Method for simulating rock fracture formation and evolution process and simulation device

Abstract

The invention particularly relates to a method for simulating rock fracture formation and evolution processes and a simulation device, and belongs to the technical field of rock fracture simulation. The method comprises the following steps: S1, treating a sampled sample into a cube structure; s2, cyclic stress loading is conducted on the first faces of the sample through a pressure applying part, the second faces of the sample are supported through a counter-force part, the first faces are three surfaces forming a first vertex of the sample, the second faces are three surfaces forming a second vertex of the sample, and the first vertex and the second vertex are located on the body diagonal line of the sample. And S3, adjusting the magnitude of the loaded stress until the sample has cracks, and recording the magnitudes of the pressures of the three first surfaces. And S4, further adjusting the magnitude of the loaded stress, and recording the length of the crack until the sample is damaged. Through the method, the formation and evolution of the cracks of the rock under the action of the long-term geological structure can be studied.

Description

Technical Field

[0001] The invention belongs to the technical field of rock fracture simulation, and in particular relates to a method and a simulation device for simulating the formation and evolution process of rock fractures. Background Art

[0002] A fissure is a fracture structure in which a rock is broken after being subjected to force and there is no significant displacement along the fracture surface. It includes rock joints, which are often regarded as synonyms with joints. The formation process of fissures is very complicated. For example, according to their causes, they are divided into two categories: primary and secondary fissures. The former is formed during the diagenesis process, while the latter is formed by external forces after the rock is diagenetic. According to the source of force, they are divided into non-tectonic and tectonic fissures. The former is formed by external geological forces, such as weathering, landslides, collapses, etc. They are often confined to the surface, small in scale and irregular in distribution. The latter is formed by tectonic action, distributed widely and regularly, extending long and deep, and can cut through different rock layers. Fissures have a great impact on engineering construction, especially on the stability of tunnels and underground projects. For example, fissures caused by crustal movement are called "tectonic fissures"; fissures caused by weathering are called "weathering fissures"; fissures generated during the condensation of igneous rocks and the solidification of sediments into rocks are called "diagenetic fissures."

[0003] At present, the research on fractures is limited to the qualitative level. For example, the current research does not take into account the changes in the control of structure on fractures in time (the impact of structural multi-stage on fracture development) and space (the control of fracture development by different structural parts). In view of the above problems, how to deepen the research on fractures is a technical problem that needs to be solved. Summary of the invention

[0004] The purpose of the present invention is to provide a method and a simulation device for simulating the formation and evolution process of rock cracks, through which the influence of geological structure on the formation and evolution of rock cracks can be studied.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: on the one hand, the embodiment of the present application provides a method for simulating the formation and evolution process of rock cracks, including: S1, processing the sampled specimen into a cubic structure; S2, cyclically loading stress on the first surface of the sample by a pressure component, and supporting the second surface of the sample by a reaction component, the first surface is the three surfaces forming the first vertex of the sample, the second surface is the three surfaces forming the second vertex of the sample, and the first vertex and the second vertex are located on the body diagonal of the sample; S3, adjust the loading stress until cracks appear on the specimen, and record the stress magnitudes on the three first surfaces; S4, further adjust the loading stress and record the length of the crack until the sample is destroyed.

[0006] In some embodiments, the cyclic loading stress refers to: S21, set the pressure value variable Δσ; S22, selecting two first surfaces from the three first surfaces, increasing the pressure value of one of them by Δσ, and decreasing the pressure value of the other by Δσ; S23, adjusting the pressure values ​​of the three first surfaces to initial values; S24, reselecting two first surfaces, increasing the pressure value of one of them by Δσ, and decreasing the pressure value of the other by Δσ.

[0007] In some embodiments, adjusting the magnitude of the loaded stress refers to increasing the value of Δσ.

[0008] In some embodiments, a pad is provided between the pressure-applying component and the sample, and the pad is made of a transparent material.

[0009] In some embodiments, a slide groove is provided at the edge of the backing plate, and a scale is accommodated in the slide groove.

[0010] In some embodiments, the pressure-applying component and the reaction-force component are disposed in a transparent simulation box.

[0011] On the other hand, an embodiment of the present application further provides a simulation device, which is applied to the method in the above embodiment, and includes a box and three pushing components. The box is used to accommodate the sample, and the three inner wall surfaces of the box intersect to form three reaction force parts, and the normals of the three inner wall surfaces extend along the first direction, the second direction and the third direction respectively, and the first direction, the second direction and the third direction are perpendicular to each other. Three pushing components are accommodated in the box and are used to apply pressure to the sample. The pushing components include a moving end, and among the three pushing components, the moving end of one of them moves along the first direction, the moving end of another one moves along the second direction, and the moving end of the third one moves along the third direction.

[0012] In some embodiments, the pushing component includes a first cavity and a first piston portion. The first cavity is disposed in the box. The first piston portion is movably accommodated in the first cavity along the axial direction of the first cavity, the first piston portion divides the interior of the first cavity into two parts, and the movable end is connected to the first piston portion.

[0013] In some embodiments, a control component is also included, which includes a control part, and the control part includes a second cavity and a second piston part. The second cavity is arranged in the housing, and the axial direction of the second cavity extends along the axial direction of the drive shaft. The second piston part is movably accommodated in the second cavity along the axial direction of the second cavity, and the second piston part divides the interior of the second cavity into two parts. The two parts of the second chamber are connected to the two parts of the first chamber in a one-to-one correspondence.

[0014] In some embodiments, the control assembly further includes a drive shaft, a drive sleeve and a transmission component. The drive shaft is rotatably connected to the housing, the drive sleeve is sleeved outside the peripheral wall of the drive shaft, the drive sleeve is provided with a spiral groove, and the axial direction of the spiral groove extends along the axial direction of the drive shaft. The transmission component is used to adjust the transmission state of the drive shaft and the drive sleeve, the connecting portion is connected to the second piston portion, and the connecting portion is inserted into the spiral groove.

[0015] The present invention has the following beneficial effects: This method can be used to study the formation and evolution of rock cracks under long-term geological structural effects, reproduce the instability process of underground natural rock masses, reveal the instability and disaster-causing mechanism of underground rock masses, and provide a theoretical reference for underground chamber stability analysis and support design optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the process of the present invention; Figure 2 This is a schematic diagram of the principle of Mohr-Coulomb theory; Figure 3 It is a structural schematic diagram of the simulation device of the present invention; Figure 4 It is a structural schematic diagram of the control component of the present invention; Figure 5 It is a schematic diagram of the cooperation of the drive shaft, the drive sleeve and the connecting cable (the drive shaft and the drive sleeve move in opposite directions) of the present invention; Figure 6 It is a schematic diagram of the cooperation of the drive shaft, the drive sleeve and the connecting cable (the drive shaft and the drive sleeve move in the same direction) of the present invention; Figure 7 It is a structural schematic diagram of the driving sleeve of the present invention; Figure 8 It is a structural schematic diagram of the transmission component of the present invention; Fig. 9 It is a schematic diagram of the cooperation between the limiting tooth and the limiting part (the limiting tooth is between the two limiting parts) of the present invention; Fig.10 It is a schematic diagram of the cooperation between the limiting teeth and the limiting part (the limiting teeth are arranged between the elastic arms) of the present invention; Fig.11 It is a result schematic diagram of the adjustment component of the present invention; Fig.12 It is a schematic diagram of the cooperation between the mounting sleeve and the adjusting shaft of the present invention.

[0017] Figure numbers: 1-box, 2-reaction part, 3-pushing component, 4-sample, 5-first cavity, 6-first piston part, 7-moving end, 8-driving sleeve, 9-adjusting column, 10-driving shaft, 11-second piston part, 12-second cavity, 13-connecting part, 14-spiral groove, 15-limiting tooth, 16-transmission ring, 17-connecting rope, 18-pushing ring, 19-limiting part, 20-elastic arm, 21-adjusting shaft, 22-rotating sleeve, 23-against wall, 24-limiting sleeve, 25-installing sleeve. DETAILED DESCRIPTION

[0018] 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. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0019] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, 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.

[0020] On the one hand, an embodiment of the present application provides a method for simulating the formation and evolution process of rock fractures, including: S1, process the sampled sample 4 into a cubic structure. Sampling needs to be carried out according to the geology to be tested. After the sample 4 is processed, it needs to be sealed and stored to improve the simulation accuracy. If the structure of the sample 4 is damaged during the processing of the sample 4, such as cracks in the sample 4, re-sampling is performed; S2, cyclically loading stress on the first surface of the sample 4 by the pressure-applying component, supporting the second surface of the sample 4 by the reaction force part 2, the first surface is the three surfaces forming the first vertex of the sample 4, the second surface is the three surfaces forming the second vertex of the sample 4, and the first vertex and the second vertex are located on the body diagonal of the sample 4; The three first faces intersect at the first vertex, and the three second faces intersect at the second vertex; The three first surfaces and the three second surfaces are arranged opposite to each other in a one-to-one correspondence, that is, when pressure is applied to one of the first surfaces, the second surface opposite to the first surface provides a supporting force; By cyclically loading stress, on the one hand, the simulation degree of rock stress can be increased. On the other hand, by adjusting factors such as stress duration, stress magnitude and stress direction, the geological structure effect on the rock can be simulated, and the influence of geological structure on the formation and evolution of rock cracks can be studied. On the other hand, the stress difference can be generated in the sample 4, so that the sample 4 can produce cracks and the cracks can develop; S3, adjust the magnitude of the applied stress until cracks appear on sample 4, and record the magnitude of the stress on the three first surfaces; S4, further adjust the loading stress and record the length of the crack until sample 4 is destroyed.

[0021] This method can analyze the relationship between rock cracks and stress through the Mohr-Coulomb theory. In summary, Coulomb was the first to propose the maximum shear stress as a measure of failure. Based on the empirical law of friction tests on sand, he expressed the shear stress (shear strength) as a linear function of the total stress on the sliding surface, as shown in the following formula: , Where: σ is the normal total stress on the sliding surface; c is the cohesion, the intercept of the shear strength line on the vertical axis of the τ-σ coordinate system; It is the internal friction angle, that is, the slope angle of the shear strength line.

[0022] Obviously, when the stress circle is within the strength envelope, the rock unit is in a stable state; when the stress circle is tangent to the strength envelope, it means that the shear stress on a pair of planes has reached its shear strength, and the unit is in a state of limit equilibrium; when the stress circle intersects the strength envelope, it means that the unit has been sheared. Therefore, the expression of the Moore-Coulomb theory, that is, the Moore-Coulomb failure criterion, can be established based on the rock mass being in a state of limit equilibrium, with the maximum principal stress as σ1 and the minimum principal stress as σ3. Figure 2 shown.

[0023] When the Mohr circle is tangent to the strength envelope: , then: , This is the limit equilibrium condition expressed in terms of total stress, from which we can derive: , Because in the formula: , then: , The above formula shows that if c, If the value is certain, but only one of σ1 and σ3 is known, it is still impossible to determine whether the point has reached failure. Only when σ3 remains unchanged and σ1 increases to a certain value; or when σ1 remains unchanged and σ3 is reduced to a certain value, the Mohr circle is tangent to the strength envelope, and the point is in a limit equilibrium state. It can be seen that the same rock mass can reach shear failure under different σ3 (or σ1). Now, if the same group of specimens are subjected to shear tests under different σ3, they must reach shear failure under different σ1. So a set of limit Mohr circles can be obtained, and their envelopes can be used to obtain the above-mentioned shear strength: , That is, the theoretical angle between the failure surface and the principal stress surface should be .

[0024] This method can be used to study the formation and evolution of rock cracks under long-term geological structural effects, reproduce the instability process of underground natural rock masses, reveal the instability and disaster-causing mechanism of underground rock masses, and provide a theoretical reference for underground chamber stability analysis and support design optimization.

[0025] In some embodiments, cyclic loading stress refers to: S21, set the pressure value variable Δσ; S22, selecting two first surfaces from the three first surfaces, increasing the pressure value of one of them by Δσ, and decreasing the pressure value of the other by Δσ; S23, adjusting the pressure values ​​of the three first surfaces to initial values; S24, reselecting two first surfaces, increasing the pressure value of one of them by Δσ, and decreasing the pressure value of the other by Δσ; The number of times the two first faces are reselected can be the end position of the traversal between all faces, that is, the three first faces can form six possibilities.

[0026] On the one hand, sample 4 is often subjected to complex and variable stresses in a real environment, and these stresses may come from different directions. By selecting two faces to adjust the pressure value, the different stress states of sample 4 in different directions can be simulated. On the other hand, under the action of the pressure value variable Δσ, a stress difference can be generated between the two faces of sample 4, so that sample 4 can produce cracks and allow the cracks to develop. On the other hand, rock mechanics research shows that rock failure is often related to stress concentration and stress difference in a specific direction. By selecting two faces for pressure adjustment, the influence of such stress concentration and stress difference on rock failure can be simulated more directly.

[0027] In some embodiments, adjusting the magnitude of the applied stress refers to increasing the value of Δσ.

[0028] For example, the value of Δσ may be adjusted to two, three, four, five or six times.

[0029] By increasing the value of Δσ, on the one hand, the formation and evolution of cracks in specimen 4 under different stress levels can be simulated. On the other hand, specimen 4 can reach the limit state, and thus specimen 4 can be destroyed.

[0030] In some embodiments, a pad is provided between the pressure-applying component and the sample 4 , and the pad is made of a transparent material.

[0031] The pad is made of transparent material, so when the pad is covered on the surface of sample 4, the surface of sample 4 can still be observed through the pad, allowing researchers to observe the formation and evolution process of cracks.

[0032] In some embodiments, a slide groove is provided at the edge of the backing plate, and a scale is accommodated in the slide groove.

[0033] The ruler is used to measure the length of the crack, making the evolution process of the crack intuitive and accurate.

[0034] In some embodiments, the pressure-applying component and the reaction force component 2 are disposed in a transparent simulation box.

[0035] The pressure component and the reaction component are placed in a transparent simulation box. On the one hand, the transparent simulation box can play a protective role to prevent splashing when the sample 4 is destroyed, which would pose a safety hazard. On the other hand, the transparent simulation box allows researchers to observe the changes of the sample 4 from the outside.

[0036] On the other hand, the embodiment of the present application further provides a simulation device, which is applied to the method in the above embodiment, and includes a box body 1 and three pushing components 3. The box body 1 is used to accommodate the sample 4. The three inner wall surfaces of the box body 1 intersect to form three reaction force parts 2. The normals of the three inner wall surfaces extend along the first direction, the second direction and the third direction respectively. The first direction, the second direction and the third direction are perpendicular to each other. The three pushing components 3 are accommodated in the box body 1 and are used to apply pressure to the sample 4. The pushing components 3 include a moving end 7. Among the three pushing components 3, the moving end 7 of one moves along the first direction, the moving end 7 of another moves along the second direction, and the moving end 7 of the third moves along the third direction.

[0037] For example, three inner wall surfaces forming a corner of the box body 1 may form three reaction force parts 2 .

[0038] The first direction may be the direction indicated by the X-axis in the figure, the second direction may be the direction indicated by the Y-axis in the figure, and the third direction may be the direction indicated by the Z-axis in the figure.

[0039] The moving end 7 of the pushing component 3 is used to contact the sample 4 to apply pressure to the sample 4 .

[0040] The three inner wall surfaces are respectively arranged opposite to the moving ends 7 of the three pushing components 3 in a one-to-one correspondence, so that when the moving ends 7 apply pressure to the sample 4, the three inner wall surfaces can play a supporting role.

[0041] The simulation device of the embodiment of the present application can apply pressure to the sample 4 to simulate the situation where the sample 4 is subjected to complex and changeable stresses, and can cause cracks to form in the sample 4 and allow the cracks to evolve.

[0042] In some embodiments, the pushing component 3 includes a first cavity 5 and a first piston portion 6. The first cavity 5 is disposed in the housing 1. The first piston portion 6 is movably accommodated in the first cavity 5 along the axial direction of the first cavity 5, and the first piston portion 6 divides the interior of the first cavity 5 into two parts, and the movable end 7 is connected to the first piston portion 6; The first piston portion 6 is accommodated in the first cavity 5 so that the first piston portion 6 can move along the first cavity 5; The first piston part 6 divides the interior of the first cavity 5 into two parts, and the two parts are arranged along the axial direction of the first cavity 5. When the volume of the medium in the two parts changes, the first piston part 6 can be driven to move. For example, the two parts can be a first part and a second part. When the amount of the medium in the first part increases, the amount of the medium in the second part decreases. At this time, the first piston part 6 will move from the first part to the second part, and then the moving end 7 can move driven by the first piston part 6. The specific connection method of the moving end 7 and the first piston part 6 can be selected from the existing structure, which will not be repeated here.

[0043] In some embodiments, a control assembly is further included, the control assembly includes a control component, the control component includes a second cavity 12 and a second piston portion 11, the second cavity 12 is arranged in the housing 1, the axial direction of the second cavity 12 extends along the axial direction of the drive shaft 10, the second piston portion 11 is movably accommodated in the second cavity 12 along the axial direction of the second cavity 12, the second piston portion 11 divides the interior of the second cavity 12 into two parts, and the two parts of the second cavity are connected to the two parts of the first cavity one by one; The second piston part 11 divides the interior of the second cavity 12 into two parts, and the two parts are arranged along the axial direction of the second cavity 12. When the volume of the medium in the two parts changes, the second piston part 11 can be driven to move. For example, the two parts can be the third part and the fourth part. When the amount of the medium in the third part increases, the amount of the medium in the fourth part decreases. At this time, the second piston part 11 will move from the third part to the fourth part; In an embodiment in which the first cavity 5 includes a first part and a second part, the third part can be connected to the first part, and the fourth part can be connected to the third part, so that when the volume of the medium in the third part and the fourth part changes, the volume of the medium in the first part and the second part can also change, that is, the movement of the first piston part 6 can be controlled by the second piston part 11, and the movement of the movable end 7 can be controlled.

[0044] In some embodiments, the control assembly further includes a drive shaft 10, a drive sleeve 8 and a transmission component. The drive shaft 10 is rotatably connected to the housing 1, the drive sleeve 8 is sleeved outside the peripheral wall of the drive shaft 10, and the drive sleeve 8 is provided with a spiral groove 14, and the axial direction of the spiral groove 14 extends along the axial direction of the drive shaft 10. The transmission component is used to adjust the transmission state of the drive shaft 10 and the drive sleeve 8, the connecting portion 13 is connected to the second piston portion 11, and the connecting portion 13 is inserted into the spiral groove 14; The driving sleeve 8 can be rotatably connected to the housing 1, and the driving shaft 10 is used to drive the driving sleeve 8 to rotate; The number of the driving sleeves 8 may be consistent with the number of the pushing components 3, and a plurality of driving sleeves 8 may be arranged at intervals on the driving shaft 10; The connecting portion 13 is connected to the second piston portion 11, so that the connecting portion 13 can drive the second piston portion 11 to move. It should be noted that in the embodiment of the present application, the second piston portion 11 can only move relative to the second cavity 12, but cannot rotate relative to the second piston portion 11; Since the connecting portion 13 is inserted into the spiral groove 14 of the driving sleeve 8, the connecting portion 13 can move axially relative to the driving sleeve 8 during the rotation of the driving sleeve 8, and then the second piston portion 11 moves relative to the second cavity 12, and the first piston portion 6 also moves relative to the first cavity 5. Finally, the movable end 7 applies pressure to the sample 4 driven by the first piston portion 6.

[0045] In conventional technology, the three pushing components 3 are independent components, so the three pushing components 3 need to be controlled separately, which makes the circuit complicated on the one hand, and reduces the synchronization rate of the three pushing components 3 on the other hand. In the embodiment of the present application, the driving shaft 10 rotates to drive the driving sleeve 8 to rotate, thereby enabling the three pushing components 3 to work. On the one hand, the structure is simple and reliable, and on the other hand, the three pushing components 3 can move synchronously and apply pressure to the sample 4 synchronously.

[0046] In the embodiment of the present application, the medium in the first chamber and the second chamber may be gas, which has a certain compressibility, so that even if the three pushing components 3 are all driven by one driving shaft 10, the three pushing components 3 can still apply pressure to the sample 4 respectively.

[0047] Of course, in other embodiments, the connecting part 13 may not be driven by the driving sleeve 8, but the flow of the medium between the first chamber and the second chamber may be directly controlled by a hydraulic device to move the first piston part 6. The hydraulic device can be selected from existing devices and will not be described in detail here.

[0048] In some embodiments, the transmission component includes a transmission ring 16, a connecting cable 17 and a limiting portion 19. The transmission ring 16 is sleeved on the drive shaft 10, and a limiting tooth 15 is provided on the inner circumferential wall of the transmission ring 16 around the circumference of the transmission ring 16. The connecting cable 17 is connected to the transmission ring 16 and the drive sleeve 8, and the limiting portion 19 is rotatably connected to the drive shaft 10, and the rotation axis of the limiting portion 19 is perpendicular to the axial direction of the drive shaft 10. The limiting portion 19 cooperates with the limiting tooth 15 to make the transmission ring 16 and the drive shaft 10 rotate synchronously; Under the action of the transmission component, the drive shaft 10 can be connected or disconnected with the drive sleeve 8; The transmission ring 16 can be rotatably connected to the box body 1; The transmission ring 16 is sleeved on the drive shaft 10 so that the transmission ring 16 can rotate relative to the drive shaft 10; The transmission ring 16 is connected to the drive sleeve 8 via a connecting cable 17, so that when the transmission ring 16 rotates, the drive sleeve 8 can be driven to rotate together; The limiting portion 19 is rotatably connected to the drive shaft 10, so that the limiting portion 19 can have two states, one is that the limiting portion 19 contacts the limiting teeth 15, at this time, when the drive shaft 10 rotates, the transmission ring 16 rotates together with the drive shaft 10, thereby enabling the drive sleeve 8 to rotate, and the other is that the limiting portion 19 does not contact the limiting teeth 15, at this time, when the drive shaft 10 rotates, it will not drive the transmission ring 16 to rotate together; The advantage of connecting the transmission ring 16 and the drive sleeve 8 through the connecting cable 17 is that, on the one hand, the transmission structure is simpler and more reliable. On the other hand, the control method for the three pushing components 3 is increased. For example, by adjusting the position of the transmission ring 16 relative to the drive shaft 10 in the initial state, the time when the pushing component 3 starts working and the parameters of the pressure applied by the pushing component 3 to the sample 4 when the drive shaft 10 rotates can be adjusted. On the other hand, the connecting cable 17 is set to a bent state, and when the drive shaft 10 rotates, the drive sleeve 8 can rotate in the opposite direction relative to the drive shaft 10. When the connecting cable 17 is straightened, when the drive shaft 10 rotates, the drive sleeve 8 rotates in the same direction as the drive shaft 10. That is, under the premise that one drive shaft 10 is used as the power source, the rotation directions of the various drive sleeves 8 can be different. On the other hand, the drive sleeve 8 and the drive shaft 10 can be set at intervals so that no wear occurs between the two.

[0049] In other embodiments, the transmission ring 16 and the connecting rope 17 can be eliminated as needed, and the limiting teeth 15 can be set on the inner wall of the driving sleeve 8. When the limiting portion 19 contacts the limiting teeth 15 on the inner wall of the driving sleeve 8, the driving sleeve 8 and the driving shaft 10 are connected in transmission.

[0050] In some embodiments, the transmission component also includes a push ring 18, and an elastic member is arranged between the limiting portion 19 and the driving shaft 10, and the elastic member is used to provide an elastic force to rotate the limiting portion 19 in a direction close to the driving shaft 10. The push ring 18 is movably mounted on the driving shaft 10 along the axial direction of the driving shaft 10, and the limiting portion 19 abuts against the outer peripheral wall of the push ring 18.

[0051] The elastic member can be a spring or a torsion spring.

[0052] Under the action of the elastic member, the limiting portion 19 tends to move away from the transmission ring 16 .

[0053] The push ring 18 can move along the axial direction of the drive shaft 10 , so that the push ring 18 can push the limiting portion 19 to rotate, and then the limiting portion 19 can contact the transmission ring 16 or move away from the transmission ring 16 .

[0054] In other embodiments, two push rings 18 may be provided at intervals along the axial direction of the drive shaft 10 , one for pushing the limiting portion 19 toward the limiting tooth 15 , and the other for pushing the limiting portion 19 from the limiting tooth 15 toward the drive shaft 10 .

[0055] In the embodiment of the present application, the power source of the drive shaft 10 can be selected from the existing structure, which will not be described in detail here. At the same time, the housing 1 can be provided with a driving component, which is used to drive the transmission ring 16 to rotate relative to the drive shaft 10 when the transmission ring 16 and the limiter 19 are disconnected, so as to adjust the position of the transmission ring 16. The drive shaft 10 can also be provided with a driving component, which is used to drive the push ring 18 to move relative to the drive shaft 10. The driving component can be selected from the existing structure, which will not be described in detail here.

[0056] In some embodiments, the limiting portion 19 includes a first end close to the transmission ring 16, the first end includes two elastic arms 20, and the first end includes a first state and a second state. In the first state, the two elastic arms 20 are inserted between two adjacent limiting teeth 15, and in the second state, a limiting tooth 15 is arranged between the two elastic arms 20.

[0057] The limiting portion 19 may be made of a material capable of elastic deformation, so that the two elastic arms 20 can be elastically deformed.

[0058] If the limiting portion 19 is an integral structure, when the limiting portion 19 contacts the limiting teeth 15, there may be two situations. One is that the limiting portion 19 is just stuck between the two limiting teeth 15, and the other is that the limiting portion 19 is against the top of the limiting teeth 15. At this time, the transmission ring 16 needs to rotate a certain angle before the limiting portion 19 can be stuck between the two limiting teeth 15, which may also cause errors in the displacement of the moving end 7 of the pushing component 3.

[0059] In the embodiment of the present application, in the first state, the limiting portion 19 can be just inserted between the two limiting teeth 15. If the limiting portion 19 is against the top of the limiting tooth 15, when the limiting portion 19 switches to the second state, that is, the two elastic arms 20 are separated, each elastic arm 20 is inserted between the two limiting teeth 15. At the same time, a limiting tooth 15 is arranged between the two elastic arms 20, so that the limiting portion 19 can play a limiting role without the need for the transmission portion to rotate.

[0060] In some embodiments, an adjustment column 9 is further included, and the adjustment column 9 is disposed between the transmission ring 16 and the driving sleeve 8; The position of the adjusting column 9 relative to the box body 1 can be adjusted, so that the position of the adjusting column 9 between the transmission ring 16 and the driving sleeve 8 can also be adjusted; On the one hand, the adjusting column 9 can play a limiting role, that is, if the connecting cable 17 is in a straight state, when the connecting cable 17 contacts the adjusting column 9, the transmission ring 16 can no longer drive the driving sleeve 8 to move further, thereby limiting the travel of the driving sleeve 8. On the other hand, the adjusting column 9 can also enable the driving sleeve 8 to move in the reverse direction, that is, by adjusting the position of the transmission ring 16 relative to the adjusting column 9, the connecting cable 17 can be initially in a bent state, and the adjusting column 9 is at the inner bend of the connecting cable 17. At this time, when the driving shaft 10 rotates, the driving sleeve 8 can be driven to rotate in the reverse direction.

[0061] In some embodiments, the position of the adjusting column 9 can be adjusted by an adjusting component, which can include an adjusting shaft 21, which is connected to the housing 1, and can also include a mounting sleeve 25, which is sleeved on the adjusting shaft 21, so that the mounting sleeve 25 can move relative to the adjusting shaft 21, and the axial direction of the adjusting shaft 21 can extend along the axial direction of the driving shaft 10. It should be noted that the mounting sleeve 25 can only move along the axial direction of the adjusting shaft 21, and will not rotate relative to the adjusting shaft 21. The adjusting shaft 21 can be provided with a locking component for locking the mounting sleeve 25 after the position of the mounting sleeve 25 is adjusted. The locking component can be selected from the existing structure and will not be described here.

[0062] The adjusting component also includes a rotating sleeve 22, which is sleeved on the mounting sleeve 25. Along the axial direction of the mounting sleeve 25, the mounting sleeve 25 is provided with abutting walls 23 and limiting sleeves 24 at intervals. The rotating sleeve 22 is arranged between the abutting walls 23 and the limiting sleeve 24. The limiting sleeve 24 is threadedly connected to the mounting sleeve 25, so that the limiting sleeve 24 can move along the axial direction of the mounting sleeve 25, and then the limiting sleeve 24 and the abutting wall 23 cooperate to clamp the rotating sleeve 22. The adjusting column 9 is connected to the rotating sleeve 22, so that the rotating sleeve 22 can carry the adjusting column 9 to move along the axial direction of the adjusting shaft 21, and the rotating sleeve 22 can rotate along the circumferential direction of the adjusting shaft 21, so that the position of the adjusting column 9 between the driving sleeve 8 and the driving shaft 10 can be adjusted. After the adjustment is completed, the rotating sleeve 22 is clamped and locked by cooperating with the limiting sleeve 24 and the abutting wall 23. In order to increase the locking effect of the limiting sleeve 24 and the abutting wall 23 , the side of the limiting sleeve 24 close to the rotating sleeve 22 may be in a frustum state. Similarly, the side of the rotating sleeve 22 facing the limiting sleeve 24 may be provided with an adaptive frustum-shaped depression.

[0063] The above embodiments are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, modifications, and substitutions made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for simulating the formation and evolution of rock fissures, characterized in that: include: Processing the sampled specimen (4) into a cubic structure; Cyclic stress is applied to the first surface of the sample (4) by a pressure-applying component, and the second surface of the sample (4) is supported by a reaction force component (2), wherein the first surface is three surfaces forming a first vertex of the sample (4), and the second surface is three surfaces forming a second vertex of the sample (4), and the first vertex and the second vertex are located on a body diagonal of the sample (4); Adjust the magnitude of the applied stress until cracks appear on the specimen (4), and record the magnitude of the stress on the three first surfaces; The loading stress is further adjusted and the length of the crack is recorded until the specimen (4) is destroyed.

2. The method for simulating the formation and evolution of rock fissures according to claim 1, characterized in that: The cyclic loading stress refers to: Set the pressure value variable Δσ; Select two first surfaces from the three first surfaces, increase the pressure value of one of them by Δσ, and decrease the pressure value of the other by Δσ; Adjust the pressure values ​​of the three first surfaces to the initial values; Reselect the two first surfaces, increase the pressure value of one of them by Δσ, and decrease the pressure value of the other by Δσ.

3. The method for simulating the formation and evolution of rock fissures according to claim 2, characterized in that: The adjustment of the magnitude of the loaded stress refers to increasing the value of Δσ.

4. The method for simulating the formation and evolution of rock fissures according to claim 1, characterized in that: A pad is provided between the pressure-applying component and the sample (4), and the pad is made of a transparent material.

5. The method for simulating the formation and evolution of rock fissures according to claim 4, characterized in that: A slide groove is arranged on the edge of the pad, and a scale is accommodated in the slide groove.

6. The method for simulating the formation and evolution of rock fissures according to claim 1, characterized in that: The pressure-applying component and the reaction force component (2) are arranged in a transparent simulation box.

7. A simulation device, applied to the method according to any one of claims 1 to 6, characterized in that: include: A box (1) is used to accommodate a sample (4), wherein three inner wall surfaces of the box (1) intersect to form three reaction force parts (2), and normal directions of the three inner wall surfaces extend along a first direction, a second direction, and a third direction, respectively, and the first direction, the second direction, and the third direction are perpendicular to each other; Three pushing components (3) are accommodated in the box (1) and are used to apply pressure to the sample (4). The pushing components (3) include a moving end (7). Among the three pushing components (3), the moving end (7) of one moves along the first direction, the moving end (7) of another moves along the second direction, and the moving end (7) of the third moves along the third direction.

8. The simulation device according to claim 7, characterized in that: The pushing component (3) comprises: A first cavity (5) is arranged in the box (1); The first piston part (6) is movably accommodated in the first cavity (5) along the axial direction of the first cavity (5); the first piston part (6) divides the interior of the first cavity (5) into two parts; and the movable end (7) is connected to the first piston part (6).

9. The simulation device according to claim 8, characterized in that The invention also comprises a control assembly, wherein the control assembly comprises the control component, and the control component comprises a second cavity (12) and a second piston portion (11), wherein the second cavity (12) is arranged in the housing (1), and the axial direction of the second cavity (12) extends along the axial direction of the drive shaft (10), and the second piston portion (11) is movably accommodated in the second cavity (12) along the axial direction of the second cavity (12), and the second piston portion (11) divides the interior of the second cavity (12) into two parts, and the two parts of the second cavity are connected to the two parts of the first cavity in a one-to-one correspondence.

10. The simulation device according to claim 9, characterized in that The control component also includes: A drive shaft (10) rotatably connected to the housing (1); A drive sleeve (8) is sleeved outside the peripheral wall of the drive shaft (10), the drive sleeve (8) being provided with a spiral groove (14), the axial direction of the spiral groove (14) extending along the axial direction of the drive shaft (10); A transmission component, used for adjusting the transmission state of the drive shaft (10) and the drive sleeve (8); The connecting portion (13) is connected to the second piston portion (11), and the connecting portion (13) is inserted into the spiral groove (14).

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