Hydro-thermal-corrosion coupling tunnel prestressed npr anchorage body mechanical performance testing machine

Abstract

This invention discloses a mechanical performance testing machine for prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling conditions, relating to the field of performance testing equipment. It solves the problems of low operational efficiency and difficulty in comprehensively simulating real-world usage scenarios in existing NPR anchor mechanical performance testing machines. The machine includes a main body, a pressure chamber, a testing mechanism, and a loading / unloading mechanism. The testing mechanism comprises anchor bolts, a composite block, and test specimens. This invention combines anchor bolts and composite blocks to form the NPR anchor. The testing mechanism controls the main body and pressure chamber to simulate a hydrothermal-corrosion coupling environment on the NPR anchor. The test specimens simulate the radial and axial stress conditions of the anchor bolts and yield mechanical performance test results. The loading / unloading mechanism assists in loading and unloading the NPR anchor, improving testing efficiency. This device is comprehensive in function and highly efficient in operation, effectively completing mechanical performance tests on NPR anchors under simulated real-world conditions.

Description

Technical Field

[0001] This invention relates to the field of performance testing equipment technology, specifically a mechanical performance testing machine for prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling. Background Technology

[0002] Deep tunnel engineering often faces complex geological environments characterized by high temperature, high water pressure, and strong corrosion. Prestressed NPR (Negative Poisson's Ratio) anchoring systems are a key technology for controlling surrounding rock stability, and their long-term mechanical properties directly determine the safety of the project. Traditional NPR anchor mechanical performance testing equipment often uses single-environment simulations, such as considering only tensile loading or a single corrosive environment. This fails to reproduce the actual service conditions of hydrothermal-corrosion coupling, leading to significant discrepancies between experimental data and actual engineering conditions.

[0003] While some existing testing machines can achieve coordinated control of temperature and pressure, they lack environmental design for corrosive media, making it difficult to simulate the cyclic dynamic loads caused by surrounding rock deformation. Furthermore, traditional testing equipment is relatively cumbersome to operate when conducting performance tests on NPR anchors, and the loading, unloading, fixing, and testing of NPR anchors are not efficient or convenient enough. Summary of the Invention

[0004] The purpose of this invention is to provide a testing machine for the mechanical properties of prestressed NPR anchor bodies in tunnels under hydrothermal-corrosion coupling, which facilitates improved testing efficiency and simulation accuracy, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a mechanical performance testing machine for prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling, comprising a machine body, a testing mechanism, and a loading and unloading mechanism. A pressure chamber is fixedly connected to the upper side of the machine body. The machine body and the pressure chamber are equipped with a temperature control module, a corrosive medium circulation module, a pressure regulation module, and an environmental parameter monitoring unit. The testing mechanism includes an anchor rod installed within the pressure chamber. A composite block is fixedly connected to the outer wall of the anchor rod. The composite block is cylindrical and coaxially fixedly connected to the anchor rod. The composite block is composed of concrete, rock mass specimens, and anchor... The simulated surrounding rock is prepared by mixing a solidifying agent. The pressure chamber contains test specimens for testing the radial and axial stress performance of the anchor bolt. The testing mechanism combines the anchor bolt with the composite block to form an NPR anchor body. The machine body and the pressure chamber simulate a hydrothermal-corrosion coupled environment for the NPR anchor body. The test specimens simulate the stress condition of the anchor bolt and obtain performance test results. The loading and unloading mechanism is installed in the pressure chamber to assist in loading and unloading the NPR anchor body, improve testing efficiency, and facilitate improved detection operation efficiency and simulation test accuracy.

[0006] Preferably, the test mechanism further includes multiple sets of three-dimensional strain gauges uniformly fixedly installed on the outer wall of the anchor rod. Wires are fixedly connected to the three-dimensional strain gauges. The multiple sets of three-dimensional strain gauges and the wires are all bonded and fixed to the outer wall of the anchor rod with adhesive. The composite block is located outside the three-dimensional strain gauges and fixedly connected to the anchor rod. A conductive plug is inserted into the inner wall of the pressure chamber. The multiple sets of wires all exit from one end of the composite block and are fixedly connected to the conductive plug, facilitating the simulation of the stress condition of the anchor rod and obtaining performance test results.

[0007] Preferably, the test piece includes a fixed frame fixedly installed on the outer walls of both ends of the pressure box. A rotating disk is rotatably connected to both sides of the pressure box. A drive groove is opened in the middle of the rotating disk. An installation cylinder is slidably connected in the drive groove along the horizontal direction. The outer wall of the installation cylinder is prismatic. A threaded hole is opened in the installation cylinder. A threaded groove is opened on the outer wall of both ends of the anchor rod, which can be threadedly connected to the threaded hole. The fixed frame is provided with a drive component for controlling the position of the installation cylinder to realize the function of detecting the axial pressure and tension of the anchor rod. The pressure box is provided with a test component for detecting the radial force of the anchor rod, which facilitates the testing of the radial and axial force performance of the anchor rod.

[0008] Preferably, the driving component includes a sliding frame and a magnetic suction frame that are slidably connected to the inner wall of the fixed frame in a horizontal direction. An elastic element that is fixedly connected to the magnetic suction frame is fixedly connected to the side of the sliding frame. A metal disk is fixedly connected to the end of the mounting cylinder away from the anchor rod. The metal disk can be magnetically attracted and fixed to the magnetic suction frame. The rotating disk is provided with a transmission component for driving the mounting cylinder to slide horizontally in conjunction with the mounting cylinder during rotation. The fixed frame is provided with a pulling component for performing a tensile test on the anchor rod, which facilitates the control of the position of the mounting cylinder to realize the function of detecting the axial pressure and tensile force of the anchor rod.

[0009] Preferably, the transmission component includes an external gear ring coaxially fixedly mounted on the side of the rotating disk, a threaded rod rotatably connected inside the fixed frame, the threaded rod passing through the sliding frame and threadedly connected to the sliding frame, a first gear coaxially fixedly connected to one end of the threaded rod, the first gear meshing with the external gear ring, a through hole in the middle of the magnetic suction frame, a first electric telescopic rod fixedly connected to the sliding frame, the telescopic end of the first electric telescopic rod passing through the through hole, facilitating horizontal sliding of the mounting cylinder in conjunction with the rotation of the mounting cylinder.

[0010] Preferably, the pulling member includes an annular frame that is movably fitted with the inner wall of the outer toothed ring, a drive ring is rotatably connected inside the annular frame, the mounting cylinder passes through the drive ring and is slidably connected to the inner wall of the drive ring in a horizontal direction, an electric push rod is fixedly connected to the fixing frame, an installation plate is fixedly connected to the telescopic end of the electric push rod, and multiple sets of connecting rods fixedly connected to the side of the drive ring are fixedly connected to the installation plate, which facilitates the tensile test of the anchor rod.

[0011] Preferably, the testing component includes an arc-shaped plate that rotates and fits against the inner wall of the pressure chamber. The inner wall of the pressure chamber has an arc-shaped groove. An arc-shaped rod that slides and connects to the inner wall of the arc-shaped groove is fixedly connected to the outer wall of the arc-shaped plate. Multiple sets of toothed grooves are evenly formed on the outer wall of the arc-shaped rod. A second electric telescopic rod is fixedly connected to the arc-shaped plate. A push block is fixedly connected to the telescopic end of the second electric telescopic rod. The pressure chamber is equipped with a rotating component for driving the arc-shaped plate to rotate and adjust, which facilitates the detection test of the radial force on the anchor rod.

[0012] Preferably, the rotating component includes a drive motor fixedly mounted on the pressure box. Two sets of second gears are rotatably connected inside the pressure box. Both sets of second gears can mesh with the tooth groove. The distance between the two sets of second gears is greater than the arc length of the arc plate opening and less than the arc length of the arc plate itself. A drive shaft is coaxially fixedly connected to the second gear. A transmission belt is connected between the two sets of drive shafts through a pulley. The output end of the drive motor is coaxially fixedly connected to any one set of drive shafts to facilitate driving the arc plate to rotate and adjust.

[0013] Preferably, the loading and unloading mechanism includes two sets of electric lifting platforms fixedly installed in the machine body. The lifting end of the electric lifting platform passes through the pressure box and slides against the inner wall of the pressure box. The lifting end of the electric lifting platform is fixedly connected to a support frame. The two sets of support frames are symmetrically arranged on both sides of the arc plate to facilitate auxiliary control of the lifting of the NPR anchor and improve loading and unloading efficiency.

[0014] Preferably, a rotating handle is fixedly connected to the side of the rotating disk, and a box cover is hinged to the upper side of the pressure box for easy manual operation.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a mechanical performance testing machine for prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling conditions. It solves the problems of low operational efficiency and difficulty in comprehensively simulating real-world application scenarios in existing NPR anchor testing machines. By combining anchor bolts with composite blocks to form NPR anchors, the testing mechanism controls the machine body and pressure chamber to simulate a hydrothermal-corrosion coupling environment on the NPR anchors. The test specimen simulates the radial and axial stress conditions of the anchor bolts and yields mechanical performance test results. A loading and unloading mechanism assists in loading and unloading the NPR anchors, improving testing efficiency. This device is comprehensive in function and highly efficient in operation, effectively enabling mechanical performance testing of NPR anchors under simulated real-world conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial structural diagram of the testing mechanism of the present invention; Figure 3 for Figure 2 Enlarged view of region A in the middle; Figure 4 This is a partial structural diagram of the loading and unloading mechanism of the present invention; Figure 5 for Figure 4 Enlarged view of region B in the middle; Figure 6 This is a schematic diagram of the internal structure of the pressure box of the present invention; Figure 7 for Figure 6 Enlarged view of region C; Figure 8 This is a partial structural breakdown diagram of the experimental mechanism of the present invention; Figure 9 This is a partial structural cross-sectional view of the test mechanism of the present invention; Figure 10 for Figure 9 Enlarged view of region D in the middle; Figure 11 This is a partial structural cross-sectional view of the test specimen of the present invention; Figure 12 for Figure 11 Enlarged view of region E in the middle.

[0017] In the diagram: 1-Body; 2-Pressure box; 3-Anchor bolt; 4-Composite block; 5-Three-dimensional strain gauge; 6-Wire; 7-Conductive plug; 8-Fixing frame; 9-Rotating disk; 10-Drive groove; 11-Mounting cylinder; 12-Threaded hole; 13-Threaded groove; 14-Sliding frame; 15-Magnetic suction frame; 16-Elastic element; 17-Metal disk; 18-External gear ring; 19-Threaded rod; 20-First gear; 21-Through hole; 22-First... 23-Electric telescopic rod; 24-Ring frame; 25-Drive ring; 26-Electric push rod; 27-Mounting plate; 28-Connecting rod; 29-Arc plate; 30-Arc groove; 31-Gear groove; 32-Second electric telescopic rod; 33-Push block; 34-Drive motor; 35-Second gear; 36-Drive shaft; 37-Transmission belt; 38-Electric lifting platform; 39-Support frame; 40-Rotating handle; 41-Box cover. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1-8 This invention provides a technical solution: a mechanical performance testing machine for prestressed NPR anchor bodies in tunnels under hydrothermal-corrosion coupling, comprising a body 1, a testing mechanism, and a loading and unloading mechanism. A pressure chamber 2 is fixedly connected to the upper side of the body 1, and a cover 41 is hinged to the upper side of the pressure chamber 2. The body 1 and the pressure chamber 2 are equipped with a temperature control module, a corrosive medium circulation module, a pressure regulation module, and an environmental parameter monitoring unit. The testing mechanism includes an anchor rod 3 installed inside the pressure chamber 2. A composite block 4 is fixedly connected to the outer wall of the anchor rod 3. The composite block 4 is cylindrical and coaxial with the anchor rod 3. The fixed connection, the composite block 4 is a simulated surrounding rock made of concrete, rock mass specimen and anchoring agent. The pressure box 2 is equipped with test specimens for radial and axial stress performance tests of the anchor rod 3. The test mechanism combines the anchor rod 3 and the composite block 4 to form the NPR anchor body. The body 1 and the pressure box 2 simulate the hydrothermal-corrosion coupling environment of the NPR anchor body. The test specimen simulates the stress condition of the anchor rod 3 and obtains the performance test results. The loading and unloading mechanism is installed in the pressure box 2 to assist in loading and unloading the NPR anchor body and improve the test efficiency.

[0020] Please see Figures 2-12The experimental mechanism shown in the diagram also includes multiple sets of three-dimensional strain gauges 5 uniformly fixedly installed on the outer wall of the anchor rod 3. Wires 6 are fixedly connected to the three-dimensional strain gauges 5. All sets of three-dimensional strain gauges 5 and wires 6 are bonded to the outer wall of the anchor rod 3 using adhesive. A composite block 4 is located outside the three-dimensional strain gauges 5 and fixedly connected to the anchor rod 3. A conductive plug 7 is inserted into the inner wall of the pressure chamber 2. Multiple sets of wires 6 exit from one end of the composite block 4 and are fixedly connected to the conductive plug 7. The test piece includes a fixing frame 8 fixedly installed on the outer walls of both ends of the pressure chamber 2. Rotary connecting rods are rotatably connected to both sides of the pressure chamber 2. The rotating disk 9 has a rotating handle 40 fixedly connected to its side. A drive groove 10 is opened in the middle of the rotating disk 9. An installation cylinder 11 is slidably connected in the horizontal direction in the drive groove 10. The outer wall of the installation cylinder 11 is prismatic. A threaded hole 12 is opened in the installation cylinder 11. The outer walls of both ends of the anchor rod 3 are respectively provided with threaded grooves 13 that can be threadedly connected to the threaded hole 12. The fixing frame 8 is provided with a drive component for controlling the position of the installation cylinder 11 to realize the function of detecting the axial pressure and tension of the anchor rod 3. The pressure box 2 is provided with a detection component for detecting the radial force of the anchor rod 3.

[0021] Please see Figures 2-12 The driving components shown in the figure include a sliding frame 14 and a magnetic suction frame 15 that are horizontally slidably connected to the inner wall of the fixed frame 8. An elastic element 16, which is fixedly connected to the magnetic suction frame 15, is fixedly connected to the side of the sliding frame 14. A metal disk 17 is fixedly connected to the end of the mounting cylinder 11 away from the anchor rod 3. The metal disk 17 can be magnetically fixed to the magnetic suction frame 15. The rotating disk 9 is provided with a transmission component for sliding the mounting cylinder 11 horizontally during the rotation of the mounting cylinder 11. The fixed frame 8 is provided with a pulling component for performing a tensile test on the anchor rod 3. The transmission component includes an external toothed ring 18 coaxially fixedly installed on the side of the rotating disk 9. A threaded rod 19 is rotatably connected inside the fixed frame 8. The threaded rod 19 passes through the sliding frame 14 and is threadedly connected to the sliding frame 14. One end of the threaded rod 19 is coaxially fixedly connected to a first gear 20, which meshes with the external gear ring 18. A through hole 21 is provided in the middle of the magnetic suction frame 15. A first electric telescopic rod 22 is fixedly connected to the sliding frame 14. The telescopic end of the first electric telescopic rod 22 can pass through the through hole 21. The pulling member includes an annular frame 23 that is movably sleeved with the inner wall of the external gear ring 18. A drive ring 24 is rotatably connected inside the annular frame 23. The mounting cylinder 11 passes through the drive ring 24 and is slidably connected to the inner wall of the drive ring 24 in the horizontal direction. An electric push rod 25 is fixedly connected to the fixed frame 8. A mounting plate 26 is fixedly connected to the telescopic end of the electric push rod 25. Multiple sets of connecting rods 27 that are fixedly connected to the side of the drive ring 24 are fixedly connected to the mounting plate 26.

[0022] Please see Figures 2-7The detection component shown in the figure includes an arc-shaped plate 28 that rotates and fits against the inner wall of the pressure chamber 2. An arc-shaped groove 29 is formed on the inner wall of the pressure chamber 2. An arc-shaped rod 30, which slides along the inner wall of the arc-shaped groove 29, is fixedly connected to the outer wall of the arc-shaped plate 28. Multiple sets of toothed grooves 31 are evenly formed on the outer wall of the arc-shaped rod 30. A second electric telescopic rod 32 is fixedly connected to the arc-shaped plate 28. A push block 33 is fixedly connected to the telescopic end of the second electric telescopic rod 32. The pressure chamber 2 contains a rotating component for driving the arc-shaped plate 28 to rotate and adjust. The rotating component includes components fixedly installed on... The pressure box 2 has a drive motor 34, preferably model Y80M1-2. Inside the pressure box 2, there are two sets of second gears 35 that are rotatably connected. Both sets of second gears 35 can mesh with the tooth groove 31. The distance between the two sets of second gears 35 is greater than the arc length of the opening of the arc plate 28 and less than the arc length of the arc plate 28 itself. A drive shaft 36 is coaxially fixedly connected to the second gear 35. The two sets of drive shafts 36 are connected by a transmission belt 37 through a pulley. The output end of the drive motor 34 is coaxially fixedly connected to any one set of drive shafts 36.

[0023] Please see Figures 2-7 The loading and unloading mechanism shown in the figure includes two sets of electric lifting platforms 38 fixedly installed in the body 1. The lifting end of the electric lifting platform 38 passes through the pressure box 2 and slides against the inner wall of the pressure box 2. The lifting end of the electric lifting platform 38 is fixedly connected to a support frame 39. The two sets of support frames 39 are symmetrically arranged on both sides of the arc plate 28.

[0024] Working principle: First, a suitable NPR anchor body is made according to the required simulated tunnel surrounding rock condition: Select an anchor rod 3 of appropriate length and open threaded grooves 13 at both ends. Attach three-dimensional strain gauges 5 to the test points on the outer wall of the middle part of the anchor rod 3, and comb and fix the wire guides 6. Then, wrap and fix the simulated surrounding rock composite block 4, which is made of concrete, rock mass specimen, and anchoring agent, to the outer wall of the middle part of the anchor rod 3, so that the outer wall of the composite block 4 is cylindrical and coaxial with the anchor rod 3. The diameter of the composite block 4 needs to be much larger than the diameter of the anchor rod 3, generally more than 10 times, and the specific setting is determined according to the needs. After the NPR anchor body is made... The box cover 41 can be opened, and the electric lifting platform 38 can be controlled to push the support frame 39 upward. At this time, the opening of the arc plate 28 faces upward, and the opening position of the arc plate 28 is aligned with the upper opening of the pressure box 2, which facilitates the loading, unloading and transportation of the NPR anchor. The bottom surfaces of both ends of the composite block 4 in the middle of the NPR anchor are placed on the support frame 39, and the electric lifting platform 38 is controlled to move downward, so that the axis of the anchor rod 3 and the axis of the rotating disk 9 are on a horizontal straight line. The conductive plug 7 at one end of the wire 6 is connected and fixed to the socket position on the inner wall of the pressure box 2. The outer wall of the wire 6 is wrapped with insulating and corrosion-resistant material to avoid interference during the test.

[0025] Based on the outer diameter of the anchor rod 3, select an installation cylinder 11 with a suitable inner diameter. At this time, the sliding brackets 14 and magnetic suction brackets 15 at both ends are on the side away from the pressure box 2. Place the installation cylinder 11 from top to bottom above the fixing bracket 8. Horizontally pass one end of the installation cylinder 11 through the drive ring 24 and drive groove 10. At this time, the drive ring 24 is on the side closer to the pressure box 2. Then rotate the handle 40, causing the rotating disk 9 to drive the installation cylinder 11 and the external gear ring 18 to rotate. At the same time, the external gear ring 18 drives the first gear 20 to rotate, and the first gear 20 drives the threaded rod 19 to rotate, causing the sliding bracket 14 to slide towards the metal disk 17. The sliding bracket 14 pushes the elastic element 16, causing the elastic element 16 to push the magnetic suction bracket 15 horizontally. The sliding elastic element 16 can adopt an existing spring-like structure. When the magnetic suction frame 15 is attracted and pushed by the metal disk 17, the metal disk 17 and the mounting cylinder 11 can be pushed to rotate and move towards the anchor rod 3 during the subsequent rotation of the rotating disk 9. When one end of the anchor rod 3 is inserted into the threaded hole 12, the threaded groove 13 and the threaded hole 12 are threadedly connected under the rotation of the mounting cylinder 11. The elastic element 16 can be compressed and rebounded to avoid jamming during the connection of the threaded groove 13 and the threaded hole 12. When the metal disk 17 reaches the set position and does not fit the drive ring 24, the rotating disk 9 stops rotating. Similarly, the rotating disk 9 on the other side is rotated to complete the fixing of the mounting cylinder 11 and the anchor rod 3. Note: During this process, it is not necessary to fully tighten the threaded hole 12 and the threaded groove 13 to the bottom for fixation. Only partial thread connection is required. This is because subsequent testing only involves axial pulling and pushing of the anchor rod 3 through the mounting cylinder 11. The corresponding pulling and pushing operations can be achieved by connecting a section of the threaded hole 12 and the threaded groove 13. The support frame 39 is Y-shaped and has a certain friction on its upper surface to prevent the anchor rod 3 and the composite block 4 from rotating together during the rotation of the mounting cylinder 11, which would affect the connection operation.

[0026] After installation, cover the pressure chamber 2 with the lid 41 and seal it. The internal temperature control module has a temperature range of -10℃ to 200℃ and a temperature control accuracy of ±0.5℃. The corrosive medium circulation module includes a medium storage tank, a peristaltic pump, a filter assembly, and a return pipeline. The medium storage tank is equipped with an ion concentration adjustment unit, which can be configured to contain Cl. - SO4 2- HCO3 -Simulated groundwater with equal composition was used, and a peristaltic pump controlled the medium circulation flow rate at 0~30L / h to achieve dynamic contact between the corrosive medium and the NPR anchor body. The NPR anchor body was then immersed in a hydrothermal-corrosion coupled environment for simulation testing. The environmental parameter monitoring unit included a pressure sensor, a pH sensor, and a conductivity sensor, which monitored the water pressure in the pressure vessel from 0.1 to 50 MPa with an accuracy of ±0.1 MPa, the medium pH value from 2 to 12, and the ion concentration changes, respectively. The pressure regulation module was used to control the pressure inside the pressure tank 2. Appropriate environmental parameters were selected and set according to the simulation scenario, and mechanical tests were conducted.

[0027] When it is necessary to test the axial tensile and compressive properties of the anchor rod 3: by controlling the first electric telescopic rod 22 on the sliding frame 14 to pass through the through hole 21 and push the metal disk 17 and the mounting cylinder 11 to slide horizontally, the axial force of the anchor rod 3 can be detected. The test results are obtained by collecting data from the three-dimensional strain gauge 5. Then, the first electric telescopic rod 22 is controlled to retract and reset. Then, the electric push rod 25 is controlled to push the mounting disk 26 so that the connecting rod 27 pulls the annular frame 23 to slide towards the side of the metal disk 17 until the side of the drive ring 24 is in contact with the metal disk 17. Then, recording begins and the electric push rod 25 is continued to push, so that the drive ring 24 drives the metal disk 17 and the mounting cylinder 11 to pull the anchor rod 3 together. At the same time, the data from the three-dimensional strain gauge 5 is recorded and analyzed to obtain the test results. When performing the above pressure and tensile tests, the initial thrust of the elastic element 16 at this time needs to be recorded and subtracted to avoid affecting the accuracy of the test results. After the test is completed, the electric push rod 25 is controlled to retract and reset.

[0028] When it is necessary to test the radial tensile and compressive properties of the anchor rod 3: by controlling the drive motor 34 to drive the drive shaft 36 to rotate, and through the transmission belt 37 to drive the drive shafts 36 on both sides to rotate synchronously, the two sets of second gears 35 can rotate synchronously. The second gears 35 drive the tooth groove 31 to make the arc rod 30 and the arc plate 28 rotate. Since the distance between the two sets of second gears 35 is greater than the arc length of the opening of the arc plate 28 and less than the arc length of the arc plate 28 itself, during the rotation of the arc plate 28, the opening position of the arc plate 28 can pass through the upper opening of the pressure box 2 and keep at least one set of the two sets of second gears 35 meshing with the tooth groove 31. The angle of the arc plate 28 can be flexibly adjusted, thereby changing the position of the second electric telescopic rod 32 and the push block 33. The second electric telescopic rod 32 drives the push block 33 to move and contact the side of the composite block 4. After contact, the compression parameters are controlled, so that a comprehensive mechanical test can be carried out on the central radial position of the NPR anchor solid anchor rod 3.

[0029] After the test, the rotating disk 9 is rotated in the opposite direction, causing the external gear ring 18 to drive the first gear 20 and the threaded rod 19 to rotate in the opposite direction. The sliding frame 14 slides away from the pressure box 2. At the same time, the rotating disk 9 drives the mounting cylinder 11 to rotate in the opposite direction through the drive groove 10, releasing the threaded connection between the threaded hole 12 and the threaded groove 13. During the reverse sliding process, the magnetic suction frame 15 pulls the metal disk 17 and the mounting cylinder 11 away from the anchor rod 3, thereby releasing the fixed state of the two ends of the anchor rod 3. The mounting cylinder 11 has a simple structure and can be replaced with mounting cylinders of different inner diameters according to different sizes of anchor rods 3. 11. After use, open the box cover 41, and push the support frame 39 with the electric lifting platform 38 to move the composite block 4 and anchor rod 3 upward. Unplug the conductive plug 7, and the NPR anchor body can be taken out of the pressure box 2 as a whole. Both ends of the arc rod 30 are equipped with sealing gaskets that fit tightly against the inner wall of the arc groove 29, so that impurities on the inner wall of the arc groove 29 can be pushed out during the sliding process, and prevented from falling into the tooth groove 31. After the test is completed, the test fluid inside the pressure box 2 needs to be drained, and it can be thoroughly cleaned and maintained with the corresponding cleaning solution before it can be stored.

[0030] It is worth noting that during the test, the support frame 39 must always support the bottom of both ends of the composite block 4 to prevent the anchor rod 3 from deforming due to the weight of the composite block 4 and affecting the accuracy of the test results. The support is located at both ends of the composite block 4, while the radial pressure test is located in the middle of the composite block 4 and is far away. During the squeezing and pushing process, the force test of the anchor rod 3 at this position will not be affected. The outer wall of the rotating disk 9 and the inner wall of the drive groove 10 are both equipped with seals to improve the sealing of the sliding gap.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A testing machine for the mechanical properties of prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling, characterized in that, include: The machine body (1) is fixedly connected to the upper side of the machine body (1). The machine body (1) and the pressure box (2) are equipped with a temperature control module, a corrosive medium circulation module, a pressure regulation module and an environmental parameter monitoring unit. Also includes: The test mechanism includes an anchor rod (3) installed in the pressure box (2). A composite block (4) is fixedly connected to the outer wall of the anchor rod (3). The composite block (4) is cylindrical and coaxially fixedly connected to the anchor rod (3). The composite block (4) is a simulated surrounding rock made of concrete, rock mass specimen and anchoring agent. The pressure box (2) is equipped with a test piece for testing the radial and axial stress performance of the anchor rod (3). The test mechanism combines the anchor rod (3) and the composite block (4) to form an NPR anchor body. The machine body (1) and the pressure box (2) simulate the hydrothermal and corrosion coupling environment of the NPR anchor body. The test piece simulates the stress condition of the anchor rod (3) and obtains the performance test results. The loading and unloading mechanism is installed inside the pressure box (2) to assist the loading and unloading of the NPR anchor. The test piece includes a fixed frame (8) fixedly installed on the outer walls of both ends of the pressure box (2). A rotating disk (9) is rotatably connected to both sides of the pressure box (2). A drive groove (10) is opened in the middle of the rotating disk (9). An installation cylinder (11) is slidably connected in the horizontal direction in the drive groove (10). The outer wall of the installation cylinder (11) is prismatic. A threaded hole (12) is opened in the installation cylinder (11). A threaded groove (13) is opened on the outer wall of both ends of the anchor (3) to be threadedly connected to the threaded hole (12). The fixed frame (8) is provided with a tool to control the position of the installation cylinder (11) to achieve axial pressure and tension on the anchor (3). The driving component for the detection function is provided in the pressure box (2) for testing the radial force of the anchor rod (3). The driving component includes a sliding frame (14) and a magnetic frame (15) that are slidably connected to the inner wall of the fixed frame (8) in the horizontal direction. An elastic element (16) that is fixedly connected to the magnetic frame (15) is fixedly connected to the side of the sliding frame (14). A metal disk (17) is fixedly connected to the end of the mounting cylinder (11) away from the anchor rod (3). The metal disk (17) can be magnetically fixed to the magnetic frame (15). A transmission component is provided on the rotating disk (9) for sliding the mounting cylinder (11) horizontally in conjunction with the rotation of the mounting cylinder (11). A pulling component is provided on the fixed frame (8) for conducting a tensile test on the anchor rod (3).

2. The testing machine for the mechanical properties of prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling as described in claim 1, characterized in that: The test mechanism also includes multiple sets of three-dimensional strain gauges (5) uniformly fixedly installed on the outer wall of the anchor rod (3). The three-dimensional strain gauges (5) are fixedly connected with wires (6). The multiple sets of three-dimensional strain gauges (5) and the wires (6) are all bonded and fixed to the outer wall of the anchor rod (3) with adhesive. The composite block (4) is located outside the three-dimensional strain gauges (5) and is fixedly connected to the anchor rod (3). The inner wall of the pressure box (2) is plugged with a conductive plug (7). The multiple sets of wires (6) are output from one end of the composite block (4) and fixedly connected to the conductive plug (7).

3. The testing machine for the mechanical properties of prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling as described in claim 2, characterized in that: The transmission component includes an external gear ring (18) coaxially fixedly installed on the side of the rotating disk (9), a threaded rod (19) rotatably connected inside the fixed frame (8), the threaded rod (19) passing through the sliding frame (14) and threadedly connected to the sliding frame (14), a first gear (20) coaxially fixedly connected to one end of the threaded rod (19), the first gear (20) meshing with the external gear ring (18), a through hole (21) is opened in the middle of the magnetic suction frame (15), a first electric telescopic rod (22) is fixedly connected to the sliding frame (14), and the telescopic end of the first electric telescopic rod (22) can pass through the through hole (21).

4. The testing machine for the mechanical properties of prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling as described in claim 3, characterized in that: The pulling member includes an annular frame (23) that is movably fitted with the inner wall of the outer toothed ring (18). A drive ring (24) is rotatably connected inside the annular frame (23). The mounting cylinder (11) passes through the drive ring (24) and is slidably connected to the inner wall of the drive ring (24) in the horizontal direction. An electric push rod (25) is fixedly connected to the fixing frame (8). An mounting plate (26) is fixedly connected to the telescopic end of the electric push rod (25). Multiple sets of connecting rods (27) that are fixedly connected to the side of the drive ring (24) are fixedly connected to the mounting plate (26).

5. The testing machine for the mechanical properties of prestressed NPR anchorages in tunnels under hydrothermal-corrosion coupling as described in claim 1, characterized in that: The detection component includes an arc-shaped plate (28) that rotates and fits against the inner wall of the pressure box (2). An arc-shaped groove (29) is provided on the inner wall of the pressure box (2). An arc-shaped rod (30) that slides and connects to the inner wall of the arc-shaped groove (29) is fixedly connected to the outer wall of the arc-shaped plate (28). Multiple sets of toothed grooves (31) are evenly provided on the outer wall of the arc-shaped rod (30). A second electric telescopic rod (32) is fixedly connected to the arc-shaped plate (28). A push block (33) is fixedly connected to the telescopic end of the second electric telescopic rod (32). A rotating component for driving the arc-shaped plate (28) to rotate and adjust is provided inside the pressure box (2).

6. The testing machine for the mechanical properties of prestressed NPR anchors in tunnels under hydrothermal-corrosion coupling as described in claim 5, characterized in that: The rotating component includes a drive motor (34) fixedly mounted on the pressure box (2). Two sets of second gears (35) are rotatably connected inside the pressure box (2). Both sets of second gears (35) can mesh with the tooth groove (31). The distance between the two sets of second gears (35) is greater than the arc length of the opening of the arc plate (28) and less than the arc length of the arc plate (28) itself. A drive shaft (36) is coaxially fixedly connected to the second gear (35). A transmission belt (37) is connected between the two sets of drive shafts (36) through a pulley. The output end of the drive motor (34) is coaxially fixedly connected to any one set of drive shafts (36).

7. The testing machine for the mechanical properties of prestressed NPR anchorages in tunnels under hydrothermal-corrosion coupling as described in claim 5, characterized in that: The loading and unloading mechanism includes two sets of electric lifting platforms (38) fixedly installed in the body (1). The lifting end of the electric lifting platform (38) passes through the pressure box (2) and slides against the inner wall of the pressure box (2). The lifting end of the electric lifting platform (38) is fixedly connected to a support frame (39). The two sets of support frames (39) are symmetrically arranged on both sides of the arc plate (28).

8. The testing machine for the mechanical properties of prestressed NPR anchorages in tunnels under hydrothermal-corrosion coupling as described in claim 1, characterized in that: A rotating handle (40) is fixedly connected to the side of the rotating disk (9), and a box cover (41) is hinged to the upper side of the pressure box (2).

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