand, and the threaded anchor is disposed at the end of the threaded rod away from the steel strand. The threaded anchor is sleeved on the threaded rod and abuts against the second anchor beam.

7. The overall tension performance testing equipment for steel strand group anchors according to claim 1, characterized in that: The test assembly also includes a fixing plate, a magnetic base, and a connecting rod. The fixing plate is disposed on the tensioning table, the magnetic base cooperates with the fixing plate, and the two ends of the connecting rod are respectively connected to the displacement gauge and the magnetic base.

8. The overall tension performance testing equipment for steel strand group anchors according to claim 1, characterized in that: A verticality measuring ruler is installed on one side of the second anchor beam.

9. A method for testing the overall tension performance of a steel strand anchor group, used in the testing equipment for the overall tension performance of a steel strand anchor group as described in any one of claims 1-8, characterized in that: It also includes the following steps: S1. Hoist the anchor group test specimen with the anchor inherent steel strand and place it on the tensioning platform, so that the anchor group test specimen is close to the tensioning platform; S2. Connect one end of multiple threaded rods to multiple steel strands one by one, so that the threaded rods pass through the test channel of the tensioning table, the first anchor beam and the second anchor beam in sequence, fix the threaded rods to the second anchor beam, and lift the second anchor beam off the ground at the same time. S3. Fix the measuring plate on multiple threaded rods, install a pair of displacement gauges symmetrically on both sides of the test channel, make the measuring end of the displacement gauge face the measuring plate, and zero the displacement gauge; S4. Control the first and second jacks to apply tension force in a coordinated manner, and collect tension force data synchronously through the pressure sensor and relative slip data synchronously through the displacement acquisition device until the predetermined test conditions are reached or the group anchor specimen is damaged, thus completing the test.

10. The method for testing the overall tension performance of a steel strand group anchor according to claim 9, characterized in that: In step S4, the average value of the displacement measured by the two displacement gauges is taken as the relative slip of the group anchor specimen.

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