Testing and Evaluation of Strong Motion Testing and Evaluation of Strong Motion Instruments for Instruments for Taiwan Strong Motion Taiwan Strong Motion

Instrumentation ProgramInstrumentation Program

C. C. LiuC. C. LiuInstitute of Earth Sciences, Academia Institute of Earth Sciences, Academia SinicaSinica, Taipei, Taiwan, Taipei, Taiwan

W. H. K. LeeW. H. K. LeeU. S. Geological Survey, Menlo Park, CA 94025, USA U. S. Geological Survey, Menlo Park, CA 94025, USA

C. F. WuC. F. WuCentral Weather Bureau, Taipei, TaiwanCentral Weather Bureau, Taipei, Taiwan

Outline of PresentationOutline of Presentation

Introduction to Strong-motion Networks and Arrays in TaiwanTesting and Evaluation of Strong-motion Instruments for TSMIPCurrent and Future WorkMost Recent Significant Event in TaiwanMost Recent Significant Event in TaiwanConclusions

Major Destructive Earthquakes in Taiwan(1900~2005)Major Destructive Earthquakes in Taiwan(1900~2005)

Top 10 Deadliest Earthquake (1900~2005)

Year Lat. Lon. Mag. Deaths Injuries

1904 23.5 120.3 6.3 145 158

1906 23.6 120.5 7.1 1258 2385

1935 24.3 120.8 7.1 3276 12053

1941 23.4 120.5 7.1 358 733

1946 23.1 120.2 6.3 74 482

1951 23.8 121.7 7.3 68 856

1959 21.8 121.3 6.8 17 68

1964 23.2 120.6 6.5 106 650

1986 23.9 121.7 6.8 13 45

1999 23.9 120.8 7.6 2415 11300

ChiChi--Chi EarthquakeChi Earthquake

1999 September 20 17:47:18 UTC1999 September 20 17:47:18 UTCMagnitude: 7.Magnitude: 7.66The Largest Earthquake on the The Largest Earthquake on the island in the past centuryisland in the past century2,415 deaths (including missing 2,415 deaths (including missing people) people) 11,300 severely wounded 11,300 severely wounded 51,753 houses completely 51,753 houses completely destroyed destroyed 54,406 houses severely damaged54,406 houses severely damagedMore than US$10 billion worth of More than US$10 billion worth of economic losseseconomic lossesAccording to the National Fire According to the National Fire Agency (NFA),Agency (NFA), 20032003

Summary of Strong-Motion Networks/Arrays in Taiwan

Network/Array Name Sponsor / Operator

Number of Accelerographs or

Arrays

Type of Accelerograph

Operation Period

Strong-Motion Accelerographs Network (SMA)

IES 79 structural Analog & 12-bit Digital

1970 - 1991

Strong-Motion Array in Taiwan, Phase I (SMART1)

UCB/IES 43 surface ground 12-bit Digital 1980 - 1991

15 surface ground

10 downhole

14 structural

45 surface groundStrong-Motion Array in Taiwan, Phase II (SMART2)

IES

4 downhole

16-bit Digital 1993 -

15 surface ground

12 downhole

15 structural

10 surface groundDownhole Accelerometers Array in Taipei Basin (DART)

CGS / IES

30 downhole

16-bit Digital 1994 -

688 free-field Taiwan Strong-Motion Instrumentation Program(TSMIP)

CWB

61 structural arrays

16/24 bit Digital 1991 -

16-bit Digital 1993 - 2002Hualien Large Scale Seismic Test Array (HLSST)

EPRI, TAIPOWER / IES

12-bit Digital 1985 1993Lotung Large Scale Seismic Test Array (LSST)

EPRI, TAIPOWER / IES

TSMIPPhase I:Phase I: 1991~1996, 1991~1996, Site selection, Instrument Site selection, Instrument installationinstallationPhase II:Phase II: 1997~2003, 1997~2003, DevelopDevelopment ofment of the the Earthquake Rapid Report Earthquake Rapid Report System (RRS)System (RRS)Phase III:Phase III: 2004~, 2004~, ImplementImplementation ofation of the the Earthquake Early Warning Earthquake Early Warning System (EWS), and Data System (EWS), and Data Management SystemManagement System

By the end of 2005, TSMIP By the end of 2005, TSMIP includeincludess 688688 freefree--field field stationsstations andand 6161 structurstructural al arraysarrays..

Goal and objectives of Instrumentation Committee

To eTo establish procurementstablish procurement standards and technical standards and technical specificationsspecificationsTo evaluate the costTo evaluate the cost--effectiveness of commercially effectiveness of commercially available available accelerographsaccelerographsTo standardize the data format, data transmission To standardize the data format, data transmission protocols, and data processing softwareprotocols, and data processing softwareTo document the testing and evaluating procedures To document the testing and evaluating procedures To encourage development of new instruments To encourage development of new instruments

Testing and Performance Testing and Performance Evaluation

Compliance Compliance TestsTests

Acceptance Acceptance

TestsTests

Functional Functional

TestsTests

Hardware Hardware

MaintenanceMaintenance

Conducted by VendorConducted by VendorInclude:Include:

System responseSystem responseStatic accuracyStatic accuracyDigitizer performanceDigitizer performanceRTD outputRTD outputTiming systemTiming systemUtility softwareUtility softwarePackaging and Packaging and ConstructionConstructionField TestsField Tests

Spot checked by CWBSpot checked by CWBInclude:Include:

Power consumptionPower consumptionSensitivitySensitivityLinearityLinearityGPS timingGPS timingDCDC--level driftlevel driftetc.etc.

Performed by 5 Performed by 5 academia groupsacademia groups

Include:Include:Site conditionSite conditionTriggering Triggering Power systemPower systemNoise levelNoise levelInstrument Instrument performanceperformanceData retrieveData retrieveetc.etc.

Performed by Performed by vendor or it agentvendor or it agent

Include:Include:3 years warranty3 years warrantyTrouble shooting Trouble shooting Parts replacementParts replacement

System Response to VibrationSystem Response to Vibration---- SShaking haking TTable able TTestsests

ThThee MoveMove showshowss the the accelerographsaccelerographs being being testedtested on the shaking on the shaking tabletableInput signals:Input signals:

1 Hz, 0.1 g sine waves1 Hz, 0.1 g sine waves in in xx, , y, and z y, and z directiondirection10 Hz, 0.1 g sine waves in x10 Hz, 0.1 g sine waves in x, , y, and z y, and z direction direction 1 Hz, 3 mm displacement 1 Hz, 3 mm displacement "steps" in one direction"steps" in one directionothersothers

Waterproof TestingWaterproof Testing

ThThee MoveMove showshowss the the accelerographsaccelerographs being being tested for their tested for their waterproof capabilities.waterproof capabilities.

CCurrenturrent andand FFutureuture WWorkork

EEvaluatvaluatee the field performance of the field performance of MEMS MEMS accelerometersaccelerometersDevelop the procedures for optimum station Develop the procedures for optimum station installations (specially for the new purchased installations (specially for the new purchased 2424--bit bit accelerographsaccelerographs))Identify both current and future applications using strongstrong--motion velocity seismometers motion velocity seismometers MMeasure rotational motions in the free field and easure rotational motions in the free field and in buildingsin buildings

EEvaluatvaluatee the the PPerformance of erformance of MEMS AMEMS Accelerometersccelerometers

MEMS accelerometers have recently beenMEMS accelerometers have recently been used used in modern in modern accelerographsaccelerographs. The main . The main advantages are: low cost, modest power advantages are: low cost, modest power consumption, wide bandwidth, excellent stability, consumption, wide bandwidth, excellent stability, etc.etc.There were There were two manufacturers proposed this two manufacturers proposed this kind of kind of accelerographsaccelerographs to the TSMIP in 2005to the TSMIP in 2005, , but neither of them was well prepared for the but neither of them was well prepared for the compliance test.compliance test.We We are now conducting extensive field tests of are now conducting extensive field tests of multiple comultiple co--located located accelerographsaccelerographs in Taiwan. in Taiwan.

Sensitivity Variations in MEMS Acceleration SensorsSensitivity Variations in MEMS Acceleration Sensors

----------------------------------------------------------------------------------S/N zS/N z--axis axis yy--axis axis xx--axis axis ----------------------------------------------------------------------------------446 0.5069 0.5153 0.4921446 0.5069 0.5153 0.4921464 0.5102 0.5182 0.5230464 0.5102 0.5182 0.5230465 0.5095 0.5269 0.5130465 0.5095 0.5269 0.5130466 0.4578 0.4615 0.5217466 0.4578 0.4615 0.5217467 0.4951 0.4907 0.4972467 0.4951 0.4907 0.4972468 0.5004 0.4893 0.4917468 0.5004 0.4893 0.4917469 0.4904 0.5284 0.5096469 0.4904 0.5284 0.5096471 0.5327 0.4912 0.4373471 0.5327 0.4912 0.4373472 0.4944 0.5166 0.4819472 0.4944 0.5166 0.4819473 0.4820 0.4793 0.4749473 0.4820 0.4793 0.4749------------------------------------------------------------------------------------

According to theAccording to the EEvaluationvaluation RReporteportof of AccelerographsAccelerographs in 2005

Sensitivity Variations

-15

-10

-5

0

5

10

0 5 10 15 20 25 30

%

in 2005

The The DDiurnal iurnal TTemperature emperature VVariation of ariation of TThe he DDigitizerigitizer

Plots CPlots Comparing the raw data omparing the raw data of seismicof seismic channels channels (1 Hz (1 Hz sampling rate)sampling rate) , VCO and , VCO and system temperature system temperature at at DANB DANB and YHNBand YHNB stationstationss (in counts(in counts). ). DDaily temperature fluctuations aily temperature fluctuations have large effect on 24have large effect on 24--bit bit digitizer.digitizer.

Testing VSETesting VSE--355G3 Strong355G3 Strong--motionmotionVVelocity elocity SSeismometereismometer in Taiwanin Taiwan

OObservations at station YHNB,bservations at station YHNB,from thefrom the earthquake ofearthquake of HHonshuonshu,,JapanJapan (200(20044/09/05/09/05,, MM 7.7.44, a, at at adistance of distance of 1,790 1,790 km)km)..Coherence of recorded data Coherence of recorded data between the between the STSSTS--2 and VSE2 and VSE--355355G3 are nearly perfectG3 are nearly perfect..

Testing VSETesting VSE--355G3 Strong355G3 Strong--motionmotionVVelocity elocity SSeismometereismometer in Taiwan (cont.)in Taiwan (cont.)

-1.5

-1

-0.5

0

0.5

1

1.5

Velo

city

(cm

/sec

)

YHNB , Time : 2004/10/15 04:07:59.998YHNB-HHZ

-1.5

-1

-0.5

0

0.5

1

1.5

Velo

city

(cm

/sec

) YHNB-HHN

60 70 80 90 100 110 120 130 140 150 160-1.5

-1

-0.5

0

0.5

1

1.5

Time (sec)

Velo

city

(cm

/sec

) YHNB-HHE

OObservations at station YHNB,bservations at station YHNB,from thefrom the earthquake earthquake of Taiwan of Taiwan region, ( 200region, ( 20044/10/15/10/15,, MMLL 7.0, a7.0, at t aa distance of distance of 115858 km)km)The records of VSEThe records of VSE--355G3 and 355G3 and EpisensorEpisensor are still within their are still within their clipping limits, while that of the clipping limits, while that of the STSSTS--2 clipped.2 clipped.

Testing VSETesting VSE--355G3 Strong355G3 Strong--motionmotionVVelocity elocity SSeismometereismometer in Taiwan (cont.)in Taiwan (cont.)

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Dis

p (c

m)

YHNB (No Filter), Time : 2004/10/15 04:07:59.998

STS-2-HHZ

-0.6

-0.4

-0.2

0

0.2

0.4

Dis

p (c

m)

STS-2-HHN

60 80 100 120 140 160 180 200 220 240 260-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Tim e (s e c)

Dis

p (c

m)

STS-2-HHE

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Dis

p (c

m)

YHNB (No Filter), Time : 2004/10/15 04:07:59.998

VSE-355G3-HHZ

-0.6

-0.4

-0.2

0

0.2

0.4

Dis

p (c

m)

VSE-355G3-HHN

60 80 100 120 140 160 180 200 220 240 260-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Tim e (s e c)

Dis

p (c

m)

VSE-355G3-HHE

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Dis

p (c

m)

YHNB (No Filter), Time : 2004/10/15 04:07:59.998

EpiSe ns or-HLZ

-5

0

5

10

Dis

p (c

m)

EpiSe ns or -HLN

60 80 100 120 140 160 180 200 220 240 260-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Tim e (s e c)

Dis

p (c

m)

EpiSe ns or -HLE

Comparisons of displacement record Comparisons of displacement record fromfrom STSSTS--2, VSE2, VSE--355G3, and 355G3, and EpisensorEpisensor, Z, N, and E components , Z, N, and E components ( 200( 20044/10/15/10/15,, MM 7.07.0 earthquakeearthquake))

Testing VSETesting VSE--355G3 in Taipei Basin355G3 in Taipei Basin

Site InvestigationsSite Investigations

The soil profileThe soil profileSPTSPT--N valueN valueWave velocity profileWave velocity profileSoil constantSoil constantParticleParticle--size analysis size analysis

0

10

20

30

40

50

60

70

80

90

100

0 500 1000 1500 2000 2500 3000

(/)

(

)

Vs Vp

Measuring Rotation Motions in the Free Field ofMeasuring Rotation Motions in the Free Field of TaiwanTaiwan

Phase I: Phase I: 2000/12 ~ 2005/12 2000/12 ~ 2005/12 AAt Ht HLSST siteLSST siteData logger: 12Data logger: 12--channel, 19channel, 19--bit, K2 by bit, K2 by KinemetricsKinemetricsWWith FBAith FBA--23 Accelerometer23 Accelerometer, , PVCPVC--5 5 ((0.2V /0.2V /radrad/sec)/sec), , and and GyroChipGyroChip rotation transducer rotation transducer (1.43 V/(1.43 V/radrad/sec)/sec)Trigger recording at 200 Trigger recording at 200 sspsps

No useful rotation data were No useful rotation data were obtained after 5 years of obtained after 5 years of observations.observations.

Phase II: Phase II: July 2004 ~ PresentJuly 2004 ~ PresentAAt station of HGSDt station of HGSDData logger: 6Data logger: 6--channel, 24channel, 24--bit, bit, Q330 by Q330 by quanterraquanterraWith CMGWith CMG--3TB 3TB downholedownhole broad broad band Seismometer, band Seismometer, downholedownholestrain meter, GPS, and R1 strain meter, GPS, and R1 rotational (50V/rad/sec)rotational (50V/rad/sec)ContinuslyContinusly recording at 100 recording at 100 spssps

Measuring Rotation Motions in the Free Field ofMeasuring Rotation Motions in the Free Field of TaiwanTaiwanEvent at a distance of 36Km away, 2006/01/08,01:01:37 UTC, ML5.3Event at a distance of 36Km away, 2006/01/08,01:01:37 UTC, ML5.3

Power spectra for the recorded signals of the January 8, 2006 earthquake.

Y-axis scale is different for each of the broadband velocity signals (top two frames) and for each of the rotation velocity signals (bottom 3 frames).

Measuring Rotation Motions in the Free Field ofMeasuring Rotation Motions in the Free Field of TaiwanTaiwan

Preliminary observations suggest: (1) Angular rotation is Preliminary observations suggest: (1) Angular rotation is important even in the midimportant even in the mid--field of an earthquake, field of an earthquake, ((22) ) A A more more sensitive sensitive and wide dynamic range and wide dynamic range transducertransducer is is needed for measuring rotational motions, and (3) A well needed for measuring rotational motions, and (3) A well calibrated sensor is very importantcalibrated sensor is very important for usfor us, we should , we should conduct proper tests in an appropriate testing facility as conduct proper tests in an appropriate testing facility as soon as possible.soon as possible.At the recent Workshop on At the recent Workshop on Measuring the Rotation Measuring the Rotation Effects of Strong Ground MotionEffects of Strong Ground Motion held on February 16, held on February 16, 2006, it was generally agreed by the experts that 2006, it was generally agreed by the experts that measuring rotational motions should be made in the free measuring rotational motions should be made in the free field and in buildings as soon as possiblefield and in buildings as soon as possible..We plan to deploy We plan to deploy moremore triaxialtriaxial rotation transducers rotation transducers in in Taiwan later this year.Taiwan later this year.

Most Recent Significant Event in TaiwanMost Recent Significant Event in Taiwan

42 people 42 people minor minor injuredinjuredPower failuresPower failuresA few buildings A few buildings sslightlight damageddamagedCracks appeared in the walls of main Cracks appeared in the walls of main fire station fire station

Most Recent Significant Event in Taiwan Most Recent Significant Event in Taiwan (Cont.)(Cont.)

CONCLUSIONSCONCLUSIONS

Over 1,000 threeOver 1,000 three--component component accelerographsaccelerographs (in free(in free--field and in equivalent structural arrays) were deployed field and in equivalent structural arrays) were deployed by the by the TSMIP during its first phase in 1991TSMIP during its first phase in 1991--19961996..This dense network of This dense network of accelerographsaccelerographs (with station (with station spacing of 2 to 5 km) recorded the main shockspacing of 2 to 5 km) recorded the main shock of Chiof Chi--Chi Chi earthquakeearthquake and thousands of and thousands of aftershocksaftershocks, with a data , with a data volume that exceeded all the strongvolume that exceeded all the strong--motion recorded motion recorded obtained for the entire world since measurements began obtained for the entire world since measurements began 70 years before. 70 years before. This success of TSMIP was beyond our expectation, and This success of TSMIP was beyond our expectation, and our efforts in instrument testing and evaluation our efforts in instrument testing and evaluation beforebeforeand and afterafter purchase paid off handsomely. purchase paid off handsomely.

Thank you!

Testing and Evaluation of Strong Motion Instruments for Taiwan Strong Motion Instrumentation ProgramOutline of PresentationMajor Destructive Earthquakes in Taiwan(1900~2005)Chi-Chi EarthquakeSummary of Strong-Motion Networks/Arrays in TaiwanTSMIPGoal and objectives of Instrumentation CommitteeTesting and Performance EvaluationSystem Response to Vibration -- Shaking Table TestsWaterproof TestingCurrent and Future WorkEvaluate the Performance of MEMS AccelerometersSensitivity Variations in MEMS Acceleration SensorsThe Diurnal Temperature Variation of The DigitizerTesting VSE-355G3 Strong-motionVelocity Seismometer in TaiwanTesting VSE-355G3 Strong-motionVelocity Seismometer in Taiwan (cont.)Testing VSE-355G3 Strong-motionVelocity Seismometer in Taiwan (cont.)Testing VSE-355G3 in Taipei BasinSite InvestigationsMeasuring Rotation Motions in the Free Field of TaiwanMeasuring Rotation Motions in the Free Field of TaiwanMost Recent Significant Event in TaiwanMost Recent Significant Event in Taiwan (Cont.)CONCLUSIONSThank you!