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Earthquake fault rupture propagation through soil
GEOLOGY:EARTHQUAKES
946046 Comparison of response spectrum amplitudes from earthquakes with a Iognormally and exponentially distributed return period M. I. Todorovska, Soil Dynamics & Earthquake Engineering, 13(2), 1994, pp 97-116. This paper addresses the significance, for engineering decisions, of replacing the Poissonian by one-step memory models in describing the occurrence of large periodic earthquakes on fault segmems along the plate boundaries. A one-step memory model with a lognormally distributed return period was chosen for the analysis. The constraint imposed on bothprobabilistic models is that, for a given magnitude interval, the median of the lognormaUy distributed return period is equal to the expected value of the exponentially distributed return period of the Poissonian model. -from Author 946047 Q and high-frequency strong motion spectra M. D. Trifunac, Soil Dynamics & Earthquake Engineering, 13(3), 1994, pp 149-161. Empirical scaling equations for Fourier amplitude spectra of strong ground motion are used to describe A0 and x in the assumed (high-frequency) shape of strong motion amplitudes: FS(f) = A e -os~f. The results show: 1) good agreement of compute~I Ao and 'c with other related estimates of spectral amplitudes; 2) smooth decay of strong motion spectral amphtudes up to f = 25 Hz, without an abrupt low-pass filtering of high frequencies; and 3) good agreement with other estimates of the regionally specific attenuation of high-frequency seismic waves. As the recorded strong earthquake shaking in the western US typically samples only the shallow (
Spectral characteristics of the seismic hazard
between the AIps and the Dinarides
L. Peruzza, L. Sirovich & D. Slejko, Soil Dynamics & Earthquake Engineering, 13(3), 1994,pp 213-217. Empirical correlations between response spectra, magnitude, distance from the source and geological site condi-
269A
tions are introduced in a regional study of seismic hazard. A 350-year earthquake catalogue is treated by means of the statistics of extremes and both the spectral amplitudes (,pseudoveloeity) corresponding to a series of frequency bands are separately mapped, and the complete predicted response spectra calculated at some sites. Three kinds of geological site conditions are considered: thick and thin (less than 20 m deep) alluvium, and rock. A particular dependence of the results on the geographical distribution of earthquakes and on their magnitudes is commented. The seismic hazard of the study area is also computed by applying a traditional regression between peak /~round velocity, magnitude and distance; a comparison with the seismic hazard given by the frequency dependent pseudovelocity indicates the extent of the uncertainty associated with the common practice of scaling response spectra directly from ground motion parameters. -Authors 946051
Seismic hazard assessment using intensity
point data
G. Monachesi, L. Pernzza, D. Slejko & M. Stucchi, Soil Dynamics & Earthquake Engineering, 13(3), 1994, pp 219-226. The influence of the attenuation model used in seismic hazard assessment in terms of intensity and acceleration is studied. For two sites in central Italy, the catalogue of the actual observed intensities during the last three centuries has been recovered. In the study region, the data collected during a recent seismic sequence give the basis for relating intensity and acceleration. The results show the importance of establishing statistical relationships among the used quantities, based on a representative set of data. -Authors 946052 Earthquake fault rupture propagation through soil J.D. Bray, R. B. Seed, L. S. Cluff & H.B. Seed, Journal of Geotechnical Engineering - ASCE, 120(3), 1994, pp 543-561. Insights are developed from the examination of surface fault rupture field case histories, laboratory, physical model tests, and physical analogies to the earthquake fault rup.ture process. Field observations and experimental results illustrate the 'typical' patterns of behavior developed in the soil overlying a base rock fault displacement. Evidence suggests that differential movement across the distinct fault rupture dissipates as the fault rupture propagates toward the ground surface through unconsolidated earth materials, and that the characteristics of the soil overlying the bedrock fault strongly influence the observed earthquake fault rupture propagation behavior. -from Authors 946053 Analysis of earthquake fault rupture propaga. tion through cohesive soil L D. Bray, R. B. Seed & H. B. Seed, Journal of Geotechnical Engineering - ASCE, 120(3), 1994, pp 562-580. The height of the shear rupture zone in the overlying saturated clay soil at a specified base rock fault displacement depends primarily on the soil's failure strain. As the clay's failure strain decreases, the shear rupture zone in the d a y overlying the bedrock fault propagates further at a specified base displacement. Other material parameters such as soil shear strength and stiffness also effect the fault rupture process, hut not to the extent of failure strain. The onentatlon of the shear rupture zone through the soil depends largely on the onentation of the underlying bedrock fault plane. -from Authors 946054 Numerical simulation of complexity of earthquake precursors (in Chinese) Zhang Guoming, Zhang Yongxian & Shi Yaolin, Earthquake (Beijing), 1, 1994, pp 2-11. In this paper the complexity of the short-term and impendhag earthquake precursors is studied with the anisotropic and quasi-elastic medium model and the source-composite model by using the finite-element numerical simulation. The result shows that the exhibitory degree depends on the closed degree of the observational site of the seismogenie structure. The closer the distance between the observa-
946046 Comparison of response spectrum amplitudes from earthquakes with a Iognormally and exponentially distributed return period M. I. Todorovska, Soil Dynamics & Earthquake Engineering, 13(2), 1994, pp 97-116. This paper addresses the significance, for engineering decisions, of replacing the Poissonian by one-step memory models in describing the occurrence of large periodic earthquakes on fault segmems along the plate boundaries. A one-step memory model with a lognormally distributed return period was chosen for the analysis. The constraint imposed on bothprobabilistic models is that, for a given magnitude interval, the median of the lognormaUy distributed return period is equal to the expected value of the exponentially distributed return period of the Poissonian model. -from Author 946047 Q and high-frequency strong motion spectra M. D. Trifunac, Soil Dynamics & Earthquake Engineering, 13(3), 1994, pp 149-161. Empirical scaling equations for Fourier amplitude spectra of strong ground motion are used to describe A0 and x in the assumed (high-frequency) shape of strong motion amplitudes: FS(f) = A e -os~f. The results show: 1) good agreement of compute~I Ao and 'c with other related estimates of spectral amplitudes; 2) smooth decay of strong motion spectral amphtudes up to f = 25 Hz, without an abrupt low-pass filtering of high frequencies; and 3) good agreement with other estimates of the regionally specific attenuation of high-frequency seismic waves. As the recorded strong earthquake shaking in the western US typically samples only the shallow (
Spectral characteristics of the seismic hazard
between the AIps and the Dinarides
L. Peruzza, L. Sirovich & D. Slejko, Soil Dynamics & Earthquake Engineering, 13(3), 1994,pp 213-217. Empirical correlations between response spectra, magnitude, distance from the source and geological site condi-
269A
tions are introduced in a regional study of seismic hazard. A 350-year earthquake catalogue is treated by means of the statistics of extremes and both the spectral amplitudes (,pseudoveloeity) corresponding to a series of frequency bands are separately mapped, and the complete predicted response spectra calculated at some sites. Three kinds of geological site conditions are considered: thick and thin (less than 20 m deep) alluvium, and rock. A particular dependence of the results on the geographical distribution of earthquakes and on their magnitudes is commented. The seismic hazard of the study area is also computed by applying a traditional regression between peak /~round velocity, magnitude and distance; a comparison with the seismic hazard given by the frequency dependent pseudovelocity indicates the extent of the uncertainty associated with the common practice of scaling response spectra directly from ground motion parameters. -Authors 946051
Seismic hazard assessment using intensity
point data
G. Monachesi, L. Pernzza, D. Slejko & M. Stucchi, Soil Dynamics & Earthquake Engineering, 13(3), 1994, pp 219-226. The influence of the attenuation model used in seismic hazard assessment in terms of intensity and acceleration is studied. For two sites in central Italy, the catalogue of the actual observed intensities during the last three centuries has been recovered. In the study region, the data collected during a recent seismic sequence give the basis for relating intensity and acceleration. The results show the importance of establishing statistical relationships among the used quantities, based on a representative set of data. -Authors 946052 Earthquake fault rupture propagation through soil J.D. Bray, R. B. Seed, L. S. Cluff & H.B. Seed, Journal of Geotechnical Engineering - ASCE, 120(3), 1994, pp 543-561. Insights are developed from the examination of surface fault rupture field case histories, laboratory, physical model tests, and physical analogies to the earthquake fault rup.ture process. Field observations and experimental results illustrate the 'typical' patterns of behavior developed in the soil overlying a base rock fault displacement. Evidence suggests that differential movement across the distinct fault rupture dissipates as the fault rupture propagates toward the ground surface through unconsolidated earth materials, and that the characteristics of the soil overlying the bedrock fault strongly influence the observed earthquake fault rupture propagation behavior. -from Authors 946053 Analysis of earthquake fault rupture propaga. tion through cohesive soil L D. Bray, R. B. Seed & H. B. Seed, Journal of Geotechnical Engineering - ASCE, 120(3), 1994, pp 562-580. The height of the shear rupture zone in the overlying saturated clay soil at a specified base rock fault displacement depends primarily on the soil's failure strain. As the clay's failure strain decreases, the shear rupture zone in the d a y overlying the bedrock fault propagates further at a specified base displacement. Other material parameters such as soil shear strength and stiffness also effect the fault rupture process, hut not to the extent of failure strain. The onentatlon of the shear rupture zone through the soil depends largely on the onentation of the underlying bedrock fault plane. -from Authors 946054 Numerical simulation of complexity of earthquake precursors (in Chinese) Zhang Guoming, Zhang Yongxian & Shi Yaolin, Earthquake (Beijing), 1, 1994, pp 2-11. In this paper the complexity of the short-term and impendhag earthquake precursors is studied with the anisotropic and quasi-elastic medium model and the source-composite model by using the finite-element numerical simulation. The result shows that the exhibitory degree depends on the closed degree of the observational site of the seismogenie structure. The closer the distance between the observa-