Integration of HVSR measures and stratigraphic constraints for seismic microzonation studies: the case of Oliveri (ME)

Abstract

Because of its high seismic hazard the urban area of Oliveri has been subject of first level seismic microzonation. The town develops on a large coastal plain made of mixed fluvial/marine sediments, overlapping a complexly deformed substrate. In order to identify points on the area probably suffering relevant site effects and define a preliminary Vs subsurface model for the first level of microzonation, we performed 23 HVSR measurements. A clustering technique of continuous signals has been used to optimize the calculation of the HVSR curves. 42 reliable peaks of the H/V spectra in the frequency range 0.6–10 Hz have been identified. A second clustering technique has been applied to the set of 42 vectors, containing Cartesian coordinates, central frequency and amplitude of each peak to identify subsets which can be attributed to continuous spatial phenomena. The algorithm has identified three main clusters that cover significant parts of the territory of Oliveri. The HVSR data inversion has been constrained by stratigraphic data of a borehole. To map the trend of the roof of the seismic bedrock, from the complete set of model parameters only the depth of the seismic interface that generates peaks fitting those belonging to two clusters characterized by lower frequency has been extracted

Validating a low-cost seismometer using a shaking table

“…This study employed MAST System 354.20, which can provide simulation frequency of 0.8 -100 Hz, linear displacement up to 140 mm, angular displacement up to 9 deg., linear velocity up to 1700 mm/s, and linear acceleration up to 15.9 g. Detail specification of the MAST System 354.20 can be seen in Table 1 [23]. [3].…”

“…Ambient vibration measurement using a seismometer represent a non-invasive and non-destructive method for seismic-related studies, i.e., [1], [2], [3], and [4]. This method may inhibit widespread applications, i.e., assessing site fundamental frequency ( [5] - [8]), estimating bedrock level ( [9] - [14]), calculating building natural frequency [15], deducing shear wave velocity profile ( [16] - [20]).…”

Shear wave velocity estimation in the metropolitan area of Málaga (S Spain)

“…Many studies have shown the correlation between the H/V frequency peak and the fundamental resonance frequency of SH waves, being its use especially useful in urban environments (Bonnefoy-Claudet et al, 2008;Di Stefano et al, 2014;Endrun, 2011;Mundepi et al, 2010;Souriau et al, 2007).…”

Horizontal-to-Vertical Spectral Ratios and Refraction Microtremor Analyses for Seismic Site Effects and Soil Classification in the City of David, Western Panama

“…Some authors have applied this method to assess the impact that seismic amplification has had on civil structures affected by past earthquakes [4,5], for the evaluation of the liquefaction potential of soils [6,7], for studies of amplification of areas for future civil projects [7,8], for the assessment of the impact of earthquakes on existing civil structures typical of urban environments [9][10][11], in studies related to landslides [12,13], in coastal and port areas [4,9,14,15] and for the site characterization of seismic stations [16][17][18]. In Panama, several studies have been carried out on the estimation of side effects in some cities [19][20][21].…”