The KiK-net ground motion database is used to develop ground motion prediction equations for Arias Intensity (I<sub>a</sub>), 5-95% Significant Duration (Ds<sub>5-95</sub>), and 5-75% Significant Duration (Ds<sub>5-75</sub>). Relationships are developed both for shallow crustal earthquakes and subduction zone earthquakes (hypocentral depth less than 45 km). The models developed consider site amplification using V<sub>S30</sub> and the depth to a layer with V<sub>S</sub>=800 m/s (h₈₀₀). We observe that the site effect for I<sub>α</sub> is magnitude dependent. For Ds<sub>5-95</sub> and Ds<sub>5-75</sub>, we also observe strong magnitude dependency in distance attenuation. We compare the results with previous GMPEs for Japanese earthquakes and observe that the relationships are similar. The results of this study also allow a comparison between earthquakes in shallow-crustal regions, and subduction regions. This comparison shows that Arias Intensity has similar magnitude and distance scaling between both regions and generally Arias Intensity of shallow crustal motions are higher than subduction motions. On the other hand, the duration of shallow crustal motions are longer than subduction earthquakes except for records with large distance and small magnitude causative earthquakes. Because small shallow crustal events saturate with distance, ground motions with large distances and small magnitudes have shorter duration for shallow crustal events than subduction earthquakes. / This thesis presents the development of new Ground Motion Prediction Equations (GMPEs) for the prediction of the duration and the Arias Intensity of earthquake strong motions. . Arias Intensity is an index for the energy in the ground motion. The GMPEs are based on the Japanese KiK-net database. Based on the causative earthquake source, source to site path, and site properties, GMPEs give estimation of the mean and standard deviation of the parameters. This information is necessary for conducting probabilistic seismic hazard analyses.
The characteristics of the ground motions with the same magnitude and source to site distance vary amongst different tectonic regimes. For this reason, we develop different GMPEs for earthquakes from different tectonic regimes (subduction zone and shallow crustal earthquakes). The primary motivation for this research is that no existing GMPEs for duration are directly applicable to subduction-zone earthquakes. In addition, because the same stations recorded both types of events, we can directly compare the effect of tectonic environment on the selected ground motion parameters. The estimation of mean duration and mean Arias intensity made by this study show while magnitude and distance scaling of Arias Intensity is the same for shallow crustal and subduction earthquakes, the tectonic regime has a significant effect on duration of ground motion.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/87704 |
| Date | 24 August 2017 |
| Creators | Bahrampouri, Mahdi |
| Contributors | Civil Engineering |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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