Rock dynamic splitting combined monitoring equipment and method

Abstract

The invention discloses rock dynamic splitting combined monitoring equipment and a rock dynamic splitting combined monitoring method, relates to the technical field of rock dynamic testing, and is used for solving the problems of single and one-sided monitoring result and low accuracy caused by the fact that a single monitoring means, such as ultrasonic monitoring and pressure monitoring, is usually adopted for monitoring in a dynamic mechanical testing process. According to the main technical scheme, the rock dynamic splitting combined monitoring equipment comprises a pressure loading system, the pressure loading system comprises a containing space, the containing space is used for containing a sample, and the pressure loading system is used for providing dynamic impact for the sample and generating impact information; the combined monitoring device comprises a deformation detection piece, and the deformation detection piece is used for being in contact with the sample so as to generate deformation information of the sample under dynamic impact; and the image monitoring system is used for generating image information of the sample under the dynamic impact. The device is mainly used for rock dynamics testing.

Description

Technical Field

[0001] The present invention relates to the technical field of rock dynamics testing, and in particular to a rock dynamic splitting joint monitoring device and method. Background Art

[0002] As shallow mineral resources are gradually depleted, deep mineral resource mining has become a trend. However, mining deep resources will encounter many challenges. For example, the greater the mining depth, the greater the ground stress the rock mass will bear. The joints and fissures in the rock mass are prone to cause rock mass instability under the action of engineering activities such as blasting, leading to a series of major engineering disasters, causing huge economic losses and waste of resources. Therefore, it is urgent to study the dynamic mechanical properties of deep rocks.

[0003] The current method for obtaining the dynamic mechanical characteristics of rock materials is mainly to use the SHPB system to dynamically load the specimens and cooperate with corresponding monitoring devices. However, due to the limitations of test conditions, monitoring during dynamic mechanical tests usually uses a single monitoring method, such as ultrasonic monitoring or pressure monitoring alone, which leads to single and one-sided monitoring results with low accuracy. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a joint monitoring device and method for rock dynamic splitting, which jointly monitors by a deformation detection component and an image monitoring system under dynamic loading conditions, thereby realizing accurate monitoring of relevant rock mechanical properties such as dynamic damage of rocks and rock-like materials, and providing a theoretical basis for research on the dynamic mechanical properties of rocks and their engineering applications.

[0005] In order to achieve the above object, the present invention mainly provides the following technical solutions:

[0006] On the one hand, an embodiment of the present invention provides a rock dynamic splitting joint monitoring device, including:

[0007] A pressure loading system, the pressure loading system comprises a placement space, the placement space is used to place the sample, and the pressure loading system is used to provide dynamic impact to the sample and generate impact information;

[0008] A combined monitoring device, the combined monitoring device comprises two deformation detection members, the deformation detection members are used to contact with the sample, and the deformation detection members are used to generate deformation information of the sample under dynamic impact;

[0009] Image monitoring system, the image monitoring system is used to generate image information of the sample under dynamic impact.

[0010] The deformation detection component includes a displacement sensor, and the deformation information includes displacement information generated by the displacement sensor.

[0011] The deformation detection member further includes an acoustic emission sensor, the acoustic emission sensor is in contact with the surface of the sample, and the deformation information further includes acoustic emission information generated by the acoustic emission sensor.

[0012] Wherein, the detection end of the displacement sensor is connected to the acoustic emission sensor.

[0013] Wherein, the deformation detection member also includes a flexible connection seat, and the detection end of the displacement sensor is connected to the acoustic emission sensor through the flexible connection seat.

[0014] The combined monitoring device further comprises a support frame, and the deformation detection member is threadedly connected to the support frame.

[0015] Wherein, the image monitoring system includes a lighting device and an image acquisition component;

[0016] Lighting equipment is used to illuminate the specimen;

[0017] The number of the image acquisition components is two, the two image acquisition components are arranged at intervals, and the angle between the optical axes of the two image acquisition components is a preset angle, and the image acquisition components are used to generate image information.

[0018] The pressure loading system includes a punch, an incident rod, a transmission rod and an absorption rod;

[0019] The incident rod and the transmission rod are coaxially arranged with an interval, a placement space is formed between the incident rod and the transmission rod, a first strain gauge and a second strain gauge are respectively arranged on the incident rod and the transmission rod, and the first strain gauge and the second strain gauge are used to generate impact information;

[0020] The punch is located on the side of the incident rod opposite to the transmission rod, and is used to impact the incident rod under the action of external force;

[0021] The absorption rod is located on the side of the transmission rod opposite to the incident rod.

[0022] On the other hand, an embodiment of the present invention further provides a rock dynamic splitting joint monitoring method, characterized in that it is implemented using any of the rock dynamic splitting joint monitoring devices described above, and the method includes:

[0023] The core is drilled from the original rock block and processed into a cylindrical shape to form a sample;

[0024] Install the specimen in the placement space;

[0025] Adjust the deformation detection piece to contact with the sample;

[0026] Adjust the image monitoring system to align with the sample;

[0027] Apply dynamic impact to the specimen using a pressure loading system;

[0028] The impact information, deformation information and image information are obtained until the test is terminated after the specimen is destroyed.

[0029] Wherein, after the steps of obtaining impact information, deformation information and image information and terminating the test after the sample is destroyed, the method further comprises:

[0030] Determine the elastic energy generated by the splitting wave in the dynamic impact based on the impact information;

[0031] Determine the residual kinetic energy of the broken specimen based on the deformation information;

[0032] The fracture energy of the specimen is determined based on the elastic energy and the residual kinetic energy.

[0033] The embodiment of the present invention proposes a rock dynamic splitting joint monitoring device and method, which applies dynamic impact conditions to the sample through a pressure loading system, and the joint monitoring device is used to monitor the deformation of the sample during the dynamic impact loading process. The image monitoring system collects and analyzes the digital image data of the sample under dynamic impact, and then realizes the deformation and image joint monitoring and analysis of the damage and destruction process of the sample under the impact load, and realizes the monitoring of rock crack development and rock fracture characteristics under dynamic load with the characteristics of multi-angle, high precision and high efficiency, so as to further explore the deep rock failure characteristics, and provide important theoretical basis for the development of deep rock engineering while providing reliable monitoring result support, and provide reliable monitoring result support for the study of the fracture development mechanism of rock under impact load. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the structure of a rock dynamic splitting joint monitoring device provided by an embodiment of the present invention;

[0035] Figure 2 A schematic structural diagram of a partial structure of a rock dynamic splitting joint monitoring device provided by an embodiment of the present invention at a first viewing angle;

[0036] Figure 3 A schematic structural diagram of a partial structure of a rock dynamic splitting joint monitoring device provided by an embodiment of the present invention at a second viewing angle;

[0037] Figure 4 A schematic structural diagram of a deformation detection component in a rock dynamic splitting joint monitoring device provided by an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of an explosion structure of a part of the structure of a deformation detection component in a rock dynamic splitting joint monitoring device provided by an embodiment of the present invention;

[0039] Figure 6 A flow chart of a rock dynamic splitting joint monitoring method provided by an embodiment of the present invention;

[0040] Among them, the sample 10, the deformation detection part 100, the displacement sensor 110, the acoustic emission sensor 120, the flexible connection seat 130, the connection plate 131, the connection head 132, the support frame 200, the connector 210, the bracket 220, the fixing seat 230, the bolt 240, the lighting device 300, the image acquisition part 400, the punch 510, the incident rod 520, the transmission rod 530, the absorption rod 540, the first strain gauge 550, the second strain gauge 560, the ultra-dynamic strain gauge 600, the data acquisition and processing system 700, the image processing system 800, and the soft pad 900. DETAILED DESCRIPTION

[0041] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation method, structure, characteristics and effects of a rock dynamic splitting combined monitoring device proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0042] On the one hand, if Figure 1 As shown, an embodiment of the present invention provides a rock dynamic splitting joint monitoring device, including:

[0043] A pressure loading system, the pressure loading system comprises a placement space, the placement space is used to place the sample 10, and the pressure loading system is used to provide dynamic impact to the sample 10 and generate impact information;

[0044] A combined monitoring device, the combined monitoring device comprises two deformation detection members 100, the deformation detection members 100 are used to contact with the sample 10, and the deformation detection members 100 are used to generate deformation information of the sample 10 under dynamic impact;

[0045] The image monitoring system is used to generate image information of the sample 10 under dynamic impact.

[0046] The rock sample is referred to as sample 10 in this application. Sample 10 is obtained by drilling a core from an original rock block on site and processing the rock into a cylindrical shape. The pressure loading system is used to apply external impact disturbance to sample 10, and the pressure loading system can be in various forms, such as a Hopkinson pressure bar (SHPB) loading device. The Hopkinson pressure bar loading device is used to provide radial dynamic impact loading conditions for sample 10. In a more specific embodiment, the pressure loading system includes a punch 510, an incident rod 520, a transmission rod 530 and an absorption rod 540. The incident rod 520 and the transmission rod 530 are made of the same material, and the incident rod 520 and the transmission rod 530 are coaxially spaced, and a placement space is formed between the incident rod 520 and the transmission rod 530. The first strain gauge 550 and the second strain gauge 560 are respectively arranged on the incident rod 520 and the transmission rod 530, and the first strain gauge 550 and the second strain gauge 560 are equidistant from the opposite ends of the incident rod 520 and the transmission rod 530. In some embodiments, the device also includes an ultra-dynamic strain gauge 600 and a data acquisition and processing system 700. The first strain gauge 550 and the second strain gauge 560 are both electrically connected to the ultra-dynamic strain gauge 600. The ultra-dynamic strain gauge 600 is electrically connected to the data acquisition and processing system 700. Shielded wires can be used as electrical connection lines to ensure signal stability and prevent distortion. The data acquisition and processing system 700 can be a computer. The punch 510 is located on the side of the incident rod 520 that is opposite to the transmission rod 530, and is used to impact the incident rod 520 under the action of an external force. The absorption rod 540 is located on the side of the transmission rod 530 that is opposite to the incident rod 520. Before the test begins, the positions of the incident rod 520, the sample 10 and the transmission rod 530 need to be adjusted so that the incident rod 520 and the transmission rod 530 are coaxial. As shown in the example Figure 1 Taking the direction shown as an example, the horizontal axis of the end face of the sample 10 is parallel to the axis of the incident rod 520 and is located at the same height. The punch 510 is driven by high-pressure gas to impact the incident rod 520 to generate a stress wave. The stress wave is continuously transmitted to the sample 10 along with the incident rod 520 and is reflected and transmitted. A part of the stress wave continues to propagate to the transmission rod 530, and then the dynamic impact loading of the sample 10 is completed. During this loading process, the first strain gauge 550 and the second strain gauge 560 are used to obtain the strain changes on the incident rod 520 and the transmission rod 530, respectively, and generate impact information, which is sent to the ultra-dynamic strain gauge 600 and the data acquisition and processing system 700.

[0047] like Figure 2-3 As shown, the number of deformation detection members 100 can be two, and the pressure loading system is used to provide dynamic impact to the sample 10 in a first direction, and the first direction can be the axial direction of the incident rod 520 and the transmission rod 530. The two deformation detection members 100 are arranged in a second direction perpendicular to the first direction and perpendicular to the axial direction of the sample 10. Figure 1In the vertical direction shown, the sample 10 is axially perpendicular to the paper surface, a deformation detection member 100 is arranged above the sample 10, another deformation detection member 100 is arranged below, an incident rod 520 is arranged on the left side, and a transmission rod 530 is arranged on the right side. The deformation information detected by the deformation detection member 100 can be multiple, such as displacement information or acoustic emission information on the surface of the sample 10. It will be described in detail below in conjunction with more specific embodiments. In some embodiments, in the aforementioned embodiment including the data acquisition and processing system 700, the deformation detection member 100 is electrically connected to the data acquisition and processing system 700.

[0048] The image monitoring system is used to monitor the damage process of the sample 10 under dynamic impact conditions. In some embodiments, the device also includes an image processing system 800, on which three-dimensional digital image correlation (3D-DIC) analysis and calculation software is installed, which can then perform data processing and analysis on the image information.

[0049] It is worth noting that the deformation information and image information obtained by the joint monitoring of the present application can be used in combination, and the two can verify each other, or they can be used alone. As specifically, in the calculation of the fracture energy mentioned below, it can be that the average speed of the fracture sample 1 and the fracture sample 2 during the fracture process is first determined according to the image information, and the first fracture energy result is calculated, and then the average speed of the fracture sample 1 and the fracture sample 2 during the fracture process is determined according to the deformation information, or the displacement information, and the second fracture energy result is calculated, and the fracture energy is determined according to the first fracture energy result and the second fracture energy result. For example, it can be an average value, or if the difference between the first fracture energy result and the second fracture energy result is greater than a threshold value, it is considered that the experiment has failed and the experiment can be repeated. Alternatively, there are other implementation methods, which will not be listed one by one without application.

[0050] The embodiment of the present invention proposes a rock dynamic splitting joint monitoring device and method, which applies dynamic impact conditions to the sample through a pressure loading system, and the joint monitoring device is used to monitor the deformation of the sample during the dynamic impact loading process. The image monitoring system collects and analyzes the digital image data of the sample under dynamic impact, and then realizes the deformation and image joint monitoring and analysis of the damage and destruction process of the sample under the impact load, and realizes the monitoring of rock crack development and rock fracture characteristics under dynamic load with the characteristics of multi-angle, high precision and high efficiency, so as to further explore the fracture characteristics of deep rocks, and provide important theoretical basis for the development of deep rock engineering while providing reliable monitoring result support, and provide reliable monitoring result support for the study of the fracture development mechanism of rock under impact load.

[0051] The deformation detection member 100 can be in various forms. In one embodiment, the deformation detection member 100 is used to monitor the vertical displacement change of the sample 10 under dynamic impact conditions. The deformation detection member 100 includes a displacement sensor 110, and the deformation information includes displacement information generated by the displacement sensor 110. The fracture energy of the sample 10 can be jointly determined by displacement monitoring and image monitoring of the sample 10. The calculation method will be further described in detail below.

[0052] In some other embodiments, the deformation detection member 100 may be intended to monitor the acoustic emission characteristics of the sample 10 and the vertical displacement change of the sample 10 under dynamic impact conditions. The deformation detection member 100 includes a displacement sensor 110, and the deformation information includes the displacement information generated by the displacement sensor 110. The deformation detection member also includes an acoustic emission sensor 120, and the acoustic emission sensor 120 abuts against the surface of the sample 10, and the deformation information also includes the acoustic emission information generated by the acoustic emission sensor 120.

[0053] The displacement sensor 110 and the acoustic emission sensor 120 are both electrically connected to the data acquisition and processing system 700. The displacement sensor 110 is a linear displacement sensor, including a sensor body and a push rod. There is an elastic member between the sensor body and the push rod, and the elastic member applies an elastic force to the push rod to move toward the outside of the sensor body or toward one side of the sample 10. The end of the push rod away from the sensor body is the detection end. When the sample 10 is deformed, it will directly or indirectly push the detection end, and then make the push rod retract toward the sensor body to achieve displacement detection. The acoustic emission sensor 120 uses acoustic emission detection technology, which is a non-destructive testing method that can be used to evaluate material properties or structural integrity. When the sample 10 is subjected to an impact load, the sample 10 will produce crack extension, plastic deformation and other phenomena, resulting in rapid release of strain energy and generation of stress waves. These stress waves eventually propagate to the surface of the sample 10, causing surface displacements, which can be detected by the acoustic emission sensor 120, and the mechanical vibration is converted into an electrical signal, which is then amplified to form acoustic emission information. By using acoustic emission real-time monitoring, the damage characteristics of the sample 10 under the impact load can be analyzed. The acoustic emission sensor 120 may be indirectly abutted against the surface of the sample 10, such as preferably applying a proper amount of vaseline for coupling.

[0054] In one embodiment, the detection end of the displacement sensor 110 is connected to the acoustic emission sensor 120. The connection may be direct, such as bonding or clamping. Alternatively, the deformation detection member 100 further includes a flexible connection seat 130, and the detection end of the displacement sensor 110 is connected to the acoustic emission sensor 120 via the flexible connection seat 130.

[0055] The flexible connection seat 130 can be made of rubber material. Figure 4-5As shown, the flexible connection seat 130 includes a connection plate 131 and a connection head 132, the connection head 132 is connected to the connection plate 131, the acoustic emission sensor 120 covers the side of the connection plate 131 opposite to the connection head 132, and the detection end of the displacement sensor 110 is embedded in the connection head 132. The flexible connection seat 130 is approximately T-shaped as a whole.

[0056] In one embodiment, the combined monitoring device further includes a support frame 200 , and the deformation detection member 100 is threadedly connected to the support frame 200 .

[0057] For example, the displacement sensor 110 may be threadedly connected to the support frame 200. The support frame 200 may have various shapes, such as Figure 3 As shown, the support frame 200 includes an approximately U-shaped connector 210, a fixing seat 230 and a bracket 220. The bracket 220 is connected to the connector 210 and the fixing seat 230. The two supporting claws of the connector 210 are respectively threadedly connected to two deformation detection members 100, or two displacement sensors 110. The position of the deformation detection member 100 as a whole in the direction of approaching or moving away from the sample 10 can be adjusted by rotating the displacement sensor 110, and then the position of the displacement sensor 110 can be adjusted. Under the force provided by the built-in spring of the displacement sensor 110, the acoustic emission sensor 120 is closely attached to the sample 10, and the displacement sensor 110 is retained with a sufficient range, thereby preventing the displacement sensor 110 and the acoustic emission sensor 120 from being damaged by impact. The fixing seat 230 and the total support platform of the detection equipment can be connected by bolts 240.

[0058] In some embodiments, a soft pad 900 is provided on one side of the connector 210 of the support frame 200 opposite to the acoustic emission sensor 120. The soft pad 900 may be a flexible pad such as a sponge pad or a rubber pad, which is used to reduce the impact force of the acoustic emission sensor 120 on the support frame 200 during the impact process.

[0059] The above implementation has the following advantages: 1. The acoustic emission sensor 120 is fixed to the support frame 200 through the displacement sensor 110, and moves outward with the fracture of the sample 10 during dynamic loading. While preventing the acoustic emission sensor 120 from being squeezed and damaged, it ensures that the acoustic emission sensor 120 is not easy to fall with the collapse of the sample 10, thereby protecting the acoustic emission sensor 120 and avoiding the problem that the acoustic emission sensor 120 is easily damaged when using the acoustic emission sensor 120 for measurement.

[0060] 2. The pressure of the elastic member built into the displacement sensor 110 can act on the acoustic emission sensor 120, providing a fixing force for it to be tightly attached to the sample 10, thereby solving the problem of cumbersome installation operation of the acoustic emission sensor 120 by means of gluing, etc., and requiring regular cleaning of residual adhesive.

[0061] In one embodiment, the image monitoring system includes an illumination device 300 and an image acquisition member 400. The illumination device 300 is used to illuminate the sample 10. There are two image acquisition members 400, the two image acquisition members 400 are arranged at intervals, and the angle between the optical axes of the two image acquisition members 400 is a preset angle, and the image acquisition member 400 is used to generate image information.

[0062] The image monitoring system uses digital image correlation technology (DIC), which is a non-contact image monitoring method based on digital image processing and a particle tracking method. This method obtains displacement information by identifying several spots in the image and tracking specific particles on the surface of the sample 10, thereby extracting the full-field displacement of the surface of the sample 10. By identifying and calculating the subset motion information between the reference image and the current image, the displacement of the sample 10 under dynamic impact can be accurately estimated, and its deformation and strain information can be extracted.

[0063] The number of lighting devices 300 can be multiple, and multiple lighting devices 300 can be symmetrically distributed outside the sample 10, such as being evenly arranged around the incident rod 520 and the transmission rod 530. The lighting device 300 is placed about 50 cm away from the surface of the sample 10. The image acquisition component 400 can be a high-speed camera. The two high-speed cameras are of the same model, located on the same side of the sample 10, and arranged in the axial direction of the incident rod 520. The preset angle range is 12° to 60° to ensure a sufficient image acquisition range.

[0064] On the other hand, Figure 6 As shown, an embodiment of the present invention further provides a rock dynamic splitting joint monitoring method, characterized in that it is implemented using any of the rock dynamic splitting joint monitoring devices described above, and the method includes:

[0065] S1. Drill a core from the original rock block and process it into a cylindrical shape to form a sample 10.

[0066] The core was drilled from the original rock block obtained on site, and according to the method recommended by the International Society of Rock Mechanics, the rock was processed into a cylindrical shape with a diameter of 50 mm and a height of 25 mm to form a sample 10. White matte paint was sprayed on the surface to be observed of the sample 10, and an artificial speckle field was produced using a speckle tool.

[0067] S2. Install the sample 10 in the placement space.

[0068] Apply a proper amount of lubricant to both ends of the sample 10 to reduce the friction effect between the sample 10 and the end faces of the incident rod 520 and the transmission rod 530. Then clamp the sample 10 between the incident rod 520 and the transmission rod 530, and make the axial direction of the sample 10 perpendicular to the central axis of the incident rod 520 and the transmission rod 530, and make the axis of the incident rod 520 and the axis of the transmission rod 530 intersect with the axis of the sample 10. In other words, Figure 1 In the direction shown, the horizontal axis of the end surface of the sample 10 is parallel to the central axis of the incident rod 520 and the transmission rod 530 and is located at the same height.

[0069] In addition, in the case where the strain gauge is not installed, before step S2, the method further includes pasting the first strain gauge 550 and the second strain gauge 560 on the incident rod 520 and the transmission rod 530 at positions equidistant from the sample 10, and then connecting the first strain gauge 550 and the second strain gauge 560 to the ultra-dynamic strain gauge 600 using a wire, and connecting the ultra-dynamic strain gauge 600 to the data acquisition and processing system 700. The bridge balance of each channel of the ultra-dynamic strain gauge 600 is adjusted.

[0070] S3 . Adjust the deformation detection member 100 to contact the sample 10 .

[0071] In the embodiment where the deformation detection member 100 only includes the displacement sensor 110, the displacement sensor 110 is mounted on the support frame 200, and the position of the displacement sensor 110 is adjusted so that the detection end of the displacement sensor 110 contacts the sample 10 and the displacement sensor 110 has a sufficient range. The displacement sensor 110 is electrically connected to the data acquisition and processing system 700 using a data connection line.

[0072] In the embodiment where the deformation detection member 100 includes an acoustic emission sensor 120 and a displacement sensor 110, the detection ends of the acoustic emission sensor 120 and the displacement sensor 110 are connected through a flexible connection seat 130 and installed on the support frame 200. The connection line of the two acoustic emission sensors 120 is perpendicular to the axis of the incident rod 520 and the axis of the sample 10, and the acoustic emission sensor 120 corresponds to the center position of the sample 10 in the direction of the axis of the incident rod 520. The position of the displacement sensor 110 is adjusted so that the probe end face of the acoustic emission sensor 120 is in close contact with the surface of the sample 10, and the displacement sensor 110 needs to have a sufficient range. The displacement sensor 110 and the acoustic emission sensor 120 are electrically connected to the data acquisition and processing system 700 using a data connection line.

[0073] S4, adjusting the image monitoring system to align with the sample 10.

[0074] Aim the lighting device 300 at the sample 10 so that the light is evenly distributed on the sample 10. The two image acquisition components 400 are arranged at a preset angle and electrically connected to the image processing system 800 with wires to ensure that the object images captured by the two image acquisition components 400 are at the center of the target surface. Adjust the position and brightness of the lighting device 300 to ensure that the image transmitted to the image processing system 800 is not overexposed.

[0075] S5. Apply dynamic impact to the sample 10 using a pressure loading system.

[0076] The punch 510 is driven by high-pressure gas to impact the incident rod 520 to generate stress waves, and then the first strain gauge 550 and the second strain gauge 560 respectively obtain the strain changes on the incident rod 520 and the transmission rod 530, and generate impact information, which is sent to the ultra-dynamic strain gauge 600 and the data acquisition and processing system 700. The ultra-dynamic strain gauge 600 and the two image acquisition components 400 are controlled by a synchronous trigger. When the ultra-dynamic strain gauge 600 acquires the signal, the real-time digital image, i.e., the image information, taken by the image acquisition component 400 is transmitted to the image processing system 800. The deformation of the sample 10 will trigger the displacement information generated by the displacement sensor 110 and the acoustic emission information generated by the acoustic emission sensor 120 and transmitted to the data acquisition and processing system 700.

[0077] S6. Obtain impact information, deformation information and image information until the test is terminated after the sample 10 is destroyed.

[0078] The data acquisition and processing system 700 and the image processing system 800 acquire information in real time until the test is terminated when the sample 10 is destroyed. Acoustic emission monitoring technology, displacement monitoring technology and image monitoring technology are used to monitor the splitting and fracture characteristics of rocks under impact loads, and the dynamic characteristics of rocks under different occurrence conditions are studied by combining the change characteristics of strength and energy when the sample 10 is destroyed with the SHPB loading system. The development of rock cracks and rock fracture characteristics under dynamic loads are monitored from multiple angles, with high precision and high efficiency, so as to further explore the fracture characteristics of deep rocks and provide an important theoretical basis for the development of deep rock engineering.

[0079] The above impact information, deformation information and image information can be used to study various rock characteristics. The following is an example of the application of impact information and deformation information in the calculation of rock fracture energy:

[0080] By studying the energy changes during rock destruction, we can understand the processes of rock internal crack generation, expansion and penetration, thereby revealing the microscopic and macroscopic mechanisms of rock destruction and providing theoretical guidance for exploring rock fracture. Since the fracture energy of rocks of different lithologies is different when they are destroyed, the fracture energy reveals the differences in the ability of rocks to resist destruction.

[0081] In blasting engineering, the essence of both traditional explosive blasting and gas blasting is the splitting and stretching problem of rocks under dynamic stress. Through the study of rock fracture energy, the corresponding blasting charge can be designed for different rock masses, so as to achieve accurate control of blasting depth and blasting range. It can reduce the probability of excessive damage to surrounding rocks caused by excessive blasting when using drilling and blasting methods to dig shafts and tunnels, or the probability of excessive blasting to damage aquifers and cause water inrush accidents.

[0082] Existing research on rock failure usually treats the dissipated energy during rock failure as fracture energy, ignoring the influence of rock kinetic energy. In the study of energy changes in the fracture of small-scale rock specimens in the laboratory, due to the problem of specimen size, the research method of ignoring kinetic energy has little effect on the overall energy change characteristics of the rock specimen. However, when the laboratory research results are extended to engineering applications, due to the different scales of the research objects, the "pseudo-fracture energy" obtained by ignoring kinetic energy during rock failure is quite different from the "real fracture energy", which may lead to deviations in the design of the support system or differences in precise blasting, and then lead to accidents. Therefore, this application proposes a method for determining the kinetic energy of broken rock blocks based on impact information and deformation information, or based on impact information and displacement information, and then calculating the fracture energy, so that the calculation of fracture energy is closer to reality and has more engineering significance.

[0083] The sample 10 is subjected to a dynamic splitting test. After the sample 10 is destroyed, a fractured sample is formed. The two deformation detection members 100 correspond to a fractured sample respectively. The displacement sensor 110 measures the displacement and time of the fractured sample during the destruction of the sample 10, and then calculates the fracture velocity of the fractured sample, so that the fracture energy of the sample 10 can be calculated. According to the one-dimensional stress wave theory and the law of conservation of energy, the elastic energy W generated by the elastic wave can be obtained as:

[0084] W=W i -W r -W t =W G +K

[0085] Where: W i is the elastic energy generated by the incident wave, Wr is the elastic energy generated by the reflected wave, and Wt is the elastic energy generated by the transmitted wave; W G is the fracture energy required to generate cracks in sample 10; K is the residual kinetic energy after sample 10 is destroyed.

[0086] In one embodiment, after the steps of obtaining impact information, deformation information and image information and terminating the test after the sample 10 is destroyed, the method further comprises:

[0087] S7-1. Determine the elastic energy generated by the elastic wave in the dynamic impact based on the impact information.

[0088] The elastic energy W generated by the incident wave i The elastic energy Wr generated by the reflected wave and the elastic energy Wt generated by the transmitted wave can be obtained through the driving data of the driving punch 510 and the impact information fed back by the first strain gauge 550 and the second strain gauge 560 .

[0089] S7-2. Determine the residual kinetic energy of the broken specimen based on the deformation information.

[0090] After the sample 10 is broken, the fractured sample 1 and the fractured sample 2 are formed. The kinetic energy T1 of the fractured sample 1 is: T1 = m1v1 2 / 2, the kinetic energy T2 of fractured specimen 2 is: T2=m2v2 2 / 2. Wherein, m1 and m2 can be obtained by weighing, such as using a balance. v1 and v2 are the average speeds of the fractured specimen 1 and the fractured specimen 2 during the fracture process, which can be calculated by the two displacement sensors 110 monitoring the displacement and time of the fractured specimen 1 and the fractured specimen 2 respectively.

[0091] Then the residual kinetic energy of sample 10 after destruction is K = T1 + T2 = (m1v1 2 +m2v2 2 ) / 2.

[0092] S7-3. Determine the fracture energy of sample 10 based on the elastic energy and the residual kinetic energy.

[0093] Then the fracture energy of sample 10 is: W G =WK.

[0094] The rock dynamic splitting joint monitoring equipment of the present application uses a displacement sensor 110 to measure the relationship between the displacement and time during the breaking process of the sample 10, thereby obtaining the fracture speed of the two fractured samples after the sample 10 is broken, and thus the fracture energy of the sample 10 can be calculated. It is more concise and efficient than calculating the fracture speed of the sample 10 by shooting with a high-speed camera. Combining acoustic emission technology and digital image related technology can better study the failure characteristics of rocks under dynamic loading. The sample 10 can be subjected to a splitting tensile test and monitored using a displacement sensor 110. The relationship between the dynamic tensile strength and the fracture energy of the sample 10 can be obtained by calculation. The characteristic quantities of the two fractured samples after the sample 10 is broken during dynamic loading fracture can be obtained through one test, and the failure characteristics of the sample 10 can be explored by analyzing the relationship between the two.

[0095] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A rock dynamic splitting joint monitoring device, characterized in that: include: A pressure loading system, the pressure loading system comprising a placement space, the placement space is used to place the sample, the pressure loading system is used to provide dynamic impact to the sample and generate impact information; A combined monitoring device, the combined monitoring device comprising two deformation detection members, the deformation detection members being used to contact the sample, and the deformation detection members being used to generate deformation information of the sample under the dynamic impact; An image monitoring system is used to generate image information of the sample under the dynamic impact.

2. The rock dynamic splitting joint monitoring device according to claim 1 is characterized in that: The deformation detection member includes a displacement sensor, and the deformation information includes displacement information generated by the displacement sensor.

3. The rock dynamic splitting joint monitoring device according to claim 2 is characterized in that: The deformation detection member further includes an acoustic emission sensor, the acoustic emission sensor is in contact with the surface of the sample, and the deformation information further includes acoustic emission information generated by the acoustic emission sensor.

4. The rock dynamic splitting joint monitoring device according to claim 3 is characterized in that: The detection end of the displacement sensor is connected to the acoustic emission sensor.

5. The rock dynamic splitting joint monitoring device according to claim 4 is characterized in that: The deformation detection member further comprises a flexible connection seat, and the detection end of the displacement sensor is connected to the acoustic emission sensor via the flexible connection seat.

6. The rock dynamic splitting joint monitoring device according to claim 1 is characterized in that: The combined monitoring device also includes a support frame, and the deformation detection member is threadedly connected to the support frame.

7. The rock dynamic splitting joint monitoring device according to claim 1 is characterized in that: The image monitoring system includes a lighting device and an image acquisition component; The lighting device is used to illuminate the sample; The number of the image acquisition components is two, the two image acquisition components are arranged at intervals, and the angle between the optical axes of the two image acquisition components is a preset angle, and the image acquisition components are used to generate the image information.

8. The rock dynamic splitting joint monitoring device according to claim 1 is characterized in that: The pressure loading system includes a punch, an incident rod, a transmission rod and an absorption rod; The incident rod and the transmission rod are coaxially arranged with an interval, the placement space is formed between the incident rod and the transmission rod, the incident rod and the transmission rod are respectively provided with a first strain gauge and a second strain gauge, the first strain gauge and the second strain gauge are used to generate the impact information; The punch is located at a side of the incident rod opposite to the transmission rod, and is used to impact the incident rod under the action of an external force; The absorption rod is located on a side of the transmission rod opposite to the incident rod.

9. A rock dynamic splitting joint monitoring method, characterized in that: The method is implemented by using the rock dynamic splitting joint monitoring device as described in any one of claims 1 to 8, and includes: The core is drilled from the original rock block and processed into a cylindrical shape to form a sample; installing the sample in a placement space; Adjusting the deformation detection member to contact with the sample; Adjusting the image monitoring system to align with the sample; applying a dynamic impact to the sample using a pressure loading system; The impact information, deformation information and image information are acquired until the test is terminated after the sample is destroyed.

10. The rock dynamic splitting joint monitoring method according to claim 9, characterized in that: After the step of obtaining the impact information, the deformation information and the image information and terminating the test after the sample is destroyed, the method further comprises: determining the elastic energy generated by the elastic wave in the dynamic impact according to the impact information; determining the residual kinetic energy of the broken specimen according to the deformation information; The fracture energy of the sample is determined based on the elastic energy and the residual kinetic energy.

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