A device and method for joint monitoring of dynamic splitting of rocks

Abstract

The present invention discloses a combined monitoring device and method for dynamic splitting of rocks. The present invention relates to the technical field of rock dynamics testing and is used to solve the problem that in the process of dynamic mechanical tests, the monitoring usually adopts a single monitoring means, such as using ultrasonic monitoring or pressure monitoring alone, resulting in a single and one-sided monitoring result and low accuracy. The main technical solution is as follows: A combined monitoring device for dynamic splitting of rocks, comprising: a pressure loading system, the pressure loading system includes a placement space for placing a specimen, and the pressure loading system is used to provide a dynamic impact to the specimen and generate impact information; a combined monitoring device, the combined monitoring device includes a deformation detection member for contacting the specimen to generate deformation information of the specimen under dynamic impact; an image monitoring system for generating image information of the specimen under dynamic impact. The present invention is mainly used for rock dynamics testing.

Description

Technical Field

[0001] The present invention relates to the technical field of rock dynamics testing, and particularly to a device and method for jointly monitoring dynamic splitting of rocks. Background Art

[0002] With the gradual depletion of shallow mineral resources, the exploitation of deep mineral resources has become a trend. However, many challenging problems will be encountered in the exploitation of deep resources. For example, the greater the mining depth, the greater the in-situ stress borne by the rock mass, and the joints and fissures in the rock mass are prone to cause rock mass instability under the action of engineering activities such as blasting, resulting in a series of major engineering disasters, causing huge economic losses and resource waste. Therefore, it is urgent to study the dynamic mechanical properties of deep rocks.

[0003] Currently, the main method for obtaining the dynamic mechanical characteristics of rock-like materials is to dynamically load the specimen using an SHPB system and cooperate with corresponding monitoring devices. However, currently limited by test conditions, the monitoring during the dynamic mechanical test usually uses a single monitoring method, such as using ultrasonic monitoring or pressure monitoring alone, resulting in a single and one-sided monitoring result and low accuracy. Summary of the Invention

[0004] In view of this, an embodiment of the present invention provides a device and method for jointly monitoring dynamic splitting of rocks, which are jointly monitored by a deformation detection component and an image monitoring system under dynamic loading conditions to accurately monitor the dynamic damage and other related rock mechanical properties of rocks and rock-like materials, providing a theoretical basis for the research on the dynamic mechanical properties of rocks and their engineering applications.

[0005] 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 device for jointly monitoring dynamic splitting of rocks, including:

[0007] A pressure loading system, which includes a placement space for placing a specimen, and the pressure loading system is used to provide a dynamic impact to the specimen and generate impact information;

[0008] A joint monitoring device, which includes two deformation detection components, and the deformation detection components are used to contact the specimen and generate deformation information of the specimen under dynamic impact;

[0009] An image monitoring system, which is used to generate image information of the specimen under dynamic impact.

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

[0011] Among them, the deformation detection component further includes an acoustic emission sensor, the acoustic emission sensor is in contact with the surface of the specimen, and the deformation information further includes the acoustic emission information generated by the acoustic emission sensor.

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

[0013] Among them, the deformation detection component further 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] Among them, the joint monitoring device further includes a support frame, and the deformation detection component is threadedly connected to the support frame.

[0015] Among them, the image monitoring system includes an illumination device and an image acquisition component;

[0016] The illumination device 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 included angle between the optical axes of the two image acquisition components is a preset included angle, and the image acquisition components are used to generate image information.

[0018] Among them, the pressure loading system includes a punch, an incident bar, a transmission bar, and an absorption bar;

[0019] The incident bar and the transmission bar are coaxially arranged at intervals, a placement space is formed between the incident bar and the transmission bar, a first strain gauge and a second strain gauge are respectively arranged on the incident bar and the transmission bar, 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 bar opposite to the transmission bar and is used to impact the incident bar under the action of an external force;

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

[0022] On the other hand, the embodiment of the present invention further provides a method for jointly monitoring the dynamic splitting of rocks, which is characterized in that it is realized by using the rock dynamic splitting joint monitoring device as described in any one of the above, and the method includes:

[0023] Drill a core from the original rock block and process it into a cylinder to form a specimen;

[0024] Install the specimen in the placement space;

[0025] Adjust the deformation detection component to be in contact with the specimen;

[0026] Adjust the image monitoring system to be aligned with the specimen;

[0027] Use the pressure loading system to apply a dynamic impact to the specimen;

[0028] Obtain impact information, deformation information, and image information until the test is terminated after the specimen is damaged.

[0029] After the step of obtaining impact information, deformation information, and image information until the test is terminated after the specimen is damaged, the method further includes:

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

[0031] Determine the residual kinetic energy of the fractured specimen according to the deformation information;

[0032] Determine the fracture energy of the specimen according to the elastic energy and the residual kinetic energy.

[0033] A rock dynamic splitting joint monitoring device and method proposed by an embodiment of the present invention apply dynamic impact conditions to a specimen through a pressure loading system. The joint monitoring device is used to monitor the deformation of the specimen during the dynamic impact loading process. The image monitoring system collects and analyzes the digital image data of the specimen under dynamic impact, and then realizes the combined deformation and image monitoring and analysis of the damage process of the specimen under the impact load, so as to monitor and analyze the crack development and rock fracture characteristics of the rock under the dynamic load from multiple angles, with high precision and high efficiency, so as to further explore the failure characteristics of deep rocks, 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 research on the crack development mechanism of rocks under impact load. Description of the Drawings

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

[0035] Figure 2 It is a schematic structural diagram of a part of the rock dynamic splitting joint monitoring device provided by an embodiment of the present invention from the first perspective;

[0036] Figure 3 It is a schematic structural diagram of a part of the rock dynamic splitting joint monitoring device provided by an embodiment of the present invention from the second perspective;

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

[0038] Figure 5 It is an exploded structural diagram of a part of the deformation detection member in a rock dynamic splitting joint monitoring device provided by an embodiment of the present invention;

[0039] Figure 6 It is a flowchart of a rock dynamic splitting joint monitoring method provided by an embodiment of the present invention;

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

[0041] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and effects of a rock dynamic splitting combined monitoring device according to the present invention as follows.

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

[0043] A pressure loading system, the pressure loading system includes a placement space for placing the specimen 10, and the pressure loading system is used to provide a dynamic impact to the specimen 10 and generate impact information;

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

[0045] An image monitoring system, the image monitoring system is used to generate image information of the specimen 10 under dynamic impact.

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

[0047] As Figures 2-3 shown, the number of deformation detection components 100 can be two. The pressure loading system is used to provide dynamic impact on specimen 10 in the first direction. The first direction can be the axial direction of the incident bar 520 and the transmission bar 530. The two deformation detection components 100 are arranged in the second direction perpendicular to the first direction and perpendicular to the axial direction of specimen 10. That is, as shown in Figure 1In the vertical direction shown, the axis of the specimen 10 is perpendicular to the paper surface. A deformation detection member 100 is provided above the specimen 10, another deformation detection member 100 is provided below it, an incident rod 520 is provided on the left side, and a transmission rod 530 is provided on the right side. The deformation information detected by the deformation detection member 100 can be various, such as the displacement information or acoustic emission information on the surface of the specimen 10. It will be described in detail in combination with more specific embodiments below. In some embodiments, in the foregoing embodiments 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 specimen 10 under dynamic impact conditions. In some embodiments, the device further includes an image processing system 800. The three-dimensional digital image correlation method (3D-DIC) analysis and calculation software is installed on the image processing system 800, and then the image information can be processed and analyzed.

[0049] It should be noted that the deformation information and image information obtained by the combined monitoring in this application can be used in combination, and the two confirm each other, or can also be used alone. Specifically, in the calculation of the fracture energy mentioned below, the average velocity during the fracture process of the fractured specimen 1 and the fractured specimen 2 can be determined according to the image information first, and the first fracture energy result can be calculated. Then, according to the deformation information, that is, the displacement information, the average velocity during the fracture process of the fractured specimen 1 and the fractured specimen 2 can be determined, and the second fracture energy result can be calculated. The fracture energy is determined according to the first fracture energy result and the second fracture energy result. For example, the average value can be taken, or if the difference between the first fracture energy result and the second fracture energy result is greater than the threshold value, it is considered that the experiment fails and the experiment can be repeated. Or, there are other embodiments, which will not be listed one by one in this application.

[0050] A rock dynamic splitting combined monitoring device and method proposed by an embodiment of the present invention apply dynamic impact conditions to the specimen through a pressure loading system. The combined monitoring device is used to monitor the deformation of the specimen during the dynamic impact loading process. The digital image data of the specimen under dynamic impact is collected and analyzed by the image monitoring system, and then the deformation and image combined monitoring and analysis of the damage process of the specimen under the impact load are realized. The development of rock cracks and the fracture characteristics of rocks under dynamic loads are monitored with the characteristics of multiple angles, high precision, and high efficiency, so as to further explore the fracture characteristics of deep rocks, provide an important theoretical basis for the development of deep rock engineering while providing reliable monitoring result support, and provide reliable monitoring result support for the research on the crack development mechanism of rocks under impact loads.

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

[0052] In some other implementations, the deformation detection component 100 can also be designed to monitor the acoustic emission characteristics of the specimen 10 and the vertical displacement change of the specimen 10 under dynamic impact conditions. The deformation detection component 100 includes a displacement sensor 110, and the deformation information includes the displacement information generated by the displacement sensor 110. The deformation detection component also includes an acoustic emission sensor 120, which is in contact with the surface of the specimen 10, and the deformation information also includes the acoustic emission information generated by the acoustic emission sensor 120.

[0053] Both the displacement sensor 110 and the acoustic emission sensor 120 are 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 it outward from the sensor body or towards the specimen 10. The end of the push rod away from the sensor body is the detection end. When the specimen 10 deforms, it will directly or indirectly push the detection end, and then cause the push rod to retract into the sensor body to achieve displacement detection. The acoustic emission sensor 120 uses acoustic emission detection technology, which is a non-destructive testing method and can be used to evaluate material properties or structural integrity. When the specimen 10 is under impact load, phenomena such as crack propagation and plastic deformation will occur in the specimen 10, resulting in rapid release of strain energy and generation of stress waves. These stress waves finally propagate to the surface of the specimen 10, causing surface displacement, which can be detected by the acoustic emission sensor 120, and the mechanical vibration is converted into an electrical signal, and then amplified to form acoustic emission information. By using real-time acoustic emission monitoring, the failure characteristics of the specimen 10 under impact load can be analyzed. The contact between the acoustic emission sensor 120 and the surface of the specimen 10 can be indirect contact, such as preferably applying an appropriate amount of vaseline for coupling.

[0054] In one implementation, the detection end of the displacement sensor 110 is connected to the acoustic emission sensor 120. It can be a direct connection, such as bonding or clamping. Or, the deformation detection component 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 through the flexible connection seat 130.

[0055] The flexible connection seat 130 can be made of rubber material. Such as Figures 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 component 400. The illumination device 300 is used to illuminate the specimen 10. The number of the image acquisition components 400 is two. The two image acquisition components 400 are arranged at intervals, and the included angle between the optical axes of the two image acquisition components 400 is a preset included angle. The image acquisition component 400 is used to generate image information.

[0062] The image monitoring system adopts 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 specimen 10, so as to extract the full-field displacement of the surface of the specimen 10. By identifying and calculating the subset motion information between the reference image and the current image, the displacement of the specimen 10 under dynamic impact can be accurately estimated, and the information of its deformation and strain can be extracted.

[0063] The number of the illumination devices 300 can be multiple. The multiple illumination devices 300 can be symmetrically distributed outside the specimen 10. For example, they can be evenly arranged around the incident rod 520 and the transmission rod 530. The illumination device 300 is arranged at a position about 50 centimeters away from the surface of the specimen 10. The image acquisition component 400 can be a high-speed camera. The two high-speed cameras have the same model. The two high-speed cameras are located on the same side of the specimen 10 and are arranged along the axial direction of the incident rod 520. The range of the preset included angle is 12° to 60° to ensure a sufficient image acquisition range.

[0064] On the other hand, as Figure 6 shown, the embodiment of the present invention further provides a method for jointly monitoring the dynamic splitting of rocks, which is characterized in that it is realized by using the rock dynamic splitting joint monitoring device as described in any one of the above. The method includes:

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

[0066] Drill a core from the obtained on-site original rock block. According to the method recommended by the International Society for Rock Mechanics, process the rock into a cylinder with a diameter of 50 mm and a height of 25 mm, and form the specimen 10. Spray white matte paint on the surface of the specimen 10 to be observed, and use a speckle tool to make an artificial speckle field.

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

[0068] Apply an appropriate amount of lubricant to both end faces of the specimen 10 to reduce the friction effect between the specimen 10 and the end faces of the incident bar 520 and the transmission bar 530. Then clamp the specimen 10 between the incident bar 520 and the transmission bar 530, make the axis of the specimen 10 perpendicular to the central axes of the incident bar 520 and the transmission bar 530, and ensure that the axes of the incident bar 520, the transmission bar 530 and the axis of the specimen 10 intersect. Or rather, in the direction as shown in Figure 1 , the horizontal axis of the end face of the specimen 10 is parallel to the central axes of the incident bar 520 and the transmission bar 530 and is at the same height.

[0069] In addition, in the case where no strain gauges are installed, before step S2, it further includes pasting a first strain gauge 550 and a second strain gauge 560 at positions equidistant from the specimen 10 on the incident bar 520 and the transmission bar 530 respectively, then connecting the first strain gauge 550 and the second strain gauge 560 to a super-dynamic strain gauge 600 using wires, and connecting the super-dynamic strain gauge 600 to a data acquisition and processing system 700. And adjust the bridge balance of each channel of the super-dynamic strain gauge 600.

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

[0071] In an embodiment where the deformation detection member 100 only includes a displacement sensor 110, install the displacement sensor 110 on the support frame 200, and adjust the position of the displacement sensor 110 so that the detection end of the displacement sensor 110 contacts the specimen 10, and leave enough range for the displacement sensor 110. Electrically connect the displacement sensor 110 to the data acquisition and processing system 700 using a data connection wire.

[0072] In an embodiment where the deformation detection member 100 includes an acoustic emission sensor 120 and a displacement sensor 110, connect the detection ends of the acoustic emission sensor 120 and the displacement sensor 110 through a flexible connection seat 130, and install them on the support frame 200. The connection line of the two acoustic emission sensors 120 is perpendicular to the axis of the incident bar 520 and perpendicular to the axis of the specimen 10, and the acoustic emission sensor 120 corresponds to the central position of the specimen 10 in the axial direction of the incident bar 520. Adjust the position of the displacement sensor 110 so that the probe end face of the acoustic emission sensor 120 is in close contact with the surface of the specimen 10, and leave enough range for the displacement sensor 110. Electrically connect the displacement sensor 110 and the acoustic emission sensor 120 to the data acquisition and processing system 700 using data connection wires.

[0073] S4. Adjust the image monitoring system to align with the specimen 10.

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

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

[0076] Use high-pressure gas to drive the punch 510 to impact the incident bar 520 to generate a stress wave. Subsequently, the first strain gauge 550 and the second strain gauge 560 respectively acquire the strain changes on the incident bar 520 and the transmission bar 530, and generate impact information, which is sent to the ultra-dynamic strain gauge 600 and the data acquisition and processing system 700. Control the ultra-dynamic strain gauge 600 and the two image acquisition components 400 through a synchronous trigger. While the ultra-dynamic strain gauge 600 acquires the signal, it transmits the real-time digital image captured by the image acquisition component 400, that is, the image information, to the image processing system 800. The deformation of the specimen 10 will trigger the displacement information generated by the displacement sensor 110, and the acoustic emission information generated by the acoustic emission sensor 120 is transmitted to the data acquisition and processing system 700.

[0077] S6. Acquire the impact information, deformation information, and image information until the specimen 10 is damaged and the test is terminated.

[0078] The data acquisition and processing system 700 and the image processing system 800 acquire information in real time until the specimen 10 is damaged and the test is terminated. Based on the acoustic emission monitoring technology, displacement monitoring technology, and image monitoring technology, the splitting and fracture characteristics of rocks under impact loads are monitored, and the dynamic characteristics of rocks under different occurrence conditions are studied by combining the SHPB loading system to analyze the strength and energy change characteristics of the specimen 10 when it is damaged. The monitoring of rock crack development and rock fracture characteristics under dynamic loads is realized at 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 for the research of various rock properties. 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 the rock failure process, the generation, propagation, and penetration of internal cracks in the rock can be understood, thus revealing the microscopic and macroscopic mechanisms of rock failure and providing theoretical guidance for exploring rock mass fractures. Since the fracture energy of rocks with different lithologies is different when they are damaged, the fracture energy reveals the differences in the ability of rocks to resist failure.

[0081] In blasting engineering, whether it is traditional explosive blasting or gas blasting, the essence is the splitting and tensile problem of rock under dynamic stress. Through the study of rock fracture energy, the corresponding blasting charge amount can be designed for different rock masses, so as to achieve precise control of the blasting depth and range. It can reduce the probability of over-damage to the surrounding rock caused by excessive blasting when using drill and blast method to excavate shafts and tunnels, or the occurrence of water inrush accidents caused by the destruction of the aquifer due to excessive blasting.

[0082] Existing research on rock failure usually regards the dissipated energy during rock failure as the fracture energy, ignoring the influence of rock kinetic energy. In the study of the energy change during the fracture of small-scale rock specimens in the laboratory, due to the specimen size problem, the research method of ignoring kinetic energy has little influence on the overall energy change characteristics of rock specimens. 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 "true 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 calculating the fracture energy by determining the kinetic energy of fractured rock blocks based on impact information and deformation information, or based on impact information and displacement information, making the calculation of fracture energy closer to the actual situation and more engineering significant.

[0083] For the dynamic splitting test of specimen 10, after specimen 10 is damaged, a fractured specimen will be formed, and two deformation detection components 100 correspond to one fractured specimen respectively. The displacement sensor 110 measures the displacement and time of the fractured specimen during the failure process of specimen 10, and then the fracture velocity of the fractured specimen can be obtained through calculation, so that the fracture energy of specimen 10 can be obtained through calculation. 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 follows:

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

[0085] In the formula: 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 for specimen 10 to generate cracks; K is the residual kinetic energy after specimen 10 is damaged.

[0086] In one implementation, after the steps of obtaining impact information, deformation information and image information until the test is terminated after specimen 10 is damaged, the method further includes:

[0087] S7-1. Determine the elastic energy generated by the elastic wave in the dynamic impact according to 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 from 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 according to the deformation information.

[0090] After the specimen 10 breaks, it forms a fractured specimen 1 and a fractured specimen 2. The kinetic energy T1 of the fractured specimen 1 is: T1 = m1v1 2 / 2, and the kinetic energy T2 of the fractured specimen 2 is: T2 = m2v2 2 / 2. Wherein, m1 and m2 can be obtained by weighing, such as using a balance for weighing. v1 and v2 are the average velocities during the breaking process of the fractured specimen 1 and the fractured specimen 2, respectively, and can be calculated by two displacement sensors 110 monitoring the displacements and times of the fractured specimen 1 and the fractured specimen 2 respectively.

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

[0092] S7-3. Determine the fracture energy of the specimen 10 according to the elastic energy and the residual kinetic energy.

[0093] Then the fracture energy of the specimen 10: W G = W - K.

[0094] The rock dynamic splitting combined monitoring device of the present application uses the displacement sensor 110 to measure the relationship between the displacement and time during the disconnection process of the specimen 10, so as to obtain the fracture velocities of the two fractured specimens after the specimen 10 fractures, and thus the fracture energy of the specimen 10 can be calculated. It is more concise and efficient than calculating the fracture velocity of the specimen 10 by shooting with a high-speed camera. Combining the acoustic emission technology and the digital image correlation technology can better study the failure characteristics of rocks under dynamic loading. The specimen 10 can be subjected to a splitting tensile test, monitored by the displacement sensor 110, and the relationship between the dynamic tensile strength and the fracture energy of the specimen 10 can be obtained through calculation. The characteristic quantities of the two fractured specimens after the specimen 10 fractures under dynamic loading fracture can be obtained through one test, and the failure characteristics of the specimen 10 can be explored by analyzing the relationship between the two.

[0095] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to 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, the image monitoring system is used to generate image information of the sample under the dynamic impact; The deformation detection member includes a displacement sensor, and the deformation information includes displacement information generated by the displacement sensor; The deformation detection member further includes an acoustic emission sensor, the acoustic emission sensor abuts against the surface of the sample, and the deformation information further includes acoustic emission information generated by the acoustic emission sensor; The detection end of the displacement sensor is connected to the acoustic emission sensor.

2. The rock dynamic splitting joint monitoring device according to claim 1 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.

3. 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.

4. 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.

5. 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.

6. 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 5, and comprises: 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; Connecting the acoustic emission sensor to the detection end of the displacement sensor, and adjusting the position of the displacement sensor so that the probe end face of the acoustic emission sensor is in close contact with the surface of 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.

7. The rock dynamic splitting joint monitoring method according to claim 6 is 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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