Table 2: Amplification factors between PGA at the building base and PGA at the free field sensor.

SensorsDirectionAmplification factor

Building A

PGA 6 versus PGA 10X0.810.92
Y0.550.82
PGA 7 versus PGA 10X0.830.92
Y0.540.82

Building B

PGA 8 versus PGA 10X0.890.93
Y0.450.88
PGA 9 versus PGA 10X0.900.93
Y0.480.87