True triaxial mechanical test device applied to variable-angle repeated loading and impact disturbance

Abstract

The invention relates to the technical field of rock mechanical tests, in particular to a true triaxial mechanical test device applied to variable-angle repeated loading and impact disturbance, which comprises a variable-angle transmission mechanism, the variable-angle transmission mechanism comprises a variable-angle transmission main body, variable-angle transmission assemblies symmetrically arranged at the two ends of the variable-angle transmission main body, a box body arranged on the peripheries of the variable-angle transmission main body and the variable-angle transmission assemblies and a force transmission assembly arranged on the box body, and the variable-angle transmission main body comprises a plurality of transmission modules arranged in an array mode in the circumferential direction of the Y axis; the variable-angle transmission assembly comprises a transmission rod and a limiting transmission plate, the limiting transmission plate is arranged in the test piece containing cavity, the transmission rod is fixedly connected with the limiting transmission plate, and when the transmission rod rotates, the limiting transmission plate is driven to rotate so as to drive the variable-angle transmission main body to rotate; therefore, the rock test piece arranged in the test piece accommodating cavity rotates, and the stress direction angle of the roadway in the rock test piece is changed.

Description

Technical Field

[0001] The invention relates to the technical field of rock mechanics testing, in particular to a true triaxial mechanics testing device applied to variable-angle repeated loading and impact disturbance. Background Art

[0002] As coal mining progresses deeper, the stress environment of the tunnel surrounding rock becomes more and more complex. Under the dual effects of high ground stress and strong mining stress, the mechanical properties and deformation and failure characteristics of the tunnel surrounding rock also change significantly. Therefore, studying the mechanical properties of tunnel surrounding rock under dynamic and static loads is crucial to revealing the deformation and failure mechanism of tunnel surrounding rock under dynamic and static loads, as well as to scientifically and rationally control tunnel surrounding rock and ensure safe production in coal mines. For mining tunnels, under the action of mining stress, the principal stress direction of the tunnel surrounding rock will deflect to varying degrees, resulting in asymmetric destruction of the surrounding rock, an increase in the scope of destruction, and an increase in the degree of destruction. In addition, during the mining of the working face, as the working face continues to advance, the roof of the mining area will break periodically, causing severe dynamic load disturbances. Some tunnels will be affected by repeated dynamic load disturbances of varying degrees in different directions during the service cycle, which has an important impact on the stability of the tunnel. At present, in rock mechanics tests, rock specimens are generally placed in prefabricated holes to simulate the mechanical properties of surrounding rocks after underground tunnel excavation. However, the existing true triaxial rock mechanics test device can only apply dynamic and static loads to rock specimens in fixed directions (x-axis, y-axis and z-axis) of the rock specimens. If you want to analyze the deformation and failure characteristics of the surrounding rock under the principal stresses in different directions and angles of the tunnel, or want to analyze the deformation and failure characteristics of the surrounding rock under the repeated dynamic load disturbance of the tunnel in different directions and angles, you can only reprocess the rock specimens and change the direction angle of the principal stress or the direction angle of the repeated dynamic load disturbance by changing the orientation of the tunnel in the rock specimen. This method of reprocessing rock specimens requires remaking specific rock specimens for each direction and angle studied, which is very time-consuming, labor-intensive and material-intensive. In addition, it is impossible to conduct repeated dynamic and static load loading tests on the same specimen with principal stresses in different directions and angles, nor is it possible to conduct repeated dynamic load disturbance tests on the same specimen in different directions and angles. Summary of the invention

[0003] The purpose of the present invention is to provide a true triaxial mechanical testing device for variable angle repeated loading and impact disturbance, so as to solve the problem that the existing true triaxial surrounding rock mechanical testing device can only apply dynamic and static loads to the rock specimen in a fixed direction of the rock specimen, resulting in the inability to realize repeated dynamic and static load loading test research on the principal stress in different directions and angles of the same specimen or repeated dynamic load disturbance test research on the same specimen in different directions and angles.

[0004] To solve the above problems, the present invention provides the following technical solutions: A true triaxial mechanical testing device for variable angle repeated loading and impact disturbance comprises a variable angle transmission mechanism, wherein the variable angle transmission mechanism comprises a variable angle transmission body, a variable angle transmission assembly symmetrically arranged at both ends of the variable angle transmission body, a box arranged at the outer periphery of the variable angle transmission body and the variable angle transmission assembly, and a force transmission assembly arranged on the box, wherein the force transmission assembly comprises a first force transmission member symmetrically arranged at both sides of the variable angle transmission body along the X axis, a second force transmission member symmetrically arranged at both sides of the variable angle transmission body along the Y axis, and a third force transmission member symmetrically arranged at both sides of the variable angle transmission body along the Z axis. The force transmission member, the variable angle transmission body includes a plurality of transmission modules arranged in a circumferential array along the Y axis, a concave cavity is provided on the inner side of the transmission module, and the concave cavities of the plurality of transmission modules are arranged to form a specimen accommodating cavity, the variable angle transmission assembly includes a transmission rod and a limiting transmission plate, the limiting transmission plate is arranged in the specimen accommodating cavity, the transmission rod is extended along the Y axis, one end of the transmission rod is connected to the second force transmission member, and the other end of the transmission rod is fixedly connected to the limiting transmission plate, when the transmission rod rotates, the limiting transmission plate is driven to rotate, so as to drive the variable angle transmission body to rotate.

[0005] As described above, in the true triaxial mechanical testing device applied to variable-angle repeated loading and impact disturbance, the specimen accommodating cavity is in the shape of a rectangular parallelepiped, and the variable-angle transmission body includes four transmission modules, and the transmission module is provided with a cavity bottom surface and two cavity side surfaces for forming the cavity, the two cavity side surfaces are parallel to each other and perpendicular to the Y-axis, and the cavity bottom surface is arranged between the two cavity side surfaces and is parallel to the Y-axis.

[0006] As described above, in the true triaxial mechanical testing device applied to variable angle repeated loading and impact disturbance, the variable angle transmission body is spherical, the first force transmission member is provided with a first arc-shaped force transmission plate cooperating with the variable angle transmission body, and the third force transmission member is provided with a third arc-shaped force transmission plate cooperating with the variable angle transmission body.

[0007] As described above, in the true triaxial mechanical testing device applied to variable-angle repeated loading and impact disturbance, the variable-angle transmission assembly also includes a boss arranged between the transmission rod and the second force transmission member, the boss is provided with an angle scale, the boss is fixedly connected to the transmission rod, and the boss is rotatably connected to the second force transmission member.

[0008] As described above, the true triaxial mechanical testing device applied to variable-angle repeated loading and impact disturbance, the box body includes a box body with an opening at one end and a box cover plate covering the box body, the box cover plate is perpendicular to the Y-axis, the box cover plate is provided with an insertion rod, the insertion rod is parallel to the Y-axis, and the box body is provided with a slot that cooperates with the insertion rod.

[0009] The true triaxial mechanical testing device applied to variable angle repeated loading and impact disturbance as described above also includes a loading mechanism, which includes a first loading member symmetrically arranged on both sides of the variable angle transmission mechanism along the X-axis, a second loading member symmetrically arranged on both sides of the variable angle transmission mechanism along the Y-axis, and a third loading member symmetrically arranged on both sides of the variable angle transmission mechanism along the Z-axis, the first loading member is connected to the first force transmission member, the second loading member is connected to the second force transmission member, and the third loading member is connected to the third force transmission member.

[0010] The true triaxial mechanical testing device applied to variable-angle repeated loading and impact disturbance as described above also includes a frame, which includes two X-axis support plates parallel to each other and perpendicular to the X-axis, two Y-axis support plates parallel to each other and perpendicular to the Y-axis, and two Z-axis support plates parallel to each other and perpendicular to the Z-axis. The first loading member is arranged on the X-axis support plate, the second loading member is arranged on the Y-axis support plate, and the third loading member is arranged on the Z-axis support plate. A loading cavity is formed between the X-axis support plate, the Y-axis support plate, and the Z-axis support plate. Guide columns and a loading mounting plate are provided on the X-axis support plate, the Y-axis support plate, or the Z-axis support plate. The variable-angle transmission mechanism is arranged on the loading mounting plate, and the frame is provided with guide grooves that cooperate with the guide columns.

[0011] The true triaxial mechanical testing device applied to variable angle repeated loading and impact disturbance as described above also includes an impact mechanism, which is connected to the first force transmission member located on one side of the variable angle transmission body to generate impact disturbance to the variable angle transmission mechanism.

[0012] As described above, the true triaxial mechanical testing device applied to variable-angle repeated loading and impact disturbance, the impact mechanism at least includes an air gun, an impact tube and an incident rod connected in sequence, and the incident rod is connected to the first force transmission member.

[0013] As described above, the true triaxial mechanical testing device applied to variable angle repeated loading and impact disturbance, the impact mechanism also includes a connecting rod and a wave rectifier arranged between the impact tube and the incident rod, and the impact mechanism also includes a high-pressure air source connected to the air gun.

[0014] Compared with the prior art, the present invention has the following advantages: The true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance provided by the present invention can drive the variable-angle transmission main body to rotate by rotating the transmission rod, thereby rotating the rock specimen placed in the specimen accommodating cavity and changing the force direction angle of the tunnel in the rock specimen. When the force transmission component is externally connected to the loading mechanism, repeated dynamic and static load loading tests on the principal stresses in different directions and angles can be carried out on the same specimen. When the force transmission component is externally connected to the impact mechanism, repeated dynamic load disturbance tests on the same specimen in different directions and angles can be carried out. There is no need to re-produce the rock specimen during the process, which can save a lot of time, labor and material costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 This is a schematic structural diagram of a true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance according to Example 1 of the present invention.

[0017] Figure 2 This is an exploded view of the partial structure of a true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance according to Example 1 of the present invention.

[0018] Figure 3 This is a cross-sectional view of a variable angle transmission mechanism of a true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to Example 1 of the present invention.

[0019] Figure 4 This is an exploded view of the variable angle transmission mechanism of the true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to Example 1 of the present invention.

[0020] Figure 5 It is a cross-sectional view of the partial structure of the variable angle transmission mechanism of the true triaxial mechanical testing device applied to variable angle repeated loading and impact disturbance according to Example 1 of the present invention.

[0021] Figure 6 This is an exploded view of the local structure of the variable angle transmission mechanism of the true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to Example 1 of the present invention.

[0022] Figure 7 This is a schematic structural diagram of a true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance according to Example 2 of the present invention.

[0023] Figure 8 This is an exploded view of the partial structure of a true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance according to Example 2 of the present invention.

[0024] Fig. 9 This is a cross-sectional view of a variable angle transmission mechanism of a true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to embodiment 2 of the present invention.

[0025] Fig.10 This is an exploded view of the variable angle transmission mechanism of the true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to embodiment 2 of the present invention.

[0026] Fig.11 It is a cross-sectional view of the partial structure of the variable angle transmission mechanism of the true triaxial mechanical testing device applied to variable angle repeated loading and impact disturbance according to embodiment 2 of the present invention.

[0027] Fig.12 This is an exploded view of the partial structure of the variable angle transmission mechanism of the true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to embodiment 2 of the present invention.

[0028] The numbers corresponding to the reference numerals are as follows: 1. variable angle transmission mechanism; 100. specimen accommodating cavity; 11. variable angle transmission body; 110. concave cavity; 111. transmission module; 1111. bottom surface of concave cavity; 1112. side surface of concave cavity; 12. variable angle transmission assembly; 121. transmission rod; 122. limit transmission plate; 123. boss; 13. box body; 131. box body; 132. box cover; 133. plug rod; 134. slot; 135. observation operation port; 136. support plate; 137. slideway; 14. force transmission assembly; 141. first force transmission member; 1411. first arc transmission member force plate; 142, second force transmission member; 143, third force transmission member; 1431, third arc-shaped force transmission plate; 2, loading mechanism; 21, first loading member; 22, second loading member; 23, third loading member; 3, impact mechanism; 31, air gun; 32, impact tube; 33, incident rod; 34, connecting rod; 35, rectifier; 36, high-pressure air source; 4, frame; 400, loading cavity; 41, X-axis support plate; 42, Y-axis support plate; 43, Z-axis support plate; 44, guide column; 45, loading mounting plate; 451, mounting groove; 46, guide groove; 5, detection mechanism. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. 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.

[0030] Example 1 Please refer to the attached Figure 1 To Attachment Figure 5 The present embodiment provides a true triaxial mechanical testing device for variable angle repeated loading and impact disturbance, comprising a variable angle transmission mechanism 1, wherein the variable angle transmission mechanism 1 comprises a variable angle transmission body 11, a variable angle transmission assembly 12 symmetrically arranged at both ends of the variable angle transmission body 11, a box body 13 arranged at the outer periphery of the variable angle transmission body 11 and the variable angle transmission assembly 12, and a force transmission assembly 14 arranged on the box body 13, wherein the force transmission assembly 14 comprises a first force transmission member 141 symmetrically arranged at both sides of the variable angle transmission body 11 along the X axis, a second force transmission member 142 symmetrically arranged at both sides of the variable angle transmission body 11 along the Y axis, and a third force transmission member 143 symmetrically arranged at both sides of the variable angle transmission body 11 along the Z axis. The variable angle transmission body 11 includes a plurality of transmission modules 111 arranged in a circumferential array along the Y axis, a concave cavity 110 is provided on the inner side of the transmission module 111, and the concave cavities 110 of the plurality of transmission modules 111 are arranged to form a specimen accommodating cavity 100, the variable angle transmission assembly 12 includes a transmission rod 121 and a limiting transmission plate 122, the limiting transmission plate 122 is arranged in the specimen accommodating cavity 100, the transmission rod 121 is extended along the Y axis, one end of the transmission rod 121 is connected to the second force transmission member 142, and the other end of the transmission rod 121 is fixedly connected to the limiting transmission plate 122, when the transmission rod 121 rotates, the limiting transmission plate 122 is driven to rotate, so as to drive the variable angle transmission body 11 to rotate. The true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance provided in the present embodiment can drive the variable-angle transmission body 11 to rotate by rotating the transmission rod 121, thereby rotating the rock specimen placed in the specimen accommodating cavity 100 and changing the force azimuth angle of the tunnel in the rock specimen. When the force transmission component 14 is externally connected to a loading mechanism, repeated dynamic and static load loading tests on the principal stresses in different directions and angles can be carried out on the same specimen. When the force transmission component 14 is externally connected to an impact mechanism, repeated dynamic load disturbance tests on the same specimen in different directions and angles can be carried out. In addition, there is no need to re-produce the rock specimen during the process, which can save a lot of time, labor and material costs.

[0031] Specifically, the first force transmission member 141 of the present embodiment is symmetrically arranged at both ends of the box body 13 along the X axis, the second force transmission member 142 is symmetrically arranged at both ends of the box body 13 along the Y axis, and the third force transmission member 143 is symmetrically arranged at both ends of the box body 13 along the Z axis. The first force transmission member 141 and the third force transmission member 143 are in contact with the variable angle transmission body 11, the second force transmission member 142 is detachably connected to the transmission rod 121, and the transmission rod 121 can rotate relative to the second force transmission member 142, and the first force transmission rod 141 and the third force transmission rod 143 are not It can only assist in fixing the positions of the transmission modules 111 in the variable angle transmission body 11, and can transmit the force to the transmission module 111, thereby transmitting the force to the rock specimen in the specimen accommodating chamber 100. The second force transmission rod 142 can not only transmit the force to the limiting transmission plate 122, thereby transmitting the force to the rock specimen in the specimen accommodating chamber 100, but also drive the limiting transmission plate 122 to rotate, thereby driving the rock specimen in the specimen accommodating chamber 100 to rotate, thereby changing the force direction angle of the tunnel in the rock specimen.

[0032] Preferably, the force transmission rod 121 and the limiting transmission plate 122 are integrally formed, and the shape of the limiting transmission plate 122 is the same as the shape of the end face of the specimen accommodating chamber 100. The area of ​​the limiting transmission plate 122 can be less than or equal to the area of ​​the end face of the specimen accommodating chamber 100, that is, there can be a fitting gap between the limiting transmission plate 122 and the specimen accommodating chamber 100, and a sealing rubber ring can be provided on the limiting transmission plate 122, and the sealing rubber ring is matched with the fitting gap.

[0033] Furthermore, the specimen accommodating chamber 100 is in the shape of a rectangular parallelepiped, and the variable angle transmission body 11 includes four transmission modules 111, and the transmission modules 111 are provided with a concave cavity bottom surface 1111 and two concave cavity side surfaces 1112 for forming the concave cavity 110, the two concave cavity side surfaces 1112 are parallel to each other and perpendicular to the Y axis, and the concave cavity bottom surface 1111 is arranged between the two concave cavity side surfaces 1112 and is parallel to the Y axis. Since conventional rock specimens are generally in the shape of a cube, it is preferred that the specimen accommodating chamber 100 of this embodiment is in the shape of a rectangular parallelepiped, wherein the length of the long side of the rectangular parallelepiped is greater than or equal to the sum of the side length of the rock specimen and the thickness of the two limit transmission plates 122. When installing the rock specimen, the concave cavity bottom surface 1111 on the transmission module 111 fits with the end surface of the rock specimen, the concave cavity side surface 1112 on the transmission module 111 is parallel to one end surface of the limiting transmission plate 122, and the other end surface of the limiting transmission plate 122 fits with the rock specimen. The transmission module 111 of this embodiment has a simple structure and is convenient and quick to match with the rock specimen.

[0034] Furthermore, the contact surfaces between the transmission modules 111 in the variable angle transmission body 11 are provided with magnetic suction parts. When the rock specimen is placed in the specimen accommodating cavity 100 of the variable angle transmission body 11, the transmission modules 111 are fixedly connected to form a whole under the action of magnetic suction.

[0035] Furthermore, in order to facilitate the rotation of the variable angle transmission body 11 and ensure the structural stability of the variable angle transmission body 11 during rotation, the variable angle transmission body 11 is spherical, and at the same time, the first force transmission member 141 is provided with a first arc-shaped force transmission plate 1411 that matches the variable angle transmission body 11, and the third force transmission member 143 is provided with a third arc-shaped force transmission plate 1431 that matches the variable angle transmission body 11. When the spherical variable angle transmission body 11 rotates, its arc-shaped end face can always match the first arc-shaped force transmission plate 1411 or the third arc-shaped force transmission plate 1431, and the rotation is smooth without interference, and the first arc-shaped force transmission plate 1411 and the third arc-shaped force transmission plate 1431 provide stable support for the variable angle transmission body 11 in the X-axis direction and the Z-axis direction, respectively.

[0036] Further, in order to improve the accuracy of the rotation of the variable angle transmission body 11, the variable angle transmission assembly 12 also includes a boss 123 disposed between the transmission rod 121 and the second force transmission member 142, an angle scale is provided on the boss 123, the boss 123 is fixedly connected to the transmission rod 121, and the boss 123 is rotatably connected to the second force transmission member 142. When the transmission rod 121 rotates, the angle scale on the boss 123 can display the degree of rotation of the transmission rod 121, which is more accurate and convenient to use. Specifically, in this embodiment, a circle of angle marks is provided on the boss 123, and an angle pointer is provided on the second force transmission member 142. When the boss 123 rotates relative to the second force transmission member 142, the angle pointer on the second force transmission member 142 points to the angle mark of the corresponding reading on the boss 123 to indicate the angle of rotation of the rock specimen. A groove is provided at one end of the boss 123 connected to the second force transmission member 142, and the second force transmission member 142 cooperates with the groove on the boss 123.

[0037] Furthermore, in order to facilitate the placement of the variable angle transmission body 11 and the variable angle transmission assembly 12, the box body 13 includes a box body 131 with an open end and a box cover 132 covering the box body 131, the box cover 132 is perpendicular to the Y axis, a plug rod 133 is provided on the box cover 132, the plug rod 133 is parallel to the Y axis, and a slot 134 is provided on the box body 131 to cooperate with the plug rod 133. When the variable angle transmission body 11 and the variable angle transmission assembly 12 need to be placed, it is only necessary to pull the box cover 132 to make it close to or away from the box body 131 along the Y axis direction, which has a simple structure and is convenient for placement. In addition, a first limiting protrusion is provided on the first force transmission member 141 on the inner side of the box body 13 to prevent the first force transmission member 141 from detaching from the box body 13, a second limiting protrusion is provided on the second force transmission member 142 on the inner side of the box body 13 to prevent the second force transmission member 142 from detaching from the box body 13, and a first limiting protrusion is provided on the third force transmission member 143 on the inner side of the box body 13 to prevent the third force transmission member 143 from detaching from the box body 13.

[0038] Furthermore, a support plate 136 is provided on the box cover 132, and the support plate 136 is fixedly connected to the third force transmission member 143. An observation operation port 135 and a slide slot 137 are provided on the box body 131, and the slide slot 137 cooperates with the third force transmission member 143. When the box cover 132 is pulled out, the support plate 136 and the third force transmission member 143 fixedly connected to the support plate 136 are pulled out together, and the variable angle transmission body 11 and the transmission assembly 12 located on the third force transmission member 143 are also pulled out, so as to facilitate the removal of the variable angle transmission body 11 and the transmission assembly 12. After the rock specimen is installed in the specimen accommodating cavity 100 in the variable angle transmission body 11, the variable angle transmission body 11 and the transmission assembly 12 are placed together on the third force transmission member 143, and the transmission assembly 12 is connected to the second force transmission member 142, and then the box cover 132 is pushed into the box body. Then, a certain load can be applied to the variable angle transmission mechanism 1 through the loading mechanism 2 to make the first force transmission member 141 and the third force transmission member 143 close to the variable angle transmission body 11, and the second force transmission member 142 close to the transmission assembly 12. When the angle of the variable angle transmission body 11 needs to be adjusted, the angle scale on the boss 123 can be observed through the observation operation opening 135, and the hand can be inserted into the box body 13 through the observation operation opening 135 to adjust the angle of the variable angle transmission body 11.

[0039] Furthermore, the true triaxial mechanical testing device for variable angle repeated loading and impact disturbance provided in this embodiment also includes a loading mechanism 2, the loading mechanism 2 includes a first loading member 21 symmetrically arranged on both sides of the variable angle transmission mechanism 1 along the X axis, a second loading member 22 symmetrically arranged on both sides of the variable angle transmission mechanism 1 along the Y axis, and a third loading member 23 symmetrically arranged on both sides of the variable angle transmission mechanism 1 along the Z axis, the first loading member 21 is connected to the first force transmission member 141, the second loading member 22 is connected to the second force transmission member 142, and the third loading member 23 is connected to the third force transmission member 143. Specifically, the first loading member 21 abuts against the first force transmission member 141, the second loading member 22 abuts against the second force transmission member 142, and the third loading member 23 abuts against the third force transmission member 143. In this embodiment, the first loading member 21, the second loading member 22 and the third loading member 23 all adopt a hydraulic system, and the load is applied to or removed from the rock specimen through the telescopic action of the hydraulic system. In this embodiment, the variable angle transmission mechanism 1 is connected to the loading mechanism 2, so that repeated dynamic and static load loading test research of the principal stresses in different directions and angles can be carried out on the same specimen.

[0040] Furthermore, the true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance provided in this embodiment also includes a frame 4, wherein the frame 4 includes two X-axis support plates 41 that are parallel, opposite and perpendicular to the X-axis, two Y-axis support plates 42 that are parallel, opposite and perpendicular to the Y-axis, and two Z-axis support plates 43 that are parallel, opposite and perpendicular to the Z-axis. The first loading member 21 is arranged on the X-axis support plate 41, the second loading member 22 is arranged on the Y-axis support plate 42, and the third loading member 23 is arranged on the Z-axis support plate 43. A loading cavity 400 is formed between the X-axis support plate 41, the Y-axis support plate 42 and the Z-axis support plate 43. A guide column 44 and a loading mounting plate 45 are provided on the X-axis support plate 41 or the Y-axis support plate 42 or the Z-axis support plate 43. The variable-angle transmission mechanism 1 is arranged on the loading mounting plate 45, and a guide groove 46 that cooperates with the guide column 44 is provided on the frame 4. In this embodiment, the X-axis support plate 41 and the Z-axis support plate 43 are fixedly connected, and the Y-axis support plate 42 is movably connected via the guide column 44 and the guide groove 46. The guide column 44 and the loading mounting plate 45 are arranged on the Y-axis support plate 42. The loading mounting plate 45 is provided with a mounting groove 451. The third force transmission member 143 can pass through the mounting groove 451 and abut against the third loading member 23.

[0041] Furthermore, the present embodiment also includes a detection mechanism 5, which includes a strain sensor, a stress sensor and an acoustic emission probe arranged on each end surface of the specimen accommodating cavity 100 for detecting the mechanical response parameters of the rock specimen during the test. Specifically, the strain sensor, the stress sensor and the acoustic emission probe are installed on the bottom surface 1111 of the concave cavity inside the transmission module 111 and on the limiting transmission plate 122.

[0042] Repeated dynamic and static load tests of principal stresses in different directions and angles were carried out on the same specimen to analyze the influence of principal stress rotation on the deformation and failure characteristics of the tunnel surrounding rock. The method is as follows: S1. Make rock specimens with holes (horseshoe shape) to simulate the deformation and failure characteristics of the tunnel surrounding rock after excavation; obtain the tunnel displacement stress distribution based on the on-site stress test, for example, the maximum principal stress (perpendicular to the tunnel axis and the maximum horizontal principal stress) is σ1; the intermediate principal stress (along the tunnel axis and the minimum horizontal principal stress) is σ2; ​​the minimum principal stress (vertical stress) is σ3. When the tunnel is disturbed by external stress such as mining, the principal stress field of the tunnel surrounding rock will rotate. For example, the maximum principal stress σ1 and the minimum principal stress σ3 will rotate by θ degrees respectively. At this time, the maximum principal stress is σ1', the intermediate principal stress is σ2', and the minimum principal stress is σ3'.

[0043] S2. Place the rock specimen in the specimen accommodating cavity 100, set the tunnel axis in the rock specimen along the Y-axis direction, set the tunnel bottom plate along the X-axis direction, and set the vertical direction of the tunnel along the Z-axis direction; place the variable angle transmission mechanism 1 in the loading cavity 400 in the loading mechanism 2; connect the first loading member 21 with the first force transmission member 141, connect the second loading member 22 with the second force transmission member 142, and connect the third loading member 23 with the third force transmission member 143; apply a stress value of σ1 to the rock specimen along the X-axis direction through the first loading member 21; apply a stress value of σ2 to the rock specimen along the Y-axis direction through the second loading member 22; apply a stress value of σ3 to the rock specimen along the Z-axis direction through the third loading member 23; obtain the deformation and failure data of the rock mass during the first loading process through the detection mechanism 5; stop the equipment and remove the forces of the first loading member 21, the second loading member 22 and the third loading member 23.

[0044] S3. Rotate the force transmission rod 121 so that the tunnel orientation in the rock specimen forms an angle of θ degrees compared to the initial orientation, apply a stress value of σ1' to the rock specimen along the X-axis direction through the first loading member 21, apply a stress value of σ2' to the rock specimen along the Y-axis direction through the second loading member 22, and apply a stress value of σ3' to the rock specimen along the Z-axis direction through the third loading member 23. Obtain the deformation and failure data of the rock mass during the second loading process through the detection mechanism 5, stop the equipment and remove the forces of the first loading member 21, the second loading member 22 and the third loading member 23.

[0045] According to the actual engineering situation, the direction and angle of the rock specimen can be rotated multiple times and loaded repeatedly. The same specimen can be subjected to repeated dynamic and static load loading tests of principal stresses in different directions and angles to analyze the influence of multiple rotations of principal stress on the deformation and failure characteristics of the tunnel surrounding rock.

[0046] Example 2 Please refer to the attached Figure 6 To Attachment Fig.10 The present embodiment provides a true triaxial mechanical testing device for variable angle repeated loading and impact disturbance, comprising a variable angle transmission mechanism 1, wherein the variable angle transmission mechanism 1 comprises a variable angle transmission body 11, a variable angle transmission assembly 12 symmetrically arranged at both ends of the variable angle transmission body 11, a box body 13 arranged at the outer periphery of the variable angle transmission body 11 and the variable angle transmission assembly 12, and a force transmission assembly 14 arranged on the box body 13, wherein the force transmission assembly 14 comprises a first force transmission member 141 symmetrically arranged at both sides of the variable angle transmission body 11 along the X axis, a second force transmission member 142 symmetrically arranged at both sides of the variable angle transmission body 11 along the Y axis, and a third force transmission member 143 symmetrically arranged at both sides of the variable angle transmission body 11 along the Z axis. The variable angle transmission body 11 includes a plurality of transmission modules 111 arranged in a circumferential array along the Y axis, a concave cavity 110 is provided on the inner side of the transmission module 111, and the concave cavities 110 of the plurality of transmission modules 111 are arranged to form a specimen accommodating cavity 100, the variable angle transmission assembly 12 includes a transmission rod 121 and a limiting transmission plate 122, the limiting transmission plate 122 is arranged in the specimen accommodating cavity 100, the transmission rod 121 is extended along the Y axis, one end of the transmission rod 121 is connected to the second force transmission member 142, and the other end of the transmission rod 121 is fixedly connected to the limiting transmission plate 122, when the transmission rod 121 rotates, the limiting transmission plate 122 is driven to rotate, so as to drive the variable angle transmission body 11 to rotate. The true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance provided in the present embodiment can drive the variable-angle transmission body 11 to rotate by rotating the transmission rod 121, thereby rotating the rock specimen placed in the specimen accommodating cavity 100 and changing the force azimuth angle of the tunnel in the rock specimen. When the force transmission component 14 is externally connected to a loading mechanism, repeated dynamic and static load loading tests on the principal stresses in different directions and angles can be carried out on the same specimen. When the force transmission component 14 is externally connected to an impact mechanism, repeated dynamic load disturbance tests on the same specimen in different directions and angles can be carried out. In addition, there is no need to re-produce the rock specimen during the process, which can save a lot of time, labor and material costs.

[0047] Specifically, the first force transmission member 141 of the present embodiment is symmetrically arranged at both ends of the box body 13 along the X axis, the second force transmission member 142 is symmetrically arranged at both ends of the box body 13 along the Y axis, and the third force transmission member 143 is symmetrically arranged at both ends of the box body 13 along the Z axis. The first force transmission member 141 and the third force transmission member 143 are in contact with the variable angle transmission body 11, the second force transmission member 142 is detachably connected to the transmission rod 121, and the transmission rod 121 can rotate relative to the second force transmission member 142, and the first force transmission rod 141 and the third force transmission rod 143 are not It can only assist in fixing the positions of the transmission modules 111 in the variable angle transmission body 11, and can transmit the force to the transmission module 111, thereby transmitting the force to the rock specimen in the specimen accommodating chamber 100. The second force transmission rod 142 can not only transmit the force to the limiting transmission plate 122, thereby transmitting the force to the rock specimen in the specimen accommodating chamber 100, but also drive the limiting transmission plate 122 to rotate, thereby driving the rock specimen in the specimen accommodating chamber 100 to rotate, thereby changing the force direction angle of the tunnel in the rock specimen.

[0048] Preferably, the force transmission rod 121 and the limiting transmission plate 122 are integrally formed, and the shape of the limiting transmission plate 122 is the same as the shape of the end face of the specimen accommodating chamber 100. The area of ​​the limiting transmission plate 122 can be less than or equal to the area of ​​the end face of the specimen accommodating chamber 100, that is, there can be a fitting gap between the limiting transmission plate 122 and the specimen accommodating chamber 100, and a sealing rubber ring can be provided on the limiting transmission plate 122, and the sealing rubber ring is matched with the fitting gap.

[0049] Furthermore, the specimen accommodating chamber 100 is in the shape of a rectangular parallelepiped, and the variable angle transmission body 11 includes four transmission modules 111, and the transmission modules 111 are provided with a concave cavity bottom surface 1111 and two concave cavity side surfaces 1112 for forming the concave cavity 110, the two concave cavity side surfaces 1112 are parallel to each other and perpendicular to the Y axis, and the concave cavity bottom surface 1111 is arranged between the two concave cavity side surfaces 1112 and is parallel to the Y axis. Since conventional rock specimens are generally in the shape of a cube, it is preferred that the specimen accommodating chamber 100 of this embodiment is in the shape of a rectangular parallelepiped, wherein the length of the long side of the rectangular parallelepiped is greater than or equal to the sum of the side length of the rock specimen and the thickness of the two limit transmission plates 122. When installing the rock specimen, the concave cavity bottom surface 1111 on the transmission module 111 fits with the end surface of the rock specimen, the concave cavity side surface 1112 on the transmission module 111 is parallel to one end surface of the limiting transmission plate 122, and the other end surface of the limiting transmission plate 122 fits with the rock specimen. The transmission module 111 of this embodiment has a simple structure and is convenient and quick to match with the rock specimen.

[0050] Furthermore, the contact surfaces between the transmission modules 111 in the variable angle transmission body 11 are provided with magnetic suction parts. When the rock specimen is placed in the specimen accommodating cavity 100 of the variable angle transmission body 11, the transmission modules 111 are fixedly connected to form a whole under the action of magnetic suction.

[0051] Furthermore, in order to facilitate the rotation of the variable angle transmission body 11 and ensure the structural stability of the variable angle transmission body 11 during rotation, the variable angle transmission body 11 is spherical, and at the same time, the first force transmission member 141 is provided with a first arc-shaped force transmission plate 1411 that matches the variable angle transmission body 11, and the third force transmission member 143 is provided with a third arc-shaped force transmission plate 1431 that matches the variable angle transmission body 11. When the spherical variable angle transmission body 11 rotates, its arc-shaped end face can always match the first arc-shaped force transmission plate 1411 or the third arc-shaped force transmission plate 1431, and the rotation is smooth without interference, and the first arc-shaped force transmission plate 1411 and the third arc-shaped force transmission plate 1431 provide stable support for the variable angle transmission body 11 in the X-axis direction and the Z-axis direction, respectively.

[0052] Further, in order to improve the accuracy of the rotation of the variable angle transmission body 11, the variable angle transmission assembly 12 also includes a boss 123 disposed between the transmission rod 121 and the second force transmission member 142, an angle scale is provided on the boss 123, the boss 123 is fixedly connected to the transmission rod 121, and the boss 123 is rotatably connected to the second force transmission member 142. When the transmission rod 121 rotates, the angle scale on the boss 123 can display the degree of rotation of the transmission rod 121, which is more accurate and convenient to use. Specifically, in this embodiment, a circle of angle marks is provided on the boss 123, and an angle pointer is provided on the second force transmission member 142. When the boss 123 rotates relative to the second force transmission member 142, the angle pointer on the second force transmission member 142 points to the angle mark of the corresponding reading on the boss 123 to indicate the angle of rotation of the rock specimen. A groove is provided at one end of the boss 123 connected to the second force transmission member 142, and the second force transmission member 142 cooperates with the groove on the boss 123.

[0053] Furthermore, in order to facilitate the placement of the variable angle transmission body 11 and the variable angle transmission assembly 12, the box body 13 includes a box body 131 with an open end and a box cover 132 covering the box body 131, the box cover 132 is perpendicular to the Y axis, a plug rod 133 is provided on the box cover 132, the plug rod 133 is parallel to the Y axis, and a slot 134 is provided on the box body 131 to cooperate with the plug rod 133. When the variable angle transmission body 11 and the variable angle transmission assembly 12 need to be placed, it is only necessary to pull the box cover 132 to make it close to or away from the box body 131 along the Y axis direction, which has a simple structure and is convenient for placement. In addition, a first limiting protrusion is provided on the first force transmission member 141 on the inner side of the box body 13 to prevent the first force transmission member 141 from detaching from the box body 13, a second limiting protrusion is provided on the second force transmission member 142 on the inner side of the box body 13 to prevent the second force transmission member 142 from detaching from the box body 13, and a first limiting protrusion is provided on the third force transmission member 143 on the inner side of the box body 13 to prevent the third force transmission member 143 from detaching from the box body 13.

[0054] Furthermore, a support plate 136 is provided on the box cover 132, and the support plate 136 is fixedly connected to the third force transmission member 143. An observation operation port 135 and a slide slot 137 are provided on the box body 131, and the slide slot 137 cooperates with the third force transmission member 143. When the box cover 132 is pulled out, the support plate 136 and the third force transmission member 143 fixedly connected to the support plate 136 are pulled out together, and the variable angle transmission body 11 and the transmission assembly 12 located on the third force transmission member 143 are also pulled out, so as to facilitate the removal of the variable angle transmission body 11 and the transmission assembly 12. After the rock specimen is installed in the specimen accommodating cavity 100 in the variable angle transmission body 11, the variable angle transmission body 11 and the transmission assembly 12 are placed together on the third force transmission member 143, and the transmission assembly 12 is connected to the second force transmission member 142, and then the box cover 132 is pushed into the box body. Then, a certain load can be applied to the variable angle transmission mechanism 1 through the loading mechanism 2 to make the first force transmission member 141 and the third force transmission member 143 close to the variable angle transmission body 11, and the second force transmission member 142 close to the transmission assembly 12. When the angle of the variable angle transmission body 11 needs to be adjusted, the angle scale on the boss 123 can be observed through the observation operation opening 135, and the hand can be inserted into the box body 13 through the observation operation opening 135 to adjust the angle of the variable angle transmission body 11.

[0055] Furthermore, the true triaxial mechanical testing device for variable angle repeated loading and impact disturbance provided in this embodiment also includes a loading mechanism 2, the loading mechanism 2 includes a first loading member 21 symmetrically arranged on both sides of the variable angle transmission mechanism 1 along the X axis, a second loading member 22 symmetrically arranged on both sides of the variable angle transmission mechanism 1 along the Y axis, and a third loading member 23 symmetrically arranged on both sides of the variable angle transmission mechanism 1 along the Z axis, the first loading member 21 is connected to the first force transmission member 141, the second loading member 22 is connected to the second force transmission member 142, and the third loading member 23 is connected to the third force transmission member 143. Specifically, the first loading member 21 abuts against the first force transmission member 141, the second loading member 22 abuts against the second force transmission member 142, and the third loading member 23 abuts against the third force transmission member 143. In this embodiment, the first loading member 21, the second loading member 22 and the third loading member 23 all adopt a hydraulic system, and the load is applied to or removed from the rock specimen through the telescopic action of the hydraulic system. In this embodiment, the variable angle transmission mechanism 1 is connected to the loading mechanism 2, so that repeated dynamic and static load loading test research of the principal stresses in different directions and angles can be carried out on the same specimen.

[0056] Furthermore, the true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance provided in this embodiment also includes a frame 4, wherein the frame 4 includes two X-axis support plates 41 that are parallel, opposite and perpendicular to the X-axis, two Y-axis support plates 42 that are parallel, opposite and perpendicular to the Y-axis, and two Z-axis support plates 43 that are parallel, opposite and perpendicular to the Z-axis. The first loading member 21 is arranged on the X-axis support plate 41, the second loading member 22 is arranged on the Y-axis support plate 42, and the third loading member 23 is arranged on the Z-axis support plate 43. A loading cavity 400 is formed between the X-axis support plate 41, the Y-axis support plate 42 and the Z-axis support plate 43. A guide column 44 and a loading mounting plate 45 are provided on the X-axis support plate 41 or the Y-axis support plate 42 or the Z-axis support plate 43. The variable-angle transmission mechanism 1 is arranged on the loading mounting plate 45, and a guide groove 46 that cooperates with the guide column 44 is provided on the frame 4. In this embodiment, the X-axis support plate 41 and the Z-axis support plate 43 are fixedly connected, and the Y-axis support plate 42 is movably connected via the guide column 44 and the guide groove 46. The guide column 44 and the loading mounting plate 45 are arranged on the Y-axis support plate 42. The loading mounting plate 45 is provided with a mounting groove 451. The third force transmission member 143 can pass through the mounting groove 451 and abut against the third loading member 23.

[0057] Furthermore, the present embodiment also includes a detection mechanism 5, which includes a strain sensor, a stress sensor and an acoustic emission probe arranged on each end surface of the specimen accommodating cavity 100 for detecting the mechanical response parameters of the rock specimen during the test. Specifically, the strain sensor, the stress sensor and the acoustic emission probe are installed on the bottom surface 1111 of the concave cavity inside the transmission module 111 and on the limiting transmission plate 122.

[0058] Furthermore, the true triaxial mechanical testing device for variable-angle repeated loading and impact disturbance provided in this embodiment also includes an impact mechanism 3, and the impact mechanism 3 is connected to the first force transmission member 141 located on one side of the variable-angle transmission body 11 to generate impact disturbance to the variable-angle transmission mechanism 1. Specifically, the impact mechanism 3 at least includes an air gun 31, an impact tube 32 and an incident rod 33 connected in sequence, and the incident rod 33 is connected to the first force transmission member 141. In this embodiment, a disturbance channel for the incident rod 33 to pass through is provided on the first loading member 21, and the incident rod 33 passes through the first loading member 21 and is connected to the first force transmission member 141. The bullet fired by the air gun 31 transmits the impact force to the incident rod 33 through the impact tube 32, and the dynamic load is transmitted to the variable-angle transmission body 11 through the incident rod, thereby generating impact disturbance to the rock specimen.

[0059] Furthermore, the impact mechanism 3 further includes a connecting rod 34 and a wave rectifier 35 disposed between the impact tube 32 and the incident rod 33, and the impact mechanism 3 further includes a high-pressure gas source 36 connected to the air gun 31. The high-pressure gas source 36 is provided with a pressure gauge and a flow meter, the high-pressure gas source 36 is connected to the air gun 31 through an air pipe, the air gun 31 is provided with an air gun seat to provide stable support for the air gun 31, the impact tube 32 and the connecting rod 34 are connected through a first connecting pipe and a first support seat to provide stable connection and stable support for the impact tube 32 and the connecting rod 34, the connecting rod 34 and the incident rod 33 and the wave rectifier 35 are connected through a second connecting pipe and a second support seat to provide stable connection and stable support for the connecting rod 34 and the incident rod 33. The high-pressure gas in the high-pressure gas source 36 enters the air gun 31 through the air pipe. The air gun 31 emits high-pressure gas to push the bullet in the impact tube 32 to hit the first connecting tube. The dynamic load is transmitted to the connecting rod 34 through the first connecting tube. The dynamic load stress wave is adjusted by the wave rectifier 35 and then transmitted to the variable angle transmission body 11 through the incident rod 33, generating impact disturbance on the rock specimen.

[0060] Repeated dynamic and static load tests of principal stresses in different directions and angles were conducted on the same specimen to analyze the influence of principal stress rotation on the deformation and failure characteristics of the tunnel surrounding rock. The following method is used: S1. Make rock specimens with holes (horseshoe shape) to simulate the deformation and failure characteristics of the tunnel surrounding rock after excavation; obtain the tunnel displacement stress distribution based on the on-site stress test, for example, the maximum principal stress (perpendicular to the tunnel axis and the maximum horizontal principal stress) is σ1; the intermediate principal stress (along the tunnel axis and the minimum horizontal principal stress) is σ2; ​​the minimum principal stress (vertical stress) is σ3. When the tunnel is disturbed by external stress such as mining, the principal stress field of the tunnel surrounding rock will rotate. For example, the maximum principal stress σ1 and the minimum principal stress σ3 will rotate by θ degrees respectively. At this time, the maximum principal stress is σ1', the intermediate principal stress is σ2', and the minimum principal stress is σ3'.

[0061] S2. Place the rock specimen in the specimen accommodating cavity 100, set the tunnel axis in the rock specimen along the Y-axis direction, set the tunnel bottom plate along the X-axis direction, and set the vertical direction of the tunnel along the Z-axis direction; place the variable angle transmission mechanism 1 in the loading cavity 400 in the loading mechanism 2; connect the first loading member 21 with the first force transmission member 141, connect the second loading member 22 with the second force transmission member 142, and connect the third loading member 23 with the third force transmission member 143; apply a stress value of σ1 to the rock specimen along the X-axis direction through the first loading member 21; apply a stress value of σ2 to the rock specimen along the Y-axis direction through the second loading member 22; apply a stress value of σ3 to the rock specimen along the Z-axis direction through the third loading member 23; obtain the deformation and failure data of the rock mass during the first loading process through the detection mechanism 5; stop the equipment and remove the forces of the first loading member 21, the second loading member 22 and the third loading member 23.

[0062] S3. Rotate the force transmission rod 121 so that the tunnel orientation in the rock specimen forms an angle of θ degrees compared to the initial orientation, apply a stress value of σ1' to the rock specimen along the X-axis direction through the first loading member 21, apply a stress value of σ2' to the rock specimen along the Y-axis direction through the second loading member 22, and apply a stress value of σ3' to the rock specimen along the Z-axis direction through the third loading member 23. Obtain the deformation and failure data of the rock mass during the second loading process through the detection mechanism 5, stop the equipment and remove the forces of the first loading member 21, the second loading member 22 and the third loading member 23.

[0063] According to the actual engineering situation, the direction and angle of the rock specimen can be rotated multiple times and loaded repeatedly. The same specimen can be subjected to repeated dynamic and static load loading tests of principal stresses in different directions and angles to analyze the influence of multiple rotations of principal stress on the deformation and failure characteristics of the tunnel surrounding rock.

[0064] The same specimen was subjected to repeated dynamic load disturbance tests in different directions and angles. The method for analyzing the influence of variable angle repeated dynamic load disturbance on the deformation and failure characteristics of the tunnel surrounding rock is as follows: S1. Make rock specimens with holes (horseshoe shape) to simulate the deformation and failure characteristics of the tunnel surrounding rock after excavation; obtain the tunnel displacement stress distribution based on the on-site stress test, for example, the maximum principal stress (perpendicular to the tunnel axis and the maximum horizontal principal stress) is σ1; the intermediate principal stress (along the tunnel axis and the minimum horizontal principal stress) is σ2; ​​the minimum principal stress (vertical stress) is σ3.

[0065] S2. Place the rock specimen in the specimen accommodating cavity 100, set the tunnel axis in the rock specimen along the Y-axis direction, set the tunnel bottom plate along the X-axis direction, and set the vertical direction of the tunnel along the Z-axis direction; place the variable angle transmission mechanism 1 in the loading cavity 400 in the loading mechanism 2; connect the first loading member 21 with the first force transmission member 141, connect the second loading member 22 with the second force transmission member 142, and connect the third loading member 23 with the third force transmission member 143; apply a stress value of σ1 to the rock specimen along the X-axis direction through the first loading member 21; apply a stress value of σ2 to the rock specimen along the Y-axis direction through the second loading member 22; apply a stress value of σ3 to the rock specimen along the Z-axis direction through the third loading member 23; obtain the deformation and failure data of the rock mass during the first loading process through the detection mechanism 5; stop the equipment and remove the forces of the first loading member 21, the second loading member 22 and the third loading member 23.

[0066] S3, turn on the high-pressure air source 36, and generate a dynamic load D1 of a specific waveform to the incident rod 33 through the air gun 31. The incident rod 33 transmits the dynamic load D1 to the rock specimen along the X-axis direction, so that the tunnel in the rock specimen is subjected to the first impact disturbance at the side, and the deformation and damage data of the rock mass during the first impact disturbance are obtained through the detection mechanism 5.

[0067] S4. Rotate the force transmission rod 121 so that the orientation of the tunnel in the rock specimen forms an angle of θ degrees compared to the initial orientation, turn on the high-pressure gas source 36, and generate a dynamic load D2 of a specific waveform to the incident rod 33 through the air gun 31. The incident rod 33 transmits the dynamic load D2 to the rock specimen along the X-axis direction, so that the tunnel in the rock specimen is subjected to a second impact disturbance at the side part, and the deformation and damage data of the rock mass during the second impact disturbance are obtained through the detection mechanism 5.

[0068] According to the actual engineering situation, the direction and angle of the rock specimen can be rotated multiple times and the impact disturbance can be repeated multiple times. The same specimen can be subjected to repeated dynamic load disturbance tests in different directions and angles to analyze the influence of variable angle repeated dynamic load disturbance on the deformation and failure characteristics of the tunnel surrounding rock.

[0069] It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the "first" information may also be referred to as the "second" information, and similarly, the "second" information may also be referred to as the "first" information. In addition, the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0070] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A true triaxial mechanical testing device for variable angle repeated loading and impact disturbance, characterized in that: The invention comprises a variable angle transmission mechanism (1), wherein the variable angle transmission mechanism (1) comprises a variable angle transmission body (11), a variable angle transmission assembly (12) symmetrically arranged at two ends of the variable angle transmission body (11), a box (13) arranged on the outer periphery of the variable angle transmission body (11) and the variable angle transmission assembly (12), and a force transmission assembly (14) arranged on the box (13), wherein the force transmission assembly (14) comprises a first force transmission member (141) symmetrically arranged on both sides of the variable angle transmission body (11) along the X axis, a second force transmission member (142) symmetrically arranged on both sides of the variable angle transmission body (11) along the Y axis, and a third force transmission member (143) symmetrically arranged on both sides of the variable angle transmission body (11) along the Z axis, wherein the variable angle transmission body (11) comprises a plurality of circumferential members along the Y axis. The transmission modules (111) are arranged in an array, a concave cavity (110) is provided on the inner side of the transmission module (111), and the concave cavities (110) of a plurality of the transmission modules (111) are arranged to surround a specimen accommodating cavity (100). The variable angle transmission assembly (12) comprises a transmission rod (121) and a limit transmission plate (122), and the limit transmission plate (122) is arranged in the specimen accommodating cavity (100). The transmission rod (121) is extended along the Y axis, one end of the transmission rod (121) is connected to the second force transmission member (142), and the other end of the transmission rod (121) is fixedly connected to the limit transmission plate (122). When the transmission rod (121) rotates, the limit transmission plate (122) is driven to rotate, thereby driving the variable angle transmission body (11) to rotate.

2. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 1, characterized in that: The specimen accommodating cavity (100) is in the shape of a rectangular parallelepiped, and the variable angle transmission body (11) comprises four transmission modules (111), and the transmission modules (111) are provided with a concave cavity bottom surface (1111) and two concave cavity side surfaces (1112) for forming the concave cavity (110), the two concave cavity side surfaces (1112) are parallel to each other and perpendicular to the Y axis, and the concave cavity bottom surface (1111) is provided between the two concave cavity side surfaces (1112) and is parallel to the Y axis.

3. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 1, characterized in that: The variable angle transmission body (11) is spherical, the first force transmission member (141) is provided with a first arc-shaped force transmission plate (1411) that cooperates with the variable angle transmission body (11), and the third force transmission member (143) is provided with a third arc-shaped force transmission plate (1431) that cooperates with the variable angle transmission body (11).

4. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 1, characterized in that: The variable angle transmission assembly (12) further comprises a boss (123) disposed between the transmission rod (121) and the second force transmission member (142), the boss (123) being provided with an angle scale, the boss (123) being fixedly connected to the transmission rod (121), and the boss (123) being rotatably connected to the second force transmission member (142).

5. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 1, characterized in that: The box body (13) comprises a box body (131) with an opening at one end and a box cover plate (132) covering the box body (131), wherein the box cover plate (132) is perpendicular to the Y axis, an insertion rod (133) is provided on the box cover plate (132), and the insertion rod (133) is parallel to the Y axis, and a slot (134) cooperating with the insertion rod (133) is provided on the box body (131).

6. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to any one of claims 1 to 5, characterized in that: The invention also comprises a loading mechanism (2), wherein the loading mechanism (2) comprises a first loading member (21) symmetrically arranged on both sides of the variable angle transmission mechanism (1) along the X axis, a second loading member (22) symmetrically arranged on both sides of the variable angle transmission mechanism (1) along the Y axis, and a third loading member (23) symmetrically arranged on both sides of the variable angle transmission mechanism (1) along the Z axis, wherein the first loading member (21) is connected to the first force transmission member (141), the second loading member (22) is connected to the second force transmission member (142), and the third loading member (23) is connected to the third force transmission member (143).

7. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 6, characterized in that: The machine also includes a frame (4), wherein the frame (4) includes two X-axis support plates (41) that are parallel to each other and perpendicular to the X-axis, two Y-axis support plates (42) that are parallel to each other and perpendicular to the Y-axis, and two Z-axis support plates (43) that are parallel to each other and perpendicular to the Z-axis. The first loading member (21) is arranged on the X-axis support plate (41), the second loading member (22) is arranged on the Y-axis support plate (42), and the third loading member (23) is arranged on the Z-axis support plate (43). A loading cavity (400) is formed between the X-axis support plate (41), the Y-axis support plate (42), and the Z-axis support plate (43); a guide column (44) and a loading mounting plate (45) are provided on the X-axis support plate (41) or the Y-axis support plate (42) or the Z-axis support plate (43); the variable angle transmission mechanism (1) is provided on the loading mounting plate (45); and a guide groove (46) cooperating with the guide column (44) is provided on the frame (4).

8. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 6, characterized in that: It also comprises an impact mechanism (3), wherein the impact mechanism (3) is connected to the first force transmission member (141) located on one side of the variable angle transmission body (11) so as to generate an impact disturbance on the variable angle transmission mechanism (1).

9. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 8, characterized in that: The impact mechanism (3) comprises at least an air gun (31), an impact tube (32), and an incident rod (33) which are connected in sequence, and the incident rod (33) is connected to the first force transmission member (141).

10. The true triaxial mechanical testing device for variable angle repeated loading and impact disturbance according to claim 9, characterized in that: The impact mechanism (3) further comprises a connecting rod (34) and a wave rectifier (35) arranged between the impact tube (32) and the incident rod (33), and the impact mechanism (3) further comprises a high-pressure air source (36) connected to the air gun (31).

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