Field Testing & Monitoring of Structural Performance University of California, Los Angeles 7 NCEEJuly 21-24, 2002 George E. Brown, Jr. Network for Earthquake Engineering Simulation John W. Wallace Joel P. Conte Deborah Estrin Patrick J. Fox Jonathan P. Stewart Daniel Whang

Acknowledgements Funding provided through a cooperative agreement with the National Science Foundation George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) – Dr. Priscilla P. Nelson, Director Division of Civil and Mechanical Systems – Joy Pauschke, Ph.D., P.E., NEES Program Director – Thomas L. Anderson, Ph.D. NEES Equipment Project Coordinator

UCLA NEES Personnel John W. Wallace (PI) PhD, UC Berkeley, 1989 Structural Joel P. Conte (co-PI) PhD, UC Berkeley, 1990 Structural Jonathan Stewart (co-PI) PhD, UC Berkeley, 1996 Geotechnical Patrick J. Fox (co-PI) PhD, University of Wisconsin- Madison 1992, Geotechnical Deborah Estrin (co-PI) PhD, MIT, 1985 Computer Science Daniel Whang (Project Manager) PhD, UCLA, 2001 Geotechnical Eunjong Yu (Graduate Student Researcher) William Elmer (Engineering Aide) Colin Means (Engineering Aide) Balaji Vasu (Webmaster)

Project Overview Wireless

Equipment Overview State-of-the-art data acquisition system w/ wireless capabilities Networking equipment to enable near real-time field connectivity to NEESgrid Forced vibration equipment (shakers) Cone penetration truck for rapid soil characterization Structural sensors for acceleration, strain, displacement Custom soil probes for measuring ground vibrations

Data Acquisition System Vendor: Kinemetrics, Inc. True 24-bit resolution/large dynamic bandwidth (155 dB) Quanterra Q330 data loggers are true network devices with wireless capabilities (TCP/IP) Powerful UNIX based data acquisition software program, Antelope – Remote monitoring – Relational database embedded

Local Area Network Sensors/Video Data acquisition system/video server Satellite Campus gigabit backbone NEESpop Visualization portal NEESgrid

Eccentric Mass Shakers MK-14A (1): – Omni-directional – 0 to 4.2 Hz – 20 kips peak force MK-15 (2): – Uni-directional – 0 to 25 Hz – 100 kips peak force – Can be synchronized MK-14B (1): – Omni-directional – 0 to 10 Hz – 50 kips peak force – Rapidly deployable (assembly time < 4 man hours)

Linear Inertial Shaker “Shake Table” – Mass on rails, Actuator – 30 gpm HPS, Accumulators – Digital control system Mounting requirements – Table with Actuator support System Limitations – M s (weight) – 1 to 7 kips – Actuator (+/- 15 inches) – Force (15,000 pounds) Advantages – Random load history – Time domain analysis Mass Actuator

Cone Penetration Truck Vendor: Hogentogler, Inc Site characterization Installation of soil probes to measure ground vibrations during forced vibration tests of full- scale structures

Custom Soil Probes Drive shoe Probe Triaxial accelerometer Cable Deployable/retrievable Triaxial (3 channels) Measure in situ ground accelerations Feed directly to Q330 data loggers

Research Vision Data Collection Point Soil Probes To Command Center Shaker Obtain detailed performance data for linear and nonlinear response of structural systems Address scale and boundary conditions issues commonly associated with lab studies Provide data to study system interactions, e.g. SFSI Develop new sensor (packaging) concepts Obtain high resolution response data to promote advances in simulation

Equipment Integration Pilot Study #1 – Data acquisition Pilot Study #2 – Laboratory testing – Shakers, sensors, data acquisition Pilot Study #3 – Field testing – Soil probes (final) – Satellite system

Pilot Study #2 SDOF steel frame – 15 ft (L) x 13 ft (H) x 6 ft (W) – Structure weight ~3.6 kips Free-vibration testing Forced-vibration testing – Shaker weight ~ 5 kips – Longitudinal direction – Acceleration sensors – Strain sensors

Basic System Identification

LAN for Pilot Study #2 Instruments: Episensors, pulser Real-time Wireless transmission of data from data logger in UCLA structural laboratory to UCLA NEES Office Real-time transmission of data from webserver in UCLA NEES Office to outside world via Antelope Mock run (at UCLA) of real operation scenario in the field Field Trailer UCLA Satellite Link

Pilot Study #3 PS #2 specimen on alternative foundation configurations – Investigate effect on SFSI Shaking in transverse direction Dense instrumentation on structure, ground surface and subsurface

Tele-observable Data Streams Excitation response history Recorded response histories at sensors Deck/foundation transfer functions (fixed base) Deck/foundation transfer functions (flexible base)

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