This paper evaluates possible directional effects from strong ground motions recorded during the last four significant subcrustal earthquakes produced in the Vrancea seismic zone（Romania） in August 1986（Mw=7.1）,Ma...This paper evaluates possible directional effects from strong ground motions recorded during the last four significant subcrustal earthquakes produced in the Vrancea seismic zone（Romania） in August 1986（Mw=7.1）,May 1990（Mw=6.9 and 6.4） and October 2004（Mw=6.0）.Several measures of the horizontal component of the ground motion given in the literature（Boore et al.,2006;Boore,2010） are computed and are related to the geometric mean of the as-recorded horizontal components.ANOVA method is applied in order to quantify the influence of the earthquake magnitude and of the soil class on some strong ground motion parameters（e.g.Arias intensity,PGV/PGA,or mean period TM）.The study of the directional effects is performed using the distribution of IJMAand of the rotation angle corresponding to a measure of the horizontal component of the ground motion（RotD 100） and the results reveal a visible directional pattern for IJMA,while in the case of RotD100 the directional patterns are less visible.展开更多
基金Romanian Ministry of National Education(MEN)under the Grant Number 72/2012
文摘This paper evaluates possible directional effects from strong ground motions recorded during the last four significant subcrustal earthquakes produced in the Vrancea seismic zone（Romania） in August 1986（Mw=7.1）,May 1990（Mw=6.9 and 6.4） and October 2004（Mw=6.0）.Several measures of the horizontal component of the ground motion given in the literature（Boore et al.,2006;Boore,2010） are computed and are related to the geometric mean of the as-recorded horizontal components.ANOVA method is applied in order to quantify the influence of the earthquake magnitude and of the soil class on some strong ground motion parameters（e.g.Arias intensity,PGV/PGA,or mean period TM）.The study of the directional effects is performed using the distribution of IJMAand of the rotation angle corresponding to a measure of the horizontal component of the ground motion（RotD 100） and the results reveal a visible directional pattern for IJMA,while in the case of RotD100 the directional patterns are less visible.
