Simulation of 2009 L’aquila Earthquake using Specific barrier model

Authors
M. H. rezaei 1
N. Khaji 2
1 tarbiat modares
2 Tarbiat Modares University
Abstract
Earthquakes are one of the most Terrible danger that are likely to cause heavy human losses and destroy entire civilization on scale of minutes. The more recent damaging events in Mexico City (1985 Mexico) in bam (2003 Iran) or Tohoku (2011 Japan) recall that so far little is known about earthquake physics that could prevent people from their deadly effects. To reduce casualties Decades of research involving numerous laboratories worldwide aim at investigating this large scale phenomenon and trying to understand how it triggers, propagates, and stops. A trusty physical modeling of strong ground motion requires to examine three crucial parameters of seismic source specifications, wave propagation path, and seismic site effects. A reliable physical modeling of strong ground motion requires to examine three crucial parameters of seismic source specifications, wave propagation path, and seismic site effects. Among various seismic source specifications, a more physically realistic source model is the specific barrier model or (SBM) for short. The SBM is specifically more suitable for regions with poor seismological data bank and/or ground motions from large earthquakes with large recurrence intervals. In order to simulate seismic ground motions from a specific earthquake source model in an efficient way, the stochastic modeling method has been widely used. An essential part of the seismological model used in this method is the quantitative description of the far-field spectrum of seismic waves emitted from the seismic source. Since shear (S) wave is primarily the main factor of earthquake damages, the application of stochastic approach of the SBM has almost been focused on the far-field S wave spectrum, in which two corner frequencies of observed earthquake are represented. The ‘two-corner-frequency’ shows two considerable length-scales of an earthquake source: a length-scale that quantifies the overall size of the fault that ruptures (e.g., the length L of a strike-slip fault) and another length-scale that measures the size of the subevents. Associated with these length-scales are two corresponding time scales: (1) the overall duration of rupture, and (2) the rise time. The SBM has a few main source parameters which have been calibrated to earthquakes of different tectonic regions. In this paper, it has been tried to simulate source, path and site of entire earthquake and compare the results of simulation with real earthquake. To this end SBM with uniform PDF for arrival time but different types of PDFs of subevent size used to simulate source. To investigate effect of PDFs of subevent size on the source spectra as well as earthquake spectra as result of simulation, uniform and fractal distribution along with classic distribution for subevent size are considered. In order to take into account, the effects of path of propagation, Geometric and inelastic Attenuation Compatible with center of Italy (L’Aquila region) have been used. Finally, to considering effect of the layers of soil (sediments) near surface on amplitude, period, duration and other characteristic of seismic waves, transfer function for linear wave propagation has been computed with the Thomson-Haskell matrix method. Transfer function in this method illustrate how a soil column with different layers attenuates and amplifies seismic waves as a function of frequency.

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[1]. Aki K. 1967 Scaling law of seismic spectrum. Journal of geophysical research, 72(4), 1217-1231.
[2]. Aki K. 2003 A perspective on the history of strong motion seismology. Physics of the Earth and Planetary Interiors, 137(1), 5-11.
[3]. Bianco F., Castellano M., Del Pezzo E. & Ibanez J. M. 1999 Attenuation of short-period seismic waves at Mt Vesuvius, Italy. Geophysical Journal International, 138(1), 67-76.
[4]. Boore D. M. 2003 Simulation of ground motion using the stochastic method. Seismic Motion, Lithospheric Structures, Earthquake and Volcanic Sources, The Keiiti Aki Volume, Springer, 635-676.
[5]. Brune J. N. 1970 Tectonic stress and the spectra of seismic shear waves from earthquakes. Journal of geophysical research, 75(26), 4997-5009.
[6]. Dabaghi M., et al. 2016 Stochastic model for simulation of near-fault ground motions. Earthquake Engineering and Structural Dynamics, 46(6), 963-984.
[7]. Govoni A., et al. 1996 Coda Qc evaluation using local seismic events in the Friuli area. Atti del XV Convegno Annuale del Gruppo Nazionale di Geofisica della Terra Solida, Roma, 11-13.
[8]. Halldorsson B. & Papageorgiou A. S. 2005 Calibration of the specific barrier model to earthquakes of different tectonic regions. Bulletin of the Seismological Society of America, 95(4), 1276-1300.
[9]. Halldorsson B. & Papageorgiou A. S. 2012 Variations of the specific barrier model—Part I: Effect of subevent size distributions. Bulletin of Earthquake Engineering, 10(4), 1299-1319.
[10]. Halldorsson B. & Papageorgiou A. S. 2012 Variations of the specific barrier model—Part II: Effect of isochron distributions. Bulletin of Earthquake Engineering, 10(4), 1321-1337.
[11]. Haskell N. A. 1953 The dispersion of surface waves on multilayered media. Bulletin of the Seismological Society of America, 43(1), 17-34.
[12]. http://www.strongmotioncenter.org/cgi-bin /CESMD /iqrStationMap.pl ID=LAquilaItaly-06Apr2009
[13]. Kostrov B. 1964 Selfsimilar problems of propagation of shear cracks. Journal of Applied Mathematics and Mechanics, 28(5), 1077-1087.
[14]. Mousavi M., et al. 2007 Analysis of Iranian strong-motion data using the specific barrier model. Journal of Geophysics and Engineering, 4(4), 415-428.
[15]. Papageorgiou A. S. & Aki K. 1983 A specific barrier model for the quantitative description of inhomogeneous faulting and the prediction of strong ground motion. I. Description of the model. Bulletin of the Seismological Society of America ,73(3), 693-722.
[16]. Papageorgiou A. S. & Aki K. 1983 A specific barrier model for the quantitative description of inhomogeneous faulting and the prediction of strong ground motion. Part II. Applications of the model. Bulletin of the Seismological Society of America, 73(4), 953-978.
[17]. Papageorgiou A. S. 1988 On two characteristic frequencies of acceleration spectra: patch corner frequency and fmax. Bulletin of the Seismological Society of America, 78(2), 509-529.
[18]. Papageorgiou A. S. 2003 The barrier model and strong ground motion. Pure and Applied Geophysics, 160(3-4), 603-634.
[19]. Sato T. & Hirasawa T. 1973 Body wave spectra from propagating shear cracks. Journal of Physics of the Earth, 21(4), 415-431.
[20]. Soghrat M., et al. 2012 Simulation of strong ground motion in northern Iran using the specific barrier model. Geophysical Journal International, 188(2), 645-679.
[21]. Sonnemann T., et al. 2016 Towards a Hybrid Earthquake Strong-motion Simulation Model for South Iceland. International Workshop on Earthquakes in North Iceland, Húsavík, North Iceland, June 2016.
[22]. Thomson W. T. 1950 Transmission of elastic waves through a stratified solid medium. Journal of applied Physics, 21(2), 89-93.
[23]. Zafarani H., et al. 2008 Calibration of the specific barrier model to Iranian plateau earthquakes and development of physically based attenuation relationships for Iran. Soil Dynamics and Earthquake Engineering, 28(7), 550-576.
[24]. Zeng Y., et al. 1994 A composite source model for computing realistic synthetic strong ground motions. Geophysical Research Letters, 21(8), 725-728
Modares Civil Engineering journal
Volume 18, Issue 2
July and August 2018
Pages 101-112