Wyniki wyszukiwania - BazTech

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Badania przemieszczeń powierzchni spowodowanych wstrząsami górniczymi z zastosowaniem satelitarnej interferometrii radarowej na przykładzie LGOM

Owczarz Katarzyna, Blachowski Jan

Przegląd Górniczy

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2019

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T. 75, nr 1

53--61

PL

W artykule przedstawiono wyniki obliczeń metodą satelitarnej interferometrii różnicowej (DInSAR) wykonanych dla trzech wstrząsów indukowanych, które wystąpiły na terenach górniczych LGOM. Wybrane do analiz zdarzenia miały magnitudy: 4.8, 4.5 oraz 3.9 i wystąpiły odpowiednio: 26.12.2017 r., 20.07.2018 r. oraz 12.08.2018 r. Do określania potencjalnych zmian na powierzchni w wyniku tych wstrząsów wykorzystano zobrazowania SAR zarejestrowane przez satelity Sentinel-1A i Sentinel-1B bezpośrednio przed i po wystąpieniu wstrząsów. Wyznaczono koherencję, opracowano interferogramy, a następnie wyznaczono przemieszczenia powierzchni w linii widoczności satelity (LOS). Dla wstrząsu o magnitudzie 4.8 obniżenia pionowe (LOS) wyniosły ponad 8 cm, a dla wstrząsu o magnitudzie 4.5 około 7 cm. Dla wstrząsu o najmniejszej magnitudzie nie zidentyfikowano wyraźnego obrazu deformacji na powierzchni. Wyniki posłużyły do analizy wielkości i zasięgu zmian na powierzchni powstałych w wyniku tych zdarzeń, a także do dyskusji na temat przydatności satelitarnej interferometrii radarowej do pozyskiwania wiarygodnych danych o deformacjach powierzchni powodowanych sejsmiką indukowaną działalnością górniczą.

EN

This paper presents the results of calculations using the differential satellite radar interferometry (DInSAR) method made for three induced shocks that occurred in the LGOM mining areas. The events selected for the analysis had the magnitudes of 4.8, 4.5 and 3.9 and occurred on the 26.12.2017, 20.07.2018 and 12.08.2018 respectively. To identify potential changes on the surface as a result of these shocks, SAR imagery recorded by Sentinel -1A and Sentinel-1B satellites immediately before and after these events was used. In the calculation process: coherence was determined, interferograms were developed, and then surface displacements in the line of the sight (LOS) were determined. For the magnitude 4.8 the vertical movements (LOS) reached - 8 cm, and for a magnitude 4.5 event approx. - 7 cm. For the seismic event with the smallest magnitude deformation, the image could not be identified on the surface. The results were used to analyze the size and extent of changes on the surface resulting from these events, as well as to discuss the usefulness of the satellite radar interferometry method to obtain reliable data on deformations caused by mining induced seismicity.

2

Transient thermo-elastic disturbances in a visco-elastic semi-space due to a moving internal heat source

Lotfy K.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 3

747-762

EN

This paper investigates the transient disturbances created by an internal line heat source that suddenly starts moving uniformly inside a visco-elastic half-space. The generalised theory of thermo-elasticity with relaxation time proposed by Lord-Shulman (1967) is applied. The material of the semi-infinite medium is isotropic visco-elastic solid of Kelvin-Voight type. Applying the Fourier and Laplace transform technique, expressions for displacement components in the transformed domain are found out. These expressions prove the existence of three waves - a modified thermal wave, a visco-elastic wave of defused nature and a transverse visco-elastic wave. Surface displacement components are evaluated on the boundary for small time only. Numerical results are given and illustrated graphically to highlight the variations of surface displacement components with distance for different values of time, source depth and velocity of the source.

3

Transient thermo-elastic disturbances in a visco-elastic semi-space due to a moving internal heat source

Lotfy K. H., Fathy R. A.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 4

1169-1184

EN

This paper investigates the transient disturbances created by an internal line heat source that suddenly starts moving uniformly inside a visco-elastic half-space. The generalised theory of thermo-elasticity with relaxation time proposed by Lord and Shulman (1967) is applied. The material of the semi-infinite medium is an isotropic visco-elastic solid of Kelvin-Voight type. Applying the Fourier and Laplace transform technique, expressions for displacement components in the transformed domain are found. These expressions prove the existence of three waves - a modified thermal wave, a visco-elastic wave of defused nature and a transverse visco-elastic wave. Surface displacement components are evaluated on the boundary for small time only. Numerical results are given and illustrated graphically to highlight the variations of surface displacement components with distance for different values of time, source depth and velocity of the source.