An in-situ stress relief simulation test equipment

Abstract

The present application provides a kind of original rock stress release simulation test equipment, can be used in laboratory to the stress release measurement technology of field stress for simulation operation. Including: stress simulation device, the stress simulation device can as far as possible to the real three-dimensional ground stress environment simulation of test rock mass;Release drilling device, with the hollow drill bit for drilling the strain measuring device installed in the test rock mass, the drilling hole is coaxially arranged with the hollow drill bit.Such, by this test equipment can calibrate the series parameters of strain measuring device required by stress release, and thus more accurate ground stress data is obtained in field application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock mass mechanics test equipment, and in particular to a simulation test equipment for original rock stress relief. BACKGROUND

[0002] At present, in deep engineering, the ground stress environment is more complex and changeable than in shallow engineering. Dynamic disasters caused by ground stress seriously threaten the life and property safety of mining enterprises. Therefore, the measurement of ground stress has become an important research content in the fields of geotechnical engineering and mining. With the continuous development of ground stress measurement technology, stress relief method is a relatively common measurement method. In the field operation, the stress relief method can obtain more accurate ground stress related values. However, due to the strain measurement equipment, there are still errors in the data. Therefore, parameter calibration and research need to be carried out in the laboratory. In related technologies, biaxial loading is mostly carried out in two-dimensional stress environment for simulation, and drilling and punching are carried out for stress relief, which cannot continuously simulate the real three-dimensional ground stress environment. This will undoubtedly lead to errors in obtaining ground stress related values. This error may affect the safety of engineering design and construction, as well as the stability of geotechnical engineering. Therefore, it is urgent to design a test equipment to make up for the defects of the current research. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a simulation test equipment for original rock stress relief, which can improve the accuracy of the related data obtained by measurement, and at least partially solve the problems in the related art.

[0004] In order to achieve the above purpose, the present application provides a simulation test equipment for original rock stress relief, which comprises:

[0005] The stress simulation device comprises a bearing table and a counterforce assembly installed on the bearing table. The bearing table is provided with a placement position for placing a test rock mass. The counterforce assembly is provided with an opening for the hydraulic loading column to pass through at both ends arranged opposite in a first direction. The end of the counterforce assembly away from the placement position is provided with an opening for the hydraulic loading column to pass through. The counterforce assembly is provided with a drilling hole and an opening for the hydraulic loading column to pass through at both ends arranged opposite in a second direction.

[0006] The relief drilling device has a hollow drill bit for drilling a strain measurement equipment installed in the test rock mass. The drilling hole and the hollow drill bit are coaxially arranged.

[0007] Optionally, the counterforce assembly comprises a counterforce frame and a counterforce plate.

[0008] The counterforce frame is connected to the upper surface of the bearing table at one end and connected to the counterforce plate at the other end, the end of the counterforce plate away from the counterforce frame is connected to the bearing table, the counterforce plate is provided with the drilling hole, and the end face of the counterforce frame away from the drilling hole is provided with the opening.

[0009] Optionally, the counterforce frame comprises a fixed plate provided with the opening and a connecting beam for connecting the fixed plate and the counterforce plate, the bearing table is provided with a first plug-in slot for plugging the fixed plate and a second plug-in slot for plugging the counterforce plate, and the two ends of the bearing table arranged opposite in the second direction are respectively provided with a first threaded hole and a second threaded hole, the fixed plate is provided with a first through hole corresponding to the first threaded hole, and the counterforce plate is provided with a second through hole corresponding to the second threaded hole.

[0010] Optionally, the connecting beam comprises a connecting rod and a mounting member fixed to both ends of the connecting rod.

[0011] The mounting member is provided with a clamping slot and a first perforation for screw rod, and the fixed plate and the counterforce plate are both provided with a second perforation corresponding to the first perforation.

[0012] The number of the connecting beams is two, the two connecting beams are arranged opposite in the first direction, and the two connecting beams are both arranged between the fixed plate and the counterforce plate.

[0013] Optionally, the placement site is configured as an open slot recessed in the upper surface of the bearing table.

[0014] The two ends of the open slot arranged opposite in the second direction are respectively a channel opening and a positioning side wall surface.

[0015] Optionally, it further comprises a first uniform force plate, the number of the first uniform force plates is two, and the two first uniform force plates are arranged at the two ends of the open slot arranged opposite in the first direction.

[0016] Optionally, the first uniform force plate is fixed with a support plate at one end close to the open slot, and the two side wall surfaces of the open slot arranged opposite in the first direction are both provided with a receiving slot for receiving the support plate.

[0017] The positioning side wall surface and the test rock mass are further provided with a second uniform force plate, and the upper surface of the test rock mass is placed with the third uniform force plate.

[0018] Optionally, it further comprises a moving assembly.

[0019] The moving assembly comprises a sliding table and a base, the sliding table is slidingly connected to the base, and the upper surface of the sliding table is installed with the drilling releasing device.

[0020] Optionally, the drilling releasing device comprises a mounting frame, a driving motor, a first transmission assembly, a driving rod, a second transmission assembly, a transmission rod, a variable-diameter joint, a core sleeve and the hollow drill bit;

[0021] The output shaft of the driving motor is connected with the driving rod through the first transmission assembly, the driving rod is connected with the transmission rod through the second transmission assembly, one end of the transmission rod away from the second transmission assembly is connected with the variable-diameter joint, the variable-diameter joint is used for connecting the core sleeve, and one end of the core sleeve away from the variable-diameter joint is connected with the hollow drill bit;

[0022] The mounting frame is provided with a bearing seat for fixing the driving rod and the transmission rod, and the mounting frame is further fixedly connected with an extension sleeve for supporting the core sleeve, the extension sleeve is provided with a ring on the inner wall surface, the core sleeve passes through the ring, and the connecting part of the core sleeve and the ring is provided with a bearing.

[0023] Optionally, the first transmission assembly comprises a first belt pulley connected with the output shaft of the driving motor and a second belt pulley mounted on the driving rod, the first belt pulley and the second belt pulley are connected through a belt, and the second transmission assembly is configured as a CVT stepless speed change mechanism.

[0024] Through the above technical solution, the plurality of hydraulic loading columns extend to the inside of the reaction force assembly through the openings provided on the reaction force assembly from multiple directions, and then abut against the test rock mass, so as to simulate the real three-dimensional stress environment as much as possible, so that the data measured by the strain measuring device installed in the test rock mass is closer to the real data, that is, after the strain measuring device is installed in the test rock mass and it is ensured that the strain on the hole wall can be obtained, the strain data is recorded as initial strain data, then the strain data is recorded in real time at a slow speed or equal interval, and the strain data is recorded after the strain data is relatively stable, the strain data is the release strain data, at this time, the stress release operation is completed, and then according to the measurement principle of the strain measuring device and the related calculation method, the related numerical value of the preset three-dimensional stress level can be solved. This device can well simulate the stress release technology of the engineering site stress test in the laboratory, improve the accuracy of the strain measuring device, and provide more accurate basis for the on-site geotechnical engineering design according to the simulation calculation results in the laboratory, which is helpful for personnel to evaluate and predict the risks that may be caused by the change of ground stress, and improves the safety of construction personnel.

[0025] Other features and advantages of the present disclosure will be described in detail in the following specific embodiments section. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only aim to some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0027] Figure 1 is a structural schematic diagram of the original rock stress relief simulation test equipment provided in the exemplary embodiments of the present disclosure;

[0028] Figure 2 is a front view structural schematic diagram of the stress simulation device provided in the exemplary embodiments of the present disclosure, wherein the connecting beams are not shown;

[0029] Figure 3 is a side view structural schematic diagram of the stress simulation device provided in the exemplary embodiments of the present disclosure, wherein the connecting beams are not shown;

[0030] Figure 4 is a structural schematic diagram of the counterforce assembly and the bearing table provided in the exemplary embodiments of the present disclosure;

[0031] Figure 5 is a structural schematic diagram of the bearing table provided in the exemplary embodiments of the present disclosure, wherein the fixed plate and the counterforce plate are installed;

[0032] Figure 6 is a structural schematic diagram of one angle of the bearing table provided in the exemplary embodiments of the present disclosure;

[0033] Figure 7 is a structural schematic diagram of the bearing table provided in the exemplary embodiments of the present disclosure, wherein the first uniform force plate is installed;

[0034] Figure 8 is a structural schematic diagram of the first uniform force plate provided in the exemplary embodiments of the present disclosure;

[0035] Figure 9 is a structural schematic diagram of the connecting beam provided in the exemplary embodiments of the present disclosure;

[0036] Figure 10 is a structural schematic diagram of another angle of the bearing table provided in the exemplary embodiments of the present disclosure;

[0037] Figure 11 is a structural schematic diagram of the fixed plate provided in the exemplary embodiments of the present disclosure;

[0038] Figure 12 is a structural schematic diagram of the counterforce plate provided in the exemplary embodiments of the present disclosure.

[0039] Reference Signs List

[0040] 1-bearings; 101-first insertion slot; 102-second insertion slot; 103-first threaded hole; 104-second threaded hole; 105-open slot; 1051-passage opening; 1052-positioning side wall surface; 1053-receiving groove; 2-counterforce frame; 201-fixed plate; 2011-first through hole; 202-connection beam; 2021-connection rod; 2022-mounting member; 20221-clamping groove; 20222-first through hole; 3-counterforce plate; 301-drilling hole; 302-second through hole; 4-drilling releasing device; 401-mounting frame; 402-driving motor; 403-first transmission assembly; 4031-first pulley; 4032-second pulley; 404-driving rod; 405-second transmission assembly; 406-transmission rod; 407-reducer; 408-core sleeve; 409-hollow drill bit; 410-extension sleeve; 411-ring sleeve; 5-second through hole; 6-first uniform force plate; 601-supporting plate; 7-second uniform force plate; 8-third uniform force plate; 9-moving assembly; 901-sliding table; 902-base; 10-test rock mass; 11-hydraulic loading column; 12-strain measuring device. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0042] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the embodiments of the present application should be understood as their common meanings to those skilled in the art to which the present disclosure pertains. The terms "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. The terms "comprise", "include" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms do not mean physical or mechanical connection, but can include electrical connection, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like only represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0043] In the specific embodiments provided in the present disclosure, a raw rock stress releasing simulation test equipment is provided, which refers to Figures 1 to 10As shown, the original rock stress relief simulation test equipment includes: a stress simulation device and a relief drilling device 4, wherein the stress simulation device can simulate a more realistic three-dimensional stress environment for the test rock 10, that is, the stress simulation device includes a bearing table 1 and a counterforce assembly installed on the bearing table 1, the bearing table 1 is provided with a placement site for placing the test rock 10, the counterforce assembly is provided with openings for the hydraulic loading columns 11 to pass through at two ends oppositely arranged in a first direction, and the two hydraulic loading columns 11 extend to the inside of the counterforce assembly from the opposite sides of the first direction through the openings and apply pressure to the test rock 10; one end of the counterforce assembly away from the placement site is provided with an opening for the hydraulic loading column 11 to pass through, that is, one hydraulic loading column 11 is arranged above the placement site, the hydraulic loading column 11 extends to the inside of the counterforce assembly through the opening and applies pressure to the test rock 10 from above the test rock 10 towards the placement site, and at this time the placement site gives the test rock 10 a reaction force towards the upper side; the two ends of the counterforce assembly oppositely arranged in a second direction are respectively provided with a drilling hole 301 and an opening for the hydraulic loading column 11 to pass through, that is, one end of the counterforce assembly towards the relief drilling device 4 is provided with a drilling hole 301 for the hollow drill bit 409 to extend to the inside of the counterforce assembly, thereby ensuring that the hollow drill bit 409 can drill the strain measuring device 12 installed in the test rock 10, therefore, the end of the counterforce assembly provided with the drilling hole 301 cannot be provided with the hydraulic loading column 11 for applying pressure to the test rock 10, and a path for the movement of the hollow drill bit 409 needs to be reserved, and at the same time, the end of the counterforce assembly away from the drilling hole 301 can be provided with an opening for the hydraulic loading column 11 to pass through, which can be understood as applying pressure to the test rock 10 from the back of the test rock 10, and when the hydraulic loading column 11 at the back of the test rock 10 applies pressure to it, the counterforce assembly can give the test rock 10 an opposite reaction force, based on which Figure 1 and Figure 1 and Figure 2As shown, four hydraulic loading columns 11 respectively apply pressure to the test rock mass 10 from above, left, right and rear of the test rock mass 10, and a counterforce assembly is used to apply a counterforce to the test rock mass 10 through the bearing table 1, so as to more truly simulate a three-dimensional ground stress environment, improve the accuracy of the relevant data obtained by measurement, and as far as possible reduce data errors, so as to provide more accurate basis for geotechnical engineering design. Meanwhile, the drilling device 4 has a hollow drill bit 409 for drilling a strain measuring device 12 installed in the test rock mass 10, that is, the strain measuring device 12 is installed in the test rock mass 10, and the strain measuring device 12 includes a hollow inclusion strain gauge or a piezomagnetic sensor. The strain measuring device 12 measures relevant strain data, and based on the relevant strain data, the relevant values of the ground stress are solved by the measurement principle of the strain measuring device 12 and the relevant calculation method, so that researchers and engineers can more accurately understand and predict the behavior of rock and soil underground, thereby providing important scientific basis for the design and construction of geotechnical engineering.

[0044] Through the above technical solution, the plurality of hydraulic loading columns 11 extend to the inside of the counterforce assembly through the openings provided on the counterforce assembly from multiple directions, and then abut against the test rock mass 10, so as to as far as possible simulate a real three-dimensional ground stress environment, so that the data measured by the strain measuring device 12 installed in the test rock mass 10 is closer to the real data. That is, before the strain measuring device 12 installed in the test rock mass 10 is drilled by the drilling device 4, the strain data needs to be recorded, and at this time, the recorded strain data is initial strain data. After the operation is completed, the strain data is recorded after being stable, and the strain data is release strain data. Then, according to the measurement principle of the strain measuring device 12 and the relevant calculation method, the relevant values of the ground stress can be solved. Through the relevant values of the ground stress, more accurate basis can be provided for geotechnical engineering design, which is helpful for personnel to evaluate and predict the risks that may be caused by the change of ground stress, and improve the safety of construction personnel.

[0045] In the present disclosure, the first direction can refer to the X direction in Figure 4 , and the second direction can refer to the Y direction in Figure 4 . The first direction can be understood as the length direction of the bearing table 1, and the second direction can be understood as the width direction of the bearing table 1.

[0046] In some embodiments, the first direction can refer to the X direction in Figures 4 to 10As shown, the reaction force assembly comprises a reaction force frame 2 and a reaction force plate 3, wherein one end of the reaction force frame 2 is connected to the upper surface of the bearing table 1, and the other end is connected to the reaction force plate 3, the end of the reaction force plate 3 away from the reaction force frame 2 is connected to the bearing table 1, the reaction force plate 3 is provided with a drilling hole 301, and the end face of the reaction force frame 2 away from the drilling hole 301 is provided with an opening, that is, when the hydraulic loading column 11 located at the back of the test rock mass 10 applies pressure to the test rock mass 10, the hydraulic loading column 11 extends to the inside of the reaction force frame 2 through the opening provided on the reaction force frame 2 and abuts against the test rock mass 10, thereby causing the reaction force plate 3 to abut against the test rock mass 10 and apply a reaction force to it.

[0047] In some embodiments, with reference to Figures 4 to 10 As shown, the reaction force frame 2 comprises two parts, namely a fixed plate 201 provided with an opening and a connecting beam 202 for connecting the fixed plate 201 and the reaction force plate 3, and the fixed plate 201 and the connecting beam 202 are detachably connected, which facilitates personnel to classify and store the fixed plate 201 and the connecting beam 202, and when the measurement operation is not needed, the reaction force frame 2 can be detached from the bearing table 1 and the fixed plate 201 and the connecting beam 202 can be separated, which can significantly save storage space, especially in the case of limited laboratory space.

[0048] In some embodiments, with reference to Figures 4 to 10 As shown, the bearing table 1 is provided with a first plug-in slot 101 for plugging the fixed plate 201 and a second plug-in slot 102 for plugging the reaction force plate 3, and the fixed plate 201 and the reaction force plate 3 are installed on the bearing table 1 in the form of plugging, and in order to ensure that the fixed plate 201 and the reaction force plate 3 can be firmly installed on the bearing table 1, the first threaded hole 103 and the second threaded hole 104 are respectively arranged at the two ends of the bearing table 1 in the second direction, the first through hole 2011 corresponding to the first threaded hole 103 is arranged on the fixed plate 201, and the second through hole 302 corresponding to the second threaded hole 104 is arranged on the reaction force plate 3, that is, when the fixed plate 201 is plugged into the first plug-in slot 101, the first through hole 2011 arranged on the fixed plate 201 is coaxial with the first threaded hole 103, at this time, the fixed plate 201 is fixed by a bolt, so that the fixed plate 201 is firmly connected to the bearing table 1; when the reaction force plate 3 is plugged into the second plug-in slot 102, the second through hole 302 arranged on the reaction force plate 3 is coaxial with the second threaded hole 104, at this time, the reaction force plate 3 is fixed by a bolt, so that the reaction force plate 3 is firmly connected to the bearing table 1.

[0049] In some embodiments not shown, the connecting beam 202 comprises connecting columns with external threads for screwing nuts, which are arranged between the fixed plate 201 and the counterforce plate 3 and have through holes for the connecting columns on the fixed plate 201 and the counterforce plate 3. Each connecting column is connected with four nuts, two nuts as a group for clamping and fixing the fixed plate 201 and the counterforce plate 3. In order to ensure the stability of the connection of the nuts, a gasket can be sleeved on the connecting column. Each nut corresponds to at least one gasket.

[0050] In some embodiments, referring to Figures 4 to 12 As shown, the connecting beam 202 comprises a connecting rod 2021 and mounting pieces 2022 fixed at both ends of the connecting rod 2021. The mounting piece 2022 is provided with a clamping groove 20221 and a first through hole 20222 for screw rods. The fixed plate 201 and the counterforce plate 3 are provided with second through holes 5 corresponding to the first through hole 20222. During installation, the two mounting pieces 2022 at both ends of the connecting rod 2021 are aligned with the fixed plate 201 and the counterforce plate 3, respectively. Then the clamping groove 20221 of the mounting piece 2022 is inserted into the fixed plate 201 and the counterforce plate 3. After the insertion is completed, the second through hole 5 of the fixed plate 201 and the second through hole 5 of the counterforce plate 3 are coaxial with the first through hole 20222 of the corresponding mounting piece 2022. Then the screw rods are inserted and fixed by nuts.

[0051] In some embodiments, the clamping groove 20221 can effectively increase the contact area of the mounting piece 2022 with the fixed plate 201 and the counterforce plate 3, thereby effectively increasing the connection strength between the connecting beam 202 and the fixed plate 201 and the counterforce plate 3. The counterforce plate 3 can better provide a counterforce to the test rock mass 10, ensuring that a more realistic three-dimensional stress environment simulation can be provided to the test rock mass 10.

[0052] In some embodiments, the number of connecting beams 202 is two. The two connecting beams 202 are arranged opposite to each other along the first direction and are arranged between the fixed plate 201 and the counterforce plate 3. The fixed plate 201, the counterforce plate 3 and the two connecting beams 202 form an opening, so that the hydraulic loading column 11 above the test rock mass 10 can extend into the inside of the counterforce assembly through the opening and apply pressure to the test rock mass 10.

[0053] In some embodiments, referring to Figure 6 and Figure 10As shown, the placing position is configured as an open slot 105 recessed on the upper surface of the bearing table 1, wherein the open slot 105 is provided with a passage opening 1051 and a positioning side wall surface 1052 at two ends arranged opposite in the second direction, respectively. The passage opening 1051 is configured to facilitate the personnel to carry the test rock 10 into the open slot 105. In order to ensure that the test rock 10 can be better pressed by the plurality of hydraulic loading columns 11, the test rock 10 placed on the upper surface of the open slot 105 needs to be in a suitable position. In order to improve the working efficiency and the placing accuracy when placing the test rock 10, the positioning side wall surface 1052 is used to position the test rock 10, that is, the test rock 10 can be directly abutted against the positioning side wall surface 1052 during the carrying process of the test rock 10. In order to further improve the placing accuracy, two marking lines can be marked on the positioning side wall surface 1052 according to the size of the test rock 10, and the test rock 10 should be placed between the two marking lines.

[0054] In some embodiments, with reference to Figure 7 and Figure 8 As shown, in order to make the hydraulic loading column 11 more uniformly apply pressure to the test rock 10, the first force equalizing plate 6 can be implemented, that is, the number of the first force equalizing plate 6 is two, and the two first force equalizing plates 6 are respectively arranged at two ends of the open slot 105 arranged opposite in the first direction. The two hydraulic loading columns 11 arranged opposite in the first direction of the test rock 10 respectively abut against the test rock 10 through the corresponding first force equalizing plate 6. The first force equalizing plate 6 can uniformly transmit the force applied by the hydraulic loading column 11 to the entire contact surface of the test rock 10, thereby avoiding local stress concentration.

[0055] In some embodiments, with reference to Figure 7 and Figure 8As shown, the first uniform force plate 6 can effectively uniformly transmit the force applied by the hydraulic loading column 11 to the entire contact surface of the test rock mass 10, thereby improving the accuracy of the data tested by the strain measuring device 12, making the test result more reliable. At the same time, the first uniform force plate 6 can also protect the test rock mass 10 from direct high-pressure impact and reduce the damage to the rock mass caused by uneven pressure. Therefore, before the three-dimensional stress environment simulation is performed by the hydraulic loading column 11, the first uniform force plate 6 needs to be placed in the appropriate position to ensure that it can uniformly transmit the force applied by the hydraulic loading column 11 to the entire contact surface of the test rock mass 10, avoiding affecting the accuracy of the test result. Based on this, in order to save manpower and improve the safety of operation, the first uniform force plate 6 is fixedly connected with a support plate 601 near one end of the open groove 105. The included angle between the connection part of the support plate 601 and the first uniform force plate 6 is 90°. The first uniform force plate 6 can be erected on the upper surface of the open groove 105 through the support plate 601. Before the test rock mass 10 is subjected to pressure by the hydraulic loading column 11, the position of the first uniform force plate 6 can be adjusted by adjusting the placement position of the support plate 601. The correct placement position can ensure that the pressure applied to the test rock mass 10 is uniformly distributed, so that the measured data is more reliable, facilitating subsequent data interpretation and analysis, and improving the accuracy of the test result.

[0056] In some embodiments, with reference to Figures 6 to 8 As shown, the two side walls of the open groove 105 arranged opposite in the first direction are each provided with a receiving groove 1053 for receiving the support plate 601. That is, before the three-dimensional stress environment simulation is performed by the hydraulic loading column 11, the first uniform force plate 6 can be arranged on the upper surface of the open groove 105. In order to stably place the first uniform force plate 6 in the open groove 105, the support plate 601 fixedly connected with the first uniform force plate 6 can be inserted into the receiving groove 1053. The support plate 601 is limited by the receiving groove 1053, so that the first uniform force plate 6 is in an erected state and placed on the upper surface of the open groove 105.

[0057] In some embodiments, with reference to Figure 2 and Figure 3 As shown, the second uniform force plate 7 is arranged between the positioning side wall 1052 and the test rock mass 10. The second uniform force plate 7 corresponds to the hydraulic loading column 11 located at the back of the test rock mass 10. The second uniform force plate 7 enables the hydraulic loading column 11 located at the back of the test rock mass 10 to more uniformly apply pressure to the test rock mass 10. The third uniform force plate 8 is placed on the upper surface of the test rock mass 10, thereby corresponding to the hydraulic loading column 11 located above the test rock mass 10. The third uniform force plate 8 enables the hydraulic loading column 11 located above the test rock mass 10 to more uniformly apply pressure to the test rock mass 10.

[0058] In some embodiments, referring to Figure 1 As shown, the mobile assembly 9 further comprises a sliding table 901 and a base 902, the sliding table 901 is slidingly connected to the base 902, and the un-drilling device 4 is mounted on the upper surface of the sliding table 901, i.e., the sliding table 901 can drive the un-drilling device 4 to move along the length direction of the base 902, so that the hollow drill bit 409 can extend to the inside of the reaction force assembly through the drilling hole 301 to contact the test rock mass 10, thereby drilling the strain measuring device 12 installed in the test rock mass 10.

[0059] In some embodiments not shown, the base 902 is fixedly connected with a sliding rail, the bottom of the sliding table 901 is provided with a sliding block matched with the sliding rail, and the base 902 is provided with a driving device for driving the base 902 to move, which can be a pneumatic cylinder or a hydraulic cylinder, and the output end of the driving device is connected with the sliding table 901.

[0060] In some embodiments not shown, the sliding table 901 and the base 902 can be replaced by a ball screw sliding table 901, i.e., the base 902 is provided with two support shaft seats, a screw shaft is installed between the support shaft seats, one end of the screw shaft is connected with the output shaft of the motor through a coupling, a screw nut is installed on the screw shaft, the sliding table 901 is detachably connected with the screw nut, the base 902 is further provided with a guide rail, and the lower surface of the sliding table 901 is provided with a guide rail block matched with the guide rail, the screw shaft is driven to rotate by the driving motor 402, so that the screw nut moves linearly along the length direction of the screw shaft, the screw nut is synchronously driven to move by the screw nut reciprocating along the length direction of the screw shaft by controlling the forward and reverse rotation of the motor output shaft, thereby realizing the movement of the un-drilling device 4, and drilling the strain measuring device 12 installed in the test rock mass 10.

[0061] In some embodiments, referring to Figure 1As shown, the releasing drilling device 4 comprises a mounting frame 401, a driving motor 402, a first transmission assembly 403, a driving rod 404, a second transmission assembly 405, a transmission rod 406, a variable diameter joint 407, a core sleeve 408 and a hollow drill bit 409, wherein the output shaft of the driving motor 402 is connected with the driving rod 404 through the first transmission assembly 403, the driving rod 404 is connected with the transmission rod 406 through the second transmission assembly 405, one end of the transmission rod 406 away from the second transmission assembly 405 is connected with the variable diameter joint 407, the variable diameter joint 407 is used for connecting the core sleeve 408, one end of the core sleeve 408 away from the variable diameter joint 407 is connected with the hollow drill bit 409, that is, the output shaft of the driving motor 402 can drive the driving rod 404 to rotate through the transmission of the first transmission assembly 403, when the driving rod 404 rotates, the driving rod 404 can drive the transmission rod 406 to rotate through the second transmission assembly 405, one end of the transmission rod is connected with the core sleeve 408 and the hollow drill bit 409 through the variable diameter joint 407, therefore, the transmission rod 406 can drive the core sleeve 408 and the hollow drill bit 409 to rotate, when it is needed to remove the strain measuring device 12 installed in the test rock mass 10, the moving assembly 9 can be started to drive the sliding table 901 to move the releasing drilling device 4 as a whole, so that the hollow drill bit 409 can contact the test rock mass 10 through the drilling hole 301 and start the drilling operation, the strain measuring device 12 drilled and the part of the rock mass wrapped outside the strain measuring device 12 are located in the core sleeve 408.

[0062] In some embodiments, the mounting frame 401 can be provided with a control panel, wherein the control panel is provided with a key for controlling the start or stop of the releasing drilling device 4 or a button for controlling the rotation speed of the hollow drill bit 409 and the like.

[0063] In some embodiments, referring to Figure 1 As shown, in order to enable the driving rod 404 and the transmission rod 406 to rotate stably, the mounting frame 401 can be provided with a bearing seat for fixing the driving rod 404 and the transmission rod 406, and in order to enable the core sleeve 408 to rotate stably, the mounting frame 401 is further fixedly connected with an extension sleeve 410 for supporting the core sleeve 408, the inner wall surface of the extension sleeve 410 is provided with a ring 411, the core sleeve 408 passes through the ring 411 and the connecting part of the core sleeve 408 and the ring 411 is provided with a bearing, that is, the extension sleeve 410 and the ring 411 support the core sleeve 408, and the bearing provided at the connecting part of the core sleeve 408 and the ring 411 can reduce the friction between the core sleeves 408, so that the core sleeve 408 can rotate more smoothly.

[0064] In some embodiments, referring to Figure 1As shown, the first transmission assembly 403 includes a first pulley 4031 connected to the output shaft of the drive motor 402 and a second pulley 4032 mounted on the drive rod 404, and the first pulley 4031 and the second pulley 4032 are connected by a belt.

[0065] In some embodiments not shown, the first transmission assembly 403 includes a first sprocket connected to the output shaft of the drive motor 402 and a second sprocket mounted on the drive rod 404, and the first sprocket and the second sprocket are connected by a chain.

[0066] Similarly, the second transmission assembly 405 can also be selected by belt drive or chain drive.

[0067] In some embodiments, referring to Figure 1 As shown, the second transmission assembly 405 is configured as a CVT variable speed mechanism, that is, when the hollow drill bit 409 drills the strain measurement device 12 in the real reproduction of the downhole stress test work in the laboratory, many factors such as the drilling speed of the hollow drill bit 409 when drilling the strain measurement device 12 and the rotation speed of the hollow drill bit 409 may cause the measured values to have errors compared to the true values. In order to reduce the error value, the CVT variable speed mechanism can overcome the problem of the rotation speed of the hollow drill bit 409 being reduced due to resistance when the hollow drill bit 409 contacts the test rock mass 10, and as much as possible to ensure that the entire drilling process is more stable, wherein the drive rod 404 and the transmission rod 406 are provided with variable gear, and the two variable gears are connected by steel belt transmission, and at the same time, a hydraulic assembly (including a hydraulic pump, a hydraulic cylinder and a control valve, wherein the hydraulic pump provides hydraulic power and delivers hydraulic oil to the hydraulic cylinder of the variable gear; the hydraulic cylinder is connected with the variable gear, and the pressure of the hydraulic oil is used to push or pull the gear to change its diameter; the control valve is used to adjust the flow direction and pressure of the hydraulic oil to accurately control the diameter change of the variable gear.) is installed on the upper surface of the sliding table 901, which is convenient for controlling and adjusting the variable gear.

[0068] In some embodiments, when the hollow drill bit 409 drills the strain measurement device 12, in order to prevent the temperature from being too high during drilling to cause the surrounding rock to crack, a water spraying cooling device can be provided, wherein the water spraying pipe of the water spraying cooling device is aimed at the drilling position, thereby reducing the temperature during drilling.

[0069] Device use instruction: before testing, the test rock mass 10 needs to be placed on the upper surface of the open slot 105, and the first uniform force plate 6, the second uniform force plate 7 and the third uniform force plate 8 are placed in the appropriate position in turn, then the counterforce assembly is installed, that is, the fixed plate 201 and the counterforce plate 3 are respectively inserted into the first insertion slot 101 and the second insertion slot 102, then the fixed plate 201 and the counterforce plate 3 are fixed through the bolt, then the connecting beam 202 is installed between the fixed plate 201 and the counterforce plate 3, the fixed plate 201 and the counterforce plate 3 are partially overlapped with the mounting part 2022 through the clamping groove 20221, so as to increase the connection strength; before drilling operation, it is necessary to ensure that the hollow drill bit 409 can contact the test rock mass 10 through the drilling hole 301 on the counterforce plate 3, and then the strain measuring device 12 installed inside is drilled.

[0070] It should be understood by those of ordinary skill in the art that the above discussion of any embodiment is merely exemplary and is not intended to suggest the scope of the disclosure (including claims) is limited to these examples; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in details for the sake of simplicity.

[0071] Embodiments of the present application are intended to cover all such alternatives, modifications, and variations as fall within the broad scope of the appended claims. Accordingly, any one of the steps of the methods provided above can be performed in any sequence. The use of "including", "comprising", "having" "containing", "carrying" or variants thereof in the description above is intended to mean that there are other steps or components that are not specifically mentioned.

Claims

1. An in-situ stress relief simulation test apparatus, characterized by, The stress simulation device comprises a bearing table and a counterforce assembly installed on the bearing table, the bearing table is provided with a placing position for placing a test rock mass, the counterforce assembly is provided with openings for penetrating a hydraulic loading column at two ends arranged oppositely along a first direction, the counterforce assembly is provided with an opening for penetrating the hydraulic loading column at an end away from the placing position, two ends arranged oppositely along a second direction of the counterforce assembly are respectively provided with a drilling hole and an opening for penetrating the hydraulic loading column, the first direction is perpendicular to the second direction; The drilling device is provided with a hollow drill bit for drilling a strain measuring device installed in the test rock mass, the drilling hole is coaxially arranged with the hollow drill bit; before the strain measuring device installed in the test rock mass is drilled by the drilling device, initial strain data measured by the strain device is recorded; after the strain measuring device installed in the test rock mass is drilled by the drilling device, release strain data measured by the strain device is recorded. The counterforce assembly comprises a counterforce frame and a counterforce plate; the counterforce plate is provided with the drilling hole, the counterforce frame comprises a fixed plate provided with an opening and a connecting beam for connecting the fixed plate and the counterforce plate, the bearing table is provided with a first insertion slot for inserting the fixed plate and a second insertion slot for inserting the counterforce plate, two ends of the bearing table arranged oppositely along the second direction are respectively provided with a first threaded hole and a second threaded hole, the fixed plate is provided with a first through hole corresponding to the first threaded hole, and the counterforce plate is provided with a second through hole corresponding to the second threaded hole; The placing position is configured as an open slot recessed on the upper surface of the bearing table; Two ends of the open slot arranged oppositely along the second direction are respectively a channel opening and a positioning side wall surface, and the positioning side wall surface is used for positioning the test rock mass; The stress simulation device further comprises two first uniform force plates, and the two first uniform force plates are arranged at two ends of the open slot arranged oppositely along the first direction; One end of the first uniform force plate close to the open slot is fixedly connected with a support plate, the support plate is perpendicular to the first uniform force plate, and the two side walls of the open slot along the first direction are both provided with receiving grooves for inserting and receiving the support plate; A second uniform force plate is further arranged between the positioning side wall surface and the test rock mass, and a third uniform force plate is placed on the upper surface of the test rock mass. An opening is arranged on the end face of the counterforce frame away from the drilling hole.

2. The in-situ stress release analog test apparatus of claim 1, wherein, The connecting beam comprises a connecting rod and mounting pieces fixedly connected at two ends of the connecting rod; 3. The in-situ stress relief analog test apparatus of claim 1, wherein, The mounting pieces are provided with clamping grooves and first through holes for penetrating a screw rod, and the fixed plate and the counterforce plate are both provided with second through holes corresponding to the first through holes; The number of the connecting beams is two, the two connecting beams are arranged oppositely along the first direction, and the two connecting beams are both arranged between the fixed plate and the counterforce plate. The simulation test equipment further comprises a moving assembly; 4. The in-situ stress relief analog test apparatus of claim 1, wherein, The moving assembly comprises a sliding table and a base, the sliding table is slidingly connected to the base, and the upper surface of the sliding table is provided with the drilling device. ​ 5. The in-situ stress relief analog test apparatus of claim 4, wherein, The drilling device includes a mounting frame, a driving motor, a first transmission assembly, a driving rod, a second transmission assembly, a transmission rod, a variable-diameter joint, a core sleeve and the hollow drill bit; The output shaft of the driving motor is connected with the driving rod through the first transmission assembly, the driving rod is connected with the transmission rod through the second transmission assembly, one end of the transmission rod away from the second transmission assembly is connected with the variable-diameter joint, the variable-diameter joint is used for connecting the core sleeve, and one end of the core sleeve away from the variable-diameter joint is connected with the hollow drill bit. The mounting frame is provided with a bearing seat for fixing the driving rod and the transmission rod, and the mounting frame is further fixedly connected with an extension sleeve for supporting the core sleeve, the inner wall surface of the extension sleeve is provided with a ring sleeve, the core sleeve passes through the ring sleeve, and the connecting part of the core sleeve and the ring sleeve is provided with a bearing.

6. The in-situ stress relief analog test apparatus of claim 5, wherein, The first transmission assembly includes a first belt pulley connected with the output shaft of the driving motor and a second belt pulley mounted on the driving rod, the first belt pulley and the second belt pulley are connected through a belt, and the second transmission assembly is configured as a stepless speed change mechanism.

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