Seismic Ground Motion Amplifications Estimated by Means of Spectral Ratio Techniques: Examples for Different Geological and Morphological Settings

Comparison of Field Data Processing Methods for the Evaluation of Topographic Effects

“…The influence of topography on earthquake ground motions has been recognized for many decades, with evidence from recordings of both weak and strong ground motions (Massa et al 2014, Barani et al 2014, Hartzell et al 2014, Formisano et al 2012, Marzorati 2011, Massa et al 2011, Buech et al 2010, Graizer 2009, Stewart and Sholtis 2005, Caserta et al 2000, and Davis and West 1973). These recordings, along with numerous numerical studies (Assimaki and Jeong 2013, Lovati et al 2011, Maufroy et al 2012, Lee et al 2009, Bakavoli et al 2011, Geli et al 1988, Sanchez-Sesma et al 1982, and Bouchon 1973), indicate amplification of ground motions at the crest of topographic features, attenuation at the base, and an irregular pattern of amplification/attenuation in between.…”

“…To better understand the spatial distribution and amplification magnitude of topographic effects on complex topographic features, many studies (Massa et al 2014, Barani et al 2014, Hartzell et al 2014, Formisano et al 2012, Marzorati 2011, Massa et al 2011, Buech et al 2010, Graizer 2009, Stewart and Sholtis 2005, Caserta et al 2000, and Davis and West 1973) have utilized arrays of seismic stations deployed temporarily to record weak ground motion data on full scale topographic features. These studies have used a variety of methods to visualize and interpret the recorded ground motion data.…”

Experimental Data Set of Mining-Induced Seismicity for Studies of Full-Scale Topographic Effects

“…Researchers and practitioners have approached the problem of topographic effects from four primary avenues: (1) field observations of earthquake damage patterns and strong motion recordings (Hough et al 2011, Rathje et al 2011, Assimaki and Gazetas 2004, Athanasopoulos et al 1999, 2001, Ashford and Sitar 1994, Celebi 1987, 1991, Boore 1972); (2) experimental studies using arrays of sensors placed strategically on topography to record aftershocks or other weak-motion data (Massa et al 2011, Hartzell et al 2014, Formisano et al 2012, Buech et al 2010, Graizer 2009, Stewart and Sholtis 2005, Caserta et al 2000, Davis and West 1973; (3) theoretical and analytical estimates of frequency content and amplification for simple two-dimensional (2-D) cross sections (Paolucci 2002, Sanchez-Sesma 1985; and (4) numerical modeling of 2-D (Assimaki and Jeong 2013, Maufroy et al 2012, Lee et al 2009 and three-dimensional (3-D) (Bakavoli et al 2011, Assimaki and Kausel 2007, Assimaki et al 2005, Geli et al 1988, Sanchez-Sesma et al 1982, Bouchon 1973) simplified topography. Although topographic amplification remains difficult to quantify for irregular 3-D topographic features, the previous studies on have revealed several key qualitative insights, originally summarized by Wood et al (2012):…”

“…Researchers and practitioners have approached the problem of topographic effects from four primary avenues: (1) field observations of earthquake damage patterns and strong motion recordings (Hough et al 2011, Rathje et al 2011, Assimaki and Gazetas 2004, Athanasopoulos et al 1999, Athanasopoulos et al 2001, Ashford and Sitar 1994, Celebi 1987, 1991, Boore 1972); (2) experimental studies using arrays of sensors placed strategically on topography to record aftershocks or other weak-motion data (Massa et al 2011, 2014, Barani et al 2014, Hartzell et al 2014, Formisano et al 2012, Marzorati et al 2011, Buech et al 2010, Graizer 2009, Stewart and Sholtis 2005, Caserta et al 2000, Davis and West 1973); (3) theoretical and analytical estimates of frequency content and amplification for simple two-dimensional (2-D) cross sections (Paolucci 2002, Ashford and Sitar 1997, Sanchez-Sesma 1985); and (4) numerical modeling of 2-D (Assimaki and Jeong 2013, Lovati et al 2011, Maufroy et al 2012, Lee et al 2009, Bakavoli et al 2011) and three-dimensional (3-D) (Bakavoli et al 2011, Lovati et al 2011, Assimaki and Kausel 2007, Assimaki et al 2005, Ashford et al 1997, Geli et al 1988, Sanchez-Sesma et al 1982, Bouchon 1973) simplified topography. Although topographic amplification remains difficult to quantify for irregular 3-D topographic features, the previous studies on have revealed several key qualitative insights, originally summarized by Wood et al (2012): The maximum amplification attributed to topography occurs at, or near, the peak/ridge of the feature, maximum de-amplification occurs near the toe/base of the feature, and irregular amplification/de-amplification patterns are observed between the two. The observed, or computed, amplification is related to the “sharpness” of the topography; the steeper the average slope, the higher the amplification. The amplifications are highly frequency-dependent and seem to occur at wavelengths comparable to a characteristic length of the feature, such as width and/or height. Amplific...…”