Field Testing & Monitoringof Structural Performance

University of California, Los Angeles7 NCEE July 21-24, 2002

George E. Brown, Jr.Network for Earthquake Engineering Simulation

John W. WallaceJoel P. ConteDeborah EstrinPatrick J. FoxJonathan P. StewartDaniel 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, DirectorDivision 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 PersonnelJohn W. Wallace (PI)PhD, UC Berkeley, 1989Structural

Joel P. Conte (co-PI)PhD, UC Berkeley, 1990Structural

Jonathan Stewart (co-PI)PhD, UC Berkeley, 1996Geotechnical

Patrick J. Fox (co-PI)PhD, University of Wisconsin-Madison 1992, Geotechnical

Deborah Estrin (co-PI)PhD, MIT, 1985Computer Science

Daniel Whang (Project Manager)PhD, UCLA, 2001Geotechnical

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– Ms (weight) – 1 to 7 kips– Actuator (+/- 15 inches)– Force (15,000 pounds)

Advantages– Random load history– Time domain analysis

3m

2m

1m

MassActuator

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

PointSoil 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

Antelope Workstation

AUXILIARY RS- 232C EXT. POW ER

CH 1-3

WirelessRouter

EM ShakerControlSystem

WirelessRouter

UCLAConcrete Lab

TerminalServer

CISCOSYSTEMS

Router

Cam

pus

Gig

abit

Bac

kbon

e

Antelope Workstation

UCLA NEESOffice

Conference Room

Legend____ Serial____ TCP/IP

Field

Trailer

UCLA

Sat

ellit

e Li

nk

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)

0 2 4 6 8 10

F req. (H z)

0

2

4

6

8

10

Ampl

ifica

tion

Website – http://cee.ucla.edu/nees/