Probabilistic seismic damage assessment of reinforced concrete buildings considering directionality effects

Abstract

Most of buildings and structures are usually projected according to two main axes. However, the geographical position of these buildings varies randomly. Such random distributions of the azimuthal positions of structures, in most of the cities, generally, are not accounted for when assessing their seismic risk; certainly, the direction of the seismic loads is another highly random variable. Moreover, an additional important source of uncertainty is related to the structural response, mainly due to the random character of the mechanical properties. There is a consensus that uncertainties must be considered for adequately assessing the seismic risk of structures, but these directionality effects have not been deeply explored so far. In this article, the influence of the high uncertainty involved in these input variables on the expected seismic damage is analysed. Thus, an actual earthquake, which affected the southern part of Spain, is studied. Notably, damages on a group of affected buildings, located close to the epicentre, are analysed and discussed in detail. The results show that the influence of the random azimuthal position of structures is an important source of uncertainty and that it should be taken into account when estimating the expected seismic risk in urban areas.

Seismic Site Classification from the Horizontal-to-Vertical Response Spectral Ratios: Use of the Spanish Strong-Motion Database

“…RotD100 is the spectrum that represents the maximum (100th percentile) values of response spectra of the two as-recorded horizontal components rotated onto all non-redundant azimuths [13]. This is due to the directionality effect of strong motion recordings, which is now considered in the GMPEs [12,14,15] and in the variability of the performance of structures due to the angle of incidence of the seismic action [16][17][18][19].…”

“…To make this comparison, the spectral shapes of each site class are first normalized at the zero-sec-period and the EC-8 design spectrum for Type 2 earthquakes and soil type A (EC8-2A spectrum) (see Table 1) is used as a reference spectrum. This reference spectral shape was selected because of the low-to-moderate seismic hazard in Spain [18] and the relatively low magnitudes of the events involved in this study (see Figure 3). Recall that Type 2 spectra are recommended for regions with earthquakes whose surface-wave magnitude (Ms) is no greater than 5.5 (low seismicity) [1,10].…”

Assessment of Post-Earthquake Damaged Building with Interferometric Real Aperture Radar

“…Buildings in the San Fernando neighborhood suffered various damage grades. Significant differences among damaged nearby buildings have been attributed to directionality effects of the strong ground motions [2,3].…”

Un enfoque alternativo para tomar en cuenta el efecto de la direccionalidad sísmica.

“…In recent studies, such as Vargas et al (2012) and Vargas et al (2017), the directionality effect of earthquakes has been evaluated from two approaches: (1) the seismic hazard (Boore et al, 2006;Hong et al, 2009;Boore, 2010;Pinzón et al 2015) and (2) the expected seismic performance and damage in buildings (Rigato and Medina, 2007;Lagaros, 2010). The first approach refers to the influence that the sensor orientation has on the ground motion predictive equations (GMPE).…”

“…As a result of the directionality analysis, relationships in function of an output variable are obtained, such as the roof displacement (δ), the base shear or the expected damage in depending on the rotation angle (θ). Greater displacements, shears and damages are obtained to those estimated with the as-recorded (non-rotated) components in a 3D analysis (Vargas et al, 2012;Vargas et al, 2017), however, the high computational cost implies multiple dynamic analyzes and make difficult the implementation of this effect.…”