Civil Engineering Reference
In-Depth Information
1.28
0.34
-0.33
0
0
Time (seconds)
48.00
0
Period (seconds)
20
38.29
116.32
-33.03
0
0
Time (seconds)
48.00
0
Period (seconds)
20
7.59
25.89
-10.29
0
0
48.00
0
Period (seconds)
20
Time (seconds)
Figure 3.24
Time histories
(left
) and response spectra (
right
) computed automatically online from Pacifi c Earth-
quake Engineering Research Center (PEER) strong-motion database: acceleration (
top
), velocity (
middle
) and dis-
placement (
bottom
) (
adapted from
Pacifi c Earthquake Engineeering Research Center, USA)
from Internet web sites such as the Utility Software for Earthquake Engineering (USEE) (available at
http://mae.ce.uiuc.edu/software_and_tools/index.html ) and Seismo -Signal (available at http://www.
seismosoft.com/Downloads/SeismoSignal.htm). The former was developed at the Mid-America
Earthquake Center in the University of Illinois at Urbana-Champaign (Inel
et al.
, 2001 ). The latter is
the new release of the software used for strong-motion processing at Imperial College, London. In both
programs, the user is guided through several data input screens.
The steps required to generate earthquake spectra can be summarized as follows:
(i)
Select the strong motion from a databank
: the input fi les should have standard extensions for
USEE, i.e. '.mae', while there are no limitations for the format utilized by Seismo- Signal.
Moreover, three types of base input accelerations are provided as default within the USEE
library: recorded ground motions, synthetic motions and simple pulse waveforms. The user can
defi ne additional motions, which should, however, conform to the standard format described in
the recorded ground-motion help topic. USEE recognizes the ground-motion data fi les only
