Strong Motion Recording and Data Processing Laboratory
Address
University of Southern California
Department of Civil Engineering
Strong Motion Data Processing Laboratory
Kaprielian Hall B26
Los Angeles, Ca 90089-2531
Tel (213) 740-0570, fax (213) 744-1426
Purpose
This
laboratory was established in 1976 by Prof. Trifunac in support of the
following research activities:
- Software development for
routine and specialized processing of analogue and digital strong motion
accelerograms.
- Routine processing of large
accelerogram data sets and database organization for use in regression
analyses.
- Large scale regression
analyses for empirical scaling of strong ground motion.
Its activities were later extended to include also:
People
Faculty:
M.D. Trifunac, V.W. Lee and M.I. Todorovska
The
USC team is the leader in the field of earthquake data processing. Prof.
Trifunac is the author of the first modern software for earthquake accelerogram
data processing, which he further developed since 1970's jointly with Prof.
Lee. The latest LeAuto software
package by Lee and Trifunac for automatic digitization of analogue
accelerograms (using a flat-bed scanner and PC) is the most advanced of its
kind. The LeBatch software
package for processing of digitized and digital strong motion
accelerograms is a standard in the profession. Various versions of
the data processing software developed by the USC group have been and continue
to be used by government organizations, universities and industry in the US and
in many countries in the world. The Trifunac-Lee team is also a leader in large
scale regression analyses and detailed empirical modeling of amplitudes,
spectra and duration of strong earthquake ground motion. Prof. Todorovska
recently developed, jointly with former team member E.I. Novikova, and
algorithm and software for routine processing of advanced field calibration
records and related correction of accelerograms recorded on film for transducer
misalignment and cross-axis sensitivity. This capability is a unique
feature of the USC software. Another unique feature is the specialized
software for instrument correction of coupled transducer-galvanometer recording
systems and for force-balanced accelerometers developed by E.I. Novikova and
M.D. Trifunac. Former team member Ali Amini (currently a Professor of
Electrical Engineering at Calif. State U. at Northridge) developed in 1986 a
prototype of the first remote system for interrogation of strong motion
acceleographs (SIFI) using a microprocessor and a
modem.
As
being simultaneously users and providers of large amounts of processed strong
motion data, the USC team brings a unique perspective to optimal
solutions in strong motion data processing, balancing the demands for high
quality processed data and efficient processing and database organization.
Recent Research Projects
Software and Hardware Products and Capabilities
- The LeAuto software package by Lee and Trifunac for
automatic digitization of accelerograms recorded on film using flat-bed
scanners and PC computers (Lee and Trifunac, 1990).
- The LeBatch software package for processing of digitized
and digital strong motion accelerograms. It consists of three
programs (Volume 1, 2 and 3; Lee and Trifunac, 1990; Trifunac et al,
1998d) that perform baseline and instrument correction, filtering of
high-frequency noise, integration in time of the recorded accelerations to
obtain velocity and displacement, and further computation of Fourier and
Response spectra (Lee and Trifunac, 1990).
- The Tilt software package for routine processing of field
calibration records to determine the transducer angular sensitivity
constants and misalignment angles (Todorovska et al., 1996; Todorovska,
1998; Todorovska et al., 1998).
- A software module for
correction of accelerograms recorded on film for transducer misalignment
and cross-axis sensitivity (Todorovska et al., 1996; Todorovska, 1998).
- A software module for
instrument correction of coupled transducer-galvanometer recording systems
and for force-balanced accelerometers (Novikova and Trifunac, 1991, 1992).
- System
for Ambient Vibration Testing of structures and soils with
PC based data acquisition and software for data analysis (Gladkov et
al., 1993).
Recent Publications - Data Processing
- Negmatullaev, S.Kh., M.I.
Todorovska, & M.D. Trifunac (1999). Simulation of strong earthquake
ground motion by explosions-experiments at the Lyaur testing range in
Tajikistan, Soil Dynamics & Earthquake Engrg, 18(3),
189-207.
- Trifunac, M.D., V.W. Lee and
M.I. Todorovska (1999). Selected
common problems in automatic digitization of accelerograms, Soil
Dynamics & Earthquake Engrg,18, 519-530.
- Todorovska, M.I. (1998).
Cross-axis Sensitivity of Accelerographs with Pendulum like
Transducers-Mathematical Model and the Inverse problem, Earthquake
Engineering and Structural Dynamics, 27(10), 1031-1051.
- Trifunac, M.D., M.I.
Todorovska & V.W. Lee (1998). The Rinaldi strong motion accelerogram
of the Northridge, California, earthquake of 17 January, 1994, Earthquake
Spectra, 14(1), 225-239.
- Todorovska, M.I., E.I.
Novikova, M.D. Trifunac and S.S. Ivanovic (1995). Correction for
Misalignment and Cross Axis Sensitivity of Strong Earthquake Motion
recorded by SMA-1 Accelerographs, Dept. of Civil Eng. Rep. No. 95-06,
Univ. of Southern California, Los Angeles, California.
- Todorovska, M.I., E.I.
Novikova, M.D. Trifunac and S.S. Ivanovic (1998). Advanced Sensitivity
Calibration of the Los Angeles Strong Motion Array, Earthquake Engineering
and Structural Dynamics, 27(10), 1053-1068.
- Lee, V.W. and M.D. Trifunac
(1990). Automatic digitization and processing of accelerograms using PC,
Report No. 90-03, Dept. of Civil Eng. U. of So. California, Los Angeles,
CA.
- Novikova, E.I. and M.D.
Trifunac (1991). Instrument correction for the coupled
transducer-galvanometer system, Dept. of Civil Eng. Report 91-02, Univ. of
Southern California, Los Angeles, California.
- Novikova, E.I. and M.D.
Trifunac (1992). Digital instrument response correction for the Force
Balance Accelerometer, Earthquake Spectra, 8(3), 429-442.
Recent Publications - Database Organization
- Todorovska, M.I, M.D.
Trifunac, V.W. Lee, C.D. Stephens, K.A. Fogleman, C. Davis and R.
Tognazzini (1999). The ML=6.4 Northridge, California, Earthquake and
Five M>5 Aftershocks between 17 January and 20 March 1994 - Summary of
processed strong motion data, Report No. 99-01, Dept. of Civil
Engrg, U. of So. California, Los Angeles, CA.
- V.W. Lee & M.D. Trifunac
(1987). Strong Earthquake Ground Motion Data in EQUINFOS: Part I, Dept.
of Civil Engineering Report No CE 87-01, University of
Southern California, Los Angeles, pp. 399.
- L.R. Jordanovski, V.W. Lee,
M.I. Manic, T. Olumceva, C. Sinadinovski, M.I. Todorovska & M.D.
Trifunac (1987). Strong earthquake ground motion data in EQINFOS :
Yugoslavia, Part I, Institute for Earthquake Engineering and Engineering
Seismology, Univ. Kiril i Metodij, and Dept. of Civil Engrg, Univ. of
Southern California, Rep. No. CE 87-05, Skopje, Yugoslavia, and Los
Angeles, California, pp. 387.
- Gupta, I.D., V. Rambabu &
R.G. Joshi (1993). Strong earthquake ground motion data in EQINFOS
for India: Part IA, Edited by M.D. Trifunac, M.I. Todorovska & V.W.
Lee, Central Water and Power Research Station, and Dept. of Civil Engrg,
Univ. of Southern California, Rep. No. CE 93-03, Khadakwasla, Pune, India
and Los Angeles, California, pp. 60.
- Chandrasekaran, A.R., &
J.D. Das (1993). Strong earthquake ground motion data in EQINFOS for
India: Part IB, Edited by M.D. Trifunac, M.I. Todorovska and V.W. Lee,
Univ. of Roorkee, Dept. of Earthqu. Engrg, and Univ. of Southern
California, Dept. of Civil Engrg, Rep. No. CE 93-04, Khadakwasla, Pune,
India and Los Angeles, California, pp. 90.
- D. Nenov, G. Georgiev, I.
Paskaleva, V.W. Lee & M.D. Trifunac (1990). Strong Earthquake
Ground Motion Data in EQINFOS: Accelerograms Recorded in Bulgaria Between
1981 And 1987, Dept. of Civil Engineering Joint Report No
CE 90-02, Bulgarian Academy of Sciences, Central Lab. for Seismic
Mechanics & Earthquake Engineering (C.L.S.M.E.E.), Bulgaria, and
University of Southern California (U.S.C.), Los Angeles, U.S.A 55
pages.
Recent Publications - Regression Analyses
- V.W. Lee & M.D.
Trifunac. Empirical Equations Describing Attenuation of the Peaks of
Strong Ground Motion, in terms of Magnitude, Distance, Path Effects and
Site Conditions, Dept. of Civil Engineering Report No. CE 95-02,
University of Southern California, Los Angeles 1995.
- V.W. Lee & M.D.
Trifunac. Frequency Dependent Attenuation Function and Fourier
Amplitude Spectra of Strong Earthquake Ground Motion in California,
Dept. of Civil Engineering Report No CE 95-03, University of
Southern California, Los Angeles, 1995.
- V.W. Lee & M.D.
Trifunac. Pseudo Relative Velocity Spectra of Strong
Earthquake Ground Motion in California, Dept. of Civil Engineering Report
No CE 95-04, University of Southern California, Los Angeles,
1995.
- V.W. Lee & M.D.
Trifunac. Characteristics of Earthquake Ground Motions for Seismic
Design, Southern California Earthquake Center Report, Task H-1:
Final Task Report, Vol. I: Empirical Equations Describing Attenuation of
Horizontal Peaks of Strong Ground Motion in Terms of Magnitude, Distance,
Path Effects and Site Conditions, Dept. of DEpt. of Civil Eng. Report
No. CE 95-02, University of Southern California, Los
Angeles, 409 pages Dec, 1995.
- V.W. Lee & M.D.
Trifunac. Characteristics of Earthquake Ground Motions for Seismic
Design, Southern California Earthquake Center Report, Task H-1: Final Task
Report, Vol. II: Frequency Dependent Attenuation Functions and Fourier
Amplitude Spectra of Horizontal Strong Earthquake Ground Motion in
California, Dept. of Civil Eng. Report No. CE 95-03, University of
Southern California, Los Angeles 355 pages Dec, 1995.
- V.W. Lee & M.D.
Trifunac. Characteristics of Earthquake Ground Motions for Seismic
Design, Southern California Earthquake Center Report, Task H-1: Final Task
Report, Vol. III: Pseudo Relative Velocity Spectra of Horizontal Strong
Earthquake Ground Motion in California, Dept. of Civil Eng. Report
No. CE 95-04, University of Southern California, Los Angeles,
332 pages Dec, 1995.
- Novikova, E.I. and M.D.
Trifunac (1994). Duration of Strong Ground Motion in Terms of Earthquake
Magnitude Epicentral Distance, Site Conditions and Site Geometry,
Earthquake Eng. and Structural Dynamics, Vol. 23, No. 6, 1023--1043.
- Novikova, E.I. and M.D.
Trifunac (1994). Influence of Geometry of Sedimentary Basins on the
Frequency Dependent Duration of Strong Ground Motion, Earthquake Eng. and
Eng. Vibration, Vol. 14, No. 2, 7-44.
- Novikova, E.I. and M.D.
Trifunac (1993). Modified Mercalli Intensity Scaling of the Frequency
Dependent Duration of Strong Ground Motion, Soil Dynamics and Earthquake
Eng., Vol. 12, No. 5, 309-322.
- Novikova, E.I. and M.D.
Trifunac (1993). Modified Mercalli Intensity and the Geometry of the
Sedimentary Basin as the Scaling Parameters of the Frequency Dependent
Duration of Strong Ground Motion, with E.I. Novikova, Soil Dynamics and
Earthquake Eng., Vol. 12, No. 4, 209-225.
- Lee, V.W. and M.D. Trifunac
(1993). Empirical Scaling of Fourier Amplitude Spectra in Former
Yugoslavia, European Earthquake Eng., Vol. VII, No. 2, 47-61.
Recent Publications - Ambient Vibration Survey and
Structural Health Monitoring
- Please look up Earthquake damage detection in buildings
and early warning based on wave travel times for most recent
publications on Structural Healtrh Monitoring.
- Trifunac, M.D., S.S. Ivanovic
and M.I. Todorovska (2000). Apparent periods of a building I: Fourier
analysis, J. of Struct. Engrg, ASCE (submitted for publication).
- Trifunac, M.D., S.S. Ivanovic
and M.I. Todorovska (2000). Apparent periods of a building II:
time-frequency analysis, J. of Struct. Engrg, ASCE (submitted for
publication).
- Ivanovic, S.S., M.D.
Trifunac, E.I. Novikova, A.A. Gladkov and M.I. Todorovska (1999).
Instrumented 7-storey reinforced concrete building in Van Nuys,
California: ambient vibration surveys following the damage from the 1994
Northridge earthquake, Dept. of Civil Eng. Rep. No. CE 99-03, pp. 92 (PDF).
- Trifunac, M.D., S.S.
Ivanovic, & M.I. Todorovska (1999). Experimental evidence for
flexibility of a building foundation supported by concrete friction piles,
Soil Dynamics & Earthquake Engrg, 18(3), 169-187.
- Ivanovic, S.S. and M.D.
Trifunac (1995). Ambient Vibration Survey of Full Scale Structures Using
Personal Computers (with examples in Kaprielian Hall), Dept. of
Civil Eng. Rep. No. 95-05, Univ. of Southern California, Los Angeles,
California.
- Trifunac, M.D. and M.I.
Todorovska (1999). Recording and interpreting earthquake response of
full-scale structures, Proc. Nato Advanced Research Workshop on Strong-Motion
Instrumentation for Civil Engineering Structures, June 2-5, 1999,
Istanbul, Turkey, pp. 20 (PDF).
- Ivanovic, S.S., M.D. Trifunac
and M.I. Todorovska (1999). On identification of damage in structures via
wave travel times, Proc. Nato Advanced Research Workshop on Strong-Motion
Instrumentation for Civil Engineering Structures, June 2-5, 1999,
Istanbul, Turkey, pp. 21 (PDF).
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