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SECTIusix Time Histories <br /> Seven sets of two-component time histories were spectrally-matched to the mean 10,000-year <br /> return period UHS. An additional three horizontal time histories was spectrally-matched to the <br /> mean 500-year return period UHS. Note that the time histories were spectally-matched to <br /> preliminary targets presented in the draft version of this report. Final spectra are 2 to 6 percent <br /> lower than the preliminary targets. This small difference did not justify rematching the time <br /> histories. Because the response spectrum of a time history has peaks and valleys that deviate <br /> from the design response spectrum (target spectrum), it is necessary to modify the motion to <br /> improve its response spectrum compatibility. The procedure proposed by Lilhanand and Tseng <br /> (1988), as modified by Al Atik and Abrahamson (2010) and contained in the computer code <br /> RSPmatch09 (Fouad and Rathje, 2012), was used to develop the acceleration time histories <br /> through spectral matching to the target (seed) spectrum. This time-domain procedure has been <br /> shown to be superior to previous frequency-domain approaches because the adjustments to the <br /> time history are only done at the time at which the spectral response occurs resulting in only <br /> localized perturbations on both the time history and the spectra(Lilhanand and Tseng, 1988). <br /> To match the design (target) spectrum, seed time histories should be from events of similar <br /> magnitude and distance (for duration) and most importantly, spectral shape as the earthquake <br /> dominating the spectrum. Table 9 lists the seed time histories used in the spectral matching. <br /> Figure 42 compares the response spectra for the seven sets of seed time histories to the 10,000- <br /> year return period UHS. The acceleration time histories for these seeds are provided on Figures <br /> 43 to 49. The spectral matches and resulting time histories are shown on Figures 50 to 77. <br /> Figure 78 compares the response spectra for the three seed time histories to the 500-year return <br /> period UHS. The acceleration time histories for these seeds are provided on Figure 79. The <br /> spectra matches are provided on Figures 80 to 85. <br /> Durations and Arias intensities for the spectrally-matched time histories are provided in Table <br /> 10. The target duration for the 10,000-year time histories was calculated using the model of <br /> Silva et al. (1997) and the modal values of magnitude and distance (M 6.7.0 at 5 km)at 1.0 sec <br /> SA. The target 5 to 95% duration is 11 sec with a ± one sigma range of 6.5 to 17.6 sec. The <br /> spectrally-matched time histories have durations ranging from 8.0 to 14.2 sec. <br /> Target Arias intensities for the 10,000-year time histories, computed using the model of <br /> Abrahamson et al.(in review)for a M 6.7 at 5 km event with a PGA of 0.43 g is 1.12 m/sec with <br /> a ± one sigma range of 0.77 to 1.63 m/sec. The spectrally-matched time histories have Areas <br /> intensities ranging from 0.97 to 2.56 m/sec. <br /> 23 <br />