Inversion method of equivalent loading stress curve of rock blasting

Abstract

The application discloses a kind of rock blasting equivalent loading stress curve inversion methods, comprising the following steps: blasting device is detonated to the rock to be measured, and the strain curve of monitoring point is obtained by high-speed acquisition instrument;According to the macroscopic mechanical properties of the rock to be measured, the rock microscopic parameters required by discrete element numerical software are calibrated, and the rock numerical test specimen of the same size as laboratory test is established;Equivalent loading stress peak value, stress loading time and unloading time and the like iteration initial value are brought into rock blasting numerical model, and the strain curve of monitoring point in model is calculated.Error between the curve measured by model and the measured curve is adjusted to stress peak value and time.Finally, when the error is less than a certain value, the rock mass blasting equivalent loading stress loading curve is determined.The application overcomes the problem of elastic inversion distortion caused by rock blasting damage;Not only the accurate calculation of blasting loading stress peak value is realized, but also the whole process of blasting loading stress path can be inverted.

Description

Technical Field

[0001] This invention belongs to the field of engineering blasting technology, and more specifically, relates to a method for inverting the equivalent loading stress curve of rock blasting. Background Technology

[0002] Blasting technology is widely used in civil engineering and mining due to its high construction efficiency. Nowadays, the requirements for controllability and safety in blasting are becoming increasingly stringent, necessitating the control of the amount of explosives used in blasting projects. To rationally control the amount of explosives, it is necessary to calculate the blasting stress wave, so as to meet the requirements of blasting construction while minimizing blasting vibration.

[0003] The equivalent stress loading curve of blasting is a crucial parameter for non-fluid-structure interaction blasting dynamic response analysis. Currently, experimental and theoretical methods are commonly used to invert the equivalent loading stress of blasting. Regarding experimental methods, due to the large blasting load, the blasted medium and sensors are easily damaged, making direct measurement of the borehole wall pressure peak very difficult. Furthermore, when stress sensors are installed in the far field, the borehole near-field region experiences severe plastic deformation and damage due to the blasting, resulting in a certain loss of blasting energy and rendering the method of calculating near-field stress based on elasticity theory ineffective. On the theoretical front, the propagation process of the detonation wave and the dynamic expansion of the blasting gases are highly complex, making it very difficult to establish a mathematical model using theoretical methods to calculate the equivalent loading stress of blasting.

[0004] Therefore, designing a method that minimizes damage to experimental equipment during testing and can accurately obtain the equivalent loading stress curve of blasting is of great significance for determining the amount of blasting charge and calculating the damage range of rock mass. Summary of the Invention

[0005] To solve at least one of the above-mentioned technical problems, according to one aspect of the present invention, a method for inverting the equivalent loading stress curve of rock blasting is provided, comprising the following steps:

[0006] S1. Conduct mechanical experiments on the rock to be tested to determine its macroscopic mechanical parameters, and prepare the rock to the size required for the blasting test. Subsequently, set tangential and radial strain monitoring points on the surface of the rock at a certain distance from the borehole, and record the positional relationship between the monitoring points and the center of the borehole.

[0007] S2, Experimental measurement of the radial direction of the monitoring point caused by the explosion. With tangential The strain-time curve is recorded, and the initial explosion equivalent loading stress is calculated according to the following formula. The maximum value of radial strain over time is also recorded. Loading time and uninstallation time

[0008]

[0009] S3. Based on the results of macroscopic mechanical experiments, calibrate the microscopic parameters required for calculation by the discrete element method (PFC); at the same time, construct a rock numerical model of the same size as the laboratory test.

[0010] S4. Match the initial explosion equivalent loading stress curve determined above with the following formula to determine the initial values ​​for iteration. That is, the maximum stress P0, the stress loading time t0, and the stress unloading time t1.

[0011] P=P0ξ(e -αt -e -βt (2)

[0012] in:

[0013]

[0014] S5. Apply the stress loading curve defined by formula (2) to the elements on the surface of the borehole in the rock model. After the model calculation is completed, obtain the radial strain versus time at the same location as the borehole. Extracting the maximum strain in the function and loading time and uninstallation time

[0015] S6. Compare the strain curves obtained from experiments and simulations. If the maximum strain obtained from both is... The maximum stress on the borehole wall during the blasting process is then redefined.

[0016] S7, if loading time Change the blasting stress loading time Similarly, if Redefining the maximum stress on the borehole wall during blasting

[0017] S8. Let P0 = P0', t0 = t'0, t1 = t'1, and repeat steps S5 to S7 until... and All less than 1 x 10 -3 At this time, P0, t0, and t1 are determined, and α and β are calculated to obtain the equivalent loading stress curve of the blast.

[0018] Furthermore, in step S1, the length, width and height of the blasting test rock are 500mm, 500mm and 50mm respectively, and a circular hole of a certain size is drilled in the middle of the rock test to install the detonator. The strain monitoring point is arranged at 40mm in the diameter direction of the blast hole.

[0019] Furthermore, in step S2, the specific steps for obtaining the radial strain variation curve over time are as follows:

[0020] S21. Fix the rock sample to be tested on the blasting platform and attach radial and circumferential strain gauges at the monitoring points at a distance from the rock.

[0021] S22. An electronic detonator is placed inside the blast hole, and the gap between the blast hole and the electronic detonator is filled with modeling clay.

[0022] S23. Connect the strain gauge acquisition end to the high-speed acquisition instrument, and connect the high-speed acquisition instrument to the program control and data acquisition system.

[0023] S24. Detonate the electronic detonator using an electronic igniter;

[0024] S25. Read the strain change curve of the monitoring point over time in the data acquisition system.

[0025] Furthermore, the macroscopic mechanical parameters that need to be determined in step S3 include: compressive strength, tensile strength, cohesion, friction angle, elastic modulus, and Poisson's ratio.

[0026] Furthermore, in step S5, the relationship between α, β and t0, t1 can be expressed as shown in equation (4); given t0 and t1, α and β can be obtained by the bisection method.

[0027]

[0028] According to another aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the method for inverting the equivalent loading stress curve of rock blasting according to the present invention.

[0029] According to another aspect of the present invention, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps in the method for inverting the equivalent loading stress curve of rock blasting according to the present invention.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects:

[0031] The inversion method for the equivalent loading stress curve of rock blasting in this invention incorporates Discrete Element Method (PFC) software, which excels at calculating large rock deformations, in its algorithm design, overcoming the elastic inversion distortion problem caused by rock blasting damage. Furthermore, this method not only achieves accurate calculation of the peak blasting loading stress but also inverts the entire blasting loading stress path. In practical applications, the aforementioned inversion program can be encapsulated using Python to further improve the algorithm's execution efficiency. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0033] Figure 1 A schematic diagram of the process for inverting the equivalent loading stress curve of blasting according to the present invention is shown;

[0034] Figure 2 A schematic diagram of the program flow for the equivalent loading curve of blasting stress of the present invention is shown;

[0035] Figure 3 A diagram of the experimental setup for testing strain at monitoring points is shown.

[0036] Figure 4 A schematic diagram of the equivalent loading stress during blasting is shown;

[0037] Figure label:

[0038] 1. Strain gauge; 2. Electronic detonator; 3. Bridge circuit; 4. High-speed data acquisition instrument; 5. Oscilloscope; 6. Workstation computer. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.

[0040] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0041] like Figure 1-4 As shown,

[0042] Example 1:

[0043] A method for inverting the equivalent loading stress curve of a blasting explosion includes the following steps:

[0044] S1. Mechanical experiments were conducted on the rock to be tested to determine its macroscopic mechanical parameters, and the rock was prepared to the size required for the blasting test. Subsequently, tangential and radial strain monitoring points were set at a certain distance from the borehole on the surface of the rock to be tested, and the positional relationship between the monitoring points and the center of the borehole was recorded. The length, width, and height of the rock for the blasting test were 500 mm, 500 mm, and 50 mm, respectively. A circular hole of a certain size was drilled in the middle of the rock test to install a detonator, and the strain monitoring points were arranged at a distance of 40 mm in the diameter direction of the borehole.

[0045] S2, Experimental measurement of the radial direction of the monitoring point caused by the explosion. With tangential The strain-time curve is recorded, and the initial explosion equivalent loading stress is calculated according to the following formula. The maximum value of radial strain over time is also recorded. Loading time and uninstallation time

[0046]

[0047] The specific steps for obtaining the radial strain versus time curve are as follows:

[0048] S21. Fix the rock sample to be tested on the blasting platform and attach radial and circumferential strain gauges at the monitoring points at a distance from the rock.

[0049] S22. An electronic detonator is placed inside the blast hole, and the gap between the blast hole and the electronic detonator is filled with modeling clay.

[0050] S23. Connect the strain gauge acquisition end to the high-speed acquisition instrument, and connect the high-speed acquisition instrument to the program control and data acquisition system.

[0051] S24. Detonate the electronic detonator using an electronic igniter;

[0052] S25. Read the strain change curve of the monitoring point over time in the data acquisition system.

[0053] S3. Based on the results of macroscopic mechanical experiments, calibrate the microscopic parameters required for calculation using the Discrete Element Method (PFC) software; simultaneously, construct a rock numerical model of the same size as the laboratory test. The macroscopic mechanical parameters that need to be determined include: compressive strength, tensile strength, cohesion, friction angle, elastic modulus, and Poisson's ratio.

[0054] S4. Match the initial explosion equivalent loading stress curve determined above with the following formula to determine the initial values ​​for iteration, namely, the maximum stress P0, the stress loading time t0, and the stress unloading time t1.

[0055] P=P0ξ(e -αt -e -βt (6);

[0056] in:

[0057]

[0058] S5. Apply the stress loading curve defined by formula (2) to the elements on the surface of the borehole in the rock model. After the model calculation is completed, obtain the radial strain versus time at the same location as the borehole. Extracting the maximum strain in the function and loading time and uninstallation time

[0059] The relationship between α, β and t0, t1 can be shown by the following formula (4). Given t0 and t1, α and β can be obtained by the bisection method.

[0060]

[0061] S6. Compare the strain curves obtained from experiments and simulations. If the maximum strain obtained from both is... The maximum stress on the borehole wall during the blasting process is then redefined.

[0062] S7, if loading time Change the blasting stress loading time Similarly, if Redefining the maximum stress on the borehole wall during blasting

[0063] S8. Let P0 = P0', t0 = t'0, t1 = t'1, and repeat steps S50 to S70 until... and All less than 1 x 10 -3 At this time, P0, t0, and t1 are determined, and α and β are calculated to obtain the equivalent loading stress curve of the blast.

[0064] Example 2:

[0065] The computer-readable storage medium of this embodiment stores a computer program that, when executed by a processor, implements the steps of the method for inverting the equivalent loading stress curve of blasting in Embodiment 1.

[0066] The computer-readable storage medium in this embodiment can be an internal storage unit of the terminal, such as the terminal's hard disk or memory; the computer-readable storage medium in this embodiment can also be an external storage device of the terminal, such as a plug-in hard disk, smart memory card, secure digital card, flash memory card, etc. equipped on the terminal; furthermore, the computer-readable storage medium can include both the terminal's internal storage unit and external storage devices.

[0067] The computer-readable storage medium of this embodiment is used to store computer programs and other programs and data required by the terminal. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0068] Example 3:

[0069] The computer device of this embodiment includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the inversion method of the equivalent loading stress curve of blasting in Embodiment 1.

[0070] In this embodiment, the processor can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The memory can include read-only memory and random access memory, and provides instructions and data to the processor. A portion of the memory can also include non-volatile random access memory. For example, the memory can also store device type information.

[0071] Those skilled in the art will understand that the content disclosed in the embodiments can be provided as a method, system, or computer program product. Therefore, this solution can take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this solution can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage) containing computer-usable program code.

[0072] This solution is described with reference to flowchart illustrations and / or block diagrams of methods and computer program products according to embodiments of this solution. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0073] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0074] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0075] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0076] The examples described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention.

Claims

1. A method for inverting the equivalent loading stress curve of rock blasting, characterized in that, Includes the following steps: S1. Conduct mechanical experiments on the rock to be tested to determine the macroscopic mechanical parameters of the rock, and prepare the rock to be tested into the size required for the blasting test. S2, Experimental measurement of the radial direction of the monitoring point caused by the explosion. and tangential The strain-time curve was obtained, and the initial explosion equivalent loading stress was calculated according to formula (1). The maximum value of the radial strain over time was recorded. Loading time and uninstallation time S3. Based on the results of macroscopic mechanical experiments, calibrate the microscopic parameters required for discrete element software calculations; at the same time, construct a rock numerical model of the same size as the laboratory experiment. S4. Match the initial explosion equivalent loading stress curve determined above with the following formula to determine the initial values ​​for iteration; that is, the maximum stress P0, the stress loading time t0, and the stress unloading time t1. P=P0ξ(e -αt -by -βt ) (2) in: S5. Apply the stress loading curve defined by formula (2) to the elements on the surface of the borehole in the rock model; after the model calculation is completed, obtain the functional relationship between radial strain and time at the same location from the borehole. Extracting the maximum strain in the function and loading time and uninstallation time S6. Compare the strain curves obtained from experiments and simulations. If the maximum strain obtained from both is... The maximum stress on the borehole wall during the blasting process is then redefined. S7, if loading time Change the blasting stress loading time Similarly, if Redefining the maximum stress on the borehole wall during blasting S8. Let P0 = P0′, t0 = t′0, t1 = t1′, and repeat steps S5 to S7 until... and All less than 1 x 10 -3 At this time, P0, t0, and t1 are determined, and α and β are calculated to obtain the equivalent loading stress curve of the blast.

2. The method according to claim 1, characterized in that, In step S2, the specific steps for obtaining the radial strain variation curve over time are as follows: S21. Fix the rock sample to be tested on the blasting platform and attach radial and circumferential strain gauges at the monitoring points at a distance from the rock. S22. An electronic detonator is placed inside the blast hole, and the gap between the blast hole and the electronic detonator is filled with modeling clay. S23. Connect the strain gauge acquisition end to the high-speed acquisition instrument, and connect the high-speed acquisition instrument to the program control and data acquisition system. S24. Detonate the electronic detonator using an electronic igniter; S25. Read the strain change curve of the monitoring point over time in the data acquisition system.

3. The method according to claim 2, characterized in that, The macroscopic mechanical parameters that need to be determined in step S3 include: compressive strength, tensile strength, cohesion, friction angle, elastic modulus, and Poisson's ratio.

4. The method according to claim 3, characterized in that, In step S5, the relationship between α, β and t0, t1 can be expressed as shown in formula (4): Given t0 and t1, α and β can be obtained using the bisection method.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When executed by the processor, the program implements the steps in the inversion method of the equivalent loading stress curve of rock blasting as described in any one of claims 1 to 4.

6. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the method for inverting the equivalent loading stress curve of rock blasting as described in any one of claims 1 to 4.

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