scholarly journals Energy Characteristics of Seismic Waves on Cardox Blasting Tube

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xuejiao Cui ◽  
Bo Ke ◽  
Songtao Yu ◽  
Ping Li ◽  
Mingsheng Zhao

In order to study the energy characteristics of seismic waves on the liquid CO2 blasting system, the blasting seismic wave signal of liquid CO2 blasting was obtained by on-site microseismic monitoring tests. The adaptive optimal kernel time-frequency analysis method was used to study the basic time-frequency properties of the seismic wave signal. Combining wavelet packet transform decomposition and reconstruction and adaptive optimal kernel time-frequency analysis method, the liquid CO2 energy distribution of the seismic wave signal was further analyzed. And the energy regression model of seismic wave source of liquid CO2 blasting system was discussed. The results show that the vibration velocity is at a low level, and the main frequency range is between 30 and 70 Hz, and the duration is about 20-30 ms. The energy is mainly distributed in 0-125 Hz, which is composed of two main regions. The power function model can be used to describe the attenuation law of the seismic wave energy. The energy conversion coefficient and characteristic coefficient of the source of liquid CO2 blasting system were defined and analyzed. Combined with the empirical formula of the Sadovsky vibration velocity, the energy regression model of the seismic wave source of liquid CO2 blasting system was obtained.

2014 ◽  
Vol 1033-1034 ◽  
pp. 444-448
Author(s):  
Ming Sheng Zhao ◽  
Xu Guang Wang ◽  
En An Chi ◽  
Qiang Kang

The distance from the blast center will directly change the blasting seismic wave wave’s energy property and eventually influence the structure’s response to the wave. To study its influence on the time-frequency (t-f) characteristics of blasting vibration signals, the single-hole blasting vibration test was conducted in Jinduicheng Open Pit Mine. Based on the measured data, wavelet analysis was used to decompose the measured signals, and signal segments at different frequency bands were got. RSPWVD quadratic form time-frequency analysis method was applied to analyze the segments’ t-f characteristics, and the domain frequencies of the blasting seismic waves under different distances from the blast center and the energy distribution and duration of the frequency bands were collected. The results show that the distance from the blasting center has a big impact on the domain frequency of the blasting seismic wave. With the increasing of the distance, the domain frequency reduces, its duration extends, the percentage of energy at the low frequency in the total energy increases and the duration of the frequency band extends. The research results provide the analysis base for understanding the influence of the distance from the blast center on signals’ t-f characteristic and studying vibration resistance and vibration reduction.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Yaxiong Peng ◽  
Ying Su ◽  
Li Wu ◽  
Chunhui Chen

Seismic wave induced by underwater drilling and blasting may exert adverse effects to the surrounding structures. Peak particle velocity (PPV) has been widely used to reflect the intensity of seismic wave, while the method fails to take other influential parameters into consideration. Synthesizing PPV and duration, seismic wave energy (SWE) is employed to quantify the intensity, and the method of time-frequency analysis is adopted to study the characteristics of vibration frequency. Besides, this paper deduces the prediction formula for SWE via dimension analysis. Based on the practical engineering, the attenuation characteristics of SWE induced by underwater drilling and blasting is analysed by the wavelet transform and adaptive optimal kernel (AOK) time-frequency analysis method. Results show that the dominant frequencies at the directions of horizontal tangential, horizontal radial, and vertical are different and the energies in high-frequency bands are extremely low. Moreover, the lower the frequency is, the slower the attenuation of SWE is. Comparing with other prediction formulas of PPV, fitting the SWE with the help of the prediction formula in this study would achieve more accurate prediction results.


2020 ◽  
Vol 51 (3) ◽  
pp. 35-43
Author(s):  
Shuang Zhao ◽  
Jian Zhang ◽  
Dongwei Kou ◽  
Cean Guo

To study the variation of the wave field of seismic waves in shallow sea of buried mines, the wave field of buried mine was simulated by employing LS-DYNA software. The effects of different distances ( R), rock density ( ρ2), buried depth ( h), and seawater height ( H) on the variation of wave field were obtained. The time-frequency analysis of the simulation results was carried out by using wavelet transform, and it was determined that the frequency domain of shallow sea is mainly concentrated below 25 Hz. To get the propagation characteristics of shallow sea seismic wave, the wave field below 25 Hz on the surface of buried mine was filtered by the low-pass filter. The buried depth has the greatest influence on the wave field of buried mine. The underwater target can be identified by the propagation characteristics of shallow sea seismic wave. The simulation results are consistent with the experimental results. The research results can provide an important reference for development of buried mine fuse.


2020 ◽  
Vol 2 (2) ◽  
pp. 35-49 ◽  
Author(s):  
Krzysztof Fuławka ◽  
Lech Stolecki ◽  
Izabela Jaśkiewicz-Proć ◽  
Witold Pytel ◽  
Piotr Mertuszka

One of the major problems associated with the excavation of the copper deposits in underground mines in Poland is the relatively high level of seismic activity. Numerous high-energy tremors can negatively affect the stability of underground workings and can have a destructive impact on the infrastructure located at the surface as well. As predicted, the seismic activity increases along with the depth of mining operations. Therefore, to face these threats, a number of organizational and technical prevention methods have been applied in the mines. One of them is the assessment of the effect of additional dynamic loads on the structures behaviour with the use of numerical modelling. Recently there have been some possibilities of conducting dynamic analyses, i.e. using the finite element method that allows gathering information on the changes in stress conditions or deformation levels within the analysed object. Unfortunately, these kinds of calculations are usually performed after the occurrence of an unwanted event, so it is rather a post factum method. This is mainly due to the lack of information about the worst scenario of seismic wave distribution. At the same time, during the preliminary risk assessment, in most cases, only the maximum predicted value of seismic wave amplitudes is taken into consideration. Other dynamic parameters such as dominant frequency and duration of seismic wave are usually omitted. In this paper, the time-frequency characteristics of induced seismic waves observed within the Lower Silesian Copper Basin were analysed. Based on the high-energy seismic events database, dominant frequencies, amplitudes and tremor durations were determined. Then the correlation between each parameter, i.e. the energy of each tremor and their hypocentic distance from the seismic source and monitoring station were determined.


2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Akio Katsumata ◽  
Masayuki Tanaka ◽  
Takahito Nishimiya

AbstractA tsunami earthquake is an earthquake event that generates abnormally high tsunami waves considering the amplitude of the seismic waves. These abnormally high waves relative to the seismic wave amplitude are related to the longer rupture duration of such earthquakes compared with typical events. Rapid magnitude estimation is essential for the timely issuance of effective tsunami warnings for tsunami earthquakes. For local events, event magnitude estimated from the observed displacement amplitudes of the seismic waves, which can be obtained before estimation of the seismic moment, is often used for the first tsunami warning. However, because the observed displacement amplitude is approximately proportional to the moment rate, conventional magnitudes of tsunami earthquakes estimated based on the seismic wave amplitude tend to underestimate the event size. To overcome this problem, we investigated several methods of magnitude estimation, including magnitudes based on long-period displacement, integrated displacement, and multiband amplitude distribution. We tested the methods using synthetic waveforms calculated from finite fault models of tsunami earthquakes. We found that methods based on observed amplitudes could not estimate magnitude properly, but the method based on the multiband amplitude distribution gave values close to the moment magnitude for many tsunami earthquakes. In this method, peak amplitudes of bandpass filtered waveforms are compared with those of synthetic records for an assumed source duration and fault mechanism. We applied the multiband amplitude distribution method to the records of events that occurred around the Japanese Islands and to those of tsunami earthquakes, and confirmed that this method could be used to estimate event magnitudes close to the moment magnitudes.


2019 ◽  
Vol 7 (2) ◽  
pp. T255-T263 ◽  
Author(s):  
Yanli Liu ◽  
Zhenchun Li ◽  
Guoquan Yang ◽  
Qiang Liu

The quality factor ([Formula: see text]) is an important parameter for measuring the attenuation of seismic waves. Reliable [Formula: see text] estimation and stable inverse [Formula: see text] filtering are expected to improve the resolution of seismic data and deep-layer energy. Many methods of estimating [Formula: see text] are based on an individual wavelet. However, it is difficult to extract the individual wavelet precisely from seismic reflection data. To avoid this problem, we have developed a method of directly estimating [Formula: see text] from reflection data. The core of the methodology is selecting the peak-frequency points to linear fit their logarithmic spectrum and time-frequency product. Then, we calculated [Formula: see text] according to the relationship between [Formula: see text] and the optimized slope. First, to get the peak frequency points at different times, we use the generalized S transform to produce the 2D high-precision time-frequency spectrum. According to the seismic wave attenuation mechanism, the logarithmic spectrum attenuates linearly with the product of frequency and time. Thus, the second step of the method is transforming a 2D spectrum into 1D by variable substitution. In the process of transformation, we only selected the peak frequency points to participate in the fitting process, which can reduce the impact of the interference on the spectrum. Third, we obtain the optimized slope by least-squares fitting. To demonstrate the reliability of our method, we applied it to a constant [Formula: see text] model and the real data of a work area. For the real data, we calculated the [Formula: see text] curve of the seismic trace near a well and we get the high-resolution section by using stable inverse [Formula: see text] filtering. The model and real data indicate that our method is effective and reliable for estimating the [Formula: see text] value.


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