Anisotropic rock mass mechanical property and ground stress in-situ testing device

Abstract

The invention provides an anisotropic rock mass mechanical property and ground stress in-situ test device, which comprises a high-pressure expansion capsule, a servo loading system, a deformation acquisition instrument, a drilling camera system and an auxiliary test system, the main body of the high-pressure expansion capsule is that a flexible outer film is clamped between two steel end covers, a steel pull rod penetrates through the center of the flexible outer film, and the steel pull rod is connected with the servo loading system; two groups of hole wall radial and circumferential deformation integrated measuring systems are arranged in the capsule; the servo loading system comprises a low-pressure liquid filling pump, a high-pressure loading pump, a servo controller and a hydraulic sensor; the auxiliary system comprises a positioning rod, a digital tilt angle sensor, a winder, a portable computer and a variable workbench transport vehicle. The in-situ testing device applies pressure of different levels and paths to a hole wall rock mass according to a loading instruction, the expansion or shrinkage deformation of a drill hole is integrally measured in real time, the state of the rock mass before and after loading is observed, and the elastic / deformation modulus and tensile strength of the anisotropic rock mass and the magnitude and direction of ground stress are calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ testing of engineering rock mass mechanical parameters and in-situ stress, and in particular to an in-situ testing device for anisotropic rock mass mechanical properties and in-situ stress. Background Art

[0002] In the fields of deep mining engineering, water conservancy and hydropower engineering, tunnel engineering, etc., layered rocks such as carbonaceous slate and phyllite are often encountered. This type of rock has a distinct bedding structure, which leads to obvious anisotropy in its mechanical properties, which has an important impact on the stability of the surrounding rock. The mechanical properties and ground stress of anisotropic rock mass are the basic data for the implementation of deep anisotropic rock mass engineering. During the construction stage of deep engineering, it is necessary to obtain these data quickly and accurately in order to reasonably design and adjust the excavation and support schemes, and avoid the occurrence of deep engineering rock mass disasters such as rock bursts, large deformations, spalling and landslides.

[0003] At present, there are two main testing methods for rock mechanical properties: indoor test and field test. The indoor test method is to drill rock cores on site, process them into standard specimens, and conduct uniaxial, shear, triaxial and other tests in the laboratory. The development of rock indoor test technology has been relatively mature, and the equipment is also very advanced. However, the rock specimens used in indoor tests are small in size and relatively complete rocks, which destroy the stress and structure of the in-situ rock mass, cannot simulate the natural environment of the in-situ rock mass, and are difficult to objectively reflect the mechanical properties of the in-situ engineering rock mass. The commonly used testing equipment for field tests includes large-scale on-site rock triaxial test equipment, drilling elastic modulus, pressure plate test equipment, etc. Large-scale on-site rock triaxial test equipment costs a lot of money, has a long test cycle, is complicated to operate, and is difficult to form test specimens. It is mainly aimed at relatively complete rock masses, while the functions of drilling elastic modulus and pressure plate test equipment are relatively single, and can only measure the elastic parameters or viscoelastic parameters of the rock mass. Currently, the more commonly used geostress testing methods include stress relief method, stress recovery method and hydraulic fracturing method. However, the geostress testing is often separated from the in-situ rock mechanical properties testing, and there is a lack of integrated measurement equipment, which leads to low efficiency of on-site rock mechanical properties and geostress testing.

[0004] Therefore, there is an urgent need for a test device that can perform complex forms of loading such as cyclic loading and unloading, long-term load retention and high-pressure fracturing loading on the in-situ rock mass without destroying the in-situ rock mass structure and stress state, monitor the deformation and fracture characteristics of the anisotropic rock mass in real time, efficiently test the mechanical properties of the in-situ rock mass in the borehole, and at the same time test the ground stress of the rock mass. Summary of the invention

[0005] In view of the technical problems that the above-mentioned large-scale rock mass triaxial test equipment costs a lot of money, has a long test cycle, is complicated to operate, and has difficulty in forming test specimens, an in-situ test device for the mechanical properties of anisotropic rock mass and ground stress is provided, which can load the in-situ borehole wall rock mass in complex ways such as cyclic loading and unloading, long-term load retention and high-pressure fracturing loading, and monitor the deformation and fracture characteristics of the borehole wall rock mass at different positions in real time. According to the load-displacement data of the borehole wall rock mass and the fracture image of the borehole wall rock mass, the mechanical properties of the anisotropic rock mass and the ground stress can be calculated, thereby realizing the integrated and efficient measurement of the mechanical properties of the deep in-situ anisotropic rock mass and the ground stress at the location of the rock mass, which is conducive to the reasonable design and adjustment of the excavation and support schemes during the construction of deep projects, ensuring the support strength and engineering stability, and providing guarantee for the safe construction of geotechnical, water conservancy and hydropower, mining and other projects.

[0006] The technical means adopted by the present invention are as follows:

[0007] An in-situ testing device for anisotropic rock mechanical properties and ground stress, comprising: a high-pressure expansion capsule, a servo loading system, a deformation acquisition instrument, a drilling camera system, and an auxiliary test system;

[0008] The main frame of the high-pressure expansion capsule is composed of a flexible outer membrane, two steel end covers and a steel tie rod. The two steel end covers are respectively screwed together with the two ends of the steel tie rod. The steel tie rod passes through the center of the flexible outer membrane. The steel end covers are used to clamp the flexible outer membrane. The flexible outer membrane is made of polyurethane material. The outer surface of the flexible outer membrane is coated with a friction reducing agent coating to reduce the friction between the flexible outer membrane and the hole wall rock during loading.

[0009] The hydraulic sensor of the servo loading system is installed on the steel pull rod in the high-pressure expansion capsule to monitor the pressure, and the servo controller adjusts the pressure in the high-pressure expansion capsule in real time based on the data monitored by the hydraulic sensor;

[0010] The data measured by the deformation measurement sensor in the high-pressure expansion capsule is collected in real time by the deformation collector;

[0011] The battery camera of the drilling camera system is installed at the front end of the high-pressure expansion capsule, and can wirelessly transmit the images taken inside the hole to the outside of the hole.

[0012] Furthermore, sealing grooves and raised sealing lips are provided on both ends of the flexible outer membrane and the two steel end covers, and a bite sealing method is adopted between the raised sealing lips on the two ends of the flexible outer membrane and the two steel end covers and the sealing grooves.

[0013] Furthermore, the flexible outer membrane has a uniform cylindrical shape in the middle and a gradually reduced ellipsoidal shell shape at both ends, the steel pull rod has a gradually reduced ellipsoidal shape at both ends, and the diameter of the steel end cap is smaller than the diameter of the cylindrical flexible outer membrane in the middle after being filled with hydraulic oil and the diameter of the drilled hole;

[0014] The steel end cover can be disassembled and the size can be changed according to different rock types.

[0015] Furthermore, two groups of integrated measurement systems for hole wall radial and circumferential deformation are arranged in the high-pressure expansion capsule, each group of integrated measurement systems for hole wall radial and circumferential deformation includes 12 deformation measurement sensors, and the two groups of integrated measurement systems for hole wall radial and circumferential deformation are arranged in the high-pressure expansion capsule at a certain interval, and each group of integrated measurement systems for hole wall radial and circumferential deformation includes a set of hole wall radial deformation measurement sensors and two sets of "triangle" shaped hole wall circumferential deformation measurement sensors, each set of hole wall radial deformation measurement sensors includes 6 radial deformation measurement sensors, which are arranged at 60° intervals on the plane, and each set of "triangle" shaped hole wall circumferential deformation measurement sensors includes 3 circumferential deformation measurement sensors, which are arranged in an equilateral triangle on the plane, and the 6 radial deformation measurement sensors in each group of integrated measurement systems for hole wall radial and circumferential deformation are arranged perpendicular to the 6 circumferential deformation measurement sensors.

[0016] Furthermore, one end of the steel pull rod in the high-pressure expansion capsule is provided with an internal hydraulic oil inlet and outlet hole, an internal line inlet and outlet hole, and a hydraulic oil and line channel, which are used as channels for the hydraulic oil and sensor lines to enter and exit the high-pressure expansion capsule, wherein one internal hydraulic oil inlet and outlet hole is provided, and 24 internal line inlet and outlet holes are provided to meet the requirements of the lines of 24 deformation measurement sensors entering and exiting the high-pressure expansion capsule;

[0017] The deformation measurement sensor circuit in the high-pressure expansion capsule and the internal circuit inlet and outlet holes are sealed by a high-voltage connector.

[0018] Furthermore, a deformation measuring hole is provided on the flexible outer membrane, and the deformation measuring sensor contacts the hole wall through the deformation measuring hole to measure the deformation of the hole wall;

[0019] The deformation measurement sensor is composed of a sensor rod body, a pressure cap and a sensor spiral press rod. The deformation measurement hole and the flexible outer membrane are sealed by the pressure cap using the oil pressure reverse sealing principle. The sealing method is similar to the valve core sealing principle, thereby achieving a sealing effect between the flexible outer membrane body and the deformation measurement hole under high hydraulic pressure.

[0020] A sensor spiral pressing rod is arranged in the middle of the pressing cap, and the position of the sensor can be quickly adjusted outside the capsule, thereby meeting the requirements of hole wall compression and expansion deformation measurement.

[0021] Furthermore, the servo loading system includes a low-pressure filling pump, a high-pressure loading pump, a servo controller and a hydraulic sensor, the low-pressure filling pump is used to fill the high-pressure loading pump and the high-pressure expansion capsule with hydraulic oil, and the high-pressure loading pump is used to continuously pressurize the high-pressure expansion capsule at a stable rate until the target pressure is reached;

[0022] The hydraulic pressure sensor is mounted on a steel pull rod in the high-pressure expansion capsule and is used to monitor the pressure in the high-pressure expansion capsule;

[0023] The servo controller adjusts the pressure in the high-pressure expansion capsule in real time based on the pressure data monitored by the hydraulic sensor.

[0024] Furthermore, the borehole camera system includes a battery camera, a hemispherical glass cover and a video display screen. The borehole camera system is used to collect the unloaded and loaded states of the borehole wall rock mass, judge the rock mass properties and occurrence of the borehole loading part before the on-site loading test, and observe the failure mode and specific failure position of the rock mass after the loading test, and analyze the anisotropic mechanical properties of the rock mass and the magnitude and direction of the ground stress in combination with the measured deformation of the borehole wall rock mass; the battery camera is installed at the front end of the high-pressure expansion capsule, and can wirelessly transmit the captured images inside the hole to the outside of the hole; the hemispherical glass cover is covered on the outside of the battery camera to prevent dust and water vapor in the hole from contaminating the camera, and the video display screen is used to display the borehole wall images captured by the battery camera in real time, and the video display screen adopts the display screen of a portable computer.

[0025] Furthermore, the auxiliary test system includes a positioning rod, a digital inclination sensor, a wire reel, a portable computer and a variable workbench transport vehicle. The positioning rod is 1m long and has threads at both ends. Multiple positioning rods can be screwed together and used to push and pull out the high-pressure expansion capsule in the borehole. The positioning rod body is marked with a length scale with an accuracy of 5mm to determine the pushing depth of the high-pressure expansion capsule. The digital inclination sensor is arranged at the tail end of the high-pressure expansion capsule and can determine the capsule inclination and the angle pointed by each deformation sensor in real time. The portable computer can display the loading pressure on the hole wall rock mass and the deformation magnitude of the hole wall rock mass in real time. The portable computer is small and is equipped with an operating system for the in-situ test device for drilling loading. It can input operating instructions in real time according to the test plan and the deformation of the rock mass on the hole wall, adjust the loading path, and cooperate with the high-pressure expansion capsule and the servo loading system to realize complex in-situ tests such as in-situ cyclic loading and unloading of deep rock, long-term load retention and hole wall fracturing. The variable workbench transport vehicle is an electric four-wheel vehicle. The variable workbench transport vehicle can carry all components of the in-situ test device for drilling loading, and can transport the in-situ test device for drilling loading to a designated test site in the complex environment of a deep underground project. The baffle on the variable workbench transport vehicle can be unfolded horizontally to become a workbench.

[0026] Due to the adoption of the above technical solution, compared with the prior art, the present invention has the following advantages:

[0027] 1. The present invention provides an in-situ testing device for anisotropic rock mechanical properties and ground stress. Through a servo loading system and a high-pressure expansion capsule, the in-situ rock mass can be subjected to complex in-situ testing such as cyclic loading and unloading, long-term load retention and high-pressure fracturing loading according to test requirements without destroying the in-situ rock structure and stress state.

[0028] 2. The present invention provides an in-situ testing device for anisotropic rock mechanical properties and ground stress, which can measure the radial and circumferential deformation of different positions of the borehole wall under the combined action of ground stress and capsule expansion pressure in real time. At the same time, through the battery camera set at the end of the high-pressure expansion capsule, the failure form and failure position of the rock mass in the loading section can be monitored in real time, providing a visual reference for studying the failure evolution of the rock mass at the engineering site. The deformation measurement sensor of the present invention is provided with a sensor spiral pressing rod, which can quickly adjust the sensor position outside the capsule, thereby meeting the needs of measuring the compression and expansion deformation of the borehole wall.

[0029] 3. The present invention provides an in-situ test device for anisotropic rock mechanical properties and ground stress. The two ends of the high-pressure expansion capsule are designed to be gradually reduced, thereby improving the expansion and contraction deformation capacity of the high-pressure expansion capsule to meet the test work of drilling holes with large deformations, and prevent the borehole diameter from shrinking after a certain period of time in deep rock formation, and the capsule cannot be removed. The steel end caps at both ends of the high-pressure expansion capsule can be disassembled, and the size can be changed according to different rock properties to adapt to different rock deformation and loading capacity requirements.

[0030] 4. The present invention provides an in-situ testing device for anisotropic rock mechanical properties and in-situ stress, which has a compact structure, safe operation, fast and efficient test efficiency, simple and reliable method, and intuitive and controllable operation process. It can realize in-situ rock deformation and failure characteristic test of hole wall under in-situ stress and capsule expansion pressure, rock elastic parameter test, rock tensile strength test, rock time failure characteristic test, and in-situ stress direction and size test in one borehole. It has broad practicality and engineering application prospects in the research of in-situ testing of engineering rock mechanical parameters and in-situ stress.

[0031] Based on the above reasons, the present invention can be promoted in the technical field of in-situ testing of engineering rock mass mechanical parameters and ground stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention 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 described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 It is a schematic diagram of field testing of an in-situ testing device for anisotropic rock mechanical properties and in-situ stress according to the present invention;

[0034] Figure 2 It is a stereoscopic diagram of a high-pressure expansion capsule of an in-situ testing device for anisotropic rock mechanical properties and ground stress according to the present invention;

[0035] Figure 3 It is a perspective view of a high-pressure expansion capsule of an in-situ testing device for anisotropic rock mechanical properties and ground stress according to the present invention;

[0036] Figure 4 It is a front view of a high-pressure expansion capsule of an in-situ testing device for anisotropic rock mechanical properties and ground stress according to the present invention;

[0037] Figure 5 It is an AA cross-sectional view of a high-pressure expansion capsule of an in-situ testing device for anisotropic rock mechanical properties and ground stress according to the present invention;

[0038] Figure 6 It is a schematic diagram of an integrated measurement system for radial and annular deformation of a borehole wall of an in-situ testing device for anisotropic rock mechanical properties and ground stress described in the present invention.

[0039] In the figure: 1. high-pressure expansion capsule; 2. low-pressure filling pump; 3. high-pressure loading pump; 4. servo controller; 5. deformation collector; 6. wire reel; 7. positioning rod; 8. portable computer; 9. variable workbench transport vehicle; 10. drilling; 11. in-situ rock mass; 12. flexible outer membrane; 13. first steel end cover; 14. second steel end cover; 15. hemispherical glass cover; 16. battery camera; 17. radial deformation measurement sensor hole; 18. circumferential deformation measurement sensor hole; 19. capsule bracket; 110. pulley; 111. inclination sensor base; 112. digital inclination sensor; 113. steel pull rod; 114. internal hydraulic oil inlet and outlet holes; 115. internal line inlet Exit hole; 116, high-voltage connector; 117, hydraulic sensor; 118, radial deformation measuring sensor base; 119, hydraulic oil and line channel; 120, flexible outer membrane sealing groove; 121, flexible outer membrane raised sealing lip; 122, steel end cover sealing groove, 123, steel end cover raised sealing lip; 124, circumferential deformation measuring sensor; 125, radial deformation measuring sensor; 126, circumferential deformation measuring sensor rod body; 127, radial deformation measuring sensor rod body; 128, circumferential deformation measuring sensor pressure cap; 129, radial deformation measuring sensor pressure cap; 130, circumferential deformation measuring sensor spiral press rod; 131, radial deformation measuring sensor spiral press rod. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0043] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0044] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0045] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0046] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0047] like Figure 1 As shown, the present invention provides an in-situ testing device for the mechanical properties of anisotropic rock mass and ground stress, comprising: a high-pressure expansion capsule 1, a low-pressure liquid filling pump 2, a high-pressure loading pump 3, a servo controller 4, a deformation collector 5, a reel 6, a positioning rod 7, a portable computer 8 and a variable workbench transport vehicle 9. The device components 1-8 of the present invention can be placed on the variable workbench transport vehicle 9 and transported to the on-site test site by it. The positioning rod 7 is 1m long, and threads are engraved on both ends of the positioning rod 7. Multiple positioning rods 7 can be screwed together and fixedly connected, which is used for pushing and pulling out the high-pressure expansion capsule 1 in the borehole 10. The positioning rod 7 is marked with a length scale with an accuracy of 5mm on the rod body, which is used to judge the pushing depth of the high-pressure expansion capsule 1 in the hole. The high-pressure expansion capsule 1 is pushed into the borehole 10 by the positioning rod 7, and the in-situ rock mass 11 is loaded, so as to test its mechanical properties and the magnitude and direction of the ground stress there.

[0048] like Figure 1 , Figure 2 and Figure 3 As shown, the main frame of the high-pressure expansion capsule 1 is composed of a flexible outer membrane 12, a first steel end cover 13, a second steel end cover 14 and a steel pull rod 113. The first steel end cover 13 and the second steel end cover 14 are respectively screwed together with the two ends of the steel pull rod 113. The steel pull rod 113 passes through the center of the flexible outer membrane 12. The first steel end cover 13 and the second steel end cover 14 are used to clamp the flexible outer membrane 12. The flexible outer membrane 12 is made of polyurethane material, and the outer surface of the flexible outer membrane 12 is coated with a friction reducer coating for reducing friction, which is used to reduce the friction between the flexible outer membrane 12 and the hole wall rock during loading.

[0049] like Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, flexible outer membrane sealing grooves 120 and flexible outer membrane raised sealing lips 121 are provided at both ends of the flexible outer membrane 12 on the high-pressure expansion capsule 1, and steel end cover sealing grooves 122 and steel end cover raised sealing lips 123 are provided at both ends of the first steel end cover 13 and the second steel end cover 14. A bite sealing method is adopted between the flexible outer membrane sealing grooves 120 and the steel end cover sealing grooves 122 on the two ends of the flexible outer membrane 12 and the first steel end cover 13 and the second steel end cover 14 and the flexible outer membrane raised sealing lips 121 and the steel end cover raised sealing lips 123. The sealing method is similar to the sealing method of automobile vacuum tires, thereby achieving a sealing effect between the flexible outer membrane 12 and the first steel end cover 13 and the second steel end cover 14 under high hydraulic pressure.

[0050] like Figure 1 , Figure 2 and Figure 3As shown, the flexible outer membrane 12 on the high-pressure expansion capsule 1 is in a uniform cylindrical shape in the middle, and in a gradually reduced ellipsoidal shell shape at both ends. The two ends of the steel pull rod 113 are in a gradually reduced ellipsoidal shape. The diameters of the first steel end cap 13 and the second steel end cap 14 are smaller than the diameter of the cylindrical flexible outer membrane 12 in the middle after being filled with hydraulic oil and the diameter of the borehole 10, thereby improving the expansion and contraction deformation capacity of the high-pressure expansion capsule 1 to meet the testing work of the borehole 10 with large deformation, and prevent the borehole 10 from shrinking in diameter after a certain period of time after the deep rock mass is drilled. In the case where the pressure expansion capsule 1 cannot be removed from the borehole 10, the first steel end cap 13 and the second steel end cap 14 can be disassembled and the sizes can be changed according to different rock types. For hard rock with good rock mechanical properties, the deformation of the borehole 10 is small, and the elastic modulus and strength of the rock mass on the hole wall are large. The steel end caps with larger diameters can be replaced to meet the larger loading capacity requirements. For soft rock with poor rock mechanical properties, the deformation of the borehole 10 is large, and the elastic modulus and strength of the rock mass on the hole wall are small. The steel end caps with smaller diameters can be replaced to meet the larger deformation capacity requirements.

[0051] like Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, one end of the steel pull rod 113 in the high-pressure expansion capsule 1 is provided with an internal hydraulic oil inlet and outlet hole 114, an internal line inlet and outlet hole 115 and a hydraulic oil and line channel 119, which are used as channels for the hydraulic oil and sensor lines to enter and exit the high-pressure expansion capsule 1. One internal hydraulic oil inlet and outlet hole 114 is provided, and 24 internal line inlet and outlet holes 115 are provided to meet the needs of 24 deformation measurement sensor lines entering and exiting the high-pressure expansion capsule 1. The hydraulic oil enters and exits the high-pressure expansion capsule 1 through the hydraulic oil and line channel 119 and the internal hydraulic oil inlet and outlet hole 114, and the sensor line enters and exits the high-pressure expansion capsule 1 through the hydraulic oil and line channel 119 and the internal line inlet and outlet hole 115. The sensor line in the high-pressure expansion capsule 1 and the internal line inlet and outlet hole 115 are sealed by a high-voltage connector 116.

[0052] like Figure 1 , Figure 3 and Figure 6As shown, two groups of hole wall radial annular deformation integrated measurement systems are arranged in the high-pressure expansion capsule 1, and each group of hole wall radial annular deformation integrated measurement systems includes 12 deformation measurement sensors. The two groups of hole wall radial annular deformation integrated measurement systems are arranged in the high-pressure expansion capsule 1 at a certain interval, and each group of hole wall radial annular deformation integrated measurement systems includes a set of hole wall radial deformation measurement sensors 125 and two sets of "triangle" shaped hole wall annular deformation measurement sensors 124. Each set of hole wall radial deformation measurement sensors 125 includes 6 radial deformation measurement sensors 125, which are arranged at 60° intervals on the plane, and each set of "triangle" shaped hole wall annular deformation measurement sensors 124 includes 3 annular deformation measurement sensors 124, which are arranged in an equilateral triangle on the plane, and the 6 radial deformation measurement sensors 125 in each group of hole wall radial annular deformation integrated measurement systems are respectively perpendicular to the 6 annular deformation measurement sensors. The sensors 124 are arranged, and the angles pointed by the deformation measurement sensors in the two groups of borehole wall radial and annular deformation integrated measurement systems are different, so as to measure the deformation characteristics of different positions of the borehole wall as much as possible. Two radial deformation measurement sensor bases 118 are arranged on the steel pull rod 113 for placing radial deformation measurement sensors 125. A digital inclination sensor 112 is provided at the tail end of the high-pressure expansion capsule, which is placed on the inclination sensor base 111. The capsule inclination and the angle pointed by each deformation measurement sensor can be judged in real time, so as to obtain the spatial relationship between the deformation measurement sensor and the occurrence of the anisotropic rock mass. The deformation collector 5 is used to collect the deformation data measured by the annular deformation measurement sensor 124 and the radial deformation measurement sensor 125 in real time. According to the data measured by 24 borehole wall radial and annular deformation measurement sensors 124 and radial deformation measurement sensors 125, the deformation of the borehole wall during the entire loading process can be fitted.

[0053] like Figure 2 , Figure 6As shown, the flexible outer membrane 12 on the high-pressure expansion capsule 1 is provided with 12 radial deformation measurement sensor holes 17 and 12 annular deformation measurement sensor holes 18. The annular deformation measurement sensor 124 and the radial deformation measurement sensor 125 contact the hole wall through the radial deformation measurement sensor holes 17 and the annular deformation measurement sensor holes 18 to measure the deformation of the hole wall. The annular deformation measurement sensor 124 is composed of an annular deformation measurement sensor rod body 126, an annular deformation measurement sensor pressure cap 128 and annular deformation measurement sensor spiral press rod 130. The radial deformation measurement sensor 125 is composed of a radial deformation measurement sensor rod body 127, a radial deformation measurement sensor pressure cap 129 and a radial deformation measurement sensor spiral press rod 131. The radial deformation measurement sensor holes 17 and the annular deformation measurement sensor holes 18 are sealed with the flexible outer membrane 12 through the annular deformation measurement sensor pressure cap 128 and the radial deformation measurement sensor pressure cap 129 using the oil pressure reverse sealing principle. The sealing method is similar to the valve core sealing principle, thereby realizing the sealing effect between the flexible outer membrane 12 body and the radial deformation measurement sensor hole 17 and the annular deformation measurement sensor hole 18 under high hydraulic pressure, and the sensor spiral pressing rod 130 and the radial deformation measurement sensor spiral pressing rod 131 are arranged between the annular deformation measurement sensor pressure cap 128 and the radial deformation measurement sensor pressure cap 129, so that the positions of the annular deformation measurement sensor 124 and the radial deformation measurement sensor 125 can be quickly adjusted outside the high-pressure expansion capsule 1, thereby meeting the requirements of hole wall compression and expansion deformation measurement.

[0054] like Figure 1 , Figure 2 and Figure 3 As shown, the high-pressure expansion capsule 1, the low-pressure filling pump 2 and the high-pressure loading pump 3 are interconnected through a high-pressure oil pipe, and a stop valve is provided. The low-pressure filling pump 2 is used to fill the high-pressure loading pump 3 and the high-pressure expansion capsule 1 with hydraulic oil. When the high-pressure loading pump 3 and the high-pressure expansion capsule 1 are filled with hydraulic oil, the filling is stopped, and the high-pressure loading pump 3 continuously pressurizes the high-pressure expansion capsule 1 at a set loading rate and loading instruction until the specified pressure is reached. A hydraulic sensor 117 is arranged on the steel pull rod 113 in the high-pressure expansion capsule 1 to monitor the pressure in the high-pressure expansion capsule 1. The servo controller 4 adjusts the density of the hydraulic oil in the high-pressure expansion capsule 1 in real time based on the data measured by the hydraulic sensor 117, thereby realizing complex loading instructions such as stable loading and unloading and long-term load maintenance of the pressure in the high-pressure expansion capsule 1.

[0055] like Figure 1 and Figure 2As shown, a hemispherical glass cover 15 and a battery camera 16 are arranged at the end of the high-pressure expansion capsule 1. The battery camera 16 is used to collect the states of the rock mass of the borehole wall before and after loading, and can wirelessly transmit the captured images inside the borehole to the outside of the borehole. The battery camera 16 has three main functions. First, before the borehole 10 is loaded, the quality of the rock mass on the borehole wall and the occurrence of the rock mass can be observed, and the rock mass properties at the loading position of the borehole 10 can be judged. During the loading process of the borehole 10, the failure form of the rock mass near the loading section can be monitored in real time. After the loading of the borehole 10 is completed, the failure form of the rock mass in the loading section can be monitored immediately. The observed rock mass failure position and the deformation monitoring result are calibrated with each other, so as to fit the change of the borehole wall morphology from the beginning to the end of loading, which provides a visual reference for studying the failure evolution of the rock mass on the engineering site. According to the observed failure mode and specific failure position of the rock mass combined with the measured deformation of the borehole wall rock mass, the anisotropic mechanical properties of the rock mass and the magnitude and direction of the ground stress can be analyzed, wherein the ground stress test principle is similar to the hydraulic fracturing method. The hemispherical glass cover 15 covers the outside of the battery camera 16 to prevent dust and water vapor in the hole from contaminating the camera. The display screen of the portable computer 8 is used to display the pictures in the hole taken by the battery camera 16 in real time.

[0056] Furthermore, the portable computer 8 can display the loading pressure and deformation size of the borehole wall rock mass in real time. The portable computer 8 is equipped with an operating system for the borehole 10 loading in-situ test device, which can input operating instructions in real time according to the test plan and the deformation of the borehole wall rock mass, adjust the loading path requirements, and cooperate with the high-pressure expansion capsule 1 and the servo loading system to achieve complex in-situ testing tests such as deep rock in-situ cyclic loading and unloading, long-term load retention and borehole wall fracturing. The variable workbench transport vehicle 9 is an electric four-wheel vehicle. The variable workbench transport vehicle 9 can carry all components of the borehole 10 loading in-situ test device 1-8, and can transport the borehole 10 loading in-situ test device to the designated test site in the complex environment of the deep underground project. The baffle on the variable workbench transport vehicle 9 can be unfolded horizontally to become a workbench to meet the needs of on-site test office.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An in-situ testing device for anisotropic rock mechanical properties and ground stress, characterized in that: include: High-pressure expansion capsule, servo loading system, deformation acquisition instrument, drilling camera system, auxiliary test system; The main frame of the high-pressure expansion capsule is composed of a flexible outer membrane, two steel end covers and a steel tie rod. The two steel end covers are respectively screwed together with the two ends of the steel tie rod. The steel tie rod passes through the center of the flexible outer membrane. The steel end covers are used to clamp the flexible outer membrane. The flexible outer membrane is made of polyurethane material. The outer surface of the flexible outer membrane is coated with a friction reducing agent coating to reduce the friction between the flexible outer membrane and the hole wall rock during loading. The hydraulic sensor of the servo loading system is installed on the steel pull rod in the high-pressure expansion capsule to monitor the pressure, and the servo controller adjusts the pressure in the high-pressure expansion capsule in real time based on the data monitored by the hydraulic sensor; The data measured by the deformation measurement sensor in the high-pressure expansion capsule is collected in real time by the deformation collector; The battery camera of the drilling camera system is installed at the front end of the high-pressure expansion capsule, and can wirelessly transmit the images taken inside the hole to the outside of the hole.

2. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: Sealing grooves and raised sealing lips are arranged on both ends of the flexible outer membrane and the two steel end covers, and a bite sealing method is adopted between the raised sealing lips on the two ends of the flexible outer membrane and the two steel end covers and the sealing grooves.

3. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: The flexible outer membrane has a uniform cylindrical shape in the middle and a gradually reduced ellipsoidal shell shape at both ends. The steel pull rod has a gradually reduced ellipsoidal shape at both ends. The diameter of the steel end cap is smaller than the diameter of the cylindrical flexible outer membrane in the middle after being filled with hydraulic oil and the diameter of the drill hole. The steel end cover can be disassembled and the size can be changed according to different rock types.

4. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: Two groups of hole wall radial annular deformation integrated measurement systems are arranged in the high-pressure expansion capsule, each group of hole wall radial annular deformation integrated measurement systems includes 12 deformation measurement sensors, and the two groups of hole wall radial annular deformation integrated measurement systems are arranged at intervals in the high-pressure expansion capsule. Each group of hole wall radial annular deformation integrated measurement systems includes a set of hole wall radial deformation measurement sensors and two sets of "triangle" shaped hole wall annular deformation measurement sensors. Each set of hole wall radial deformation measurement sensors includes 6 radial deformation measurement sensors, which are arranged at 60° intervals on the plane, and each set of "triangle" shaped hole wall annular deformation measurement sensors includes 3 annular deformation measurement sensors, which are arranged in an equilateral triangle on the plane, and the 6 radial deformation measurement sensors in each group of hole wall radial annular deformation integrated measurement systems are arranged perpendicular to the 6 annular deformation measurement sensors.

5. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: One end of the steel pull rod in the high-pressure expansion capsule is provided with an internal hydraulic oil inlet and outlet hole, an internal line inlet and outlet hole, and a hydraulic oil and line channel, which are used as channels for the hydraulic oil and sensor lines to enter and exit the high-pressure expansion capsule, wherein one internal hydraulic oil inlet and outlet hole is provided, and 24 internal line inlet and outlet holes are provided to meet the needs of the lines of 24 deformation measurement sensors entering and exiting the high-pressure expansion capsule; The deformation measurement sensor circuit in the high-pressure expansion capsule and the internal circuit inlet and outlet holes are sealed by a high-voltage connector.

6. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 2, characterized in that: The flexible outer film is provided with a deformation measuring hole, and the deformation measuring sensor contacts the hole wall through the deformation measuring hole to measure the deformation of the hole wall; The deformation measurement sensor is composed of a sensor rod body, a pressure cap and a sensor spiral press rod. The deformation measurement hole and the flexible outer membrane are sealed by the pressure cap using the oil pressure reverse sealing principle, thereby achieving a sealing effect between the flexible outer membrane body and the deformation measurement hole under high hydraulic pressure; A sensor spiral pressing rod is arranged in the middle of the pressing cap, and the position of the sensor can be quickly adjusted outside the capsule, thereby meeting the requirements of hole wall compression and expansion deformation measurement.

7. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: The servo loading system includes a low-pressure filling pump, a high-pressure loading pump, a servo controller and a hydraulic sensor, the low-pressure filling pump is used to fill the high-pressure loading pump and the high-pressure expansion capsule with hydraulic oil, and the high-pressure loading pump is used to continuously pressurize the high-pressure expansion capsule at a stable rate until the target pressure is reached; The hydraulic pressure sensor is mounted on a steel pull rod in the high-pressure expansion capsule and is used to monitor the pressure in the high-pressure expansion capsule; The servo controller adjusts the pressure in the high-pressure expansion capsule in real time based on the pressure data monitored by the hydraulic sensor.

8. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: The drilling camera system includes a battery camera, a hemispherical glass cover and a video display screen. The drilling camera system is used to collect the states of the rock mass on the borehole wall before and after loading, to judge the rock mass properties and occurrence of the loaded part of the borehole before the on-site loading test, and to observe the failure mode and specific failure position of the rock mass after the loading test, and to analyze the anisotropic mechanical properties of the rock mass and the magnitude and direction of the ground stress in combination with the measured deformation of the borehole wall rock mass; the battery camera is installed at the front end of the high-pressure expansion capsule, and the captured images inside the hole can be wirelessly transmitted to the outside of the hole; the hemispherical glass cover is covered on the outside of the battery camera to prevent dust and water vapor in the hole from contaminating the camera, and the video display screen is used to display the borehole wall images captured by the battery camera in real time, and the video display screen adopts the display screen of a portable computer.

9. The in-situ testing device for anisotropic rock mechanical properties and ground stress according to claim 1, characterized in that: The auxiliary test system includes a positioning rod, a digital inclination sensor, a wire reel, a portable computer and a variable workbench transport vehicle. The positioning rod is 1m long and has threads at both ends. Multiple positioning rods can be screwed together and used to push and pull out the high-pressure expansion capsule in the borehole. The positioning rod body is marked with a length scale with an accuracy of 5mm to determine the pushing depth of the high-pressure expansion capsule. The digital inclination sensor is arranged at the tail end of the high-pressure expansion capsule and can determine the capsule inclination and the angle pointed by each deformation sensor in real time. The portable computer can display the loading pressure on the hole wall rock mass and the deformation size of the hole wall rock mass in real time. The portable computer is equipped with an operating system for the borehole loading in-situ test device, which can input operating instructions in real time according to the test plan and the deformation of the borehole wall rock mass, adjust the loading path, and cooperate with the high-pressure expansion capsule and the servo loading system to realize complex in-situ testing experiments such as deep rock in-situ cyclic loading and unloading, long-term load retention and borehole wall fracturing. The variable workbench transport vehicle is an electric four-wheel vehicle. The variable workbench transport vehicle can carry all components of the borehole loading in-situ test device, and can transport the borehole loading in-situ test device to a designated test site in the complex environment of a deep underground project. The baffle on the variable workbench transport vehicle can be unfolded horizontally to become a workbench.

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