Digital Twin Method for Blasting Equivalent Loading Stress during On-site Construction

Abstract

The present invention discloses a digital twin method for blasting equivalent loading stress during on-site construction. First, blasting vibration sensors are installed at the construction site, and blasting operations are carried out to obtain the vibration waveforms at the monitoring points through the sensors. Subsequently, the mechanical parameters of the experimental site are tested, the rock parameters required for calibrating the discrete element method program (UDEC) are determined according to the mechanical parameters of the rock formation to be measured, and a numerical model equal in size to the site and with the same blasthole arrangement is established. Then, the initial iteration values such as the peak value of the blasting equivalent loading stress, the stress loading time, and the unloading time are substituted into the numerical model of rock formation blasting, and the vibration velocity at the monitoring points in the model is extracted. The blasting equivalent loading stress is adjusted based on the error between the curve measured by the model and the measured curve. Finally, when the error is less than a certain value, the time history curve of the blasting equivalent loading stress during on-site construction is determined. The present invention introduces the discrete element software UDEC in the algorithm design, overcoming the problem of elastic inversion distortion caused by rock blasting damage.

Description

Technical Field

[0001] The present invention belongs to the technical field of geotechnical blasting, and more specifically, relates to a digital twin method for blasting equivalent loading stress during on-site construction. Background Art

[0002] The drill and blast method is widely used in fields such as water conservancy and hydropower, tunnel excavation, and mineral resource development due to its high construction efficiency and low cost. Among them, accurately obtaining the blasting equivalent loading stress is one of the key parameters for effectively evaluating the construction quality of blasting projects and performing numerical calculations of non-fluid-solid coupling blasting. Therefore, accurately obtaining the time history curve of the blasting equivalent loading stress during on-site construction has attracted much attention from engineering and technical personnel.

[0003] At present, there are mainly two methods for obtaining the time history curve of the blasting equivalent loading stress: the theoretical method and the measured method. In terms of the theoretical method, due to the complexity of the explosive detonation process, a large number of assumptions need to be introduced in the derivation of the blasting stress peak, resulting in a certain degree of distortion of the derivation results. Moreover, the variability of on-site construction parameters also affects the inversion results to a certain extent. In the measured method, it is very difficult to directly monitor because it is difficult to arrange strain gauges to monitor the stress of the rock mass due to the complexity of the working face on-site. It should be noted that when the rock mass is disturbed by dynamic loads, the structure will emit a vibration response. However, in traditional construction, the maximum vibration velocity is often used to evaluate the construction risk, and the time from the start of the vibration process to the maximum vibration velocity and the time from the maximum vibration velocity to the stop of the vibration are not effectively utilized. Summary of the Invention

[0004] In view of the above problems, the present invention designs a digital twin method combining "blasting vibration - numerical simulation" to fully explore the dynamic disturbance information hidden behind the time history curve of blasting vibration, so as to accurately obtain the time history curve of the blasting equivalent loading stress during on-site construction.

[0005] To solve at least one of the above technical problems, according to one aspect of the present invention, there is provided a digital twin method for blasting equivalent loading stress during on-site construction, including the following steps:

[0006] S10. Arrange a single blast hole at the construction site, and set 1# and 2# blasting vibration monitoring and recording points at a certain distance from the blast hole, and respectively record the positions L1 and L2 between the blast hole source and the #1 and #2 monitoring points;

[0007] S20. Conduct blasting operations on-site, collect the vibration velocity waveform diagrams of #1 and #2, and record the maximum vibration velocity of the waveform diagram of the #1 monitoring point loading time and unloading time as well as the longitudinal wave arrival times of the #1 and #2 monitoring points and the first arrival time of shear waves

[0008] S30. Calculate the longitudinal wave velocity C of the rock mass based on the first arrival times of the longitudinal and shear waves at monitoring points #1 and #2 p and the shear wave velocity C s ; Subsequently, calculate the elastic parameters (dynamic elastic modulus E d , dynamic Poisson's ratio υ d ) of the rock mass according to the longitudinal and shear wave velocities;

[0009]

[0010] S40. Select the rock used in on-site construction and test its uniaxial compressive strength, uniaxial tensile strength, internal friction angle, and cohesion. Combine the rock parameters tested in S30 to calibrate the microscopic parameters required for the discrete element program (UDEC).

[0011] S50. In the discrete element method program (UDEC), establish a numerical model identical to the actual on-site working conditions, and input the rock microscopic parameters determined in S30 - 40 into the model. Subsequently, set monitoring point #1 at the same position in the model;

[0012] S60. Determine the peak explosion stress P0 according to the following formula:

[0013]

[0014] where ρ0 is the density of the explosive; V c and V b represent the volume of the explosive and the volume of the blast hole respectively; n is the magnification factor, taking values from 8 - 11; Q v is the heat of explosion of the explosive.

[0015] S70. Input the peak explosion stress, loading time, and unloading time into the following formula (3) to determine the initial iteration value.

[0016] P = P0ξ(e -αt - e -βt ) (3)

[0017] where:

[0018]

[0019] S80. At the borehole in the numerical model, apply the stress loading curve defined by formula (3). After the model calculation is completed, obtain the functional relationship V model (t) between the blasting vibration velocity and time at the monitoring point of the model, and extract the maximum vibration velocity in the function, the vibration velocity loading time the vibration velocity unloading time

[0020] S90. The vibration curves obtained from the comparative experiment and simulation. If the maximum vibration velocities obtained by both are then redefine the maximum stress on the blast hole wall during the blasting process

[0021] S100. If the loading time Change the blasting stress loading time Similarly, if Redefine the maximum stress on the blast hole wall during the blasting process

[0022] S110. Let P0 = P0', t0 = t'0, t1 = t′1, and repeat steps S70 - S110 until and are both less than 1x10 -3 At this time, determine P0, t0, and t1 at this time, and calculate α and β from this to obtain the stress time - history curve of the coal seam blasting face.

[0023] Furthermore, in step S10, vibration monitoring points #1 and #2 are respectively arranged at radial distances of 40 m and 80 m from the blast source. The positions of the monitoring points can be appropriately adjusted according to construction needs, but they cannot be too close to the blast source.

[0024] Furthermore, in step S40, if it is not necessary to analyze the blast - induced cracks, numerical calculations can also be carried out using finite - difference software (Flac3D) to speed up the solution progress.

[0025] Furthermore, in step S20, the specific steps for obtaining the vibration velocity - time variation curve are as follows:

[0026] S21. Drill blast holes on - site and place vibration sensors at the monitoring points.

[0027] S22. Use PVC shells to assist in charging in the blast holes and install detonation leads in the PVC shells.

[0028] S23. Connect the vibration sensors to the vibration signal receivers, and connect the vibration signal collectors to the program control and data acquisition system.

[0029] S24. Conduct blasting operations at the construction site.

[0030] S25. Read out the vibration - time variation curve of the monitoring points in the data acquisition system.

[0031] Furthermore, in step S70, the relationship between α, β and t0, t1 can be shown by the following formula (4); in the case of known t0 and t1, α and β can be obtained by the bisection method.

[0032]

[0033] According to another aspect of the present invention, there is provided a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps in the digital twin method for blasting equivalent loading stress during on-site construction of the present invention.

[0034] According to still another aspect of the present invention, there is provided a computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the program, it implements the steps in the digital twin method for blasting equivalent loading stress during on-site construction of the present invention.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] In the method for calculating the time history curve of blasting equivalent loading stress during on-site construction of the present invention, the discrete element software UDEC is introduced in the algorithm design, which overcomes the problem of elastic inversion distortion caused by rock blasting damage. In addition, this method not only realizes the accurate calculation of the peak value of blasting loading stress, but also can invert the whole process of the blasting loading stress path. In practical applications, the above-mentioned inverse calculation program can be encapsulated using the Python language to further improve the execution efficiency of the algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention and do not limit the present invention.

[0038] Figure 1 Shows the on-site construction layout diagram of the present invention;

[0039] Figure 2 Shows the method flow chart of the present invention;

[0040] Figure 3 Shows the schematic diagram of blasting loading stress inversion;

[0041] Figure 4 Shows the schematic diagram of vibration curve loading;

[0042] 1. Engineering rock mass, 2. Blasting drill hole, 3. Explosive, 4. Vibration sensor, 5. Signal connection cable, 6. Control computer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0044] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present invention pertains.

[0045] As Figures 1-4 shown,

[0046] Embodiment 1:

[0047] A digital twin method for blasting equivalent loading stress during on-site construction processes, comprising the following steps:

[0048] S10. Arrange a single blast hole at the construction site, and set up blasting vibration monitoring and recording points #1 and #2 at a certain distance from the blast hole, and respectively record the positions L1 and L2 between the blast hole explosion source and monitoring points #1 and #2.

[0049] S20. Conduct blasting operations at the site, collect the vibration velocity waveform diagrams of #1 and #2, and record the maximum vibration velocity of the waveform diagram of monitoring point #1 loading time and unloading time as well as the longitudinal wave arrival times and transverse wave arrival times

[0050] S30. Calculate the longitudinal wave C p and transverse wave C s wave velocities of the rock mass according to the longitudinal wave and transverse wave arrival times of monitoring points #1 and #2; subsequently, calculate the elastic parameters (dynamic elastic modulus E d , dynamic Poisson's ratio υ d ) of the rock mass based on the longitudinal wave and transverse wave velocities.

[0051]

[0052] S40. Select the on-site construction rock, and test its uniaxial compressive strength, uniaxial tensile strength, internal friction angle, and cohesion. Combine the rock parameters tested in S30 to calibrate the microscopic parameters required for the discrete element program (UDEC).

[0053] S50. In the discrete element method program (UDEC), establish a numerical model identical to the actual on-site working conditions, and substitute the rock microscopic parameters determined in S30 - 40 into the model. Subsequently, set up monitoring point #1 at the same position in the model.

[0054] S60. Determine the peak explosion stress P0 according to the following formula:

[0055]

[0056] In the formula, ρ0 is the explosive density; V c and V b represent the explosive volume and the borehole volume respectively; n is the magnification factor, taking 8 - 11; Q v is the heat of explosion of the explosive.

[0057] S70. Substitute the peak explosion stress, loading time, and unloading time into the following formula (3) to determine the initial iteration value.

[0058] P = P0ξ(e -αt -e -βt ) (3)

[0059] Where:

[0060]

[0061] S80. At the borehole of the numerical model, apply the stress loading curve defined by formula (3). After the model calculation is completed, obtain the functional relationship V model (t) between the blasting vibration velocity and time at the model monitoring point, and extract the maximum vibration velocity vibration velocity loading time vibration velocity unloading time

[0062] S90. Compare the vibration curves obtained from the experiment and the simulation. If the maximum vibration velocities obtained by the two then re - define the maximum stress on the borehole wall during the blasting process

[0063] S100. If the loading time change the blasting stress loading time Similarly, if re - define the maximum stress on the borehole wall during the blasting process

[0064] S110. Let P0 = P0', t0 = t'0, t1 = t′1, and repeat steps S70 - S110 until and are both less than 1x10 -3 At this time, determine P0, t0, and t1 at this time, and calculate α and β from this to obtain the stress time - history curve of the coal seam blasting face.

[0065] In step S10, vibration monitoring points #1 and #2 are respectively arranged at radial distances of 40 m and 80 m from the blast source. The positions of the monitoring points can be adjusted appropriately according to construction needs, but they cannot be too close to the blast source.

[0066] In step S40, if it is not necessary to analyze the blast-induced cracks, numerical calculations can also be carried out using finite difference software (Flac 3D) to accelerate the solution progress.

[0067] In step S20, the specific steps for obtaining the curve of vibration velocity varying with time are as follows:

[0068] S21. Drill blast holes at the construction site and place vibration sensors at the monitoring points.

[0069] S22. Use PVC casings to assist in charging the blast holes and install initiation leads inside the PVC casings.

[0070] S23. Connect the vibration sensors to the vibration signal receivers, and connect the vibration signal collectors to the program control and data acquisition system.

[0071] S24. Conduct blasting operations at the construction site.

[0072] S25. Read out the curve of vibration at the monitoring points varying with time in the data acquisition system.

[0073] In step S70, the relationships between α, β and t0, t1 can be shown by the following formula (4); in the case of known t0 and t1, α and β can be obtained by the dichotomy method.

[0074]

[0075] Example 2:

[0076] The computer-readable storage medium of this embodiment stores a computer program, and when the program is executed by a processor, it implements the steps of the digital twin method for blasting equivalent loading stress during on-site construction in Example 1.

[0077] The computer-readable storage medium of this embodiment can be the internal storage unit of the terminal, such as the hard disk or memory of the terminal; the computer-readable storage medium of this embodiment can also be the external storage device of the terminal, such as the plug-in hard disk, smart memory card, secure digital card, flash memory card, etc. equipped on the terminal; further, the computer-readable storage medium can also include both the internal storage unit and the external storage device of the terminal.

[0078] The computer-readable storage medium of this embodiment is used to store the computer program and other programs and data required by the terminal, and the computer-readable storage medium can also be used to temporarily store the data that has been output or will be output.

[0079] Example 3:

[0080] The computer device in this embodiment includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps in the digital twin method for blasting equivalent loading stress during on-site construction in Example 1.

[0081] In this embodiment, the processor can be a central processing unit, or it can also be 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 this processor can also be any conventional processor, etc.; the memory can include a read-only memory and a random access memory, and provides instructions and data to the processor. A part of the memory can also include a non-volatile random access memory. For example, the memory can also store information about the device type.

[0082] Those skilled in the art should understand that the content disclosed in the embodiments can be provided as a method, a system, or a computer program product. Therefore, this solution can be implemented in the form of a hardware embodiment, a software embodiment, or a form combining software and hardware embodiments. Moreover, this solution can be implemented in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories and optical memories, etc.) containing computer-usable program code.

[0083] This solution is described with reference to the flowcharts and / or block diagrams of the method and computer program product according to the embodiments of this solution. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented; these computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0084] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide for implementing the process Figure 1 a process or multiple processes and / or blocks Figure 1 the steps of the functions specified in a block or multiple blocks.

[0086] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above various methods. Among them, the storage medium can be a magnetic disk, an optical disc, a read-only memory (ROM), or a random access memory (RAM), etc.

[0087] The examples described in the present invention are only descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various deformations and improvements made by those skilled in the art to the technical solutions of the present invention should all fall within the protection scope of the present invention.

Claims

1. A method for calculating the time history curve of equivalent loading stress during on-site construction blasting, characterized in that, It includes the following steps: S10. Arrange a single blast hole at the construction site, and set blasting vibration monitoring recording points #1 and #2 to record the positions L1 and L2 between the blast hole explosion source and monitoring points #1 and #2 respectively; S20. Conduct on-site blasting operations, collect the vibration velocity waveform diagrams of #1 and #2, and record the maximum vibration velocity of the waveform diagram at the #1 monitoring point Loading time And unloading time And the longitudinal wave first arrival times at the #1 and #2 monitoring points And the transverse wave first arrival times S30. Calculate the longitudinal wave velocity C and the shear wave velocity C of the rock mass based on the first arrival times of the longitudinal wave and the shear wave at monitoring points #1 and #2. Calculate the elastic parameters of the rock mass, the dynamic elastic modulus E and the dynamic Poisson's ratio υ, based on the longitudinal wave velocity and the shear wave velocity. p and the shear wave velocity C s of the rock mass; Calculate the elastic parameters of the rock mass, the dynamic elastic modulus E d and the dynamic Poisson's ratio υ d ; S40. Select the on-site construction rock, test the uniaxial compressive strength, uniaxial tensile strength, internal friction angle and cohesion of the rock, and combine with the rock parameters tested in S30 to calibrate the microscopic parameters required for the discrete element program; S50. In the discrete element method program, establish a numerical model identical to the actual on-site working conditions, and input the rock microscopic parameters determined in S30 - 40 into the model. Subsequently, set monitoring point #1 at the same position in the model; S60. Determine the peak explosion stress P0 according to the following formula: Where ρ0 is the density of the explosive; V c and V b represent the volume of the explosive and the volume of the blast hole respectively; n is the magnification factor, taking values from 8 to 11; Q v is the explosion heat of the explosive; S70. Input the peak explosion stress, loading time and unloading time into the following formula (3) to determine the initial iteration value, P = P0ξ(e -αt -e -βt ) (3) where: At the borehole of the numerical model, apply the stress loading curve defined by formula (3). After the model calculation is completed, obtain the functional relationship V(t) between the blasting vibration velocity and time at the model monitoring point, and extract the maximum vibration velocity in the function. model (t), and extract the maximum vibration velocity in the function. Vibration velocity loading time Vibration velocity unloading time Vibration curves obtained from S90, comparative experiments, and simulations. If the maximum vibration velocities obtained from both are then redefine the maximum stress on the blast hole wall during the blasting process S100. If the loading time Change the blasting stress loading time Similarly, if Redefine the maximum stress on the hole wall during the blasting process t0' and t1' are the loading time and unloading time variables in the iteration, and t0 and t1 are the finally obtained loading time and unloading time; S110. Let P0 = P0', t0 = t'0, t1 = t1', and repeat steps S70 - S110 until and are both less than 1×10 -3 At this time, determine P0, t0, and t1 at this time, and calculate α and β from this to obtain the stress time history curve of the coal seam blasting face.

2. The method according to claim 1, characterized in that, In step S10, vibration monitoring points #1 and #2 are respectively arranged at radial distances of 40 m and 80 m from the explosion source.

3. The method according to claim 1, wherein In step S20, the specific steps to obtain the vibration velocity waveform diagram are as follows: S21. Drill a blasting hole at the construction site and place a vibration sensor at the monitoring point; S22. Use PVC casing to assist in charging in the blasting hole and install a detonating lead in the PVC casing; S23. Connect the vibration sensor to the vibration signal receiver, and connect the vibration signal collector to the program control and data acquisition system; S24. Conduct blasting operations at the construction site; S25. Read the curve of the vibration at the monitoring point changing with time in the data acquisition system.

4. The method according to claim 1, characterized in that In step S70, the relationship between α, β and t0, t1 can be as shown in formula (5): When t0 and t1 are known, α and β can be obtained by the bisection method.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, it realizes the steps in the method for calculating the blasting equivalent loading stress time history curve during on-site construction as described in any one of claims 1 to 4.

6. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it realizes the steps in the method for calculating the blasting equivalent loading stress time history curve during on-site construction as described in any one of claims 1 to 4.

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