Question 3: (a) A GMPE predicts a median peak horizontal acceleration of 0.4 g. If the standard deviation in In units is 0.5, what is the 84th percentile estimate for the peak horizontal acceleration? (b) The measured peak horizontal ground acceleration at a site is 0.4 g. A GMPE predicts 0.6 g. What is the residual in In units? (c) A strong ground motion station records peak horizontal accelerations of 0.3 and 0.5 g in the north-south and east-west directions, respectively. What is the geometric mean peak horizontal acceleration? (d) A soil profile that is horizontally layered has 6 m of medium-dense sand (uniform V, of 180 m/s), underlain by 12 m of dense clayey sands (uniform V, of 280 m/s), underlain by 30 m of very dense gravels (uniform V, of 380 m/s), underlain by bedrock (V, of 900 m/s). What is the V.30 for this site? (e) Consider the response spectra in Figure 6(b) of Abrahamson et al. (2014; same figure used for Question 2). Estimate the peak absolute superstructure acceleration and peak relative displacement for 5%-damped SDOF structures having fundamental periods of 1.0 and 4.0 seconds. Vs30-760 M=8 M-7 M=6 A M=5 AS 2008 ASK 2014 0.1 Period (sec) (a) 0.01 INI 10 0.01 Vs30-270 AS 2008 ASK 2014 0.1 Period (sec) (b) 1 M=8 M=7 KI M=6 M=5 10 Figure 6. Comparison of the median spectral acceleration from the current model with the median from the AS08 model for vertical strike-slip earthquakes for RJB = 30 km. (a) VS30 = 760 m/s, (b) VS30 = 270 m/s.