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Figure 7. (a) Original earthquake acceleration time history; (b) Velocity time history without any baseline correction;
(c) Displacement time history without any baseline correction

(a) Acceleration: original data
0.5
0.3

0.1
g
-0.1

-0.3

-0.5
0 10 20 30 40 50 60
second

(b) Velocity: integration from original acceleration
0.5

0.3

0.1
m/s
-0.1

-0.3
-0.5
0 10 20 30 40 50 60
second

(c) Displacement: integration from original velocity
4

3
2
m
1
0

-1
0 10 20 30 40 50 60
second

have to integrate the acceleration integrated from acceleration time
time history to get velocity time h istor y w ithout a ny basel i ne
Application on history; and integrate again to get correction.
Seismic Time displacement time history. But if the Fig ure 7c shows the ma x imum

History Analysis acceleration time history has a shift displacement is over 2 meters, it’s
to zero mean (either constant or
obviously impossible, thus the
inclined) then the integration will
baseline correction procedures are
he seismic data are always amplify this shift, thereby causes needed, and the procedures are
recorded in acceleration the velocity and displacement
Tunit, but the velocity and time history into incorrect results. – For recorded acceleration a(t),
displacement are also the important Figure 8 illustrates the velocity least square fit straight line:
parameters for analysis, thus we and displacement time history a 0 +c 0 (t)

NEW FAB TECHNOLOGY JOURNAL JUNE 2013 17