WO2022051890A1 - Vibration reduction method based on blast vibration prediction technology - Google Patents

Abstract

A vibration reduction method based on a blast vibration prediction technology, comprising the following steps: S1: selecting a blast hole as a reference blasting hole in multiple holes of a blasting area; S2: selecting a plurality of measuring points on the periphery of the reference blasting hole, and arranging a vibration measuring instrument in the radial direction of the reference blasting hole and the measuring points; S3: collecting vibration data of the reference blasting hole and other blast holes, and recording blasting parameters; S4: analyzing the collected vibration data of the reference blasting hole by using Matlab software, inputting millisecond times of multi-hole blasting in n segments, and predicting a complete blasting vibration waveform of the measuring points and the maximum multi-hole blasting vibration speed; S5: using Matlab software to fit a relationship curve between different millisecond times and a particle maximum blasting vibration speed and a relationship curve between different millisecond times and a vibration reduction rate. According to the method, the change rule of a multi-hole blasting vibration waveform predicted by a single-hole blasting vibration waveform is basically consistent with that of an actually measured blasting vibration waveform, and compared with a conventional formula plus experience prediction method, the method is more effective and reliable.

Description

Vibration reduction method based on blasting vibration prediction technology technical field

The invention relates to the technical field of blasting vibration safety, in particular to a vibration reduction method based on blasting vibration prediction technology.

Background technique

Deep hole step blasting is large in scale and has a wide range of influence. It is very necessary to effectively predict the blasting vibration intensity in the design stage. To describe the vibration intensity, physical quantities such as acceleration, velocity or displacement can be used. A large number of research experiments show that the velocity index can better reflect the relationship between the building and the degree of damage caused by blasting vibration, and is little affected by the thickness of the cover layer of the transmission medium.

The formula empirical method for predicting the peak value of blasting vibration velocity is based on a large number of engineering practices. Several factors that have a greater impact on blasting vibration intensity are summarized. Through dimensional analysis, the calculation formula of vibration intensity is continuously revised according to different blasting conditions on site. Up to now, blasting workers in various countries and regions have obtained different empirical calculation formulas according to their own test conditions. Generally speaking, they can be summarized into the following mathematical expressions:

In the formula: A-vibration intensity (displacement, velocity, acceleration, etc.); Q-one-time priming charge or single-stage maximum priming charge (kg); β-charge index; R-distance from detonation source to measuring point (m) ; K, α - coefficients related to geological conditions, reflecting the attenuation degree of seismic waves to a certain extent.

The Sadowski formula used in China:

The empirical formula of the US Bureau of Mines:

Japanese empirical formula:

Regarding the safety criteria of blasting vibration, China's National "Blasting Safety Regulations" (GB 6722-2014) stipulates that the vibration speed and frequency are used as the comprehensive judgment criteria for ground buildings. Follow the former Soviet MA Sadowski formula. The derivation of Sadowski's formula is obtained by dimensional analysis on the basis of the blasting of the ketone chamber in the concentrated charge, and has clear physical meaning and usage conditions. If it is applied to deep hole step blasting, many problems are bound to occur. However, blasting workers have found in a large number of engineering practices that the Sadowski formula can still meet the engineering requirements for the prediction of blasting vibration in the middle and far-reaching areas.

The reason is that when the blast center distance is large enough relative to the distribution range of the blast area, the long-distance group-hole charge can be approximately regarded as a concentrated charge, which satisfies the basic assumption of Sadowski's formula. However, in the blasting near area, the prediction error of the vibration peak value of the measuring point can reach 200%-300%, and the result is not satisfactory. This is obviously unfavorable for knowing and evaluating the impact degree of blasting vibration in advance in blasting construction of adjacent structures and buildings.

SUMMARY OF THE INVENTION

Based on the technical problems existing in the background technology, the present invention proposes a vibration reduction method based on blasting vibration prediction technology. The vibration waveform of group-hole blasting predicted by the vibration waveform of single-hole blasting is basically consistent with the variation law of the measured blasting vibration waveform. Compared with the traditional blasting vibration waveform The formula plus empirical prediction method is more effective and reliable.

The vibration reduction method based on blasting vibration prediction technology proposed by the present invention, the method steps are as follows:

S1: Select a blast hole as the reference blast hole in the group of holes in the blasting area;

S2: Select several measuring points on the periphery of the reference blasting hole, and arrange the vibrometer in the radial direction of the reference blasting hole and the measuring points;

S3: Collect the vibration data of the reference blasting hole, and record the blasting parameters;

S4: Use the Matlab software to analyze the collected vibration data of the reference blasting hole, input the differential time of the group hole blasting under the n segment, and predict the complete blasting vibration waveform of the measuring point and the maximum blasting vibration velocity of the particle; the details are: Use the xlsread function of Matlab software to read the single-hole blasting vibration signal in the specified path of the document, select the maximum blasting vibration velocity in the three channels (vertical, radial, tangential) of the measured single-hole blasting vibration signal, and set the number of overlapping segments n (the number of blasting holes in the group hole) and the differential time Δt, and the total duration of the group hole waveform is determined by the number of superpositions. Under the for loop, the n-segment group hole blasting waveform superimposed by the channel waveform under the set differential time is realized. At the same time, the maximum blasting vibration velocity of the particle is predicted.

S5: Use Matlab software to fit the relationship curve between different differential time and the maximum blasting vibration velocity of the particle, and the relationship between different differential time and vibration reduction rate. Specifically: on the basis of the S4 prediction program, determine the sampling frequency of the vibration measuring instrument, set the differential time range (1-100ms), and perform n superimposition cycles on the single-hole blasting vibration signal at different differential times. Cycle to determine a maximum blasting vibration velocity, thereby obtaining the relationship curve between the maximum blasting vibration velocity and the particle under the differential time.

Preferably, the reference blasting hole is the last blasting hole in the group of holes, and the delay time interval between the blasting of the last blasting hole and the adjacent blasting hole is not less than 500ms.

Preferably, there are no less than three vibrometers, and the vibrometers are arranged on the bedrock or wedged into the ground with vibrometers.

Preferably, the blasting parameters include the position of the blasting hole, the distance between the measuring points, the depth of the hole, the propagation medium, the charge per hole, the distance between the holes and the blasting network.

Preferably, the expression of the complete blasting vibration waveform in the S4 is:

In the formula: S(T) is the total blasting vibration velocity of the measuring point, T is a certain moment in the whole process of blasting vibration; K _i is the charge coefficient of the ith segment, when the charge amount of each segment, explosive When the blasting parameters such as the type are the same, and the topographic and geological conditions from the blast source to the measuring point are not much different, take 1; S(t _i ) is the vibration velocity of the particle generated after the explosion of the ith subsection explosive; t _i is the ith The time for the seismic wave to travel from the source to the measuring point after the explosion of a segmented explosive; n is the number of segments; δ(t) is the unit step signal. The expression is:

Compared with the prior art, the beneficial technical effects of the present invention:

(1) The present invention uses Matlab program numerical simulation, and the group hole blasting vibration waveform predicted by the single hole blasting vibration waveform is basically consistent with the variation law of the measured blasting vibration waveform, and the group hole blasting vibration peak velocity error rate is within 16%. It is more effective and reliable than the traditional formula plus empirical prediction method.

(2) The micro-difference time to reduce the blasting vibration effect of blasting is not in half the main vibration waveform period. In the period of 0-100ms, the vibration reduction rate of blasting vibration intensity in the interval of 16ms-20ms is particularly obvious. When it reaches more than 60ms, the group The hole vibration signal acts independently of the single hole blasting vibration signal.

(3) The application of high-precision digital electronic detonators to change the differential time can realize the interference and superposition of the blasting vibration signals of each blasting area. In the mid-to-far area, the vibration reduction effect of the differential time is general. Before the blasting construction, the invention predicts the optimal vibration reduction effect of the program by the micro-difference time, and the blasting vibration intensity can be effectively controlled at different distances.

(4) The influence of the differential time on the blasting vibration effect of the open-pit mine of the present invention adopts the method of controlled blasting to reduce the harmful effect of the seismic wave, and the engineering feasibility is stronger, which is convenient for promotion in practical engineering.

Description of drawings

Fig. 1 is the blast hole and measuring point arrangement diagram of the embodiment proposed by the present invention;

Fig. 2 is the reference blasting hole blasting vibration waveform measured by the measuring point M1 of the embodiment proposed by the present invention;

Fig. 3 is the reference blasting hole blasting vibration waveform measured by the measuring point M2 of the embodiment proposed by the present invention;

Fig. 4 is the reference blasting hole blasting vibration waveform measured by the measuring point M3 of the embodiment proposed by the present invention;

Fig. 5 is the measurement point M1 simulation and actual measurement group hole blasting vibration waveform of the embodiment proposed by the present invention;

Fig. 6 is the measurement point M2 simulation and actual measurement group hole blasting vibration waveform of the embodiment proposed by the present invention;

Fig. 7 is the differential time of the embodiment proposed by the present invention and the maximum blasting vibration velocity relationship curve of the particle;

Fig. 8 is the relationship curve of differential time and vibration reduction rate of the embodiment proposed by the present invention;

Fig. 9 is the damping law of blasting vibration velocity of S1 measuring point under different differential time of the verification example proposed by the present invention;

Fig. 10 is the vibration velocity peak value of each measuring point under different differential time of the verification example proposed by the present invention;

FIG. 11 is the main frequency of each measuring point under different differential time of the verification example proposed by the present invention.

detailed description

The present invention will be further explained below in conjunction with specific embodiments.

Example

According to the test implementation steps, the single-hole blasting hole (reference blasting hole) is selected as the final blasting hole for group blasting, and the delay time interval between single-hole blasting and the penultimate blasting hole for group blasting is set to 500ms, and the positions of blasting holes and measuring points are as follows: Figure 1.

Figure 2-4 is the single-hole blasting vibration data record of the three measuring points M1, M2 and M3. Table 1 shows the single-hole blasting parameters and the measured single-hole blasting true poison velocity peak value.

Table 1 Single-hole blasting parameters and peak vibration velocity

Before carrying out group blasting, according to the existing blasting design parameters, the single-hole vibration waveform with the largest vibration velocity among the three channels is retrieved, and the prediction program of the present application is used to carry out 10 superimposed groups at a differential time of 22ms. The hole blasting vibration waveform was numerically simulated, and compared with the measured group hole blasting vibration data after blasting. The waveform of measuring point 3 is distorted, and the simulated and measured vibration waveforms of group hole blasting at measuring points 1 and 2 are shown in Figure 5-6.

It can be seen from Figure 5-6 that the predicted blasting vibration waveform at two different positions is basically the same as the actual blasting vibration waveform (by measuring the vibration data of group hole blasting to determine the actual blasting vibration waveform). The occurrence times of enhancement and weakening are also close, and the blasting vibration waveform predicted in this study basically reflects the variation trend of blasting vibration at each measuring point. From Table 2, it can be found that the measured vibration velocity peak value v _a of the two vibration measuring points is close to the predicted vibration velocity peak value v _p , and the error rate does not exceed 16%, which is much lower than the regression prediction analysis method using the Sadowsky formula. The method of blasting vibration velocity peak prediction is effective and reliable.

Table 2 Comparison of simulated and measured group blasting vibration data

Measuring point	L/m	v a	v p	|Δv|	Error rate/%
M1	65	1.246	1.0536	0.1924	15.4
M2	95	0.747	0.6565	0.0905	12.1
M3	125	-	-	-	-

The intensity of blasting vibration is mainly reflected by the maximum blasting vibration velocity when the main vibration frequency is similar, so the relationship curve between different differential time and the maximum blasting vibration velocity of the particle can be fitted.

The "vibration reduction rate" is used to describe the degree to which the maximum vibration velocity is weakened after n times of single-hole blasting vibration signals are superimposed. The ratio of the difference to the burst vibration velocity is used to measure the vibration reduction rate, that is,

In the formula: v ₀ is the maximum blasting vibration velocity of the homogeneous blasting particle; v _i is the maximum blasting vibration velocity of the particle under the n segments with different differential times. By compiling the calculation program of formula (3), the variation curve of the vibration reduction rate with the differential time can be obtained.

As shown in Figure 7, in the entire differential time period of 0-100ms, the peak value of the superimposed signal of group hole blasting increases and decreases to varying degrees with the existence of the differential time, and the maximum vibration reduction rate is at 18ms. The vibration reduction rate reaches 92.5%, which is not in line with the interference vibration reduction theory that half of the main vibration waveform period is subtracted when "Δt=T/2" (25ms). This is because the blasting vibration signal is a typical non-stationary random The signal has the characteristics of short duration and rapid mutation.

As shown in Figure 8, the variation law of the superimposed group hole blasting vibration signal with the differential time is as follows. The peak value of the superimposed signal decreases rapidly with the generation of the differential time, and the drop rate reaches the maximum at 18ms, reaching 92.5%. Above, the vibration reduction rate of group hole blasting vibration signal in the interval of 16ms-20ms is particularly obvious, reaching more than 91.5%. When the differential time is more than 60ms, the vibration reduction rate of the group-hole blasting vibration signal is close to a straight line, and the peak value of the blasting vibration is close to the peak value of the single-hole blasting vibration signal, indicating that the mutual interference and superposition of the main vibration of each single-hole vibration signal has been eliminated. The group-hole vibration signal at this time is the result of the independent action of the single-hole blasting vibration signal.

Verification example

Four groups of hole blasting tests were carried out in a limestone stope in Hangzhou. The on-site experimental instruments were NUBOX-8016 and GPS measuring instrument from Sichuan Tuopu. Through the actual measurement of blasting vibration velocity peaks at different differential times in blasting tests, the predicted blasting vibration was verified. Differential time accuracy. The blasting parameters of the group hole and the single hole are the same. The blasting hole diameter is 120mm, the hole depth is 10.0m, the hole mesh parameter is 5m×4m, the single hole charge is 49kg, a total of 10 holes, the total blasting charge is 490kg, and there is no spaced coupling charge. , install 1 digital electronic detonator per hole. Digital electronic detonators are used in the 4 groups of experimental rows to form a differential detonation network with differential times of 18ms, 22ms, 27ms and 50ms. In each vibration measurement area, three monitoring points are arranged from the near and far radial directions, which are recorded as S1, S2 and S3, the measured peak value of blasting vibration velocity of group holes is shown in Table 3, and the attenuation law of blasting vibration velocity of S1 measuring point in the four monitoring is shown in Figure 9.

Table 3 Blasting vibration velocity data of each measuring point under different differential time

Through the analysis of the peak vibration velocity measured at 12 measuring points in 4 groups of differential test blasting areas, it is found that the main vibration frequency of blasting vibration of each measuring point is basically kept within 9-20HZ, and the influence of differential time on the main vibration frequency is not obvious. . At 65m, when the differential time is selected as 18ms, the peak value of the minimum blasting vibration velocity measured at the S1 measuring point is 0.701cm/s; at 95m, when the differential time is selected as 18ms, the minimum blasting vibration velocity peak value measured at the S1 measuring point is 0.477cm /s; at 125m, when the differential time is 18ms, the minimum blasting vibration velocity peak measured at the S1 measuring point is 0.305cm/s;

The test results show that when 18ms is selected for differential hole-by-hole blasting, the peak value of blasting vibration velocity at each measuring point is lower than the other three cases, which confirms that the single-hole blasting vibration superposition prediction method carried out in this study is consistent with reality.

It can be seen from Fig. 10-11 that in the process of blasting seismic wave propagation, the peak value of blasting vibration velocity decreases continuously with the increase of blasting center distance; the main frequency of blasting vibration basically lasts in the same interval, and only a few measuring points change the main frequency. With the change of the differential time at the same measuring point, the peak value of blasting vibration velocity decreases to different degrees, and the main vibration frequency of blasting vibration does not change significantly; It can be reduced by 69.7%; in the middle and far areas of the blasting area, the vibration reduction effect is general with the change of the differential time, and the optimal differential time for the vibration reduction effect is 18ms. Although the vibration reduction effect is not obvious, the main vibration frequency of blasting vibration is significantly increased, which It has a certain protective effect on structures (the own frequency is generally lower than 10Hz).

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (5)

1. The vibration reduction method based on blasting vibration prediction technology is characterized in that the method steps are as follows:

   S1: Select a blast hole as the reference blast hole in the group of holes in the blasting area;

   S2: Select several measuring points on the periphery of the reference blasting hole, and arrange the vibrometer in the radial direction of the reference blasting hole and the measuring points;

   S3: Collect the vibration data of the reference blasting hole, and record the blasting parameters;

   S4: Use the Matlab software to analyze the collected vibration data of the reference blasting hole, input the differential time of the group hole blasting under the n segment, and predict the complete blasting vibration waveform of the measuring point and the maximum blasting vibration speed of the group hole;

   S5: Use Matlab software to fit the relationship curve between different differential time and the maximum blasting vibration velocity of the particle, and the relationship between different differential time and vibration reduction rate.
2. The vibration reduction method based on blasting vibration prediction technology according to claim 1, wherein the reference blasting hole is the last blasting hole in the group of holes, and the delay time of blasting between the last blasting hole and the adjacent blasting hole The interval is not less than 500ms.
3. The vibration reduction method based on blasting vibration prediction technology according to claim 1, characterized in that there are no less than three vibrometers, and the vibrometers are arranged on the bedrock or wedged into the ground with vibrators .
4. The vibration reduction method based on blasting vibration prediction technology according to claim 1, wherein the blasting parameters include blasting hole position, measuring point distance, hole depth, propagation medium, single hole charge, hole row spacing and blasting The internet.
5. The vibration reduction method based on blasting vibration prediction technology according to claim 1, is characterized in that, the expression of complete blasting vibration waveform in described S4 is:

   

   In the formula: S(T) is the total blasting vibration velocity of the measuring point, T is a certain moment in the whole process of blasting vibration; K _i is the charge coefficient of the ith segment, when the charge amount of each segment, explosive When the blasting parameters such as the type are the same, and the topographic and geological conditions from the blast source to the measuring point are not much different, take 1; S(t _i ) is the vibration velocity of the particle generated after the explosion of the ith subsection explosive; t _i is the ith The time for the seismic wave to travel from the source to the measuring point after the explosion of a segmented explosive; n is the number of segments; δ(t) is the unit step signal. The expression is:

   

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