In-situ test system monitoring device and monitoring method

Abstract

The invention relates to the technical field of tunnel construction, and mainly provides an in-situ test system monitoring device and monitoring method. The monitoring device comprises a loading oil cylinder, a load sensor, a stay wire encoder and a data collector. The load sensor comprises a connecting part and a metal strain gauge, the connecting part is connected to the output end of the loading oil cylinder, and the metal strain gauge is arranged at the other end of the connecting part. The pull wire encoder comprises a contour device with a precision sensor and a pull rope, and the contour device is connected with a chassis of the loading oil cylinder. And the data collector is in communication connection with the load sensor and the stay wire encoder. The stress and displacement data obtained through monitoring are accurate, the monitoring method is rapid, interference caused by the on-site complex environment can be well resisted, and the measurement precision and stability are improved.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to an in-situ testing system monitoring device and monitoring method. Background Technology

[0002] In-situ rock mechanics testing is fundamental for obtaining rock mechanics data and performing rock mechanics parameter inversion. However, the field environment is complex and variable. Test areas often present extreme geological conditions such as high ground stress and high permeability, and the testing process often overlaps with engineering construction, resulting in adverse factors such as strong vibration and high noise in the test environment. These complex conditions pose severe challenges to the stability, reliability, and measurement accuracy of test monitoring equipment.

[0003] In related technologies, commonly used monitoring methods in rock mechanics field tests mainly include traditional contact sensors (such as strain gauges, displacement gauges, pressure cells, etc.) and some non-contact measurement methods (such as total stations, close-range photogrammetry, etc.). These are used to monitor the loads applied and received by the loading device during the test, as well as the displacement at the load output end.

[0004] However, existing monitoring methods in related technologies are complex to install and susceptible to interference from the field environment, leading to data drift or failure, and making it difficult to guarantee measurement accuracy and stability. Furthermore, the monitoring device and the loading system often operate independently, resulting in poor compatibility and calibration difficulties, which increases the complexity of on-site installation and commissioning. Summary of the Invention

[0005] This invention provides an in-situ testing system monitoring device and method. The monitored stress and displacement data are accurate, the monitoring method is rapid, and it can effectively resist interference from complex on-site environments, improving measurement accuracy and stability. The specific technical solution is as follows: In a first aspect, embodiments of the present invention provide an in-situ test system monitoring device, including a loading cylinder, wherein the cylinder body of the loading cylinder is disposed at the reaction support end of the in-situ test loading system; A load sensor includes a connecting part and a metal strain gauge. The connecting part is connected to the output end of the loading cylinder, and the metal strain gauge is disposed at the other end of the connecting part for connection with the loading end of the in-situ test loading system. A pull-wire encoder includes a profile device with a precision sensor and a pull rope with one end wound inside the profile device. The profile device is connected to the chassis of the loading cylinder, and the other end of the pull rope is used to connect to the loading end of the in-situ test loading system. The data acquisition unit is communicatively connected to the load sensor and the wire encoder.

[0006] Optionally, the output end of the loading cylinder is coaxially protruding with a threaded rod, the connecting part is cylindrical, the connecting part is provided with an internal threaded hole that matches the threaded rod, and one end is threadedly connected to the threaded rod through the internal threaded hole, and the metal strain gauge is disposed on the other end face of the connecting part.

[0007] Optionally, multiple metal strain gauges are provided and arranged at equal angular intervals around the internal threaded hole.

[0008] Optionally, it also includes an anti-loosening bolt, wherein the length of the threaded rod is greater than the length of the connecting portion, and the anti-loosening bolt is threaded to the end of the threaded rod and abuts against the connecting portion.

[0009] Optionally, the outer diameter of the anti-loosening bolt gradually increases in the direction away from the loading cylinder.

[0010] Optionally, two wire encoders are provided and arranged symmetrically with respect to the loading cylinder.

[0011] Optionally, the contouring device is detachably connected to the chassis of the loading cylinder.

[0012] Optionally, the contouring device is rotatably provided with a spool in the horizontal direction. One end of the spool is provided with a rotation sensor in the axial direction, and the other end is connected to the contouring device through a spiral spring. The pull rope is wound around the spool and one end is connected to the spool.

[0013] Optionally, it also includes a servo controller that is communicatively connected to the loading cylinder, wherein the data acquisition unit and the servo controller of the loading cylinder are integrated into the same control module.

[0014] In a second aspect, embodiments of the present invention provide a monitoring method, implemented based on the in-situ test system monitoring device described in the first aspect, comprising: After connecting the loading cylinder to the reaction support end of the in-situ test loading system, the load sensor and the loading cylinder are assembled. Connect the contour device of the pull-wire encoder to the chassis of the loading cylinder, and connect the other end of the pull rope to the loading end of the in-situ test loading system. Connect the signal lines of the load sensor and the wire encoder to the data acquisition unit; The pre-loading step for in-situ testing involves controlling the extension and retraction of the output end of the loading cylinder to drive the loading end to load and unload. The data acquisition device feeds back response load data and displacement data, which are then detected by the host computer. Once the load is determined to be stable, the in-situ test begins. After the in-situ test is completed, the loading cylinder, the load sensor, and the wire encoder are removed as needed.

[0015] Compared with the prior art, the beneficial effects of the embodiments of the present invention include at least the following: The in-situ testing system monitoring device provided in this embodiment achieves tight integration between the monitoring device and the loading system by connecting the load sensor's connector to the output end of the loading cylinder and the wire encoder's profile device to the loading cylinder's chassis. On one hand, the monitoring device is directly mounted on the loading cylinder, avoiding the complex operation of traditional monitoring devices that require additional sensor placement in the test area, thus simplifying the installation process. On the other hand, the integrated design of the monitoring device and the loading system improves the monitoring device's anti-interference capability, avoids the influence of complex on-site environments on monitoring data, and ensures measurement accuracy and stability. Furthermore, the data acquisition unit uniformly collects load and displacement data, facilitating data integration and analysis and real-time monitoring of the test process. The obtained stress and displacement data are accurate, the monitoring method is fast, and it can effectively resist interference from complex on-site environments, improving measurement accuracy and stability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the in-situ testing system monitoring device provided in an embodiment of the present invention; Figure 2 An exploded view of the monitoring device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the top structure of the connecting portion provided in an embodiment of the present invention; Figure 4 An exploded view of the structure of a draw-wire encoder provided in an embodiment of the present invention; Figure 5 A flowchart of a monitoring method provided in an embodiment of the present invention.

[0017] In the diagram: 1-Loading cylinder; 11-Chassis; 12-Threaded rod; 2-Load sensor; 21-Connecting part; 211-Internal threaded hole; 22-Metal strain gauge; 3-Wire encoder; 31-Contour device; 311-Wire wheel; 312-Rotation sensor; 313-Coil spring; 32-Wire rope; 4-Data acquisition unit; 5-Anti-detachment bolt; 6-Servo controller. 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 a part of the present invention, and not all of the 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] Figure 1 This is a schematic diagram of the structure of the in-situ testing system monitoring device provided in an embodiment of the present invention; Figure 2 An exploded view of the monitoring device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the top structure of the connecting portion provided in an embodiment of the present invention; Figure 4 This is an exploded view of the structure of a draw-wire encoder provided in an embodiment of the present invention. Figures 1 to 4 As shown, this embodiment of the invention provides an in-situ testing system monitoring device, including a loading cylinder 1, a load sensor 2, a wire encoder 3, and a data acquisition device 4.

[0020] Specifically, the loading cylinder 1 is the core power component of the entire monitoring device. The cylinder body of loading cylinder 1 is located at the reaction support end of the in-situ test loading system, providing loading power for the in-situ test. Loading cylinder 1 applies test force to the loading end through its output end. During the in-situ test, loading cylinder 1 can extend and retract according to test requirements, thereby driving the loading end to load or unload the surrounding rock of the tunnel. By placing the cylinder body of loading cylinder 1 at the reaction support end, a stable support foundation is ensured during operation, thus guaranteeing the accurate transmission of loading force.

[0021] The load sensor 2 is a key component for monitoring test stress. The load sensor 2 includes a connecting part 21 and a metal strain gauge 22. The connecting part 21 is connected to the output end of the loading cylinder 1, establishing a mechanical connection between the load sensor 2 and the loading cylinder 1. The metal strain gauge 22 is located on the other end of the connecting part 21, which is used to connect to the loading end of the in-situ test loading system; that is, the metal strain gauge 22 is located on the end face of the connecting part 21 furthest from the loading cylinder 1.

[0022] The working principle of load sensor 2 is as follows: When the loading cylinder 1 outputs a loading force, this force is transmitted to the loading end through the connecting part 21. During this process, the connecting part 21 bears compressive stress. When the material of the connecting part 21 is subjected to an external force, its shape will undergo a slight change, i.e., strain will be generated. The metal strain gauge 22 is attached to the force-bearing end face of the connecting part 21. As the connecting part 21 deforms, the metal strain gauge 22 is stretched or compressed accordingly, causing the resistance value of the metal strain gauge 22 to change accordingly. The metal strain gauge 22 outputs a voltage signal proportional to the magnitude of the force. This analog voltage signal is amplified and enhanced, then converted into a digital signal by an analog-to-digital converter, and finally transmitted to a display screen or computer through the data acquisition unit 4 to present intuitive numerical information. By measuring the actual test force F applied by the loading cylinder 1, and according to the loading area S, the stress P acting on that area of ​​the cavern can be calculated using the formula P=F / S.

[0023] The draw-wire encoder 3 is a key component for monitoring test displacement. The draw-wire encoder 3 includes a profile device 31 with a precision sensor and a draw-wire 32. One end of the draw-wire 32 is wound around the profile device 31 and fixed at the other end. The profile device 31 is connected to the base 11 of the loading cylinder 1. The other end of the draw-wire 32 is used to connect to the loading end of the in-situ test loading system. In this embodiment, the draw-wire 32 can be made of stainless steel, which has high strength and corrosion resistance, and can adapt to complex field environments.

[0024] The working principle of the wire encoder 3 is as follows: When the loading end of the in-situ test loading system is displaced under the drive of the loading cylinder 1, the wire 32 connected to the loading end extends or retracts accordingly. The movement of the wire 32 drives the precision sensor inside the contour device 31 to work, and the contour device 31 outputs an electrical signal proportional to the distance the wire 32 moves. This electrical signal can be converted to obtain the displacement, direction, or speed of the loading end. By arranging the wire encoder 3 along the radial direction of the loading cylinder 1, the displacement value along the radial loading direction of the loading cylinder 1 can be accurately monitored.

[0025] The data acquisition unit 4 is communicatively connected to the load sensor 2 and the draw-wire encoder 3, and is used to acquire, store, display, and analyze the monitoring data output by the load sensor 2 and the draw-wire encoder 3 in real time. The data acquisition unit 4 can integrate and process the stress data acquired by the load sensor 2 and the displacement data acquired by the draw-wire encoder 3, and connect to a computer via USB or other communication methods to realize the real-time transmission and display of monitoring data.

[0026] The in-situ testing system monitoring device provided in this embodiment achieves tight integration between the monitoring device and the loading system by connecting the connection part 21 of the load sensor 2 to the output end of the loading cylinder 1 and connecting the contour device 31 of the wire encoder 3 to the chassis 11 of the loading cylinder 1. On the one hand, the monitoring device is directly installed on the loading cylinder 1, avoiding the complex operation of traditional monitoring devices that require additional sensor deployment in the test area, thus simplifying the installation process. On the other hand, the integrated design of the monitoring device and the loading system improves the anti-interference capability of the monitoring device, avoids the influence of complex on-site environments on monitoring data, and ensures measurement accuracy and stability. In addition, the data acquisition unit 4 uniformly collects load and displacement data, facilitating data integration and analysis and real-time monitoring of the test process.

[0027] Furthermore, in this embodiment, a threaded rod 12 is coaxially protruding from the output end of the loading cylinder 1. The threaded rod 12 extends along the axial direction of the loading cylinder 1 and is coaxially arranged with the output end of the loading cylinder 1, ensuring that the force transmission direction is consistent with the loading direction. The outer surface of the threaded rod 12 is provided with external threads for threaded connection with the load sensor 2.

[0028] The connecting part 21 is cylindrical, possessing good structural strength and load-bearing capacity. The connecting part 21 is provided with an internally threaded hole 211 that matches the threaded rod 12, and the internally threaded hole 211 extends through the axis of the connecting part 21. One end of the connecting part 21 is threadedly connected to the threaded rod 12 through the internally threaded hole 211, achieving a reliable connection between the load sensor 2 and the loading cylinder 1. A metal strain gauge 22 is disposed on the other end face of the connecting part 21, that is, on the end face of the connecting part 21 away from the threaded rod 12.

[0029] The use of a threaded connection has the following technical advantages: First, the threaded connection has a self-locking property, making it less prone to loosening during loading and ensuring the reliability of the connection between the load sensor 2 and the loading cylinder 1. Second, the threaded connection facilitates installation and disassembly; when the load sensor 2 needs to be replaced or maintained, the disassembly and assembly operations can be completed simply by rotating the connecting part 21, greatly improving on-site maintenance efficiency. Third, the connecting part 21 and the threaded rod 12 are coaxially arranged, ensuring that the loading force is transmitted axially and avoiding the influence of eccentric loads on measurement accuracy. Finally, the metal strain gauge 22 is set on the end face of the connecting part 21, which can fully sense the compressive stress borne by the connecting part 21, improving the accuracy of stress measurement.

[0030] Furthermore, in this embodiment, multiple metal strain gauges 22 are provided and arranged at equal angular intervals around the internal threaded hole 211. Specifically, in one possible implementation of this embodiment, four metal strain gauges 22 are provided, and the four metal strain gauges 22 are arranged at equal angular intervals of 90 degrees around the axis of the internal threaded hole 211, that is, the four metal strain gauges 22 are symmetrically distributed in pairs.

[0031] In actual monitoring, the resistance change of a single metal strain gauge 22 is extremely small, making direct measurement difficult. This embodiment arranges multiple metal strain gauges 22 at equal angular intervals around the internal threaded hole 211 to form a Wheatstone bridge structure. When the connection 21 is subjected to external force, due to the different positions of the metal strain gauges 22, some strain gauges 22 are stretched while others are compressed, disrupting the bridge balance and resulting in a voltage signal output proportional to the magnitude of the applied force.

[0032] The use of multiple metal strain gauges 22 arranged at equal angular intervals offers the following technical advantages: Firstly, the bridge structure effectively amplifies the output signal, improving measurement sensitivity and enabling accurate detection of even minute stress changes. Secondly, the equally spaced metal strain gauges 22 automatically counteract interference from environmental factors such as temperature and humidity changes, enhancing measurement stability and reliability. Furthermore, the coordinated operation of multiple metal strain gauges 22 eliminates measurement errors caused by uneven material distribution or stress at the connection point 21. The entire load acquisition process is completed within milliseconds, achieving seamless and rapid conversion between force, electricity, and data, meeting the real-time monitoring requirements of in-situ testing.

[0033] Furthermore, in this embodiment, the length of the threaded rod 12 is greater than the length of the connecting portion 21. When the connecting portion 21 is threadedly connected to the threaded rod 12 through the internal threaded hole 211, the end of the threaded rod 12 will protrude from the end face of the connecting portion 21. The monitoring device in this embodiment also includes an anti-loosening bolt 5, which is threadedly connected to the end of the threaded rod 12 and abuts against the connecting portion 21.

[0034] Specifically, during installation, first, the connecting part 21 is screwed into the threaded rod 12, so that the connecting part 21 is in contact with the output end of the loading cylinder 1; then, the anti-loosening bolt 5 is screwed into the end of the threaded rod 12, so that the anti-loosening bolt 5 abuts against the end face of the connecting part 21 away from the loading cylinder 1. The anti-loosening bolt 5 serves to lock and prevent loosening, preventing the connecting part 21 from falling off the threaded rod 12 during the test due to vibration or repeated loading and unloading.

[0035] The technical solution of using anti-loosening bolt 5 has the following technical effects: First, the anti-loosening bolt 5 is threadedly connected to the threaded rod 12, forming a double locking structure with the connecting part 21, which greatly improves the reliability of the connection between the load sensor 2 and the loading cylinder 1, and will not loosen or fall off even during high-intensity and long-term tests; Second, the setting of anti-loosening bolt 5 does not affect the normal operation of the load sensor 2, the loading force is still transmitted through the connecting part 21, and the metal strain gauge 22 can still accurately sense stress changes; Third, when it is necessary to disassemble the load sensor 2, it is only necessary to first unscrew the anti-loosening bolt 5 and then unscrew the connecting part 21, which is simple to operate and convenient for on-site maintenance.

[0036] Furthermore, in this embodiment, the outer diameter of the anti-loosening bolt 5 gradually increases in the direction away from the loading cylinder 1, forming a frustum-shaped structure. Specifically, the diameter of the anti-loosening bolt 5 is smaller at the end near the connecting part 21 and larger at the end away from the connecting part 21, giving it an overall conical or frustum-shaped appearance.

[0037] The structure of the anti-loosening bolt 5 with gradually increasing outer diameter has the following technical advantages: In the in-situ test loading system, the other end of the load sensor 2 needs to be connected to the loading end, which usually adopts a structure such as an arc-shaped pressure plate. The frustum-shaped structure of the anti-loosening bolt 5 increases the contact area with the loading end (such as the arc-shaped pressure plate), allowing the loading force to be transmitted more evenly and avoiding stress concentration. At the same time, the larger contact area improves the force transmission efficiency, reduces local wear in the contact area, and extends the service life of the equipment. In addition, the frustum-shaped structure is easy to match with loading ends of different shapes, improving the applicability and versatility of the monitoring device.

[0038] Furthermore, in this embodiment, two pull-wire encoders 3 are provided and arranged symmetrically relative to the loading cylinder 1. Specifically, the two pull-wire encoders 3 are respectively arranged on both sides of the loading cylinder 1, symmetrically distributed along the radial direction of the loading cylinder 1. The contour devices 31 of the two pull-wire encoders 3 are respectively connected to the chassis 11 of the loading cylinder 1, and the pull ropes 32 of the two pull-wire encoders 3 are respectively connected to the loading end of the in-situ test loading system.

[0039] The use of two symmetrically arranged draw-wire encoders 3 has the following technical advantages: First, the two draw-wire encoders 3 can simultaneously monitor the displacement of the loading end from two directions, improving the comprehensiveness and accuracy of displacement measurement; second, the symmetrically arranged draw-wire encoders 3 can mutually verify each other, and when there is a large difference in the measurement data of the two draw-wire encoders 3, it can be determined whether there is an abnormality such as sensor failure or loading end misalignment; third, even if one draw-wire encoder 3 fails, the other draw-wire encoder 3 can continue to work, ensuring the continuity and reliability of monitoring; finally, the symmetrical arrangement of the two draw-wire encoders 3 can eliminate measurement errors caused by rotation or offset of the loading end, improving the accuracy of displacement measurement.

[0040] Furthermore, in this embodiment, the contouring device 31 is detachably connected to the chassis 11 of the loading cylinder 1. Specifically, the chassis 11 of the loading cylinder 1 is provided with positioning holes, and the contouring device 31 is connected to the chassis 11 by bolts passing through the positioning holes. The positioning holes are symmetrically arranged relative to the loading cylinder 1, providing accurate positioning for the installation of the wire encoder 3.

[0041] The detachable connection method offers the following technical advantages: First, it facilitates the installation and removal of the wire encoder 3, allowing for quick and easy operation during equipment maintenance, sensor replacement, or equipment removal after testing. Second, the positioning holes ensure consistent positioning of the wire encoder 3 during each installation, guaranteeing measurement repeatability and comparability. Third, the detachable connection gives the monitoring device a modular design, allowing for flexible configuration of the number and position of the wire encoders 3 according to different testing needs. Finally, the detachable connection reduces the risk of the entire monitoring device becoming unusable due to a fault in a single wire encoder 3; simply replacing the faulty component restores normal operation.

[0042] Furthermore, in this embodiment, the contouring device 31 is rotatably equipped with a reel 311 in the horizontal direction. The reel 311 is the core transmission component of the contouring device 31, and its outer periphery is provided with threads or grooves for winding the pull rope 32. A rotation sensor 312 is provided at one end of the reel 311 in the axial direction, and the other end is connected to the contouring device 31 via a spiral spring 313. The pull rope 32 is tied to the reel 311 and one end is connected to the reel 311.

[0043] Specifically, the rotation sensor 312 can be a hybrid or conductive plastic rotary potentiometer used to detect the rotation angle of the reel 311 and convert it into an electrical signal. One end of the spiral spring 313 is connected to the reel 311, and the other end is connected to the housing of the contouring device 31. The spiral spring 313 is in a preloaded state, providing a continuous restoring torque to the reel 311.

[0044] The working process of the pull-wire encoder 3 is as follows: When the loading end of the in-situ test loading system moves outward (loading process), the pull rope 32 is pulled out, and the pulley 311 rotates in one direction under the drive of the pull rope 32, while the spiral spring 313 is further compressed to store energy; the rotation sensor 312 detects the rotation angle of the pulley 311 and outputs an electrical signal proportional to the rotation angle. The length of the pull rope 32 extending, i.e., the displacement of the loading end, can be calculated based on the diameter of the pulley 311. When the loading end moves inward (unloading process), the spiral spring 313 releases the stored elastic potential energy, driving the pulley 311 to rotate in the opposite direction, and retracting the pull rope 32 into the contour device 31; at the same time, the rotation sensor 312 detects the reverse rotation angle of the pulley 311 and outputs a corresponding electrical signal.

[0045] The draw-wire encoder 3 with this structure has several advantages. First, the spiral spring 313 ensures that the draw-wire 32 remains taut throughout the measurement process, avoiding measurement errors caused by slack in the draw-wire 32 and ensuring flexible measurement of the extension and retraction of the device. Second, the rotation sensor 312 converts the mechanical rotation of the reel 311 into an electrical signal, enabling non-contact displacement measurement and improving measurement accuracy and reliability. Third, the spiral spring 313 allows the draw-wire encoder 3 to automatically follow the movement of the loading end without additional power. Finally, this structure gives the draw-wire encoder 3 the characteristics of small installation size, compact structure, large measurement stroke, and high accuracy. Its measurement stroke ranges from a few millimeters to tens of centimeters, making it suitable for various in-situ testing applications in complex environments.

[0046] Furthermore, in this embodiment, the monitoring device also includes a servo controller 6 that is communicatively connected to the loading cylinder 1. The servo controller 6 is used to control the movement of the loading cylinder 1, including controlling parameters such as the extension and retraction speed, extension and retraction position, and output force of the loading cylinder 1. The data acquisition unit 4 and the servo controller 6 of the loading cylinder 1 are integrated into the same control module.

[0047] Specifically, the data acquisition unit 4 and the servo controller 6 are integrated to form a unified control terminal, which is connected to a computer via USB or other communication methods. Test personnel can monitor the displacement and load data collected by the load sensor 2 and the wire encoder 3 in real time through the computer terminal, and can flexibly adjust the output of the loading cylinder 1 based on the monitoring data to achieve precise control of the test process.

[0048] The technical solution integrating the data acquisition unit 4 and the servo controller 6 offers the following advantages: First, integrating data acquisition and loading control into the same control module enables real-time interaction between monitoring data and control commands, facilitating various loading modes such as force-controlled loading and displacement-controlled loading. Second, the integrated design reduces the number of field devices and connecting cables, simplifying the installation and commissioning process and lowering system complexity. Third, the unified control terminal allows test personnel to perform monitoring and control operations on a single interface, improving the convenience of test operations. Finally, the data acquisition unit 4 adopts a modular design, with each data acquisition unit 4 constituting a module. Multiple data acquisition units 4 can be configured for multiple loading cylinders 1 in the in-situ test loading system. When a module fails, only that acquisition unit needs to be replaced, greatly improving system maintenance efficiency and adapting to various online monitoring sites. The data acquisition unit 4 also includes a storage module for storing the integrated and processed load and displacement information, ensuring real-time data storage without loss.

[0049] Figure 5 A flowchart illustrating a monitoring method provided in an embodiment of the present invention. Figure 5As shown, embodiments of the present invention also provide a monitoring method, based on, as Figures 1 to 4 The in-situ test system monitoring device shown includes the following steps: Step S1: Assembly of the load sensor.

[0050] After connecting the loading cylinder 1 to the reaction support end of the in-situ test loading system, the load sensor 2 and the loading cylinder 1 are assembled.

[0051] Specifically, first, install the loading cylinder 1 onto the reaction support end of the in-situ test loading system, ensuring the accurate installation position and angle of the loading cylinder 1 and that the cylinder body is securely fixed. Then, align the connecting part 21 of the load sensor 2 with the output end of the loading cylinder 1. Specifically, align the internal threaded hole 211 of the connecting part 21 with the threaded rod 12 at the output end of the loading cylinder 1, and rotate the connecting part 21 to thread it onto the threaded rod 12 until the connecting part 21 is in contact with the output end of the loading cylinder 1. If the monitoring device is equipped with an anti-loosening bolt 5, after the connecting part 21 is installed, screw the anti-loosening bolt 5 into the end of the threaded rod 12 so that the anti-loosening bolt 5 abuts against the connecting part 21 to complete the locking.

[0052] The technical benefits of this step are as follows: by installing the loading cylinder 1 first and then the load sensor 2, the operating space and convenience during the installation of the load sensor 2 are ensured; the double fixing of the threaded connection and the anti-loosening bolt 5 ensures the reliability of the connection between the load sensor 2 and the loading cylinder 1, and avoids loosening or falling off due to vibration or repeated loading and unloading during the test.

[0053] Step S2: Installation of the wire encoder.

[0054] Connect the contour device 31 of the pull-wire encoder 3 to the chassis 11 of the loading cylinder 1, and connect the other end of the pull rope 32 to the loading end of the in-situ test loading system.

[0055] Specifically, the contour device 31 with a precision sensor of the wire encoder 3 is fixed on the chassis 11 of the loading cylinder 1. It can be installed and positioned through the preset positioning holes on the chassis 11, and the contour device 31 is detachably connected to the chassis 11 using bolts. If two wire encoders 3 are provided, the two wire encoders 3 are respectively installed at the positioning holes on both sides of the loading cylinder 1, ensuring that the two wire encoders 3 are symmetrically arranged relative to the loading cylinder 1. Then, one end of the pull rope 32 (stainless steel pull rope) of the wire encoder 3 is pulled out, and the other end of the pull rope 32 is fixed to the loading end of the in-situ test loading system, such as the arc pressure plate or other structures that are in direct contact with the surrounding rock, by bolts or other connection methods.

[0056] The technical benefits of this step are as follows: the installation of the wire encoder 3 through the positioning hole ensures the accuracy and consistency of the installation position; the two symmetrically arranged wire encoders 3 can monitor displacement from two directions simultaneously, improving the comprehensiveness and accuracy of the measurement; after the wire 32 is connected to the loading end, the wire encoder 3 can follow the movement of the loading end to monitor displacement.

[0057] Step S3: Signal line connection and system integration.

[0058] Connect the signal lines of load sensor 2 and wire encoder 3 to data acquisition unit 4.

[0059] Specifically, connect the signal output terminal of load sensor 2 to the corresponding input port of data acquisition unit 4 via a signal line; connect the signal output terminal of pull-wire encoder 3 (if two are provided, connect them separately) to the corresponding input port of data acquisition unit 4 via a signal line. If the monitoring device is equipped with servo controller 6, integrate data acquisition unit 4 and servo controller 6 into the same control terminal, and connect this control terminal to the host computer (computer) via USB or other communication methods. After completing the connection, check whether the signal lines are securely connected to ensure that the signal transmission channel is unobstructed.

[0060] The technical effect of this step is that by connecting the signal lines of the load sensor 2 and the wire encoder 3 to the data acquisition unit 4, centralized acquisition of monitoring data is achieved; the integration of the data acquisition unit 4 with the servo controller 6 enables the monitoring data to be correlated with the load control in real time, which facilitates precise load control and monitoring of the test process.

[0061] Step S4: Preloading and test start-up.

[0062] The pre-loading step of the in-situ test involves controlling the extension and retraction of the output end of the loading cylinder 1 to drive the loading end to load and unload. The response load data and displacement data are fed back through the data acquisition device 4 and detected by the host computer. Once the load is determined to be stable, the in-situ test begins.

[0063] Specifically, before the formal test begins, a pre-loading operation is performed. The host computer sends control commands to the servo controller 6, controlling the loading cylinder 1 to perform small-amplitude extension and retraction movements, driving the loading end to pre-load and pre-unload the surrounding rock. During the pre-loading process, the data acquisition unit 4 collects load data output from the load sensor 2 and displacement data output from the wire encoder 3 in real time, and transmits this data to the host computer for display and analysis. The test personnel observe the monitoring data displayed on the host computer to determine whether the sensors are working properly and whether the data is stable. Once the monitoring data is stable (e.g., the load data no longer drifts and the displacement data responds normally), the formal in-situ test can begin.

[0064] The technical benefits of this step are as follows: the preloading step can verify the working status of each component of the monitoring device, and promptly detect and eliminate potential faults; by preloading, the sensor enters a stable working state, eliminating the drift and interference of the initial state, and improving the accuracy and reliability of the formal test data; the real-time monitoring and feedback mechanism enables the test personnel to keep abreast of the equipment status, ensuring the safety of the test process.

[0065] Step S5: End of test and dismantling of equipment.

[0066] After the in-situ test is completed, the loading cylinder 1, load sensor 2 and wire encoder 3 are removed as required.

[0067] Specifically, after the in-situ test is completed, first stop the movement of the loading cylinder 1 to put the loading system in an unloaded state. Then, dismantle the equipment in the reverse order of installation: first, separate the pull rope 32 of the pull-wire encoder 3 from the loading end, and remove the contour device 31 from the chassis 11; then, unscrew the anti-loosening bolt 5 (if any), and unscrew the connecting part 21 to separate the load sensor 2 from the loading cylinder 1; finally, disassemble the loading cylinder 1 as needed. The disassembled load sensor 2 and pull-wire encoder 3 should be covered with protective covers or other safety devices and properly stored for future use.

[0068] The technical benefits of this step are: the standardized dismantling sequence (dismantling the sensor first, then the hydraulic cylinder) avoids equipment damage and protects the precision sensor; the protective treatment of the sensor extends the service life of the equipment; and the detachable design allows the monitoring device to be reused, reducing testing costs.

[0069] The monitoring method provided in this embodiment achieves accurate monitoring of load and displacement during in-situ testing through standardized installation, connection, preloading, testing, and dismantling procedures. This method is simple to operate and follows standardized procedures, effectively ensuring the accuracy and reliability of monitoring data. Simultaneously, the preloading step ensures the safety of the testing process, and the standardized dismantling procedure protects the monitoring equipment, demonstrating significant engineering practical value.

[0070] In summary, the in-situ testing system monitoring device and method provided in the embodiments of the present invention have the following beneficial effects: 1. By placing the load sensor 2 at the output end of the loading cylinder 1 and the wire encoder 3 on the chassis 11 of the loading cylinder 1, the monitoring device and the loading system are tightly integrated, which greatly ensures the safety of the monitoring device, simplifies the installation process, and improves the anti-interference capability of the monitoring device.

[0071] 2. The load sensor 2 forms a bridge structure by arranging metal strain gauges 22 at equal angles, which can effectively amplify the output signal and automatically cancel the interference of environmental factors such as temperature and humidity, improve the sensitivity and stability of the measurement, and realize the millisecond-level rapid conversion of "force-electricity-data".

[0072] 3. The pull-wire encoder 3 adopts a combination structure of pulley 311, rotary sensor 312 and spiral spring 313, which has the characteristics of small installation size, compact structure, large measuring stroke and high accuracy. The spiral spring 313 ensures that the pull rope 32 is always taut, and can flexibly measure the extension and retraction process of the device.

[0073] 4. The data acquisition unit 4 and the servo controller 6 are integrated into the same control module, which facilitates the installation and debugging of the test site. It realizes real-time interaction between monitoring data and control commands, and supports multiple loading modes such as force-controlled loading and displacement-controlled loading, ensuring the safety of the test process and the stability of the device.

[0074] 5. The data acquisition unit 4 adopts a modular design. If a module fails, only the acquisition unit needs to be replaced, which greatly improves the system maintenance efficiency and can adapt to the needs of various online monitoring sites.

[0075] 6. The monitoring method and process are standardized. The pre-loading step is used to check the equipment status and bring the sensor into a stable working state, which ensures the accuracy of the test data and the safety of the test process.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A monitoring device for an in-situ testing system, characterized in that, include: Loading cylinder (1), the cylinder body of the loading cylinder (1) is set at the reaction support end of the in-situ test loading system; The load sensor (2) includes a connecting part (21) and a metal strain gauge (22). The connecting part (21) is connected to the output end of the loading cylinder (1), and the metal strain gauge (22) is disposed at the other end of the connecting part (21) for connection with the loading end of the in-situ test loading system. The pull-wire encoder (3) includes a profile device (31) with a precision sensor and a pull rope (32) with one end wound inside the profile device (31). The profile device (31) is connected to the chassis (11) of the loading cylinder (1), and the other end of the pull rope (32) is used to connect to the loading end of the in-situ test loading system. The data acquisition unit (4) is communicatively connected to the load sensor (2) and the wire encoder (3).

2. The in-situ testing system monitoring device according to claim 1, characterized in that, The output end of the loading cylinder (1) is coaxially provided with a threaded rod (12). The connecting part (21) is cylindrical. The connecting part (21) is provided with an internal threaded hole (211) that matches the threaded rod (12). One end is threadedly connected to the threaded rod (12) through the internal threaded hole (211). The metal strain gauge (22) is provided on the other end face of the connecting part (21).

3. The in-situ testing system monitoring device according to claim 2, characterized in that, Multiple metal strain gauges (22) are provided and are arranged at equal angular intervals around the internal threaded hole (211).

4. The in-situ testing system monitoring device according to claim 2, characterized in that, It also includes an anti-loosening bolt (5), the length of the threaded rod (12) is greater than the length of the connecting part (21), and the anti-loosening bolt (5) is threaded to the end of the threaded rod (12) and abuts against the connecting part (21).

5. The in-situ testing system monitoring device according to claim 4, characterized in that, The outer diameter of the anti-loosening bolt (5) gradually increases in the direction away from the loading cylinder (1).

6. The in-situ testing system monitoring device according to any one of claims 1 to 5, characterized in that, Two pull-wire encoders (3) are provided and are arranged symmetrically relative to the loading cylinder (1).

7. The in-situ testing system monitoring device according to claim 6, characterized in that, The contouring device (31) is detachably connected to the chassis (11) of the loading cylinder (1).

8. The in-situ testing system monitoring device according to claim 6, characterized in that, The contouring device (31) is rotatably provided with a spool (311) in the horizontal direction. A rotation sensor (312) is provided at one end of the spool (311) in the axial direction, and the other end is connected to the contouring device (31) through a spiral spring (313). The pull rope (32) is wound around the spool (311) and one end is connected to the spool (311).

9. The in-situ testing system monitoring device according to any one of claims 1 to 5, characterized in that, It also includes a servo controller (6) that is communicatively connected to the loading cylinder (1), and the data acquisition unit (4) and the servo controller (6) of the loading cylinder (1) are integrated in the same control module.

10. A monitoring method, implemented based on the in-situ testing system monitoring device according to any one of claims 1 to 9, characterized in that, include: After the loading cylinder (1) is connected to the reaction support end of the in-situ test loading system, the load sensor (2) is assembled with the loading cylinder (1). Connect the contour device (31) end of the pull-wire encoder (3) to the loading end of the in-situ test loading system; Connect the signal lines of the load sensor (2) and the wire encoder (3) to the data acquisition unit (4); The pre-loading step of the in-situ test is to control the extension and retraction of the output end of the loading cylinder (1) to drive the loading end to load and unload. The response load data and displacement data are fed back through the data acquisition device (4) and detected by the host computer. When the load is determined to be stable, the in-situ test is started. After the in-situ test is completed, the loading cylinder (1), the load sensor (2) and the wire encoder (3) are removed as required.

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