scholarly journals THE ANALYSIS OF SEISMIC LOAD CHARACTRESITIC OBSERVED IN THE LOWER SILESIAN COPPER BASIN

2020 ◽  
Vol 2 (2) ◽  
pp. 35-49 ◽  
Author(s):  
Krzysztof Fuławka ◽  
Lech Stolecki ◽  
Izabela Jaśkiewicz-Proć ◽  
Witold Pytel ◽  
Piotr Mertuszka
Keyword(s):  
Seismic Wave ◽  
Seismic Activity ◽  
Seismic Waves ◽  
Seismic Source ◽  
High Energy ◽  
Dominant Frequency ◽  
Underground Mines ◽  
Seismic Load ◽  
Mining Operations ◽  
Time Frequency

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.

scholarly journals Near-Field Measurement of Six Degrees of Freedom Mining-Induced Tremors in Lower Silesian Copper Basin

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6801
Author(s):  
Krzysztof Fuławka ◽  
Witold Pytel ◽  
Bogumiła Pałac-Walko
Keyword(s):  
Seismic Wave ◽  
Degrees Of Freedom ◽  
Seismic Waves ◽  
Near Field ◽  
High Energy ◽  
Rotational Component ◽  
Empirical Formulas ◽  
Six Degrees Of Freedom ◽  
The Impact

The impact of seismicity on structures is one of the key problems of civil engineering. According to recent knowledge, the reliable analysis should be based on both rotational and translational components of the seismic wave. To determine the six degrees of freedom (6-DoF) characteristic of mining-induced seismicity, two sets of seismic posts were installed in the Lower Silesian Copper Basin, Poland. Long-term continuous 6-DoF measurements were conducted with the use of the R-1 rotational seismometer and EP-300 translational seismometer. In result data collection, the waveforms generated by 39 high-energy seismic events were recorded. The characteristic of the rotational component of the seismic waves were described in terms of their amplitude and frequency characteristics and were compared with translational measurements. The analysis indicated that the characteristic of the rotational component of the seismic wave differs significantly in comparison to translational ones, both in terms of their amplitude and frequency distribution. Also, attenuation of rotational and translational components was qualitatively compared. Finally, the empirical formulas for seismic rotation prediction in the Lower Silesian Copper Basin were developed and validated.

scholarly journals Model for Calculating Seismic Wave Spectrum Excited by Explosive Source

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qian Xu ◽  
Zhong-Qi Wang
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Wave Spectrum ◽  
Seismic Source ◽  
Source Model ◽  
Detonation Pressure ◽  
Adiabatic Expansion ◽  
Main Frequency ◽  
Explosive Source ◽  
Seismic Source Model

To reveal the characteristics and laws of the seismic wavefield amplitude-frequency excited by explosive source, the method for computing the seismic wave spectrum excited by explosive was studied in this paper. The model for calculating the seismic wave spectrum excited by explosive source was acquired by taking the seismic source model of spherical cavity as the basis. The results of using this model show that the main frequency and the bandwidth of the seismic waves caused by the explosion are influenced by the initial detonation pressure, the adiabatic expansion of the explosive, and the geotechnical parameters, which increase with the reduction of initial detonation pressure and the increase of the adiabatic expansion. The main frequency and the bandwidth of the seismic waves formed by the detonation of the explosives in the silt clay increase by 23.2% and 13.6% compared to those exploded in the silt. The research shows that the theoretical model built up in this study can describe the characteristics of the seismic wave spectrum excited by explosive in a comparatively accurate way.

scholarly journals Seismicity induced by hard coal mining in the vicinity of faults

2018 ◽  
Vol 66 ◽  
pp. 01008 ◽  
Author(s):  
Zbigniew Burtan ◽  
Jerzy Cieślik ◽  
Dariusz Chlebowski
Keyword(s):  
Seismic Activity ◽  
High Energy ◽  
Hard Coal ◽  
Seismic Events ◽  
Mining Operations ◽  
Rockburst Hazard ◽  
Inherent Feature ◽  
Hard Coal Mining ◽  
High Level ◽  
Time And Energy

An inherent feature of Polish collieries within the Upper Silesia Coal Basin is the high level of mining induced seismicity, resulting in elevated rockburst hazard levels. One of the major causes of high-energy seismic events is that mining operations are continued in the vicinity of major faulting zones. The study summarises the results of geo-mechanical and statistical analysis of mining-induced seismic activity in the region of major faults, in a selected section within a colliery. Seismic activity assessment involves the categorisation of seismic events due to tectonic movements in the context of various face development systems with respect to the faulting zone: perpendicular (advancing towards the faulting zone or retreating) or parallel (along the faulting zone). Registered seismic activity was analysed in the context of epicenter locations and variations of seismic activity in relation to the developing face operations in the function of time and energy ratings (Gutenberg-Richter formulas). Results have demonstrated that increased levels of seismic activity in the strata can be attributable to mining operations in the vicinity of major faulting zones.

Procedural framework for explosion classification by the seismic load criterion

2021 ◽  
pp. 98-102
Author(s):  
A. N. Kholodilov ◽  
A. P. Gospodarikov ◽  
A. A. Eremenko
Keyword(s):  
Statistical Analysis ◽  
Seismic Activity ◽  
Building Materials ◽  
Attenuation Factor ◽  
Ground Surface ◽  
Seismic Effect ◽  
Underground Mines ◽  
Seismic Load ◽  
Seismic Action ◽  
Quantitative Classification

For the first time the quantitative classification of blasting operations as sources of blasting vibrations is constructed. According to the classification, all sources are divided into the sources of increased, normal and reduced action. The classification is based on the rectilinear dependences of the PPV attenuation factor on the logarithm of the seismicity coefficient, which are included in Sadovsky’s formula to predict the peak particle velocity under the seismic action of explosions. The classification is based on the statistical analysis of 76 seismicity coefficient—PPV attenuation factor couples reflective of the wide geography of blasting operations carried out in solid minerals mining and in civil engineering. The reliability of the statistical analysis result is proved using the Fisher criterion and Student statistics. The classification boundaries of seismic sources are verified. The sources of increased seismic activity are compared by the conditions of blasting in watered and in very strong rocks, the use of largediameter blast holes, the choice of explosive mass for simultaneous blasting and the influence of the initiation method on the seismic effect produced. The sources of normal and reduced seismic activity were compared by the conditions of blasting in underground mines, at quarries of building materials with ground surface recording, blasting in civil construction and with preliminary borehole slotting. The classification allows the quantitative comparison of blasting operations by the level of seismic action in the intervals of 6–2700 and 0.6–2.8 by the seismicity coefficient and PPV attenuation factor, respectively, for PPV in cm/s. The classification is representative of the current technology of blasting in the world practice.

The research of time-frequency characteristics of buried mine of seismic waves in shallow sea

2020 ◽  
Vol 51 (3) ◽  
pp. 35-43
Author(s):  
Shuang Zhao ◽  
Jian Zhang ◽  
Dongwei Kou ◽  
Cean Guo
Keyword(s):  
Wave Field ◽  
Seismic Wave ◽  
Seismic Waves ◽  
Propagation Characteristics ◽  
Shallow Sea ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Rock Density ◽  
Time Frequency ◽  
Simulation Results

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.

scholarly journals The nature of seismic sources associated with a proton-reach solar flare

2007 ◽  
Vol 3 (S247) ◽  
pp. 59-65 ◽  
Author(s):  
Valentyna V. Zharkova ◽  
Serhij I. Zharkov
Keyword(s):  
Electron Beam ◽  
Solar Flare ◽  
Seismic Wave ◽  
Lower Energy ◽  
Seismic Waves ◽  
Power Laws ◽  
High Energy ◽  
Seismic Sources ◽  
Γ Rays ◽  
High Energy Particles

AbstractThe momenta and start times measured from the TD diagrams in 3 seismic sources observed in the flare of 28 October 2003 are compared with those delivered to the photosphere by different kinds of high energy particles as well as by the hydrodynamic shocks caused by these particles. The energetic protons with energy power laws combined with quasi-thermal ones are shown to form hydrodynamic shocks deeply in a flaring atmosphere which deliver the required momentum to the photosphere within a measured timescale. The seismic waves observed in two sources associated with γ-rays can be explained by the momenta produced by hydrodynamic shocks caused by mixed proton beams and jets. The seismic wave in the source asociated with HXR only and delayed by 4 and 2 minutes from the first and second HXR bursts is likely to be associated with a hydrodynamic shock occurring from precipitation of a very powerful and hard electron beam possibly mixed with quasi-thermal lower energy protons.

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
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Vibration Velocity ◽  
Analysis Method ◽  
Wave Source ◽  
Energy Characteristics ◽  
Time Frequency ◽  
Wave Signal ◽  
Liquid Co2 ◽  
Optimal Kernel

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.

Influence of Distance from Blast Center on Time-Frequency Characteristics of Blast Vibration Signals

2014 ◽  
Vol 1033-1034 ◽  
pp. 444-448
Author(s):  
Ming Sheng Zhao ◽  
Xu Guang Wang ◽  
En An Chi ◽  
Qiang Kang
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Low Frequency ◽  
Open Pit ◽  
Blasting Vibration ◽  
Analysis Method ◽  
Vibration Signals ◽  
Frequency Bands ◽  
Time Frequency ◽  
Energy Property

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.

scholarly journals Geological CO2 quantified by high-temporal resolution stable isotope monitoring in a salt mine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexander H. Frank ◽  
Robert van Geldern ◽  
Anssi Myrttinen ◽  
Martin Zimmer ◽  
Johannes A. C. Barth ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Underground Mining ◽  
Stable Carbon Isotope ◽  
Underground Mines ◽  
Background Concentration ◽  
High Temporal Resolution ◽  
Salt Mine ◽  
Gas Migration ◽  
Mining Operations ◽  
Anthropogenic Contributions

AbstractThe relevance of CO2 emissions from geological sources to the atmospheric carbon budget is becoming increasingly recognized. Although geogenic gas migration along faults and in volcanic zones is generally well studied, short-term dynamics of diffusive geogenic CO2 emissions are mostly unknown. While geogenic CO2 is considered a challenging threat for underground mining operations, mines provide an extraordinary opportunity to observe geogenic degassing and dynamics close to its source. Stable carbon isotope monitoring of CO2 allows partitioning geogenic from anthropogenic contributions. High temporal-resolution enables the recognition of temporal and interdependent dynamics, easily missed by discrete sampling. Here, data is presented from an active underground salt mine in central Germany, collected on-site utilizing a field-deployed laser isotope spectrometer. Throughout the 34-day measurement period, total CO2 concentrations varied between 805 ppmV (5th percentile) and 1370 ppmV (95th percentile). With a 400-ppm atmospheric background concentration, an isotope mixing model allows the separation of geogenic (16–27%) from highly dynamic anthropogenic combustion-related contributions (21–54%). The geogenic fraction is inversely correlated to established CO2 concentrations that were driven by anthropogenic CO2 emissions within the mine. The described approach is applicable to other environments, including different types of underground mines, natural caves, and soils.

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