Testing device and method for measuring crustal stress by simulating field stress relieving method

Abstract

The invention discloses a test device and method for measuring crustal stress by simulating a field stress relief method, and belongs to the technical field of test equipment. The device comprises a combined visualization mechanism, an environment simulation mechanism, an operation mechanism and a control mechanism; meanwhile, the invention discloses a method based on the test device for measuring the ground stress by simulating the on-site stress relief method, the test device and the method for measuring the ground stress by simulating the on-site stress relief method are provided with the strain gauge installation unit, and are suitable for installation of various types of strain gauges; the test hole cleaning unit cleans the hole wall in a scraping, blowing and sucking mode, blow-dries the hole wall while cleaning, avoids subsequent connection affecting bonding, and detects the hole diameter, so that subsequent glue filling can be set according to the hole diameter, the filling effectiveness is improved, a CT imaging device and a scanning type sound wave imaging device are added, and the production efficiency is improved. Visualization of the whole testing process is achieved, and more image data are provided for subsequent stress analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of test equipment, and in particular to a test device and method for measuring ground stress by simulating on-site stress relief method. Background Art

[0002] The stress relief method is a measurement method used to directly measure in-situ ground stress in rock mass. The deformation of rock in its natural state is monitored by drilling holes and installing strain gauges. The stress in the local area is then released by cutting or heating. The observed deformation changes can be used to calculate the magnitude and direction of ground stress at that location.

[0003] After searching, the patent with announcement number CN105092105B discloses a local contact method test device for deep geostress, which is equipped with a drilling mechanism, a cleaning mechanism and a testing mechanism, which work in sequence and realize the characteristics of miniaturization, intelligence and modularization. However, in actual application, there are still the following problems: (1) In actual testing, the GSIR triaxial strain gauge, CSIRO hollow inclusion strain gauge and UNSW solid inclusion strain gauge all need to be fixed by gluing. The existing technology of direct insertion using a telescopic structure is only applicable to USBM aperture strain gauges, but the error is large for uneven rock masses, resulting in low measurement accuracy.

[0004] (2) The cleaning mechanism uses water washing, but excessive humidity will also affect subsequent testing and the installation of subsequent strain gauges.

[0005] (3) There is no visualization equipment, which makes it impossible to obtain image data during the stress relief process. Summary of the invention

[0006] The purpose of the present invention is to provide a test device and method for measuring ground stress by simulating on-site stress relief method, so as to solve the above technical problems.

[0007] To achieve the above object, the present invention provides a test device for measuring ground stress by simulating on-site stress relief method, comprising: Combined visualization mechanism, used to collect the internal image of the sample throughout the process; An environmental simulation mechanism, which includes a confining pressure applying unit and a temperature regulating unit, and is used to simulate the confining pressure and temperature environment of the sample; Operating mechanism for drilling test holes, stress relief, cleaning test holes and installing strain gauges; The control mechanism is used to control the combined visualization mechanism, the environmental simulation mechanism and the operating mechanism, and collect data from the environmental simulation mechanism and the strain gauge in real time for display.

[0008] Preferably, the combined visualization mechanism includes a CT imaging device and a scanning acoustic wave imaging device; The CT imaging device includes a bracket, on which two mounting side plates are arranged, on which a transmitter and a detector are connected via a lift, and a turntable is arranged in the middle of the bracket; The scanning acoustic wave imaging device includes a plurality of ultrasonic transducers and a plurality of relatively arranged receivers, and both the ultrasonic transducers and the receivers are connected to the acoustic wave analyzer; The turntable, the transmitter, the detector and the sound wave analyzer are all electrically connected to the control mechanism.

[0009] Preferably, the confining pressure applying unit comprises an L-shaped fixing plate and two pressure plates, the two pressure plates are connected to a pressure hydraulic cylinder, the two pressure plates and the L-shaped fixing plate form a frame structure, pressure sensors are arranged on the two pressure plates, the L-shaped fixing plate and the pressure hydraulic cylinder are fixed on the turntable, the L-shaped fixing plate and one of the pressure plates are provided with through holes, a lifting mounting plate is arranged in the through holes, the two lifting mounting plates are respectively installed with an ultrasonic transducer and a receiver, a tightening member is arranged on one side of the lifting mounting plate, the tightening member comprises a lifting ball, the lifting ball is connected to one end of a tightening spring, and the other end of the tightening spring is arranged in a blind hole of the lifting mounting plate; The lifting and lowering mounting plate, the pressure hydraulic cylinder and the pressure sensor are all electrically connected to the control mechanism.

[0010] Preferably, the temperature regulating unit includes a lower heating plate arranged on the turntable, and side heating plates and temperature detection optical fibers are arranged on the inner sides of an L-shaped fixing plate and another pressure plate. The lower heating plate, the side heating plate and the temperature detection optical fiber are all electrically connected to the control mechanism.

[0011] Preferably, the operating mechanism comprises a rotating bracket, on which a test hole drilling unit, a test hole cleaning unit, a strain gauge installation unit and a stress relief unit are respectively arranged; The rotating bracket, the test hole drilling unit, the test hole cleaning unit, the strain gauge installation unit and the stress relief unit are all electrically connected to the control mechanism.

[0012] Preferably, a cross mounting frame is provided on the top of the rotating bracket, and the test hole drilling unit, the test hole cleaning unit, the strain gauge mounting unit and the stress relief unit are respectively installed at the four extension ends of the cross mounting frame. The cross mounting frame is connected to a rotating drive motor, which is installed on the rotating bracket and electrically connected to the control mechanism.

[0013] Preferably, the test hole drilling unit comprises a first lifting hydraulic cylinder, and a drilling machine is provided at the telescopic end of the first lifting hydraulic cylinder; the stress relief unit comprises a second lifting hydraulic cylinder, and a thin-walled casing drilling machine is provided at the telescopic end of the second lifting hydraulic cylinder; The first lifting hydraulic cylinder, the drilling machine, the second lifting hydraulic cylinder and the thin-wall casing drilling machine are all electrically connected to the control mechanism.

[0014] Preferably, the test hole cleaning unit comprises a rotating tube, two telescopic scrapers are symmetrically arranged on the outer side of the rotating tube, the two telescopic scrapers are arranged in the groove on the outer side of the rotating tube by a spring, the two telescopic scrapers divide the rotating tube into a cleaning side and a detection side, the lower half of the cleaning side is provided with an air blowing port, the air blowing port is provided with a filter, the upper plate part of the cleaning side and the detection side are both provided with a dust suction port, the dust suction port is connected to the dust suction pipe inside the rotating tube through a connecting pipe, the rotating tube and the dust suction pipe are connected to the dust collector through a multi-channel rotating joint, the rotating tube is connected to the air outlet pipe of the dust collector, and the dust suction pipe is connected to the air inlet pipe of the dust collector; a heater is arranged on the air inlet pipe, and at least one row of distance detection sensors is arranged on the detection side; the rotating tube is arranged at one end of the ball spline, the ball spline is connected to the cleaning drive motor through a belt, the cleaning drive motor is installed on a cross mounting frame, the cleaning drive motor is connected to the lifting gear rack assembly through a bevel gear set and a chain, and the gears and bevel gear sets in the lifting gear rack assembly are arranged on the cross mounting frame; The cleaning drive motor, the dust collector, the distance detection sensor and the heater are all electrically connected to the control mechanism.

[0015] Preferably, the strain gauge mounting unit comprises a mounting sleeve, which is hollow and has a plurality of glue outlets at its open end, a vacuum suction cup is arranged inside the mounting sleeve, and the vacuum suction cup is connected to an air pump through an air pipe, the mounting sleeve is mounted on one end of a rotating spline, and the other end of the rotating spline is mounted on a cross mounting frame through a lifting cylinder, the rotating spline is connected to a mounting drive motor through a belt, the mounting drive motor is mounted on the cross mounting frame, the spline shaft of the rotating spline is a hollow shaft, the hollow shaft is connected to a glue supply pump and an air pump through a multi-channel rotating joint, and the mounting sleeve and the air pipe are both connected to the multi-channel rotating joint; a plugging assembly is arranged at the bottom of the turntable, the plugging assembly comprises a plugging motor, and a plugging plate is arranged on the output shaft of the plugging motor; The plugging motor, the glue supply pump, the air pump, the lifting cylinder and the installation drive motor are all electrically connected to the control mechanism.

[0016] Based on the above-mentioned method of the test device for measuring ground stress by simulating on-site stress relief method, the specific steps are as follows: Step S1: Prepare a sample, place the sample on a turntable, and arrange strain gauges on the sample surface according to test requirements to form a sample surface strain measurement and collection mechanism; Step S2: starting the confining pressure unit so that the sample is in the test position, starting the CT imaging device to collect the initial sample image, and then starting the scanning acoustic wave imaging device to collect the initial acoustic wave of the sample; Step S3: Start the rotary drive motor so that the test hole drilling unit is arranged opposite to the sample, and start the first lifting hydraulic cylinder and the drilling machine to drill a test hole with a diameter ranging from 20 to 50 mm at the center of the sample; Step S4: After drilling the test hole, start the rotary drive motor so that the test hole cleaning unit is arranged opposite to the sample, start the vacuum cleaner, heater and cleaning drive motor in the test hole cleaning unit, and under the action of the ball spline, the rotary tube rotates and descends into the test hole at the same time, scrapes the pumice stone from the hole wall of the test hole, flushes the hole wall and removes the dust; at the same time, the aperture detection is performed through the distance detection sensor; Step S5: After the test hole is cleaned, the rotation drive motor is started so that the strain gauge installation unit is arranged relative to the sample, the lifting cylinder drives the installation sleeve to descend to the bottom of the test hole, the plugging motor is started so that the plugging plate is arranged relative to the test hole, and the vacuum suction cup is released by controlling the air pump so that the strain gauge is placed on the plugging plate under the action of gravity, ensuring that the strain gauge is installed in the center of the test hole, the installation drive motor is started to drive the installation sleeve to rotate, and the glue supply pump and the lifting cylinder are started at the same time, so that the adhesive inside the installation sleeve flows in a spiral manner into the gap between the strain gauge and the test hole; according to the test hole diameter measured in step S4, the rotation speed of the installation drive motor and the lifting speed of the lifting cylinder are adjusted; Step S6: After the adhesive is cured, the CT imaging device is started to collect the sample image before the test, and then the scanning acoustic wave imaging device is started to collect the acoustic wave of the sample before the test; Step S7: starting the temperature regulating unit to heat the sample until the set test temperature is reached, and after the heating is completed, starting the pressure hydraulic cylinder until the set confining pressure is reached; Step S8: Start the rotary drive motor so that the stress relief unit is arranged relative to the sample, start the second lifting hydraulic cylinder and the thin-walled casing drilling machine to drill a relief hole concentric with the test hole, the aperture of the relief hole is in the range of 110-160mm, so that the core around the strain gauge is separated from the sample, thereby achieving stress relief. At the same time, the sample image is collected in real time by the CT imaging device, and the data of the strain gauge and the strain gauge are collected in real time to realize the collection of the stress change data on the surface of the sample and the stress change data inside the sample. The sample sound wave is collected regularly during the stress relief process. The process of collecting the sample sound wave is as follows: Turn off the CT imaging equipment, the second lifting hydraulic cylinder and the thin-walled casing drilling rig, raise the lifting mounting plate so that the ultrasonic transducer and the receiver are set relative to the sample, start the ultrasonic transducer and the receiver to collect sound waves, and after the collection is completed, lower the lifting mounting plate, start the CT imaging equipment, the second lifting hydraulic cylinder and the thin-walled casing drilling rig to continue stress relief until the stress relief is completed.

[0017] Therefore, the present invention adopts the above-mentioned test device and method for measuring ground stress by simulating on-site stress relief method, which has the following beneficial effects: (1) A strain gauge installation unit is provided for installing the strain gauge by bonding, so that when the strain gauge is installed, the adhesive extruded from the installation sleeve fills the gap between the strain gauge and the test hole in a spiral manner, which is suitable for the installation of many types of strain gauges.

[0018] (2) The test hole cleaning unit uses scraping, blowing and suction to clean the hole wall. While cleaning, the hole wall is blown dry to avoid subsequent impact on the bonding connection. The hole diameter is also detected so that the subsequent glue filling can be set according to the hole diameter to improve the effectiveness of filling.

[0019] (3) The addition of CT imaging equipment and scanning acoustic wave imaging equipment enables visualization of the test process and provides more image data for subsequent stress analysis.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a test device for measuring ground stress by simulating on-site stress relief method according to the present invention; Figure 2 It is a schematic diagram of the structure of the environment simulation mechanism of the present invention; Figure 3 This is a schematic diagram of the structure of the lifting plate installed in the present invention; Figure 4 This is a schematic diagram of the structure of the tensioning member of the present invention; Figure 5 This is a schematic diagram of the structure of the test hole cleaning unit of the present invention; Figure 6 This is a schematic diagram of the rotary tube structure of the present invention; Figure 7 It is a cross-sectional view of the rotating tube of the present invention; Figure 8 This is a schematic diagram of the structure of the strain gauge installation unit of the present invention.

[0022] Reference numerals 1. Control mechanism; 2. CT imaging equipment; 21. Bracket; 22. Mounting side plate; 23. Lifter; 24. Transmitter; 25. Detector; 26. Turntable; 3. Scanning acoustic imaging equipment; 31. Ultrasonic transducer; 32. Receiver; 33. Acoustic wave analyzer; 4. Confining pressure applying unit; 41. L-shaped fixing plate; 42. Pressure plate; 43. Pressure hydraulic cylinder; 44. Pressure sensor; 45. Through hole; 46. Lifting mounting plate; 47. Top ball; 48. Tightening spring; 5. Temperature regulating unit; 51. Lower heating plate; 52. Side heating plate; 53. Temperature detection optical fiber; 6. Rotating bracket; 61. Cross mounting frame; 62. Rotating drive motor; 7. Drilling test hole unit; 71. First lifting Hydraulic cylinder; 72, drilling machine; 8, stress relief unit; 81, second lifting hydraulic cylinder; 82, thin-walled casing drilling machine; 9, test hole cleaning unit; 91, rotating tube; 92, telescopic scraper; 93, spring; 94, air outlet; 95, dust suction port; 96, connecting pipe; 97, dust suction pipe; 98, vacuum cleaner; 99, heater; 910, distance detection sensor; 911, cleaning drive motor; 912, lifting gear rack assembly; 10, strain gauge installation unit; 101, installation sleeve; 102, glue outlet; 103, vacuum suction cup; 104, air pump; 105, lifting cylinder; 106, installation drive motor; 107, glue supply pump; 108, blocking motor; 109, blocking plate; 11, ball spline. DETAILED DESCRIPTION

[0023] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] like Figure 1As shown, a test device for measuring ground stress by simulating on-site stress relief method includes a combined visualization mechanism, an environmental simulation mechanism, an operating mechanism and a control mechanism 1, and the combined visualization mechanism, the environmental simulation mechanism and the operating mechanism are all electrically connected to the control mechanism 1.

[0026] The combined visualization mechanism is used to collect the whole internal image of the sample. The combined visualization mechanism includes a CT imaging device 2 and a scanning acoustic wave imaging device 3. The CT imaging device 2 includes a bracket 21. Two mounting side plates 22 are arranged on the bracket 21. The two mounting side plates 22 are connected with a transmitter 24 and a detector 25 through a lift 23. A turntable 26 is arranged in the middle of the bracket 21. The scanning acoustic wave imaging device 3 includes a plurality of ultrasonic transducers 31 and a plurality of relatively arranged receivers 32. The ultrasonic transducers 31 and the receivers 32 are all connected to an acoustic wave analyzer 33. The turntable 26, the transmitter 24, the detector 25 and the acoustic wave analyzer 33 are all electrically connected to the control mechanism 1.

[0027] The environmental simulation mechanism includes a confining pressure applying unit 4 and a temperature regulating unit 5, which are used to simulate the confining pressure and temperature environment of the sample. Figure 2 As shown, the confining pressure applying unit 4 includes an L-shaped fixing plate 41 and two pressure plates 42, the two pressure plates 42 are connected to a pressure hydraulic cylinder 43, the two pressure plates 42 and the L-shaped fixing plate 41 form a frame structure, the two pressure plates 42 are provided with a pressure sensor 44, the L-shaped fixing plate 41 and the pressure hydraulic cylinder 43 are fixed on the rotating disk 26, the L-shaped fixing plate 41 and one of the pressure plates 42 are provided with a through hole 45, and a lifting installation plate 46 is provided in the through hole 45, as shown in FIG. Figure 3-Figure 4 As shown, two lifting and mounting plates 46 are respectively installed with ultrasonic transducers 31 and receivers 32. A tightening member is provided on one side of the lifting and mounting plates 46. The tightening member includes a top ball 47. The top ball 47 is connected to one end of a tightening spring 9348. The other end of the tightening spring 9348 is arranged in a blind hole of the lifting and mounting plates 46. The lifting and mounting plates 46, the pressure hydraulic cylinder 43 and the pressure sensor 44 are all electrically connected to the control mechanism 1. When performing CT detection, the lifting and mounting plates 46 are lowered so that the upper part of the lifting and mounting plates 46 is arranged in the through hole 45 for continuous support to prevent the ultrasonic transducer 31 and the receiver 32 from affecting the CT detection. When clamping the sample, the lifting and mounting plates 46 are in the turntable 26 to avoid interfering with the movement of the pressure plate 42.

[0028] The temperature regulating unit 5 includes a lower heating plate 51 arranged on the turntable 26, and a side heating plate 52 and a temperature detection optical fiber 53 are arranged on the inner side of the L-shaped fixing plate 41 and another pressure plate 42. The lower heating plate 51, the side heating plate 52 and the temperature detection optical fiber 53 are all electrically connected to the control mechanism 1 for simulating the temperature environment of the sample, and can also monitor the real-time sample temperature.

[0029] The operating mechanism is used for drilling test holes, stress relief, cleaning test holes and installing strain gauges. The operating mechanism includes a rotating bracket 6, on which a test hole drilling unit 7, a test hole cleaning unit 9, a strain gauge installation unit 10 and a stress relief unit 8 are respectively arranged. The rotating bracket 6, the test hole drilling unit 7, the test hole cleaning unit 9, the strain gauge installation unit 10 and the stress relief unit 8 are all electrically connected to the control mechanism 1.

[0030] A cross mounting frame 61 is provided on the top of the rotating bracket 6, and the test hole drilling unit 7, the test hole cleaning unit 9, the strain gauge mounting unit 10 and the stress relief unit 8 are respectively mounted on the four extending ends of the cross mounting frame 61. The cross mounting frame 61 is connected to a rotation drive motor 62, which is mounted on the rotating bracket 6 and electrically connected to the control mechanism 1 for adjusting the position of each unit.

[0031] The test hole drilling unit 7 includes a first lifting hydraulic cylinder 71, and a drilling machine 72 is provided at the telescopic end of the first lifting hydraulic cylinder 71; the stress relief unit 8 includes a second lifting hydraulic cylinder 81, and a thin-walled casing drilling machine 82 is provided at the telescopic end of the second lifting hydraulic cylinder 81. The first lifting hydraulic cylinder 71, the drilling machine 72, the second lifting hydraulic cylinder 81 and the thin-walled casing drilling machine 82 are all electrically connected to the control mechanism 1.

[0032] like Figure 5-Figure 7 As shown, the test hole cleaning unit 9 includes a rotating tube 91, and two telescopic scrapers 92 are symmetrically arranged on the outer side of the rotating tube 91. The two telescopic scrapers 92 are arranged in the groove on the outer side of the rotating tube 91 through a spring 93. The two telescopic scrapers 92 divide the rotating tube 91 into a cleaning side and a detection side. The lower half of the cleaning side is provided with a blowing port 94, and the blowing port 94 is provided with a filter. The upper plate part of the cleaning side and the detection side are both provided with a dust suction port 95, and the dust suction port 95 is connected to the dust suction pipe 97 inside the rotating tube 91 through a connecting pipe 96. The rotating tube 91 and the dust suction pipe 97 are connected to the dust collector 98 through a multi-channel rotating joint, and the rotating tube 91 is connected to the air outlet pipe of the dust collector 98. The dust suction pipe 97 is connected to the air inlet pipe of the dust collector 98; a heater 99 is arranged on the air inlet pipe, and at least one row of distance detection sensors 910 are arranged on the detection side; the rotating tube 91 is arranged at one end of the ball spline 11, and the ball spline 11 is connected to the cleaning drive motor 911 through a belt, and the cleaning drive motor 911 is installed on the cross mounting frame 61. The cleaning drive motor 911 is connected to the lifting gear rack assembly 912 through a bevel gear set and a chain. The gears and bevel gear sets in the lifting gear rack assembly 912 are arranged on the cross mounting frame 61, and the cleaning drive motor 911, the dust collector 98, the distance detection sensor 910 and the heater 99 are all electrically connected to the control mechanism 1.

[0033] like Figure 8As shown, the strain gauge installation unit 10 includes a mounting sleeve 101, the mounting sleeve 101 is hollow, and a plurality of glue outlets 102 are provided at the open end of the mounting sleeve 101, a vacuum suction cup 103 is provided inside the mounting sleeve 101, and the vacuum suction cup 103 is connected to an air pump 104 through an air pipe, the mounting sleeve 101 is installed at one end of a rotating spline, and the other end of the rotating spline is installed on a cross mounting frame 61 through an installation drive motor 106, and the rotating spline is connected to the installation drive motor through a belt, and the installation drive motor is installed on On the cross mounting frame 61, the spline shaft of the rotating spline is a hollow shaft, which is connected to the glue supply pump 107 and the air pump 104 through a multi-channel rotary joint, and the mounting sleeve 101 and the air pipe are both connected to the multi-channel rotary joint; a blocking component is provided at the bottom of the turntable 26, and the blocking component includes a blocking motor 108, and a blocking plate 109 is provided on the output shaft of the blocking motor 108, and the blocking motor 108, the glue supply pump 107, the air pump 104, the installation drive motor 106 and the installation drive motor are all electrically connected to the control mechanism 1.

[0034] The control mechanism 1 is used to control the combined visualization mechanism, the environmental simulation mechanism and the operating mechanism, and collect data from the environmental simulation mechanism and the strain gauge in real time for display.

[0035] Based on the above-mentioned method of the test device for measuring ground stress by simulating on-site stress relief method, the specific steps are as follows: Step S1: Prepare a sample, place the sample on the turntable 26, and arrange strain gauges on the surface of the sample according to test requirements to form a sample surface strain measurement and collection mechanism.

[0036] Step S2: Start the confining pressure unit to place the sample in the test position, start the CT imaging device 2 to collect the initial sample image, and then start the scanning acoustic wave imaging device 3 to collect the initial acoustic wave of the sample.

[0037] Step S3: Start the rotary drive motor 62, so that the test hole drilling unit 7 is arranged opposite to the sample, and start the first lifting hydraulic cylinder 71 and the drilling machine 72 to drill a test hole with a diameter ranging from 20 to 50 mm at the center of the sample; Step S4: After drilling the test hole, start the rotary drive motor 62 so that the test hole cleaning unit 9 is arranged opposite to the sample, start the vacuum cleaner 98, heater 99 and cleaning drive motor 911 in the test hole cleaning unit 9, and under the action of the ball spline 11, the rotary tube 91 rotates and descends into the test hole at the same time to scrape the pumice from the hole wall of the test hole, flush the hole wall and remove the dust; at the same time, the aperture detection is performed through the distance detection sensor 910.

[0038] Step S5: After cleaning the test hole, start the rotation drive motor 62, so that the strain gauge installation unit 10 is arranged opposite to the sample, the installation drive motor 106 drives the installation sleeve 101 to descend to the bottom of the test hole, and start the plugging motor 108, so that the plugging plate 109 is arranged opposite to the test hole, and the vacuum suction cup 103 is released by controlling the air pump 104, so that the strain gauge is placed on the plugging plate 109 under the action of gravity, ensuring that the strain gauge is installed in the center of the test hole, and start the installation drive motor to drive the installation sleeve 101 to rotate, and at the same time start the glue supply pump 107 and the installation drive motor 106, so that the adhesive inside the installation sleeve 101 flows in a spiral manner into the gap between the strain gauge and the test hole; according to the test aperture measured in step S4, the rotation speed of the installation drive motor and the lifting speed of the installation drive motor 106 are adjusted.

[0039] Step S6: After the adhesive is fully cured so that the strain gauge is in close contact with the wall of the test hole and is firmly adhered, the CT imaging device 2 is started to collect the sample image before the test, and then the scanning acoustic wave imaging device 3 is started to collect the acoustic wave of the sample before the test.

[0040] Step S7: Start the temperature regulating unit 5 to heat the sample until the set test temperature is reached. After the heating is completed, start the pressure hydraulic cylinder 43 until the set confining pressure is reached.

[0041] The rotary drive motor 62 is started to arrange the stress relief unit 8 relative to the sample, and the second lifting hydraulic cylinder 81 and the thin-walled casing drilling machine 82 are started to drill a relief hole concentric with the test hole. The diameter of the relief hole is in the range of 110-160 mm, so that the core around the strain gauge is separated from the sample, thereby achieving stress relief. At the same time, the sample image is collected in real time by the CT imaging device 2, and the data of the strain gauge and the strain gauge are collected in real time to realize the collection of the stress change data on the surface of the sample and the stress change data inside the sample. The sample sound wave is collected regularly during the stress relief process. The process of collecting the sample sound wave is as follows: The CT imaging device 2, the second lifting hydraulic cylinder 81 and the thin-walled casing drilling machine 82 are turned off, and the lifting installation plate 46 is raised, so that the ultrasonic transducer 31 and the receiver 32 are arranged relative to the sample, and the ultrasonic transducer 31 and the receiver 32 are started to collect sound waves. After the collection is completed, the lifting installation plate 46 is lowered, and the CT imaging device 2, the second lifting hydraulic cylinder 81 and the thin-walled casing drilling machine 82 are started to continue stress relief until the stress relief is completed. Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot make the modified technical solution deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A test device for measuring ground stress by simulating on-site stress relief method, characterized in that: include, Combined visualization mechanism, used to collect the internal image of the sample throughout the process; An environmental simulation mechanism, which includes a confining pressure applying unit and a temperature regulating unit, and is used to simulate the confining pressure and temperature environment on site; Operating mechanism for drilling test holes, stress relief, cleaning test holes and installing strain gauges; The control mechanism is used to control the combined visualization mechanism, the environmental simulation mechanism and the operating mechanism, and to continuously collect data from the environmental simulation mechanism and the strain gauge in real time and display them.

2. The test device for measuring ground stress by simulating on-site stress relief method according to claim 1, characterized in that: The combined visualization mechanism includes a CT imaging device and a scanning acoustic wave imaging device; The CT imaging device includes a bracket, on which two mounting side plates are arranged, on which a transmitter and a detector are connected via a lift, and a turntable is arranged in the middle of the bracket; The scanning acoustic wave imaging device includes a plurality of ultrasonic transducers and a plurality of relatively arranged receivers, and both the ultrasonic transducers and the receivers are connected to the acoustic wave analyzer; The turntable, the transmitter, the detector and the sound wave analyzer are all electrically connected to the control mechanism.

3. The test device for measuring ground stress by simulating on-site stress relief method according to claim 2, characterized in that: The confining pressure applying unit includes an L-shaped fixing plate and two pressure plates, the two pressure plates are connected to a pressure hydraulic cylinder, the two pressure plates and the L-shaped fixing plate form a frame structure, pressure sensors are arranged on the two pressure plates, the L-shaped fixing plate and the pressure hydraulic cylinder are fixed on the turntable, the L-shaped fixing plate and one of the pressure plates are provided with through holes, a lifting mounting plate is arranged in the through holes, the two lifting mounting plates are respectively installed with an ultrasonic transducer and a receiver, a tightening member is arranged on one side of the lifting mounting plate, the tightening member includes a lifting ball, the lifting ball is connected to one end of a tightening spring, and the other end of the tightening spring is arranged in a blind hole of the lifting mounting plate; The lifting and lowering mounting plate, the pressure hydraulic cylinder and the pressure sensor are all electrically connected to the control mechanism.

4. The test device for measuring ground stress by simulating on-site stress relief method according to claim 3, characterized in that: The temperature regulating unit comprises a lower heating plate arranged on the turntable, and side heating plates and temperature detection optical fibers are arranged inside an L-shaped fixing plate and another pressure plate. The lower heating plate, the side heating plates and the temperature detection optical fibers are all electrically connected to the control mechanism.

5. The test device for measuring ground stress by simulating on-site stress relief method according to claim 4, characterized in that: The operating mechanism comprises a rotating bracket, on which a test hole drilling unit, a test hole cleaning unit, a strain gauge installation unit and a stress relief unit are respectively arranged; The rotating bracket, the test hole drilling unit, the test hole cleaning unit, the strain gauge installation unit and the stress relief unit are all electrically connected to the control mechanism.

6. The test device for measuring ground stress by simulating on-site stress relief method according to claim 5, characterized in that: A cross mounting frame is arranged on the top of the rotating bracket. The test hole drilling unit, the test hole cleaning unit, the strain gauge mounting unit and the stress relief unit are respectively mounted on the four extension ends of the cross mounting frame. The cross mounting frame is connected to a rotating drive motor, which is mounted on the rotating bracket and electrically connected to the control mechanism.

7. The test device for measuring ground stress by simulating on-site stress relief method according to claim 6, characterized in that: The test hole drilling unit includes a first lifting hydraulic cylinder, and a drilling machine is provided at the telescopic end of the first lifting hydraulic cylinder; the stress relief unit includes a second lifting hydraulic cylinder, and a thin-walled casing drilling machine is provided at the telescopic end of the second lifting hydraulic cylinder; The first lifting hydraulic cylinder, the drilling machine, the second lifting hydraulic cylinder and the thin-wall casing drilling machine are all electrically connected to the control mechanism.

8. The test device for measuring ground stress by simulating on-site stress relief method according to claim 7, characterized in that: The test hole cleaning unit includes a rotating tube, two telescopic scrapers are symmetrically arranged on the outer side of the rotating tube, the two telescopic scrapers are arranged in the groove on the outer side of the rotating tube through a spring, the two telescopic scrapers divide the rotating tube into a cleaning side and a detection side, the lower half of the cleaning side is provided with an air blowing port, the air blowing port is provided with a filter, the upper plate part of the cleaning side and the detection side are both provided with a dust suction port, the dust suction port is connected to the dust suction pipe inside the rotating tube through a connecting pipe, the rotating tube and the dust suction pipe are connected to the vacuum cleaner through a multi-channel rotating joint, the rotating tube is connected to the air outlet pipe of the vacuum cleaner, and the dust suction pipe is connected to the air inlet pipe of the vacuum cleaner; a heater is arranged on the air inlet pipe, and at least one row of distance detection sensors is arranged on the detection side; the rotating tube is arranged at one end of the ball spline, the ball spline is connected to the cleaning drive motor through a belt, the cleaning drive motor is installed on a cross mounting frame, the cleaning drive motor is connected to the lifting gear rack assembly through a bevel gear set and a chain, and the gears and bevel gear sets in the lifting gear rack assembly are arranged on the cross mounting frame; The cleaning drive motor, the dust collector, the distance detection sensor and the heater are all electrically connected to the control mechanism.

9. The test device for measuring ground stress by simulating on-site stress relief method according to claim 8, characterized in that: The strain gauge installation unit includes an installation sleeve, which is hollow and has a plurality of glue outlets at its open end. A vacuum suction cup is provided inside the installation sleeve, which is connected to an air pump through an air pipe. The installation sleeve is installed at one end of a rotating spline, and the other end of the rotating spline is installed on a cross mounting frame through a lifting cylinder. The rotating spline is connected to an installation drive motor through a belt, and the installation drive motor is installed on the cross mounting frame. The spline shaft of the rotating spline is a hollow shaft, which is connected to a glue supply pump and an air pump through a multi-channel rotating joint, and the installation sleeve and the air pipe are both connected to the multi-channel rotating joint. A plugging assembly is provided at the bottom of the turntable, and the plugging assembly includes a plugging motor, and a plugging plate is provided on the output shaft of the plugging motor. The plugging motor, the glue supply pump, the air pump, the lifting cylinder and the installation drive motor are all electrically connected to the control mechanism.

10. A method for testing a device for measuring ground stress by simulating on-site stress relief method according to claim 9, characterized in that: The specific steps are as follows: Step S1: Prepare a sample, place the sample on a turntable, and arrange strain gauges on the sample surface according to test requirements to form a sample surface strain measurement and collection mechanism; Step S2: starting the confining pressure unit so that the sample is in the test position, starting the CT imaging device to collect the initial sample image, and then starting the scanning acoustic wave imaging device to collect the initial acoustic wave of the sample; Step S3: Start the rotary drive motor so that the test hole drilling unit is arranged opposite to the sample, and start the first lifting hydraulic cylinder and the drilling machine to drill a test hole with a diameter ranging from 20 to 50 mm at the center of the sample; Step S4: After drilling the test hole, start the rotary drive motor so that the test hole cleaning unit is arranged opposite to the sample, start the vacuum cleaner, heater and cleaning drive motor in the test hole cleaning unit, and under the action of the ball spline, the rotary tube rotates and descends into the test hole at the same time, scrapes the pumice stone from the hole wall of the test hole, flushes the hole wall and removes the dust; at the same time, the aperture detection is performed through the distance detection sensor; Step S5: After the test hole is cleaned, the rotation drive motor is started so that the strain gauge installation unit is arranged relative to the sample, the lifting cylinder drives the installation sleeve to descend to the bottom of the test hole, the plugging motor is started so that the plugging plate is arranged relative to the test hole, and the vacuum suction cup is released by controlling the air pump so that the strain gauge is placed on the plugging plate under the action of gravity, the installation drive motor is started to drive the installation sleeve to rotate, and the glue supply pump and the lifting cylinder are started at the same time, so that the adhesive inside the installation sleeve flows into the gap between the strain gauge and the test hole in a spiral manner; according to the test aperture measured in step S4, the rotation speed of the installation drive motor and the lifting speed of the lifting cylinder are adjusted; Step S6: After the adhesive is cured and the strain gauge is bonded to the wall of the test hole, the CT imaging device is started to collect the sample image before the test, and then the scanning acoustic wave imaging device is started to collect the acoustic wave of the sample before the test; Step S7: starting the temperature regulating unit to heat the sample until the set test temperature is reached, and after the heating is completed, starting the pressure hydraulic cylinder until the set confining pressure is reached; Step S8: Start the rotary drive motor so that the stress relief unit is arranged relative to the sample, start the second lifting hydraulic cylinder and the thin-walled casing drilling machine to drill a relief hole concentric with the test hole, the aperture of the relief hole is in the range of 110-160mm, so that the core around the strain gauge is separated from the sample, thereby achieving stress relief. At the same time, the sample image is collected in real time by the CT imaging device, and the data of the strain gauge and the strain gauge are collected in real time to realize the collection of the stress change data on the surface of the sample and the stress change data inside the sample. The sample sound wave is collected regularly during the stress relief process. The process of collecting the sample sound wave is as follows: Turn off the CT imaging equipment, the second lifting hydraulic cylinder and the thin-walled casing drilling rig, raise the lifting mounting plate so that the ultrasonic transducer and the receiver are set relative to the sample, start the ultrasonic transducer and the receiver to collect sound waves, and after the collection is completed, lower the lifting mounting plate, start the CT imaging equipment, the second lifting hydraulic cylinder and the thin-walled casing drilling rig to continue stress relief until the stress relief is completed.

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