Simulation test device for distributed optical fiber rock-soil coupling performance

Abstract

The utility model discloses a distributed optical fiber rock-soil coupling performance simulation test device, which is applied to the technical field of rock-soil engineering and comprises a frame, a confining pressure oil cylinder, a transmission device, a front clamping seat and a rear clamping seat, a cross beam at one end of the frame is embedded in the confining pressure oil cylinder; the front clamping seat is slidably connected with the inner side wall of the cross beam at the other end of the frame and fixedly connected with the transmission device; the transmission device is fixedly connected with a vertical beam at the other end of the frame; a guide rail is arranged on the top face of a cross beam of the frame. The rear clamping base is slidably connected with the guide rail through guide wheels. The centers of the confining pressure oil cylinder, the front clamping seat and the rear clamping seat are coaxially aligned; a displacement sensor and a tension sensor are fixed on the rear clamping seat; and a distributed optical fiber sensor is arranged in the confining pressure oil cylinder. The device can adapt to a drawing thread of a distributed optical fiber test, simulates the real confining pressure condition of a rock-soil body, and facilitates the realization of the real condition simulation of the coupling of the distributed optical fiber and rock-soil, thereby obtaining reliable performance test data.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical engineering, and more specifically to a distributed optical fiber geotechnical coupling performance simulation test device. Background Art

[0002] With the rapid development of the national economy, various types of infrastructure construction are also in full swing, and the safety issues of geological and geotechnical engineering have become an important research topic today. It has become an urgent requirement for engineering development to carry out corresponding safety monitoring, prediction and evaluation of the stability of geological and geotechnical engineering. At present, conventional internal deformation monitoring of rock and soil bodies often uses strain gauges, convergence meters, multi-point displacement meters, inclinometers and inclinometers. These equipment involve rock and soil surface convergence monitoring technology, stress change monitoring technology, TDS rock and soil deformation monitoring technology, GPS rock and soil deformation monitoring technology, coupling monitoring technology, etc. Among them, traditional monitoring instruments such as differential resistance, steel string, resistance strain gauge and induction sensor are easily disturbed by external conditions, easily corroded, and have poor long-term monitoring stability. They cannot meet the requirements of modern engineering monitoring, which greatly restricts researchers' understanding of the internal deformation mechanism of rock and soil bodies.

[0003] In recent years, distributed fiber optic sensing monitoring technology has developed rapidly and has become a new monitoring technology. Distributed fiber optic sensors are sensors that use unique distributed fiber optic detection technology to measure or monitor the spatial distribution and time-varying information along the fiber optic transmission path. It has broken through the technical difficulties of traditional detection technology in achieving distributed continuous monitoring, and has become a hot technology in the field of geotechnical engineering monitoring and detection with its advantages of full distribution, quasi-real-time, anti-interference, and high durability. Since there is still a lot of room for development in the application of optical sensing technology in rock and soil deformation monitoring, further experimental research is needed to explore better monitoring effects.

[0004] Generally, the friction characteristics of the interface between the anchor body and the reinforced soil are understood through the pull-out test, so as to test the coupling performance of the distributed optical fiber sensor in geotechnical monitoring. At present, a set of methods and systems for simulating the coupling performance of distributed optical fiber geotechnical sensors has not been fully designed in the market, and the following problems cannot be solved well:

[0005] Mechanical structure limitations: Most experimental processes use a drawing device used in production to test the tensile capacity of metal and non-metallic materials. The characteristic of this type of drawing device is that they implement the drawing process in the vertical direction, which limits the actual test length of the drawn material. At the same time, due to the relatively simple fixture of the drawing device, the drawing requirements of different materials cannot be met during the drawing process. Some materials are damaged in the mismatched fixture and affect the measured results. Although there have been some experiments that have made some modifications to the existing drawing equipment, adopted a horizontal drawing method with flat ground, and designed some fixtures suitable for special materials, it has still not been possible to achieve changes in threads and diversity in fixtures.

[0006] Limitations of test functions: During the distributed optical fiber rock-soil coupling simulation test through the assembled pulling device, it is necessary to ensure that the optical fiber can smoothly pass through the core area of ​​the rock-soil body. The test of different soil samples requires the construction of multiple experimental environments, and the process of artificial filling and compacting the rock-soil samples to be tested greatly prolongs the preparation period of the experiment, and it is easy to cause errors in the experimental results during these processes. In addition, during the pulling test, as the applied pulling force continues to increase, the shear layer at the interface between the distributed optical fiber and the rock-soil is completely destroyed, and then the interface between the distributed optical fiber and the sand and soil will have relative sliding, at this time the interface between the distributed optical fiber and the rock-soil body will be peeled off, which will cause a significant distortion of the measurement data results.

[0007] Intelligence of equipment: Many factors will restrict the experimental results during the test, such as the monitoring of rock and soil humidity and temperature during the pull-out test, and the use of a higher-precision micrometer to detect the relative displacement between the optical fiber and the rock and soil. How to accurately collect the test results through a computer and be able to process and analyze the data under a scientific system. These are the current problems in the intelligence of pull-out test equipment and the directions that need to be broken through.

[0008] Therefore, how to achieve accurate simulation testing of the coupling performance of distributed optical fiber sensors in geotechnical monitoring is an urgent problem to be solved by those skilled in the art. Utility Model Content

[0009] In view of this, the utility model provides a distributed optical fiber rock-soil coupling performance simulation test device, which can adapt to the pulling thread of distributed optical fiber testing, simulate the actual rock and soil confining pressure conditions, and help to realize the real situation simulation of the coupling between distributed optical fiber and rock and soil, so as to obtain reliable optical fiber performance test data.

[0010] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0011] A distributed optical fiber rock-soil coupling performance simulation test device, comprising: a frame, a confining pressure cylinder, a transmission device, a front clamp seat and a rear clamp seat;

[0012] The crossbeam at one end of the frame is embedded in the confining pressure cylinder; the front clamping seat is slidably connected to the inner side wall of the crossbeam at the other end of the frame, and is fixedly connected to the transmission device; the transmission device is slidably connected to the inner side wall of the crossbeam at the other end of the frame, and is fixedly connected to the front clamping seat;

[0013] A guide rail is provided on the top surface of the crossbeam of the frame, and the rear clamp seat is slidably connected to the guide rail via a guide wheel; the confining pressure cylinder, the front clamp seat and the rear clamp seat are coaxially aligned;

[0014] A displacement sensor and a tension sensor are fixed on the rear clamp seat; and a distributed optical fiber sensor is arranged in the confining pressure cylinder.

[0015] Preferably, the confining pressure cylinder includes a confining pressure cylinder body, a detachable sample positioning chamber, a confining pressure end cover and a plurality of fixing nuts; the crossbeam of the frame is embedded in the confining pressure cylinder body; a movable clamping position is provided on the inner wall of the confining pressure cylinder body, and the detachable sample positioning chamber is fixed to the movable clamping position by the evenly distributed fixing bolts; the confining pressure end cover seals the opening of the confining pressure cylinder body. The removable sample positioning chamber contains rock and soil samples. There is a sealing gasket or a sealing ring between the confining pressure end cover and the opening of the confining pressure cylinder body to prevent the leakage of hydraulic oil and ensure the sealing between the two. The removable sample positioning chamber is loaded with rock and soil samples, and the distributed optical fiber runs through the central axis of the rock and soil samples and passes through the confining pressure end cover, and a plurality of distributed optical fiber sensors are fixed on the distributed optical fiber in the removable sample positioning chamber.

[0016] Preferably, the transmission device includes a pull rod, a movable vertical beam and a servo motor; the two ends of the movable vertical beam are slidably connected to the inner wall of the cross beam of the frame, one side of the movable vertical beam is fixedly connected to the front clamp seat through the pull rod, and the other side is connected to the servo motor through a transmission structure; the servo motor is fixed on the frame away from one end of the rear clamp seat.

[0017] Preferably, the transmission structure includes a screw and a nut, the nut is sleeved on the screw and fixed on the moving vertical beam, and one end of the screw is fixedly connected to the output shaft of the motor. The rotation of the servo motor drives the screw to rotate, and the nut moves on the screw, driving the moving vertical beam to move. By controlling the rotation speed of the servo motor, the moving speed of the moving vertical beam can be adjusted.

[0018] Preferably, the confining pressure cylinder also includes a hydraulic device and a cylinder, which are fixed on the frame at one end of the confining pressure cylinder body; the cylinder is connected to the hydraulic device to supply oil to the hydraulic device; the hydraulic device is connected to the confining pressure cylinder body to adjust the pressure inside the confining pressure cylinder body; a through hole is provided on the confining pressure end cover, and a temperature sensor and a humidity sensor are arranged on the inner side of the confining pressure end cover.

[0019] The hydraulic device includes a piston, a hydraulic pump, a hydraulic motor, an electromagnetic pilot valve and an electric ball valve. The cylinder is connected to the confining pressure cylinder by an oil pipe through the hydraulic device, wherein the electromagnetic pilot valve, the electric ball valve and the hydraulic pump pump the hydraulic oil in the cylinder into the confining pressure cylinder, or the electromagnetic pilot valve, the electric ball valve and the hydraulic motor pump the hydraulic oil in the confining pressure cylinder into the cylinder, thereby adjusting the flow direction and pressure of the hydraulic oil, and controlling the advancement and recovery of the piston set in the confining pressure cylinder by injecting or extracting the hydraulic oil, thereby realizing accurate adjustment of the confining pressure value of the confining pressure cylinder, ensuring the smooth operation and flexible control of the confining pressure system, and meeting the requirements of applying different confining pressures to the samples in the card disassembly sample positioning chamber under different experimental conditions.

[0020] Preferably, it also includes a computer controller, which is electrically connected to the servo motor, the displacement sensor, the tension sensor, the distributed optical fiber sensor, the temperature sensor and the humidity sensor.

[0021] Preferably, a protective cover is provided at one end of the frame on which the front clamp seat is installed, and the protective cover is slidably connected to the guide rail. The protective cover can be moved and fixed on the frame through a built-in guide wheel, and the safety of the tester during the pulling process is ensured by the movement of the protective cover, so as to prevent the pulled material and rock and soil sample from being splashed due to cracking.

[0022] Preferably, the bottom surface of the crossbeam of the frame is provided with a plurality of symmetrical legs for fixing and supporting the test device.

[0023] It can be seen from the above technical solutions that, compared with the prior art, the utility model discloses a distributed optical fiber rock-soil coupling performance simulation test device, which automatically collects test data in real time, can monitor and summarize various test data through a computer controller, and output a control signal to control the adjustment of test conditions. Compared with the traditional simple optical fiber rock-soil coupling experimental environment, it replaces some cumbersome test processes such as observation and recording data, manual pulling instruments, and multi-terminal data collection, and realizes high-precision data input and output from the input end and the collection end, improves the test efficiency and ensures the test quality; by setting a confining pressure cylinder and a detachable sample positioning chamber, it can simulate the existence of confining pressure in a real rock-soil environment, improve the coupling performance of the distributed optical fiber and its surrounding rock-soil, and the obtained optical fiber monitoring data will be more reliable and real data results, which solves the problem of continuous increase in the applied pulling force during the pulling experiment. The shear layer of the interface between the distributed optical fiber and the rock and soil is completely destroyed, and then the interface between the distributed optical fiber and the sand and soil produces relative sliding, and the interface between the distributed optical fiber and the rock and soil will be peeled off, resulting in a large distortion of the measurement data results. At the same time, the rock and soil samples can be replaced to achieve rapid testing of different rock and soil environments; the front clamp and the rear clamp used in conjunction in the horizontal frame change the limitations of the traditional vertical pulling device on the thread of the pulling material, and liberate the actual test length of the pulling material. At the same time, the guide rail is designed on the metal frame, and the guide wheel is designed on the rear clamp to facilitate the change of the thread of the pulling test optical fiber during the test; the distributed optical fiber sensor is buried in the rock and soil in the detachable sample positioning chamber to sense the deformation degree of the rock and soil, and the coupling between the distributed optical fiber sensor and the rock and soil, as well as the stress transfer law between the distributed optical fiber and the rock and soil, is studied by changing the external simulated environment and the confining pressure environment. Provide scientific guidance for the application of distributed optical fiber sensing technology in rock and soil deformation monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 The accompanying drawing is a schematic structural diagram of a distributed optical fiber rock-soil coupling performance simulation test device provided by the present invention;

[0026] Figure 2 The accompanying drawing is a schematic diagram of the structure of the confining pressure cylinder provided by the present invention;

[0027] Figure 3 The accompanying drawing is a schematic diagram of the connection structure of the control system provided by the present invention.

[0028] In the attached drawings: 1-frame, 2-leg, 3-protective cover, 4-movable vertical beam, 5-front clamping seat, 6-rear clamping seat, 7-guide rail, 8-confining pressure cylinder, 81-detachable sample positioning chamber, 82-fixing nut, 83-confining pressure cylinder body, 9-pull rod, 10-guide wheel. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] The utility model discloses a distributed optical fiber rock-soil coupling performance simulation test device, including a test loading part, a transmission part, and a control monitoring part. The test loading part and the transmission part are both connected to the control monitoring part, the test loading part is connected to the transmission part, and the transmission part is placed on a horizontal metal frame in the test loading part for easy support.

[0031] The test loading part includes a frame 1, legs 2, a front clamp seat 5, a rear clamp seat 6, a guide wheel 10, a guide rail 7, a confining pressure cylinder 8, a hydraulic device and a protective cover 3. The frame 1 can be a metal frame, the frame 1 is combined with the legs 2, the front clamp seat 5 is fixed on the horizontal beam of the frame 1, the rear clamp seat 6 is combined with the guide wheel 10, the guide rail 7 is arranged above the frame 1 and combined with the guide wheel 10, the confining pressure cylinder 8 is embedded in the frame 1, covers the beam of the frame 1, the center of the annular confining pressure cylinder 8 is coaxial with the center of the frame 1 (the symmetrical dividing line of the two beams of the frame 1), the hydraulic device is connected to the confining pressure cylinder, and the protective cover 3 is connected to the guide rail 7.

[0032] By means of the laterally movable guide wheel 10 and guide rail 7, and combining the rear clamp seat 6 with the guide wheel 10, the distance between the front clamp seat 5 and the rear clamp seat 6 can be changed by moving the guide wheel 10 on the guide rail 7, and the actual test length of the distributed optical fiber involved in the drawing test can be adjusted, thereby solving the problem that the traditional drawing device has great limitations on the thread of the drawing material when completing the drawing process in the vertical direction. At the same time, the fixed design of the frame 1 makes the clamp seat, confining pressure cylinder, and distributed optical fiber center coaxial to ensure the accuracy of the test process.

[0033] Frame 1 is a metal frame in the form of pressure-sensitive load, which is the main structure of the device and is used to support and fix other components, such as legs, protective covers, movable vertical beams, front clamps, rear clamps, guide rails and confining pressure cylinders. Frame 1 can sense and transmit the load applied to the device through pressure sensors, thereby achieving precise control of the confining pressure of the rock and soil samples. This design of pressure-sensitive load form enables the device to more accurately simulate the rock and soil stress conditions in actual engineering, improving the accuracy and reliability of the test.

[0034] The protective cover 3 is slidably coupled to the guide rail 7 on the frame 1 to prevent injuries to test personnel due to sample sputtering and breakage of drawn materials during the test, thereby ensuring the safety and reliability of the test process.

[0035] In order to further optimize the above technical solution, the confining pressure cylinder 8 includes a confining pressure cylinder body 83, a movable clamp, a fixing nut 82, a detachable sample positioning chamber 81 and a confining pressure end cap. Among them, the detachable sample positioning chamber is used to load the rock and soil samples to be tested and is fixed in the confining pressure cylinder body by the fixing nut. The movable clamp is a component inside the confining pressure cylinder 8, which is used to fix or adjust the position of the test sample. The confining pressure end cap plays the role of sealing the cylinder body, and a through hole is left in the middle for the optical fiber to pass through.

[0036] The rock and soil samples required for simulation test are loaded through the detachable sample positioning chamber 81. Since the scientific test method of controlling variables will be used in the simulation test of distributed optical fiber rock and soil coupling performance, rock and soil samples of different temperatures, humidity and properties will be involved. The detachable sample positioning chamber 81 can efficiently realize the diversity of sample replacement, which fundamentally solves the problem that traditional test equipment lacks convenient replacement and compaction rock and soil sample equipment, thereby reducing the test error and the complexity of the experiment. A through hole is left in the middle of the confining pressure end cover for the optical fiber to pass through, and the end cover plays the role of sealing the cylinder body. At the same time, since the temperature and humidity parameters of the rock and soil during the test will have a great impact on the test results, a temperature sensor and a humidity sensor are set inside the confining pressure end cover to collect the temperature and humidity data of the rock and soil samples and transmit them to the control and monitoring part through a data line, thereby ensuring the scientific reliability of the entire experiment. The mobile card position can form a vacant position after the pressure-sensitive load is loaded, providing space for movement when the rock and soil is compressed or stretched.

[0037] In order to further optimize the above technical solution, the transmission device includes a pull rod 9, a movable vertical beam 4, a servo motor, a displacement sensor and a tension sensor. The movable vertical beam 4 is combined with the front clamping seat 5 through the pull rod 9, and the movable vertical beam 4 is slidably fixed in the middle of the frame 1. The displacement sensor and the tension sensor are located on the rear clamping seat 6, and the servo motor is connected to the movable vertical beam 4 through a transmission mechanical structure. The servo motor is connected to the control and monitoring part.

[0038] The present invention controls the rotation speed of the servo motor by controlling the monitoring part. The rotation of the motor drives the internal screw to rotate. The screw is equipped with a nut. The nut and the moving vertical beam 4 are fixed as one. The moving vertical beam 4 is connected to the front clamp seat to realize the pulling of the test material. The working principle of the whole driving system is to control the speed of the servo motor by the control monitoring end, and realize the pulling function through the transmission mechanical structure. The real-time monitoring of the tension acting on the distributed optical fiber during the test is realized by setting the tension sensor on the rear clamp seat. The displacement sensor is set to detect the relative displacement of the front clamp seat during the test, that is, the stretching amount of the distributed optical fiber, so as to obtain accurate and effective test data. The displacement can be used to calculate the stress change of the rock and soil body to analyze the relationship between the pulling force, rock and soil coupling performance, and distributed optical fiber performance.

[0039] In order to further optimize the above technical solution, the control and monitoring part includes a computer controller, which burns the confining pressure control system program. The computer controller is connected to sensors of various parts, transmission devices, hydraulic devices in the test loading device, and distributed optical fiber sensors.

[0040] The confining pressure control system mainly realizes the control of the "confining pressure cylinder" structure in the device. The confining pressure cylinder is responsible for simulating the confining pressure of rock and soil. It realizes the confining pressure control of rock and soil samples by changing the pressure of the hydraulic device, and realizes the simulation of rock and soil confining pressure by changing the load pressure. During the pull-out test, as the applied pull-out force continues to increase, the shear layer of the distributed optical fiber and rock and soil interface is completely destroyed, and then the distributed optical fiber and sand interface will produce relative sliding. At this time, the distributed optical fiber and rock and soil interface will be peeled off. In order to ensure the coupling between the distributed optical fiber and rock and soil, simulate the real environmental conditions, and obtain more accurate and reliable test data, the pressure changes applied to the entire device are monitored on the frame, and then the dynamic and precise adjustment of the rock and soil confining pressure is realized in the pull-out experiment. During the test, the confining pressure intensity is continuously adjusted to ensure that the optical fiber and the rock and soil samples maintain a good contact state. At the same time, in order to achieve accurate testing, it is necessary to comprehensively consider a variety of factors, including but not limited to the stability of the test environment, the accuracy of the equipment, and the use of scientific testing methods, and emphasize the use of safety measures such as the use of protective covers to maintain the safety of the test environment and the smoothness of the test process.

[0041] Several distributed fiber optic sensors are fixed on the distributed optical fiber loaded in the detachable sample positioning chamber to measure or monitor the spatial distribution and time-varying information of the distributed optical fiber along the optical fiber transmission path, collect the strain data of the geotechnical samples, and thus obtain the relationship between the strain and pressure of the geotechnical samples and the performance of the distributed optical fiber. Each distributed fiber optic sensor can independently sense the changes in the surrounding environment, and this information can be summarized to form a detailed monitoring image of the entire optical fiber coverage area.

[0042] The intelligent control and intelligent data acquisition of the distributed optical fiber rock-soil coupling performance simulation test are realized through the control and monitoring part. The computer controller is connected to the optical fiber, and the strain distribution of the rock-soil body is detected through the distributed optical fiber sensor.

[0043] The method for testing using a distributed optical fiber rock-soil coupling performance simulation test device specifically includes the following steps:

[0044] One end of the distributed optical fiber is fixedly connected to the front clamp seat 5, and the other end passes through the rear clamp seat 6 and the confining pressure end cover in sequence, and extends into the detachable sample positioning chamber 81 loaded with the sample, and the detachable sample positioning chamber 81 is fixed in the confining pressure cylinder 83, and the confining pressure end cover is closed. At the same time, the rear clamp seat 6 and the metal frame 1 are fixed to prevent relative sliding, and the loading of the test sample and the test distributed optical fiber is completed, and the protective cover 3 is moved to the optical fiber loading area.

[0045] The distributed optical fiber is fixed by a movable rear clamp 6 to meet the test length requirements of the distributed optical fiber, and then fixed to the metal frame 1 to ensure that there is no relative sliding between the rear clamp and the metal frame during the subsequent experimental process. Such a fixing operation is to ensure the stability of the optical fiber tension during the test, to prevent the test error caused by the movement of the rear clamp, and thus to ensure the accuracy and repeatability of the experimental data.

[0046] The computer controller of the operation control monitoring part is used to control the confining pressure parameters required for the test, and the transmission device is controlled to realize the movement of the moving vertical beam 4 to generate the pulling stress on the distributed optical fiber. During the test, the control monitoring end can collect and summarize the data detected by the sensors of each part. The temperature sensor and humidity sensor of the confining pressure end cover monitor the temperature and humidity parameters of the rock and soil samples, the tension sensor and displacement sensor of the rear clamp seat 6 monitor the stress value and relative displacement of the optical fiber, and the distributed optical fiber sensor detects the strain distribution of the rock and soil body.

[0047] During the test process, if you need to replace the soil sample, change the type of distributed optical fiber, or change the thread of the distributed optical fiber, you can use the convenient mechanical structure designed by the device itself to complete it. The door of the detachable sample positioning chamber 81 is opened to realize the convenient replacement of different soil samples and distributed optical fiber types; the rear clamp seat 6 can change its position on the frame 1 through the guide wheel 10 to change the thread of the test optical fiber (i.e. the length of the optical fiber between the rear clamp seat and the front clamp seat) and adjust the different lengths of the test optical fiber. In summary, the simulated test method, the final measured data can output the test results through the data processing platform of the computer controller, and present them through the relevant chart model. The entire test method is safe, fast, scientific and accurate, and can realize intelligent control.

[0048] In order to realize the convenient replacement of rock and soil samples, the detachable sample positioning chamber 81 is usually designed to have a structure with a quick locking and unlocking mechanism. It is connected by a threaded and snap-on locking device so that the positioning chamber can be easily removed from the confining pressure cylinder 83.

[0049] Ensure the tightness of the positioning chamber and prevent leakage during the test. This is achieved by using sealing elements such as O-rings and sealing gaskets.

[0050] To adapt to different sizes and types of geotechnical samples, the detachable sample positioning chamber is designed in various specifications and has the characteristics of adjustable internal dimensions.

[0051] The replacement of distributed optical fibers is usually achieved by designing flexible optical fiber paths and interfaces. The optical fiber can easily pass through the positioning chamber and the confining pressure cylinder, and the type of optical fiber can be replaced by simple operations (such as plugging, unplugging, rotating, etc.).

[0052] Embodiment 1:

[0053] like Figure 1 As shown, a structural diagram of a distributed optical fiber rock-soil coupling performance simulation test device includes a frame 1 of the device, a support leg 2 of the support frame located at the lower part of the frame 1, a protective cover 3, a movable vertical beam 4, a front clamp seat 5, and a rear clamp seat 6 located in the frame 1; a guide rail 7 is located on a horizontal long frame of the frame 1, and a guide wheel 10 is connected to the rear clamp seat 6 and placed on the guide rail 7; a confining pressure cylinder 8 is located on the frame 1 and is coaxial with the frame 1; and a pull rod 9 is connected to the movable crossbeam 4.

[0054] The rear clamp seat 6 is connected to the guide wheel 10. During the test, the distributed optical fiber is fixed on the front clamp seat 5. The distributed optical fiber passes through the central axis of the rock sample in the confining pressure cylinder 8. The rear clamp seat 6 can be moved on the guide rail 7 through the guide wheel 10, and after the distributed optical fiber passes through the confining pressure cylinder 8, the rear clamp seat 6 is fixed to the metal frame, thereby realizing the fixation of the rear end of the distributed optical fiber and being able to flexibly change the thread of the distributed optical fiber being tested.

[0055] The front clamping seat 5 is connected to the movable vertical beam 4 through the pull rod 9. During the test, the computer controller controls the rotation speed of the servo motor. The rotation of the motor drives the internal screw to rotate. The screw is equipped with a nut. The nut and the movable vertical beam 4 are fixed together. The front clamping seat is moved to pull the test material. The working principle of the entire drive system is that the speed of the servo motor is controlled by the control monitoring end, and the tension function is realized through the transmission mechanical structure. The speed and size of the tension can be controlled. This control makes the test process more accurate and repeatable.

[0056] Adjusting the position of the rear clamp seat can change the length of the straight part of the optical fiber, thereby stretching or relaxing the optical fiber to achieve the required test conditions. The rear clamp seat is usually equipped with sensors (tension sensors, displacement sensors) to monitor the applied tension and displacement changes to ensure accurate adjustment. The front clamp seat and the rear clamp seat work together. The front clamp seat fixes the starting end of the optical fiber, and the rear clamp seat fixes the end of the optical fiber after setting the position. The distance between the two determines the effective length of the test optical fiber. In this way, it can be ensured that the position of the optical fiber is fixed throughout the experimental area and can withstand the necessary tension without slipping or being damaged.

[0057] More specifically, a tension sensor is provided on the rear clamp seat 6 to realize real-time monitoring of the tension acting on the distributed optical fiber during the test. A displacement sensor is provided to detect the relative displacement during the test. Both the tension sensor and the displacement sensor are connected to the control monitoring end, so as to obtain accurate and effective test data during the test.

[0058] The protective cover 3 is connected to the guide rail 7 via a built-in pulley, and the safety of the experimenter is ensured by moving the protective cover 3 to a position where the exposed loaded optical fiber is easily damaged.

[0059] Embodiment 2:

[0060] like Figure 2 As shown, the structural schematic diagram of the confining pressure cylinder 8 is shown, the confining pressure cylinder 8 is located on the frame 1 and is coaxial with the frame 1, and the detachable sample positioning chamber 81 is loaded with the rock and soil sample to be tested and is disassembled and assembled in the confining pressure cylinder body 83 through the fixing nut 82. The confining pressure cylinder also includes a hydraulic device and a cylinder, which are fixed on the frame at one end of the confining pressure cylinder body; the cylinder is connected to the hydraulic device to supply oil to the hydraulic device; the hydraulic device is connected to the confining pressure cylinder body to adjust the pressure in the confining pressure cylinder body; a through hole is provided on the confining pressure end cover, and a temperature sensor and a humidity sensor are arranged on the inner side of the confining pressure end cover.

[0061] More specifically, during the test, the rock and soil sample to be tested is loaded into the removable sample positioning chamber 81 and fixed in the confining pressure cylinder body by the fixing nut 82. When fixing the removable sample positioning chamber 81, the distributed optical fiber is passed through the central axis of the rock and soil sample and the middle pore of the confining pressure end cover, and then the confining pressure end cover is installed and sealed on the confining pressure cylinder by the nut. During the test, the hydraulic device is controlled by a computer controller to change the confining pressure value of the confining pressure cylinder, so as to achieve the purpose of simulating the confining pressure required for the test rock and soil. The hydraulic device is connected to the confining pressure cylinder through a hydraulic oil pipe. The hydraulic pump of the hydraulic device generates and delivers high-pressure hydraulic oil. Through the adjustment of the control valve (pressure valve), the hydraulic oil enters one end of the confining pressure cylinder, pushing the piston to move, thereby applying pressure to the sample inside the confining pressure cylinder body to adjust the confining pressure value.

[0062] The hydraulic device includes a piston, a hydraulic pump, a hydraulic motor, an electromagnetic pilot valve and an electric ball valve. The cylinder is connected to the confining pressure cylinder by an oil pipe through the hydraulic device, wherein the electromagnetic pilot valve, the electric ball valve and the hydraulic pump pump the hydraulic oil in the cylinder into the confining pressure cylinder, or the electromagnetic pilot valve, the electric ball valve and the hydraulic motor pump the hydraulic oil in the confining pressure cylinder into the cylinder, thereby adjusting the flow direction and pressure of the hydraulic oil, and controlling the advancement and recovery of the piston set in the confining pressure cylinder by injecting or extracting the hydraulic oil, thereby realizing accurate adjustment of the confining pressure value of the confining pressure cylinder, ensuring the smooth operation and flexible control of the confining pressure system, and meeting the requirements of applying different confining pressures to the samples in the card disassembly sample positioning chamber under different experimental conditions.

[0063] In this embodiment, a temperature sensor and a humidity sensor are arranged inside the confining pressure end cover to collect temperature and humidity data of the rock and soil and transmit the data to the computer controller through a data line. The temperature sensor and the humidity sensor collect the temperature and humidity parameters of the rock and soil during the test and control the variable values ​​to prevent a significant impact on the test results.

[0064] Embodiment three:

[0065] like Figure 3 As shown, the control system connection diagram of the present invention realizes intelligent control and intelligent data collection of distributed optical fiber rock-soil coupling performance simulation test by controlling the monitoring part.

[0066] More specifically, the computer controller is connected to the distributed optical fiber, and the strain distribution of the rock and soil body is detected through the distributed optical fiber sensor; the computer controller is connected to the hydraulic device, and the hydraulic device is controlled to change the confining pressure value around the rock and soil sample to control the test variables; the computer controller is connected to the sensor on the confining pressure end cover, and the temperature and humidity of the rock and soil to be tested are monitored in real time through the temperature sensor and the humidity sensor; the computer controller is connected to the displacement sensor and the tension sensor of the rear clamp seat, and the stress and relative displacement of the distributed optical fiber during the pulling test are detected in real time through the displacement sensor and the tension sensor; the computer controller is connected to the drive speed regulation system to control the speed of the servo motor, and the pulling stress is controlled through the mechanical transmission equipment.

[0067] Embodiment 4:

[0068] A test method using a distributed optical fiber rock-soil coupling performance simulation test device specifically comprises the following steps:

[0069] Fix the distributed optical fiber to the front clamp seat 5, fix the middle section of the optical fiber (that is, the end of the optical fiber for pulling test) through the movable rear clamp seat 6 according to the test length of the optical fiber, and pass through the detachable sample positioning chamber 81 loaded with the sample, fix the detachable sample positioning chamber 81 in the confining pressure cylinder body 83 by fixing the nut, close the confining pressure end cover, adjust the confining pressure value of the sample in the confining pressure cylinder by adjusting the hydraulic device, fix the rear clamp seat 6 to the frame 1, and complete the loading of the test sample and the test distributed optical fiber.

[0070] When the optical fiber passes through the confining pressure cylinder area where the rear clamp seat 6 is located, in order to ensure that the optical fiber can maintain the correct tension and position at the predetermined test length, the rear clamp seat needs to be used to fix the optical fiber. This can keep the entire optical fiber straight and stable under controlled tension, avoiding signal attenuation or measurement errors caused by too long or too short a length.

[0071] After that, it is only necessary to operate the computer controller of the control and monitoring part to control the confining pressure parameters required for the test and control the transmission device to realize the movement of the moving vertical beam 4 to generate the pulling stress on the distributed optical fiber. During the test, the control and monitoring end can collect and summarize the data detected by the sensors of each part. Thus, an intelligent test method for the rock-soil coupling of distributed optical fiber is realized.

[0072] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0073] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A distributed optical fiber rock-soil coupling performance simulation test device, characterized in that: include: Frame, confining pressure cylinder, transmission device, front clamping seat and rear clamping seat; The crossbeam at one end of the frame is embedded in the confining pressure cylinder; the front clamping seat is slidably connected to the inner side wall of the crossbeam at the other end of the frame, and is fixedly connected to the transmission device; the transmission device is slidably connected to the inner side wall of the crossbeam at the other end of the frame, and is fixedly connected to the front clamping seat; A guide rail is provided on the top surface of the crossbeam of the frame, and the rear clamp seat is slidably connected to the guide rail via a guide wheel; the confining pressure cylinder, the front clamp seat and the rear clamp seat are coaxially aligned; A displacement sensor and a tension sensor are fixed on the rear clamp seat; and a distributed optical fiber sensor is arranged in the confining pressure cylinder.

2. A distributed optical fiber rock-soil coupling performance simulation test device according to claim 1, characterized in that: The confining pressure oil cylinder includes a confining pressure cylinder body, a detachable sample positioning chamber, a confining pressure end cover and a plurality of fixing nuts; the crossbeam of the frame is embedded in the confining pressure cylinder body; a movable clamping position is provided on the inner wall of the confining pressure cylinder body, and the detachable sample positioning chamber is fixed to the movable clamping position by the evenly distributed fixing bolts; the confining pressure end cover seals the opening of the confining pressure cylinder body.

3. A distributed optical fiber rock-soil coupling performance simulation test device according to claim 2, characterized in that: The transmission device includes a pull rod, a movable vertical beam and a servo motor; the movable vertical beam is slidably connected to the inner wall of the cross beam of the frame, one side of the movable vertical beam is fixedly connected to the front clamp seat through the pull rod, and the other side is connected to the servo motor through a transmission structure; the servo motor is fixed on the frame.

4. A distributed optical fiber rock-soil coupling performance simulation test device according to claim 3, characterized in that: The transmission structure comprises a screw rod and a nut, wherein the nut is sleeved on the screw rod and fixed on the movable vertical beam, and one end of the screw rod is fixedly connected to the output shaft of the motor.

5. The distributed optical fiber rock-soil coupling performance simulation test device according to claim 3 is characterized in that: The confining pressure cylinder also includes a hydraulic device and a cylinder, which are fixed on the frame at one end of the confining pressure cylinder body; the cylinder is connected to the hydraulic device; the hydraulic device is connected to the confining pressure cylinder body; a through hole is provided on the confining pressure end cover, and a temperature sensor and a humidity sensor are also arranged on the inner side of the confining pressure end cover.

6. A distributed optical fiber rock-soil coupling performance simulation test device according to claim 5, characterized in that: It also includes a computer controller, which is electrically connected to the servo motor, the displacement sensor, the tension sensor, the distributed optical fiber sensor, the temperature sensor and the humidity sensor.

7. The distributed optical fiber rock-soil coupling performance simulation test device according to claim 1 is characterized in that: One end of the frame on which the front clamping seat is installed is provided with a protective cover, and the protective cover is slidably connected with the guide rail.

8. The distributed optical fiber rock-soil coupling performance simulation test device according to claim 1, characterized in that: The bottom surface of the crossbeam of the frame is provided with a plurality of symmetrical supporting legs.

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