where ci(T) is an individual site amplification factor for each of 12 stations.
Response parameter is acceleration for 5% damping.
Focal depths between 0 and 60km.
Use data either recorded at ground surface where 0.5 ≤ Vs≤ 2.7km∕s (1.7 ≤ Vp≤ 5.5km∕s) or obtained
by analytically removing effects of uppermost surface layers of ground from underground observation data
(or by stripping-off analysis) using underground structure.
Use only ground motion after arrival of first S wave because most important for aseismic design.
Do not give table of coefficients, only graphs of coefficients.
Define amplification factors, di(T) = ci(T) - c0(T) for horizontal motion and di(T) = cv,i(T) - c0(T) for
vertical motion, where c0(T) is the regression coefficient for data observed at ground layer equivalent to
Find Sh(T) = Sb(T)αh(T)βh(T) where Sb(T) is S0(T). αh(T) = (Vs∕Vs,b)-δh(T) for T ≤ Ts,1 and
αh(T) = αh(Ts,1) for T > Ts,1 where Ts,1 is the primary predominant period of surface layer. βh(T) = 1
for T ≤ Ts,1, βh(T) = (T∕Ts,1)-log(αh(Ts,1)) for 10Ts,1> T > Ts,1 and βh(T) = 10-log(αh(Ts,1)) for
T ≥ 10Ts,1. Vs,b= 2.2km∕s. Similar relationships are defined for vertical motion, Sv(T).
Note that relation does not include effect of source mechanism or rupture propagation, so probably less
valid in near-fault region.