scholarly journals Study of Rotational Motions Caused by Multiple Mining Blasts Recorded by Different Types of Rotational Seismometers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4120
Author(s):  
Krzysztof P. Teisseyre ◽  
Michał Dudek ◽  
Leszek R. Jaroszewicz ◽  
Anna T. Kurzych ◽  
Leopold Stempowski
Keyword(s):  
Ground Motions ◽  
Double Pendulum ◽  
Strong Ground Motions ◽  
Different Types ◽  
Variable Character ◽  
Rotational Motions ◽  
The Difference ◽  
Fiber Optic System ◽  
Low Sensitivity ◽  
Strong Ground

Digging two vertical shafts with the multiple blasts technique gave the opportunity to measure the induced angular motions in a horizontal plane with well-defined positions of sources. Three kinds of rotation rate sensors, sharing an underground location, were used. Two of them—a Fiber-Optic System for Rotational Events & phenomena Monitoring (FOSREM) and a prototypical seismometer housing the liquid-filled torus—sensed the rotation, while a microarray of two double-pendulum seismometers sensed both the rotation and symmetric strain. The FOSREM was sampled at 656.168 Hz, while all the others were only sampled at 100 Hz. There were considerable differences within the results gathered from the mining blasts, which should be attributed to two causes. The first one is the difference in principles of the operation and sampling rates of the devices used, while the other is the complex and spatially variable character of the studied wave fields. Additionally, we established that the liquid-filled sensor, due to its relatively low sensitivity, proved to be viable only during a registration of strong ground motions. Overall, a comparative study of three different rotational seismometers was performed during mining-induced strong ground motions with well-localized sources.

scholarly journals INFLUENCE OF THE SOILS TYPES ON THE STRONG GROUND MOTIONS INTENSITY

2015 ◽  
Author(s):  
А.Н. Баскаев ◽  
К.С. Харебов
Keyword(s):  
Wave Speed ◽  
Ground Motions ◽  
Correlation Dependence ◽  
Hypocentral Distance ◽  
Strong Ground Motions ◽  
Horizontal Acceleration ◽  
Different Types ◽  
Peak Horizontal Acceleration ◽  
Strong Ground ◽  
Different Soils

Проведено исследование влияния различных видов грунтов на интенсивность проявления сильных грунтовых движений на примере записей базы данных, созданной авторами. Для различных типов грунта (скала, песок, гравий, ил, глина) получены корреляционные зависимости интенсивности от логарифма пикового горизонтального ускорения и от гипоцентрального расстояния по отдельности. Показано, что при высоких магнитудах интенсивность проявляется на различных грунтах в порядке убывания следую- щим образом: глина, песок, ил, гравий, скала. Проведенное исследование показало слабую зависимость интенсивности от скорости поперечной волны. Проведеное сравнение корреляционных зависимостей интенсивности от магнитуды и от гипоцентрального расстояния для записей базы данных SMDBCGI с уравнением Шебалина, показало что точность формулы авторов для всех типов грунтов и формулы Шебалина одинакова в пределах ошибки. Показано, что для станций системы KNET лучше использовать формулу корреляционной зависимости интенсивности от магнитуды и от логарифма пикового горизонтального ускорения, чем от магнитуды и от логарифма гипоцентрального расстояния Study of the different soils forms influence on the intensity of the strong ground motions manifestation based on the records data base, created by the authors is carried out. The correlation dependences of intensity on the logarithm of peak horizontal accelerationandon the hypocentral distance separately are obtained for different types of soil (rock, sand, gravel, silt, clay). For the different groundswith the high magnitudes the intensity valueis in follows descending order: clay, sand, silt, gravel, rock. The conducted investigation showed the weak dependence of intensity on the transverse wave speed. The comparison of the correlation dependences of intensity on the magnitude and on the hypocentral distance for records of database SMDB CGI with Shebalin formula showed thatthe accuracy of the authors formula for all types of grounds and Shebalin formula is identical in the ranges of error. For the system KNET stations it is better to use the formula of correlation dependence of intensity on the magnitude and on the logarithm of peak horizontal acceleration, than the correlation dependence on the magnitude and on the hypocentral distance logarithm

scholarly journals Broadband Strong-Motion Prediction for Future Nankai-Trough Earthquakes Using Statistical Green’s Function Method and Subsequent Building Damage Evaluation

2021 ◽  
Vol 11 (15) ◽  
pp. 7041
Author(s):  
Baoyintu Baoyintu ◽  
Naren Mandula ◽  
Hiroshi Kawase
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Nankai Trough ◽  
Ground Motions ◽  
Building Damage ◽  
Steel Buildings ◽  
Ground Acceleration ◽  
Attenuation Relations ◽  
Strong Ground Motions ◽  
Strong Ground

We used the Green’s function summation method together with the randomly perturbed asperity sources to sum up broadband statistical Green’s functions of a moderate-size source and predict strong ground motions due to the expected M8.1 to 8.7 Nankai-Trough earthquakes along the southern coast of western Japan. We successfully simulated seismic intensity distributions similar to the past earthquakes and strong ground motions similar to the empirical attenuation relations of peak ground acceleration and velocity. Using these results, we predicted building damage by non-linear response analyses and find that at the regions close to the source, as well as regions with relatively thick, soft sediments such as the shoreline and alluvium valleys along the rivers, there is a possibility of severe damage regardless of the types of buildings. Moreover, the predicted damage ratios for buildings built before 1981 are much higher than those built after because of the significant code modifications in 1981. We also find that the damage ratio is highest for steel buildings, followed by wooden houses, and then reinforced concrete buildings.

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