Subcell-resolution finite-difference modelling of seismic waves in Biot and JKD poroelastic media

2020 ◽  
Vol 224 (2) ◽  
pp. 760-794
Author(s):  
David Gregor ◽  
Peter Moczo ◽  
Jozef Kristek ◽  
Arnaud Mesgouez ◽  
Gaëlle Lefeuve-Mesgouez ◽  
...  
Keyword(s):  
Finite Difference ◽  
Ground Motion ◽  
Seismic Waves ◽  
Heterogeneous Medium ◽  
Seismic Wave Propagation ◽  
Earthquake Ground Motion ◽  
Material Interfaces ◽  
Frequency Dependent ◽  
Poroelastic Media ◽  
Efficiency And Reliability

SUMMARY We present a discrete representation of strongly heterogeneous poroelastic medium with the JKD-model of the frequency-dependent permeability and resistive friction, and the corresponding finite-difference (FD) scheme for numerical modelling of seismic wave propagation and earthquake ground motion in structurally complex media. The scheme is capable of subcell resolution, that is, allows for an arbitrary shape and position of an interface in the spatial grid. The medium can have either a zero resistive friction or non-zero constant resistive friction or JKD frequency-dependent resistive friction. The scheme has the same computational efficiency as the scheme for a smoothly and weakly heterogeneous medium (medium without material interfaces) because the number of operations for updating wavefield is the same. Several comparisons with a semi-analytical approach proves the efficiency and reliability of the subcell-resolution FD scheme. An illustrative example demonstrates differences between earthquake ground motion in the Biot's and JKD variants of the model of the surface sedimentary basin. The example indicates that it is desirable to perform an extensive parametric study in order to find out when it is necessary to apply relatively complicated and computationally more demanding JKD model and when much simpler Biot's model is sufficient.

Seismic waves in medium with poroelastic/elastic interfaces: a two-dimensional P-SV finite-difference modelling

2021 ◽  
Vol 228 (1) ◽  
pp. 551-588
Author(s):  
David Gregor ◽  
Peter Moczo ◽  
Jozef Kristek ◽  
Arnaud Mesgouez ◽  
Gaëlle Lefeuve-Mesgouez ◽  
...  
Keyword(s):  
Finite Difference ◽  
Seismic Waves ◽  
Heterogeneous Medium ◽  
Spectral Element ◽  
Seismic Wave Propagation ◽  
Material Interfaces ◽  
Material Interface ◽  
Frequency Dependent ◽  
Arbitrary Position ◽  
Elastic Interfaces

SUMMARY We present a new methodology of the finite-difference (FD) modelling of seismic wave propagation in a strongly heterogeneous medium composed of poroelastic (P) and (strictly) elastic (E) parts. The medium can include P/P, P/E and E/E material interfaces of arbitrary shapes. The poroelastic part can be with (i) zero resistive friction, (ii) non-zero constant resistive friction or (iii) JKD model of the frequency-dependent permeability and resistive friction. Our FD scheme is capable of subcell resolution: a material interface can have an arbitrary position in the spatial grid. The scheme keeps computational efficiency of the scheme for a smoothly and weakly heterogeneous medium (medium without material interfaces). Numerical tests against independent analytical, semi-analytical and spectral-element methods prove the efficiency and accuracy of our FD modelling. In numerical examples, we indicate effect of the P/E interfaces for the poroelastic medium with a constant resistive friction and medium with the JKD model of the frequency-dependent permeability and resistive friction. We address the 2-D P-SV problem. The approach can be readily extended to the 3-D problem.

scholarly journals Basin Resonance and Seismic Hazard for Jakarta, Indonesia

2018 ◽  
Author(s):  
Athanasius Cipta ◽  
Phil Cummins ◽  
Masyhur Irsyam ◽  
Sri Hidayati
Keyword(s):  
Ground Motion ◽  
Seismic Waves ◽  
Response Spectrum ◽  
Capital City ◽  
Earthquake Ground Motion ◽  
Computational Domain ◽  
Near Surface ◽  
Earthquake Scenario ◽  
Design Response Spectrum ◽  
Intraslab Earthquake

We use earthquake ground motion modelling via Ground Motion Prediction Equations (GMPEs) and numerical simulation of seismic waves to consider the effects of site amplification and basin resonance in Jakarta, the capital city of Indonesia. While spectral accelerations at short periods are sensitive to near-surface conditions (i.e., Vs30), our results suggest that, for basins as deep as Jakarta’s, available GMPEs cannot be relied upon to accurately estimate the effect of basin depth on ground motions at long periods (>1 s). Amplitudes at such long periods are influenced by entrapment of seismic waves in the basin, resulting in longer duration of strong ground motion, and interference between incoming and reflected waves as well as focusing at basin edges may amplify seismic waves. In order to simulate such phenomena in detail, a basin model derived from a previous study is used as a computational domain for deterministic earthquake scenario modeling in a 2-dimensional cross-section. A Mw 9.0 megathrust, a Mw 6.5 crustal thrust and a Mw 7.0 instraslab earthquake are chosen as scenario events that pose credible threats to Jakarta, and the interactions with the basin of seismic waves generated by these events were simulated. The highest PGV amplifications are recorded at sites near the middle of the basin and near its southern edge, with maximum amplifications of PGV in the horizontal component of 200% for the crustal, 600% for the megathrust and 335% for the deep intraslab earthquake scenario, respectively. We find that the levels of ground motion response spectral acceleration fall below those of the 2012 Indonesian building Codes's design response spectrum for short periods (< 1 s), but closely approach or may even exceed these levels for longer periods.

scholarly journals 3D NUMERICAL MODELLING OF THE SEISMIC RESPONSE OF THE THESSALONIKI URBAN AREA: THE CASE OF THE 1978 VOLVI EARTHQUAKE

2017 ◽  
Vol 50 (3) ◽  
pp. 1433
Author(s):  
C. Smerzini ◽  
K. Pitilakis ◽  
K. Hashemi
Keyword(s):  
Numerical Modelling ◽  
Urban Area ◽  
Ground Motion ◽  
Large Scale ◽  
Spectral Element ◽  
Seismic Wave Propagation ◽  
Earthquake Ground Motion ◽  
Ground Shaking ◽  
3D Numerical Modelling ◽  
Wide Scale

This study aims at showing the numerical modelling of earthquake ground motion in the Thessaloniki urban area, using a 3D spectral element approach. The availability of detailed geotechnical/geophysical data together with the seismological information regarding the relevant fault sources allowed us to construct a large-scale 3D numerical model suitable for generating physics based ground shaking scenarios within the city of Thessaloniki up to maximum frequencies of about 2 Hz. Results of the numerical simulation of the destructive MW6.5 1978 Volvi earthquake are addressed, showing that realistic estimates can be obtained. Shaking maps in terms of ground motion parameters such as PGV are used to discuss the main seismic wave propagation effects at a wide scale.

EFFICIENCY AND OPTIMIZATION OF THE 3-D FINITE-DIFFERENCE MODELING OF SEISMIC GROUND MOTION

2001 ◽  
Vol 09 (02) ◽  
pp. 593-609 ◽  
Author(s):  
PETER MOCZO ◽  
JOZEF KRISTEK ◽  
ERIK BYSTRICKÝ
Keyword(s):  
Finite Difference ◽  
Elastic Medium ◽  
Ground Motion ◽  
Viscoelastic Medium ◽  
Optimization Techniques ◽  
Displacement Velocity ◽  
Staggered Grid ◽  
Earthquake Ground Motion ◽  
Finite Difference Schemes ◽  
Seismic Ground Motion

We present a tutorial introduction to the 3-D finite-difference modeling of seismic ground motion in elastic and viscoelastic media with special emphasis on its computational efficiency. We consider four basic types of the finite-difference schemes — the displacement-stress, displacement-velocity-stress and velocity-stress schemes on a staggered grid, and displacement scheme on a conventional grid. Their memory requirements in the case of perfectly elastic medium, elastic medium with aposteriori approximate attenuation correction, and realistic viscoelastic medium are reviewed. We also present application of the powerful optimization techniques to the 3-D fourth-order displacement-stress and displacement-velocity-stress modeling in the case of viscoelastic medium whose rheology is based on the generalized Maxwell body. Description of a medium using material cell types and use of a discontinuous grid with combined memory optimization makes it possible to simulate earthquake ground motion in realistic large-scale models.

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