Vertical to Horizontal UHS Ratios for Low to Medium Seismicity Regions with Deep Soil atop Deep Geological Sediments—An Example of the City of Osijek, Croatia

The severity of vertical seismic ground motions is often factored into design regulations as a component their horizontal counterparts. Furthermore, most codes, including Eurocode 8, ignore the impact local soil on spectra. This paper investigates pseudo-absolute acceleration spectral estimates, well ratios estimates for strong motion in and directions, low to medium seismicity regions with deep geological sediments beneath soil. case study region encompasses city Osijek Croatia. New regional frequency-dependent empirical scaling equations are derived According these equations, 0.3 s amplitude at soils atop compared rock sites, maximum amplification 1.48 times. spectra components various real recorded surrounding response new used construct Uniform Hazard Spectra Osijek. generated, examined, 8 recommendations. All results show that geology conditions have significant motions. also strata, can underestimate by factor three Type 2 while overestimating them two 1