JP3683090B2 - Prediction method of ground vibration due to blasting and blasting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for predicting ground vibration due to blasting and a method for blasting. More specifically, the present invention relates to a method for predicting ground vibration when blasting is performed a plurality of times so as to cause interference with ground vibration, and causes interference with ground vibration. Thus, the present invention relates to a blasting method capable of making ground vibrations arbitrary when blasting is performed a plurality of times.
[0002]
[Prior art]
Regarding the compaction of loose sand ground by blasting, there have been many examples of construction mainly in Europe and North America. The inventors of the present invention have been studying application of the compaction method by blasting to soft ground such as a landfill or a reclaimed land.
[0003]
[Problems to be solved by the invention]
However, ground vibrations caused by blasting can propagate over several hundred meters and affect nearby buildings and structures, and can make residents feel uncomfortable if there are houses around the site. It was a problem. In particular, it was necessary to pay attention to the fact that surface waves are not easily attenuated by ground vibration of soft ground.
[0004]
In other words, when many blast holes are drilled in the ground and explosives are installed in each of these blast holes, or when multiple explosives are installed at different depths in one blast hole, these explosives are simultaneously initiated. Then, since a vibration larger than necessary is generated, it is desirable to blast a plurality of times by detonating each explosive at different times. However, even if the blasting is performed multiple times with a slight time difference, the surface wave is difficult to attenuate, so if the vibration at one stage remains, the remaining vibration interferes with the vibration from the blasting at the next stage or later. As a result of this, vibration larger than expected may occur. On the other hand, blasting can be performed a plurality of times so as not to cause interference with ground vibration, but in that case, the time interval between the blasting becomes too long, and it is inevitable that the work is prolonged.
[0005]
Therefore, if the ground vibration in the case of performing blasting a plurality of times so as to cause interference with the ground vibration can be predicted, it is convenient because excessive vibration can be prevented in advance. Moreover, it is more desirable if such ground vibration can be suppressed.
[0006]
Therefore, the main problem of the present invention is to make it possible to predict ground vibration when blasting is performed multiple times so as to cause interference with ground vibration, and to perform blasting multiple times so as to cause interference with ground vibration. It is to be able to make the ground vibration in the case of any.
[0007]
[Means for Solving the Problems]
The method for predicting ground vibration by blasting according to the present invention that solves the above-described problem includes a first test blasting actual measurement step of performing a first test blasting for performing a single blasting and actually measuring ground vibrations at that time ,
After the first test blasting actual process if, based on the measured result of ground vibration by the first test blasting was carried out a second test blasting performing multiple blasting to produce a interference Ground Vibration A second test blast prediction process for predicting ground vibration of
After the first test blasting actual process, carried out the second test blasting, actually measuring the ground vibration at that time, a second test blasting actual process,
After the first test blasting actual process, based on the measured result of ground vibration by the first test blasting, the number of times of blasting than the second test blasting with a time difference that produces interference to ground vibration The blast prediction process for predicting ground vibration when performing the blasting to be performed ,
After performing both said second test blasting prediction step and the second test blasting actual process, the measurement result of ground vibration by the second test blasting, and the prediction result of ground vibration by the second test blast A correction coefficient calculation step for calculating a correction coefficient based on the comparison of
After performing both the main blast prediction step and the correction coefficient calculation step, multiplying the ground vibration prediction result when performing the main blast by a correction coefficient, and correcting the prediction result ;
Is performed, and the corrected ground vibration prediction result of the blasting is obtained .
[0008]
On the other hand, the blasting method according to the present invention uses the ground vibration prediction method of the present invention, predicts ground vibration assuming the time difference in the main blasting, and each prediction result is an arbitrary ground vibration. A time difference between blasts is determined, and the blasting is performed with each time difference.
[0009]
<Action>
In the present invention, since the prediction is performed based on the actual measurement result of the ground vibration, it is possible to perform a highly accurate prediction that is not affected by the ground structure. On the other hand, in the blasting method of the present invention, the time difference between blasting is determined such that any ground vibration occurs due to the ground vibration interference by each blasting, and the blasting is performed a plurality of times based on this time difference. Is optional.
[0010]
The “one blast” referred to in the present invention includes blasting with a plurality of explosives in addition to blasting with one explosive. Therefore, the “multiple blasts” referred to in the present invention is to carry out such a single blast multiple times at different times. This “multiple blasts” includes those with different time differences between blasts.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a comparative example will be described first, and then an embodiment of the present invention will be described in detail based on comparison with the comparative example.
<Comparison form>
FIG. 1 shows a comparison method of ground vibration prediction methods, that is, a method of predicting ground vibration when blasting is performed a plurality of times so as to cause interference with ground vibration based on the actual measurement result of ground vibration due to blasting. ing. In addition, even if it is a case where it charges to each of several positions in one blasting hole, and it is the case where it charges to each of several charging holes, it is the same.
[0012]
More specifically, first, blasting is performed once on the target ground (hereinafter referred to as test blasting), and ground vibration at that time is measured. The test blasting is performed, for example, by providing a blasting hole for test blasting in the vicinity of the blasting hole for main blasting described later, and charging an appropriate amount of explosive at an appropriate position in the hole. This charge amount and the charge depth are preferably matched to any one of a plurality of blasts scheduled to be performed in the following blasting. In the actual measurement of ground vibration, for example, the temporal change of the vertical speed of the ground is measured by a three-component speedometer or the like installed at a desired position on the ground.
[0013]
Next, based on this test blast, the ground vibration is predicted when blasting is performed a plurality of times so as to cause interference with the ground vibration (hereinafter referred to as the main blasting). For this prediction, first, individual ground vibrations caused by each blast in this blast are predicted. This local vibration can be predicted based on the ground vibration measured in the test blasting and the relationship (eg, proportional relationship) between the ground vibration and the charge amount. In addition, when the amount of charge and the depth of charge of the test blast are set to any one of the multiple blasts scheduled to be performed in this blast as described above, this is used as a prediction result. In addition to this, for other blasts, it is possible to predict the local vibration due to each blast. After that, by taking into account the time difference between each blasting, by synthesizing the local vibrations due to each blasting, the prediction result of the ground vibrations due to this blasting is obtained.
[0014]
In the following, an example is shown in which the ground vibration generated in the blasting in which the blasting with the charge amount of 2 kg and the blasting with the charge amount of 3 kg are continuously performed so as to cause interference with the ground vibration is predicted according to the basic example.
[0015]
FIG. 2 shows an example of ground vibration measurement of test blasting, and is a graph (hereinafter referred to as vibration waveform) in which the vertical axis represents the vertical movement speed of the ground surface and the horizontal axis represents time.
[0016]
The test blast charge is 3 kg. The vertical movement speed of the ground was obtained from the result of measuring the ground vibration at a point 90 m away from the test blast hole in a substantially horizontal direction with a three-component speedometer. In the vibration waveform of FIG. 2, the maximum value of the vertical movement speed is 0.517 cm / second.
[0017]
Next, FIG. 3 shows a waveform delayed by 0.50 seconds with respect to the result of predicting the vibration waveform generated by the blasting of the charge amount of 2 kg based on the actual measurement result of the test blasting.
[0018]
Then, by combining the measured waveform of ground vibration due to blasting with a charge of 2 kg and the predicted waveform of ground vibration due to blasting with a charge of 3 kg at an arbitrary time difference, this blasting is performed at the arbitrary time difference. A vibration waveform (composite waveform) is obtained. FIG. 4 shows a prediction result of a vibration waveform generated when blasting with a charge amount of 3 kg is performed and then blasting with a charge amount of 2 kg is delayed by 0.34 seconds. From this, when the time difference between blasts in this blasting is 0.34 seconds, it is predicted that the maximum value of the vertical movement speed of the ground will be 0.870 cm / second. On the other hand, FIG. 5 shows a prediction result of a vibration waveform generated when blasting with a charge amount of 3 kg is performed and then blasting with a charge amount of 2 kg is delayed by 0.50 seconds. From this, when the time difference between blasts in this blasting is 0.50 seconds, it is predicted that the maximum value of the vertical movement speed of the ground will be 0.696 cm / second. The actual measurement result of the vibration waveform generated when the time difference is 0.50 seconds is shown in FIG. The measured waveform shown in FIG. 6 is in good agreement with the predicted waveform shown in FIG. 5, and it can be seen that highly accurate prediction is possible.
[0019]
<Embodiment of the present invention>
In the above comparison mode, the difference in location of each blast and the influence of geology (vibration attenuation, etc.) are ignored. Therefore, when the influence is large, high-precision prediction cannot be expected. Therefore, when higher prediction accuracy is required, it is desirable to employ the embodiment of the present invention shown in FIG.
[0020]
The point of this embodiment is that the vibration prediction based on the actual measurement result of the test blast is obtained in light of the actual measurement result of other test blasting under the same conditions as the prediction, and the prediction of the main blast is corrected by this correction coefficient. There is. That is, as a first test blast, ground vibration due to one blast is measured. Next, based on the actual measurement result of the first blast, the ground vibration in the case of performing the blast twice (hereinafter also referred to as the second test blast) so as to interfere with the ground vibration of the test blast is predicted. Further, the second test blasting is performed to measure the ground vibration at that time. From these results, the actual measurement result of the ground vibration related to the second test blasting and the prediction result are compared, and a correction coefficient is obtained. After that, based on the actual measurement results of ground vibration related to the first test blast, the ground vibration due to this blast (more blasts than the second test blast) is predicted and corrected by multiplying this prediction result by a correction coefficient. To do.
[0021]
The present embodiment will be described more specifically based on an example of predicting the vibration waveform of the main blast with 12 blasts. The first test blast is performed in the same manner as the test blast of the basic example described above. Therefore, the actual measurement result of the ground vibration by the first test blasting is a vibration waveform (charge amount 3 kg) shown in FIG. Next, the second test blasting is performed in the same manner as the above-described basic blasting. That is, the oscillating waveform is measured when the blasting of the charge amount of 3 kg is performed first, and then the blasting of the charge amount of 2 kg is initiated with a delay of 0.50 seconds. The actually measured waveform is as shown in FIG. On the other hand, when the vibration waveform due to the second test blast is predicted based on the first test blast, the vibration waveform shown in FIG. 5 described above is obtained. Then, a correction coefficient is obtained based on a comparison between the actually measured vibration waveform of the second test blast shown in FIG. 6 and the predicted vibration waveform of the second test blast shown in FIG.
[0022]
After that, the vibration waveform of this blast is predicted. In this prediction, as described above, each vibration waveform generated by each blast in the main blast is predicted based on the actually measured vibration waveform of the first test blast and the relationship between the vibration waveform and the charge amount. Then, each predicted vibration waveform is synthesized in consideration of the time difference between each blast of the blast, and the synthesized waveform is corrected by the correction coefficient, thereby obtaining the predicted oscillating waveform of the main blast shown in FIG. FIG. 8 also shows the actual vibration waveform of the blasting. As can be seen from the figure, the vibration waveform predicted according to this application example is almost the same as the actually measured vibration waveform, and it can be seen that more accurate prediction is possible according to the embodiment of the present invention.
[0023]
In addition, this invention is not limited to the procedure of the said embodiment. That is, the second test blast and the actual measurement of the ground vibration at that time, the prediction of the ground vibration in the second test blast, and the prediction of the local vibration caused by each blast in the main blast and the ground vibration in the main blast Any of these predictions may be performed first or in parallel.
[0024]
The correction coefficient is calculated after the second test blasting, the ground vibration at that time, and the ground vibration prediction at the second test blasting, before the ground blasting prediction result correction. Yes, whenever possible.
[0025]
<Example of blasting method>
On the other hand, according to the prediction method of the present invention described above, the ground vibration when the blasting is performed a plurality of times so as to cause interference with the ground vibration, the ground vibration generated by each blasting is considered in consideration of the time difference between each blasting. It can be predicted by synthesizing. Therefore, from this relationship, the time difference between each blasting is determined so that the ground vibration due to multiple blasting becomes arbitrary vibration, and the ground vibration caused by blasting is arbitrarily determined by performing multiple blasting based on this time difference. Can be.
[0026]
More specifically, the blasting method example shown in FIG. 9 is proposed. In this method, first, as in the prediction method of the present invention described above, the first test blasting and the ground vibration prediction at that time, the ground vibration prediction in the second test blasting, the second test blasting Implementation and actual measurement of ground vibration, calculation of correction coefficient, and prediction of local vibration caused by each blast in this blast.
[0027]
After that, assuming the time difference between each blast in this blast, and by synthesizing the predicted results of local vibrations caused by each blast in this blast with this assumed time difference, the ground vibration due to this blast is predicted. The prediction result is corrected by multiplying it by a correction coefficient.
[0028]
Then, it is determined whether or not the corrected ground vibration prediction result is arbitrary, and if it is arbitrary, the blasting is performed based on the assumed time difference. If the corrected ground vibration prediction result is not arbitrary, the assumption of the time difference between each blast in this blast, the prediction of ground vibration due to this blast, correction, and It is repeatedly determined whether or not the corrected ground vibration prediction result is arbitrary, a time difference between each blasting that causes an arbitrary ground vibration is obtained, and the main blasting is performed based on this time difference. In carrying out this blasting, it is desirable to confirm the prediction accuracy by actually measuring the ground vibration and comparing the measured result of the ground vibration with the predicted result. From this comparison, a new correction coefficient can be obtained as necessary.
[0029]
Thus, in the blasting method according to the present invention, since the ground vibration due to the blasting can be arbitrary, for example, the magnitude of the ground vibration can be set to a target value or less. That is, in the flowchart shown in FIG. 9, the magnitude of ground vibration (for example, the maximum value of the vertical movement speed of the ground) is evaluated from the ground vibration prediction result (corrected) by this blasting, and this evaluation result is below the target value. If the result is below the target value, this blasting is carried out. If the evaluation result is equal to or greater than the target value, the assumption of the time difference between each blast in this blast, prediction of ground vibration due to this blast, correction, evaluation of the magnitude of vibration, and the evaluation result By repeating the comparison with the target value, a time difference that is less than or equal to the target value is obtained, and this blasting is performed based on this time difference.
[0030]
Also, in all cases of possible time difference between blasts, the magnitude of ground vibration is predicted, and from these prediction results, the time difference between blasts when the magnitude of ground vibration is minimum is obtained, or the smallest vibration It is also possible to obtain an appropriate time difference (eg, minimum value) from among the time differences, and perform the blasting based on this time difference.
[0031]
On the other hand, in the above example, the predicted ground vibration may not be arbitrary for all possible time differences between blasts. In addition, even if it is predicted that the ground vibration at a certain time difference will be arbitrary, the blast at that time difference may not be practical because the time difference in that case is below the ignition accuracy of the detonator. It is possible.
[0032]
In such a case, among the blasts scheduled to be performed individually, some blasts are detonated simultaneously as one group, and one or a plurality of groups are defined. Based on these time differences, the time difference between individual blasts, the time difference between individual blasts and group blasts, or the time difference between group blasts, where the ground vibration due to these individual blasts or group blasts becomes arbitrary, is determined. This blasting can also be carried out. Also, if there are multiple explosives that detonate in one blast, divide the blast into multiple blasts, set the time difference between each blast so that the ground vibration in this blast becomes arbitrary, The blasting can be carried out based on the time difference.
[0033]
<Others>
In the present invention, as test blasting, blasting can be performed a plurality of times so as to cause interference with ground vibration. In the present invention, the ground on which the test blasting is performed is not limited to the ground near the blasting position. The ground on which the test blasting is performed may be a ground having the same geological conditions as the blasting, and the results of the past test blasting can be used.
[0034]
【The invention's effect】
As described above, according to the present invention, it is possible to predict the ground vibration when blasting is performed a plurality of times so as to cause interference with the ground vibration, and to perform the blasting multiple times so as to cause interference with the ground vibration. The ground vibration when performed can be arbitrary.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a comparative form of a ground vibration prediction method.
FIG. 2 is a graph showing an actual measurement result of ground vibration due to test blasting.
FIG. 3 is a graph showing a prediction result of ground vibration due to blasting of another charge amount.
FIG. 4 is a graph showing the ground vibration waveform due to this blasting predicted with a time difference of 0.34 seconds.
FIG. 5 is a graph showing the ground vibration waveform due to the blasting predicted with a time difference of 0.50 seconds.
FIG. 6 is a graph showing a ground vibration waveform by actual blasting measured with a time difference of 0.50 seconds.
FIG. 7 is a flowchart showing an example of a ground vibration prediction method according to the present invention.
FIG. 8 is a graph showing a ground vibration waveform due to actual blasting predicted by an example of a ground vibration prediction method according to the present invention and an actually measured waveform thereof;
FIG. 9 is a flowchart showing an example of a blasting method according to the present invention.

Claims (2)

A first test blast measurement step of performing a first test blast for performing a single blast and measuring ground vibration at that time ;
After the first test blasting actual process if, based on the measured result of ground vibration by the first test blasting was carried out a second test blasting performing multiple blasting to produce a interference Ground Vibration A second test blast prediction process for predicting ground vibration of
After the first test blasting actual process, carried out the second test blasting, actually measuring the ground vibration at that time, a second test blasting actual process,
After the first test blasting actual process, based on the measured result of ground vibration by the first test blasting, the number of times of blasting than the second test blasting with a time difference that produces interference to ground vibration The blast prediction process for predicting ground vibration when performing the blasting to be performed ,
After performing both said second test blasting prediction step and the second test blasting actual process, the measurement result of ground vibration by the second test blasting, and the prediction result of ground vibration by the second test blast A correction coefficient calculation step for calculating a correction coefficient based on the comparison of
After performing both the main blast prediction step and the correction coefficient calculation step, multiplying the prediction result of ground vibration when performing the main blast by a correction coefficient, and correcting the prediction result ;
A method for predicting ground vibration due to blasting, characterized in that the following results are obtained to obtain a corrected ground vibration predicted result of this blasting . Using the ground vibration prediction method according to claim 1, the ground vibration is predicted assuming the time difference in the main blasting, and the time difference between each blasting is determined so that the prediction result is an arbitrary ground vibration. A blasting method comprising performing the blasting with a time difference.

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