Site-specific amplification function assessment and variability analysis using KiK-Net single-station strong motion data

The core of seismic hazard analysis is to establish quantitative relations for site characteristics, which can be incorporated into site amplification function. Selecting two Kik-net sites (i.e., hard ground and soft site), the quantitative site amplification function and the corresponding probabilistic model are established via single-station seismic records analysis. The co-relation of site amplification function and input pseudo-spectral amplification (PSAR) is illustrated as well the variance (or standard deviation). The conclusive points can be outlined: (1) the site amplification function closely depends on input PSAR, which can be described using a linear or quadratic logarithmic relation; (2) the regression standard deviations for linear and quadratic linear equations and unconditional site amplification function are fairly close, but the standard deviation for soft site is smaller than that of hard ground; (3) at T<0.3s for hard ground, log10 (SAF) decrease with respect to increasing log10 (PSAR), while it remains constant or slightly increases for T>0.3s; (4) for soft site, log10 (SAF) decrease with respect to increasing log10 (PSAR) for wide period range, typically T<1.0s.