A method, device and system for determining the initiation interval of millisecond blasting

Abstract

The application discloses a kind of millisecond blasting initiation interval determination method, device and system.Compared with prior art, according to actual working condition, single-hole blasting test is carried out, and the measured vibration data of multiple monitoring points are obtained, then the frequency domain distribution is obtained by Fourier transform, the most dangerous monitoring point is determined according to the frequency domain distribution of each monitoring point and its measured vibration velocity and control vibration velocity, and the initiation interval is determined according to the measured vibration data of the most dangerous monitoring point, so that the vibration velocity is effectively controlled, and the construction is safer.Secondly, by adjusting the initiation interval in real time, the vibration velocity is less than the control vibration velocity, which further ensures the safety of blasting construction.

Description

Technical Field

[0001] This invention relates to the field of blasting construction, and specifically to a method, apparatus and system for determining the detonation interval of micro-delay blasting. Background Technology

[0002] Blasting is widely used in tunnel construction, foundation pit excavation, and mining. Especially when encountering intact, hard rock, drill-and-blast methods are more efficient and economical than mechanical excavation. However, blasting inevitably generates vibrations. With societal progress and development, the frequency of blasting near buildings is gradually increasing. Simultaneously, as people's living standards improve, their tolerance for the disturbances caused by blasting is decreasing. Therefore, blasting will inevitably have adverse effects on nearby buildings and people. Strict control of vibrations during blasting is essential to ensure safe and efficient blasting operations.

[0003] To reduce peak blasting vibrations, micro-delay blasting technology is widely used in various blasting projects. Its main principle is to control the detonation interval between adjacent boreholes, ensuring that they detonate sequentially according to the designated interval. This causes the seismic waves generated during the blasting of each borehole to interfere with each other, thereby reducing peak vibrations. With improvements in detonator precision, the actual detonation interval between boreholes is closer to the designed interval, making micro-delay blasting more accurate and efficient.

[0004] The core of micro-delay blasting lies in determining the detonation interval. However, in most engineering micro-delay blasting, the detonation interval is determined based on engineering experience or numerical simulation. But in actual engineering, the micro-delay time is affected by factors such as lithology, stratum thickness, terrain, and obstacles, which often leads to the detonation interval not meeting the actual needs. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a method, device and system for determining the detonation interval of micro-delay blasting. Based on the single-hole blasting test data of actual engineering, the blasting vibration period that is more in line with the actual working conditions can be obtained, thereby initially determining the detonation interval, and further fine-tuning the detonation interval according to the vibration velocity, and finally determining the optimal detonation interval.

[0006] To achieve the above objectives, this application adopts the following technical solution.

[0007] On the one hand, a method for determining the detonation interval of micro-delay blasting is provided, including the following steps:

[0008] S1. Set up monitoring points in all adjacent buildings around the blasting zone;

[0009] S2. Conduct a single-hole detonation test in the blasting zone and obtain vibration data at each monitoring point; the vibration data is the data of vibration velocity changing with time.

[0010] S3. Perform Fourier transform on the vibration data of each monitoring point to obtain the frequency domain data of each monitoring point, and determine the dominant frequency and maximum vibration velocity of each monitoring point based on the frequency domain data of each monitoring point; the dominant frequency is the frequency corresponding to the maximum amplitude.

[0011] S4. Calculate the risk coefficient ζ for each monitoring point according to the following formula: The monitoring point with the highest risk factor value is defined as the most dangerous monitoring point; where v is the maximum vibration velocity of each monitoring point, and v′ is the control vibration velocity standard of each monitoring point;

[0012] S5. The detonation interval t is calculated using the following formula:

[0013]

[0014] in, f is the dominant frequency of the most dangerous monitoring point, and k is a natural number;

[0015] S6. Conduct continuous blasting tests according to the above-mentioned detonation interval t. If the vibration velocity at the most dangerous monitoring point shows a significant superposition phenomenon and / or exceeds the control vibration velocity standard, then... Adjust the detonation interval t within the range; where f l f r For the two frequencies corresponding to the set amplitude A and f l <f<f r A = P × A max A max The maximum amplitude is represented by P, which ranges from 80% to 90%.

[0016] This invention conducts single-hole blasting tests under actual working conditions to obtain measured vibration data from multiple monitoring points. The frequency domain distribution is then obtained through Fourier transform. Based on the frequency domain distribution of each monitoring point, along with the measured and control vibration velocities, the most dangerous monitoring point is determined. The detonation interval is then determined based on the measured vibration data from the most dangerous monitoring point, effectively controlling the vibration velocity and making construction safer. Furthermore, by adjusting the detonation interval in real time to keep the vibration velocity below the control velocity, the safety of the blasting operation is further guaranteed.

[0017] In some embodiments, in step S6, the relationship between frequency and amplitude is obtained by fitting a log-normal function or a polynomial fitting method, and f is calculated based on this relationship. l and f r .

[0018] On another front, a device for determining the detonation interval of micro-delay blasting is provided, comprising:

[0019] Microseismic monitoring instruments are deployed in adjacent buildings around the blasting area to acquire vibration data at each monitoring point;

[0020] The first processing unit is used to perform Fourier transform on the vibration data of each monitoring point after a single-hole detonation test in the blasting zone to obtain the frequency domain data of each monitoring point, and to determine the dominant frequency and maximum vibration velocity of each monitoring point based on the frequency domain data of each monitoring point; the dominant frequency is the frequency corresponding to the maximum amplitude.

[0021] The first calculation unit is used to calculate the risk factor ζ for each monitoring point according to the following formula: The monitoring point with the highest risk factor value is defined as the most dangerous monitoring point; where v is the maximum vibration velocity of each monitoring point, and v′ is the control vibration velocity standard of each monitoring point;

[0022] The second calculation unit is used to calculate the detonation interval t according to the following formula:

[0023]

[0024] in, f is the dominant frequency of the most dangerous monitoring point, and k is a natural number; and

[0025] The correction unit is used when, after continuous blasting tests according to the above-mentioned detonation interval t, the vibration velocity at the most dangerous monitoring point shows a significant superposition phenomenon and / or exceeds the control vibration velocity standard, in... Adjust the detonation interval t within the range; where f l f r For the two frequencies corresponding to the set amplitude A and f l <f<f r A = P × A max A max The maximum amplitude is represented by P, which ranges from 80% to 90%.

[0026] In some embodiments, the correction unit calculates f based on the relationship between frequency and amplitude. l and f r The relationship between frequency and amplitude is obtained by fitting a log-normal function or a polynomial fitting method.

[0027] In another aspect, a system is provided that includes a computer device, the computer device including a memory, a processor and program instructions stored in the memory that are executable by the processor, wherein the processor executes the program instructions to implement the steps of the above-described method for determining the micro-differential detonation interval.

[0028] This invention has at least the following technical effects or advantages:

[0029] 1. Single-hole blasting tests are conducted based on actual working conditions to obtain measured vibration data from multiple monitoring points. The frequency domain distribution is then obtained through Fourier transform. The most dangerous monitoring point is determined based on the frequency domain distribution of each monitoring point, its measured vibration velocity, and the control vibration velocity. The detonation interval is determined based on the measured vibration data of the most dangerous monitoring point, thereby effectively controlling the vibration velocity and making construction safer.

[0030] 2. By adjusting the detonation interval in real time to keep the vibration velocity lower than the control vibration velocity, the safety of blasting operations is further ensured. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating a method for determining the detonation interval of a micro-delay blasting process according to an embodiment of this application.

[0032] Figure 2 This is a schematic diagram of the monitoring point layout in one embodiment of this application;

[0033] Figure 3 Vibration velocity diagram of single-hole blasting test at monitoring point 1;

[0034] Figure 4 Vibration velocity diagram of single-hole blasting test at monitoring point 2;

[0035] Figure 5 This is the frequency-amplitude plot of monitoring point 1 obtained through Fourier transform;

[0036] Figure 6 The frequency-amplitude plot of monitoring point 2 obtained by Fourier transform;

[0037] Figure 7 Peak vibration velocity graphs at monitoring points during 10 consecutive blasts in the construction process;

[0038] Figure 8 The measured data of vibration velocity of the residential building using the optimal detonation interval is shown in the figure. Detailed Implementation

[0039] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0040] Example 1

[0041] See Figure 1 A method for determining the detonation interval of micro-delay blasting includes the following steps:

[0042] S1. Set up monitoring points in all adjacent buildings around the blasting zone;

[0043] Specifically, such as Figure 2As shown, based on the distribution of nearby buildings around the blasting zone, two monitoring points were set up in this example to simplify calculations: Monitoring Point 1 and Monitoring Point 2. Monitoring Point 1 was located in a residential building closest to the blasting zone, and Monitoring Point 2 was located in a subway station closest to the blasting zone. Vibration data were collected from both monitoring points. In this example, only two monitoring points were set up for calculation simplification. In actual construction, to ensure the accuracy and reliability of the data, multiple monitoring points should be set up in nearby buildings.

[0044] S2. Conduct a single-hole detonation test in the blasting zone and obtain vibration data at each monitoring point; the vibration data is the data of vibration velocity changing with time.

[0045] After the single-hole detonation test, a clear vibration velocity waveform appeared in the microseismic monitoring instrument, which automatically saved the vibration data of the monitoring points locally. Furthermore, if the microseismic monitoring instrument is connected to a dedicated server or host computer via a network, the collected data will be automatically uploaded to the dedicated server or directly transmitted to the host computer. Personnel can download relevant data from the server or view the vibration data directly from the host computer. The server or host computer should have sufficient storage space to ensure the vibration data is completely saved. The vibration velocity variation over time at the two monitoring points is shown in the following figure. Figure 3 and Figure 4 As shown.

[0046] S3. Perform Fourier transform on the vibration data of each monitoring point to obtain the frequency domain data of each monitoring point, and determine the dominant frequency and maximum vibration velocity of each monitoring point based on the frequency domain data of each monitoring point; the dominant frequency is the frequency corresponding to the maximum amplitude.

[0047] After obtaining the data, it is imported into dedicated software (Python is used in this example) for PFFT time-frequency conversion. Considering the small number of sampling points in this example, only two processes are used for solving the problem. After transformation, frequency domain data is obtained. The frequency domain data is then plotted using functions from the matplotlib library in Python to obtain the frequency-amplitude distribution plot of the monitoring points, as shown below. Figure 5 and Figure 6 As shown. By Figure 5 It can be seen that the frequency f1 of the seismic wave that has the greatest impact on the vibration velocity of monitoring point 1 is approximately 22Hz. Figure 6 It is known that the frequency f2 of the seismic wave that has the greatest impact on the vibration velocity of monitoring point 2 is approximately 21 Hz.

[0048] S4. Calculate the risk coefficient ζ for each monitoring point according to the following formula:

[0049] The monitoring point with the highest risk factor value is defined as the most dangerous monitoring point; where v is the maximum vibration velocity of each monitoring point, and v′ is the control vibration velocity standard of each monitoring point;

[0050] The control vibration velocity standard value can be determined with reference to expert opinions or according to relevant standard documents. In this embodiment, the control vibration velocity v′1 of monitoring point 1 is 0.3 cm / s, and the control vibration velocity v′2 of monitoring point 2 is 0.3 cm / s. The calculated danger coefficients ζ11 and ζ2 of monitoring point 1 and monitoring point 2 are 33 and 66, respectively, and monitoring point 2 is determined to be the most dangerous monitoring point.

[0051] S5. The detonation interval t is calculated using the following formula:

[0052]

[0053] in, f is the dominant frequency of the most dangerous monitoring point, and k is a natural number;

[0054] In micro-delay blasting, the first detonated borehole not only breaks the rock within the blast funnel area but also generates a stress field and fissures in the rock surrounding the blast funnel. The adjacent borehole is detonated before this stress field disappears. The stress generated in the subsequently detonated borehole superimposed on the residual stress of the first detonated borehole, thus supplementing and reinforcing the secondary fracturing effect. Therefore, to achieve better blasting results, the adjacent borehole should be detonated before the stress field of the first detonated borehole disappears, and the detonation interval should be minimized. Therefore, k=0, i.e., 1 / 2 vibration period, or 23.8 ms, is selected as the detonation interval between adjacent boreholes in the next blasting operation.

[0055] S6. Conduct continuous blasting tests according to the above-mentioned detonation interval t. If the vibration velocity at the most dangerous monitoring point shows a significant superposition phenomenon and / or exceeds the control vibration velocity standard, then... Adjust the detonation interval t within the range; where f l f r For the two frequencies corresponding to the set amplitude A and f l <f<f r A = P × A max A max The maximum amplitude is represented by P, which ranges from 80% to 90%.

[0056] Considering that various noises during actual construction will have a certain impact on the calculation of the dominant frequency, the calculated result will deviate from the actual dominant frequency. Furthermore, the frequency domain data may contain frequencies with amplitudes very close to the dominant frequency, which also significantly affect vibration velocity. Therefore, it is necessary to calculate the relationship between these frequencies and the dominant frequency to facilitate adjustment of the dominant frequency during actual construction. Based on the frequency domain data of the most dangerous monitoring point, statistical methods are used to obtain its dominant frequency and frequencies with amplitudes close to the dominant frequency (in this embodiment, frequencies with amplitudes reaching more than 85% of the dominant frequency amplitude are selected).

[0057] Based on the frequency distribution of the most dangerous monitoring point, i.e., monitoring point 2, it is observed that the frequency distribution range of monitoring point 2 is relatively small, and the frequency intervals are small. Therefore, the frequencies with the maximum amplitude of 85% can be directly obtained from the frequency-amplitude plot, which are: f l =20Hz, f r =23Hz. If the frequency interval is too large, the frequency-amplitude relationship can be determined by fitting a polynomial or log-normal function, thereby finding f. l ,f r Further calculations yield f l The adjustment range of the detonation interval t is [-9.1%, 4.7%].

[0058] Real-time monitoring of vibration velocity changes during blasting operations revealed that, in a certain continuous blasting process, although the peak blasting vibration velocity did not exceed the control velocity, the peak velocity increased rapidly. Figure 7 In the first five consecutive blasting operations shown, the peak vibration velocity increased from 0.125 cm / s to 0.2241 cm / s, an increase of 79.1%, which is too large a change. Therefore, for safety reasons, the detonation interval must be adjusted. During the adjustment, the detonation interval was first increased by 4%, setting it to 24.8 ms. It was found that the peak vibration velocity in the sixth blast was 0.2291 cm / s, which was larger than the fifth. Therefore, the detonation interval was decreased by 4%, setting it to 22.8 ms. It was observed that the peak vibration velocity decreased significantly in subsequent blasting operations. Figure 7 The peak vibration velocities for detonation sequences 7, 8, 9, and 10 were all less than 0.2 cm / s, proving the effectiveness of this method. Subsequent construction using a 22.8 ms detonation interval yielded good blasting results, controlling the peak vibration velocities below 0.2 cm / s with minimal variation. Measured data are as follows: Figure 8 As shown.

[0059] Example 2

[0060] A device for determining the detonation interval of micro-delay blasting includes:

[0061] Microseismic monitoring instruments are deployed in adjacent buildings around the blasting area to acquire vibration data at each monitoring point;

[0062] The first processing unit is used to perform Fourier transform on the vibration data of each monitoring point after a single-hole detonation test in the blasting zone to obtain the frequency domain data of each monitoring point, and to determine the dominant frequency and maximum vibration velocity of each monitoring point based on the frequency domain data of each monitoring point; the dominant frequency is the frequency corresponding to the maximum amplitude.

[0063] The first calculation unit is used to calculate the risk factor ζ for each monitoring point according to the following formula: The monitoring point with the highest risk factor value is defined as the most dangerous monitoring point; where v is the maximum vibration velocity of each monitoring point, and v′ is the control vibration velocity standard of each monitoring point;

[0064] The second calculation unit is used to calculate the detonation interval t according to the following formula:

[0065]

[0066] in, f is the dominant frequency of the most dangerous monitoring point, and k is a natural number; and

[0067] The correction unit is used when, after continuous blasting tests according to the above-mentioned detonation interval t, the vibration velocity at the most dangerous monitoring point shows a significant superposition phenomenon and / or exceeds the control vibration velocity standard, in... Adjust the detonation interval t within the range; where f l f r For the two frequencies corresponding to the set amplitude A and f l <f<f r A = P × A max A max The maximum amplitude is represented by P, which ranges from 80% to 90%.

[0068] If the frequency interval is too large, the correction unit calculates f based on the relationship between frequency and amplitude. l and f r The relationship between frequency and amplitude is obtained by fitting a log-normal function or a polynomial fitting method.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the detonation interval of micro-delay blasting, comprising the following steps: S1. Set up monitoring points in all adjacent buildings around the blasting zone; S2. Conduct a single-hole detonation test in the blasting zone and obtain vibration data at each monitoring point; the vibration data is the data of vibration velocity changing with time. S3. Perform Fourier transform on the vibration data of each monitoring point to obtain the frequency domain data of each monitoring point, and determine the dominant frequency and maximum vibration velocity of each monitoring point based on the frequency domain data of each monitoring point; the dominant frequency is the frequency corresponding to the maximum amplitude. S4. Calculate the risk factor for each monitoring point according to the following formula. : ; The monitoring point with the highest risk factor value is defined as the most dangerous monitoring point; among them... The maximum vibration velocity at each monitoring point, The control vibration velocity standard for each monitoring point; S5. The detonation interval is calculated using the following formula. : ； in, , The dominant frequency for the most dangerous monitoring point. It is a natural number; S6. Based on the above detonation interval If, during continuous blasting tests, the vibration velocity at the most dangerous monitoring point exhibits significant superposition and / or exceeds the control vibration velocity standard, then... Adjust the detonation interval within the range ;in, , To match the set amplitude The corresponding two frequencies and , , This represents the maximum amplitude. The value range is 80% to 90%.

2. The method for determining the initiation interval of micro-delay blasting according to claim 1, characterized in that: In step S6, the relationship between frequency and amplitude is obtained by fitting a log-normal function or a polynomial fitting method, and the frequency is calculated based on this relationship. and .

3. A device for determining the detonation interval of micro-delay blasting, characterized in that, include: Microseismic monitoring instruments are deployed in adjacent buildings around the blasting area to acquire vibration data at each monitoring point; The first processing unit is used to perform Fourier transform on the vibration data of each monitoring point after a single-hole detonation test in the blasting zone to obtain the frequency domain data of each monitoring point, and to determine the dominant frequency and maximum vibration velocity of each monitoring point based on the frequency domain data of each monitoring point; the dominant frequency is the frequency corresponding to the maximum amplitude. The first calculation unit is used to calculate the risk factor of each monitoring point according to the following formula. : ; The monitoring point with the highest risk factor value is defined as the most dangerous monitoring point; among them... The maximum vibration velocity at each monitoring point, The control vibration velocity standard for each monitoring point; The second calculation unit is used to calculate the detonation interval according to the following formula. : ； in, , The dominant frequency for the most dangerous monitoring point. For natural numbers; and Correction unit, used when the above-mentioned detonation interval is... After continuous blasting tests, if the vibration velocity at the most dangerous monitoring point shows a significant superposition phenomenon and / or exceeds the control vibration velocity standard, then... Adjust the detonation interval within the range ;in, , To match the set amplitude The corresponding two frequencies and , , This represents the maximum amplitude. The value range is 80% to 90%.

4. The micro-delay blasting initiation interval determining device according to claim 3, characterized in that: The correction unit calculates the relationship between frequency and amplitude. and The relationship between frequency and amplitude is obtained by fitting a log-normal function or a polynomial fitting method.

5. A system for determining the detonation interval of a differential blasting operation, the system comprising a computer device, the computer device including a memory, a processor, and program instructions stored in the memory that are executable by the processor, wherein the processor executes the program instructions to implement the steps of the method as claimed in claim 1 or 2.

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