The surface profiles in Grenoble area determined by the MASW measurements

The surface profilesin Grenoble area

determinedby the MASW

measurements

The surface profilesin Grenoble area

determinedby the MASW

measurements

Seiji Tsuno, Cecile Cornou, Pierre-Yves Bard (LGIT)

Seiji Tsuno, Cecile Cornou, Pierre-Yves Bard (LGIT)

QSHA meeting, 1/Juin/2007, NiceQSHA meeting, 1/Juin/2007, Nice

Today’s presentationToday’s presentation

• Procedure of the MASW measurements in Grenoble area and those analyses

• Inversion of Rayleigh wave to S-wave velocity profiles

• Wave-length of Rayleigh in Grenoble area (combining between our results and the results by BRGM)

• Distribution maps of surface velocities and engineering bedrock

(combining between our results and the results by BRGM)

• On higher modes obtained by the MASW method

• Estimation of damping factors on surface

MASW measurements and the analyses

MASW measurements and the analyses

Concept of MASW methodConcept of MASW method

Measurement sitesMeasurement sites

ILL

MONSIEUR

G15

STADE

RAILWAY

MSPORT

G12KAWASE2

KAWASE1

IMPOT

CASERNE

BASTILE

CAMPUSTAILLAT

FORAGE

G03

ROCK Belledonne G10

ROCK Vercors G17

ROCK Bastile

G18

H/V Seismic station

MASW by BRGM

Outline of MeasurementOutline of MeasurementSite Longitude Latitude Date Interval Sampling Off-set distance Mass

Campus 5.772694 45.198379 22/1/2007 2m 4000Hz 0, 5, 10, 15, 20m 3, 5kg

Taillat 5.789989 45.194184 23/1/2007 3m 1000Hz 0, 10, 20m 5kg

G03 5.808 45.217 23/1/2007 2m 1000Hz 0, 10, 33m 3, 5kg

Forage 5.821 45.209 26/1/2007 3m 1000Hz 0, 10, 20, 40, 60m 5kg

Caserne 5.725 45.184 30/1/2007 2m 1000Hz 0, 10, 20m 5kg

Kawase1 5.722326 45.176963 29/1/2007 3m 1000Hz 0, 10,20m 5kg

Impot 5.705763 45.177218 25/1/2007 2m 1000Hz 0, 10m 5kg

Ill 5.695507 45.20791 29/1/2007 3m 1000Hz 0, 10, 20, 40m 5kg

Kawase2 5.720384 45.162182 25/1/2007 3m 1000Hz 0, 10, 20, 30m 5kg

G12 5.750955 45.154165 25/1/2007 2m 1000Hz 0, 10, 20, 30m 5kg

Msport 5.727886 45.144167 31/1/2007 3m 1000Hz 0, 20m 5kg

Railway 5.707417 45.150354 31/1/2007 3m 1000Hz 0, 20m 5kg

G18 5.676175 45.225047 24/1/2007 2m 1000Hz 0, 10m 5kg

Monsieur 5.683277 45.20038 24/1/2007 3m 1000Hz 0, 10, 15, 20, 40m 5kg

G15 5.686412 45.195187 24/1/2007 2m 1000Hz 0, 10, 20, 40m 5kg

Stade 5.693 45.165 25/1/2007 3m 1000Hz 0,10, 20m 5kg

Bastille 5.725 45.2 31/1/2007 1, 4m 4000Hz 0m 3, 5kg

G17 5.632 45.167 1/2/2007 1m 4000Hz 0, 20m 3kg

G10 5.85 45.198 1/2/2007 1m 4000Hz 0, 20, 40m 3kg

* Except Kawase1, we made hammer shots at both sites.

* At Bastille in Chartreuse, at G17 in Vercors, at G10 in Belledonne, we also made the measurements of MASW on horizontal waves.

Process of analysisProcess of analysis

Normalization (for the distance between a shot point and receivers)

High resolusion method (Capon)

Using the records integrated

Stacking (in time domain)

Multi-offset (in frequency domain)

HR BFM

Offset-40m

Offset-0m

Does the excitation of modes depend on the condition of shot points ? (and on the wave-length ?)

Recording

Sampling 1000Hz (4000Hz in rock site)

Array length of 46 or 69m – interval 2 or 3m (23 and/or 92m in rock site)

4.5Hz (Vertical sensors)

14Hz (Horizontal sensors in rock site)

Dispersion curve - north-east basin

Dispersion curve - north-east basin

Campus Taillat

G03 Forage

1st higher mode ?

Fundamental mode

PV =

100m/s

Dispersion curve - centre villeDispersion curve - centre ville

Caserne Kawase1

Impot Ill

PV =

200m/s

Dispersion curve - south of Grenoble

Dispersion curve - south of Grenoble

Kawase2 G12

Msport Railway

PV =

250m/s

Dispersion curve - west of Grenoble

Dispersion curve - west of Grenoble

G18 Monsieur

G15 Stade

PV =

100m/s

Dispersion curve - Rock sitesDispersion curve - Rock sites

Bastille G17

G10

2000m/s

1000m/s

2000m/s

Array response

- Array length 24m

Dispersion curve of Love wave - Rock sites

Dispersion curve of Love wave - Rock sites

Bastille G17

G10

1200m/s 500m/s

1400m/s

Array response

- Array length 24m

Comparison with dispersion curves

determined by microtremors

Comparison with dispersion curves

determined by microtremors

Campus Forage Taillat

Frequency (Hz)P

hase

ve

loci

ty (

m/s

ec)

Taillat

MASW(MLM) FK(F0) FK(H1) SPAC

0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Forage

MASW(MLM) MASW(MLM) MASW(MLM) FK(F0) FK(H1) SPAC

0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Campus

MASW(MLM) MASW(MLM) FK(F0) FK(H1) SPAC

0 10 20 30 40 50

100

200

300

400

500

Array response

Inversion of Rayleigh wave to S-wave velocity

profiles

Inversion of Rayleigh wave to S-wave velocity

profiles

InversionInversion Genetic algorithm after Yamanaka and Ishida (1995)

Target of fundamental mode of Rayleigh wave

Adopting of 3 or 4 layers

5 trials with different random numbers

Selection of minimum misfit result

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Campus

Observation Theoretical

0 10 20 30 40 50

100

200

300

400

500

De

pth

(m

)S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

GA

S-wave vel. profiles - north-east basin

S-wave vel. profiles - north-east basin

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Campus


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Taillat


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Forage


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G03


0 10 20 30 40 50

100

200

300

400

500

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

S-wave vel. profiles - centre ville

S-wave vel. profiles - centre ville

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

CASERNE


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Kawase1


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

IMPOT


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

ILL


0 10 20 30 40 50 60 70

100

200

300

400

500

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

S-wave vel. profiles - south of Grenoble

S-wave vel. profiles - south of Grenoble

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

KAWASE2


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G12


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

MSPORT


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

RAILWAY


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

S-wave vel. profiles - west of Grenoble

S-wave vel. profiles - west of Grenoble

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G18


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Monsieur


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G15


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

STADE


0 10 20 30 40 50

100

200

300

400

500

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

S-wave velocity profiles - Rock sites

S-wave velocity profiles - Rock sites

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Dep

th (

m)

S-wave vel. (m/s)0 1000 2000 3000

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 1000 2000 3000

-60

-50

-40

-30

-20

-10

0

Dep

th (

m)

S-wave vel. (m/s)0 1000 2000 3000

-60

-50

-40

-30

-20

-10

0

Comparison of Love wave dispersion

Comparison of Love wave dispersion

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

1000

2000

3000

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50

500

1000

1500

2000

Love Wave

Rayleigh Wave

Wave-length of Rayleigh in Grenoble

area

Wave-length of Rayleigh in Grenoble

area

Dispersion of Rayleigh waves- Sedimentary basin -

Dispersion of Rayleigh waves- Sedimentary basin -

Measurement by LGIT Measurement by BRGM

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

LGIT

0 10 20 30 40 50 60 70 80

100

200

300

400

500

600

700

800

900

1000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BRGM

0 10 20 30 40 50 60 70 80

100

200

300

400

500

600

700

800

900

1000

Wave length of Rayleigh waves

- Sedimentary basin -

Wave length of Rayleigh waves

- Sedimentary basin -

Measurement by LGIT Measurement by BRGM

Wa

ve le

ngth

(m

)

Phase velocity (m/s)

BRGM

0 200 400 600 800 1000

-140

-120

-100

-80

-60

-40

-20

0

Wa

ve le

ngth

(m

)


LGIT

0 200 400 600 800 1000

-140

-120

-100

-80

-60

-40

-20

0

Dispersion and Wave-length of Rayleigh waves - Rock site -

Dispersion and Wave-length of Rayleigh waves - Rock site -

Dispersion curve Wave-length

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BRGM LGIT Rock sites

0 10 20 30 40 50 60 70 80

500

1000

1500

2000

2500

3000

Wa

ve le

ngth

(m

)


BRGM LGIT Rock sites

0 500 10001500200025003000

-140

-120

-100

-80

-60

-40

-20

0

Dispersion and Wave-length of Love waves - Rock site -

Dispersion and Wave-length of Love waves - Rock site -

Wa

ve le

ngth

(m

)


Rayleigh Love

G17

0 500 1000 1500 2000 2500 3000

-140

-120

-100

-80

-60

-40

-20

0


Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Rayleigh Love

G170 10 20 30 40 50 60 70 80

500

1000

1500

2000

2500

3000

Dispersion and Wave-length of Rayleigh waves -

Microtremors -

Dispersion and Wave-length of Rayleigh waves -

Microtremors -


Phase velocity (m/sec)

Wa

ve le

ngth

(m

)

MASW(F0) SPAC(F0) FK(F0) ESG model

0 500 1000 1500 2000-4000

-3000

-2000

-1000

0

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)


1 100

500

1000

1500

2000

Comparison of wave-lengh of observation with ESG

model

Comparison of wave-lengh of observation with ESG

model

Wave-length


Wa

ve le

ngth

(m

)


0 100 200 300 400 500 600 700-700

-600

-500

-400

-300

-200

-100

0

Vs 400m/s

Distribution maps of surface velocity and engineering

bedrockin Grenoble area

Distribution maps of surface velocity and engineering

bedrockin Grenoble area

Distribution of surface velocity of Rayleigh

wave

Distribution of surface velocity of Rayleigh

wave

Bedrock map in Grenoble basin


Wa

ve le

ngth

(m

)


0 100 200 300 400 500 600 700-700

-600

-500

-400

-300

-200

-100

0

Distribution of surface velocity of Rayleigh wave - comparison of dif.

WL

Distribution of surface velocity of Rayleigh wave - comparison of dif.

WL

On surface

At WL 20m

At WL 50m

Distribution of surface velocity of Rayleigh wave -2

Distribution of surface velocity of Rayleigh wave -2

Distribution of surface velocity of Rayleigh wave - (m/s)

Observation map in Grenoble area

Observation map in Grenoble area

ILL -221

MONSIEUR -118

G15 -124

STADE -149

RAILWAY -256

MSPORT -327

G12 -232KAWASE2 -312

KAWASE1 -243

IMPOT -237

CASERNE -220

BASTILE -218

CAMPUS -116

TAILLAT -160

FORAGE -102

G03 -113

ROCK Belledonne G10 -217

ROCK Vercors G17 -145

ROCK Bastile -218

G18 -146

Unit – m/sec

253

86177

113

188151

262

146207276

167

115

119136

14286

172130

184

127117

115133177174

133

Depth of engineering bedrock (Vs 400 - 500m/s)

Depth of engineering bedrock (Vs 400 - 500m/s)

Bedrock map in Grenoble basin

Distribution of surface velocity of Rayleigh wave - (m/s)

Higher mode

- Can we use the dispersion of higher mode to invert for S-

wave velocity profiles ?

Higher mode

- Can we use the dispersion of higher mode to invert for S-

wave velocity profiles ?

Comparison of theoretical

dispersions with observations

Comparison of theoretical

dispersions with observations

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G03

Fundamental Higher mode

0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Taillat


0 10 20 30 40 50

100

200

300

400

500

Phase velocity - TaillatPhase velocity – G03

F-K

Spe

ctra

Frequency (Hz)

TAILLAT

Fundamental 1st higher mode

0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

G03


0 10 20 30 40 50

0.1

0.2

0.3

0.4

Power spectra (G03 and Taillat)

Dispersion curve in Forage

(borehole site)

Dispersion curve in Forage

(borehole site)

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Forage


0 10 20 30 40 50

100

200

300

400

500

Phase velocityF-K spectra

F-K

Spe

ctra

Frequency (Hz)

Forage


0 10 20 30 40 50

0.005

0.01

0.015

0.02

Power spectra

Estimation of damping factors

- Examples -

Estimation of damping factors

- Examples -

Waveform inversion using recordings of the MASW measurment (at Forage)

Waveform inversion using recordings of the MASW measurment (at Forage)

Comparison of theoretical waveforms (red line) calculated by DWM with observation recording (black line) generated by hammer hit

Q = 15 Q = 50(Frequency independent model)Propagation

Forage

Time (sec)

6m

9m

12m

15m

18m

21m

24m

27m

30m

0 0.2 0.4 0.6 0.8 1-180000

-170000

-160000

-150000

-140000

-130000

-120000

-110000

-100000

-90000

-80000

-70000

-60000

-50000

-40000

-30000

-20000

-10000

0

10000

20000

Forage

Time (sec)

6m

9m

12m

15m

18m

21m

24m

27m

30m

0 0.2 0.4 0.6 0.8 1-180000

-170000

-160000

-150000

-140000

-130000

-120000

-110000

-100000

-90000

-80000

-70000

-60000

-50000

-40000

-30000

-20000

-10000

0

10000

20000

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Ricker wavelet used in DWM (Forage)

Ricker wavelet used in DWM (Forage)

F-K spectraSource (Ricker wavelet 0.03s)

Dominant Period - 0.03s

0.4 0.45 0.5 0.55 0.6

-1

0

1

Frequency (Hz)

Po

we

r sp

ect

rum

Forage

Observation - offset 6m Ricker wave - 0.03s

1 10 1001e-06

1e-05

0.0001

0.001

0.01

0.1

Waveform inversion using recordings of the MASW

measurment (at G03)

Waveform inversion using recordings of the MASW

measurment (at G03)

Comparison of theoretical waveforms (red line) calculated by DWM with observation recording (black line) generated by hammer hit

Q = 15 Q = 50(Frequency independent model)Propagation

G03

Time (sec)

4m

8m

10m

12m

14m

16m

18m

20m

6m

0 0.2 0.4 0.6 0.8 1-200000

-190000

-180000

-170000

-160000

-150000

-140000

-130000

-120000

-110000

-100000

-90000

-80000

-70000

-60000

-50000

-40000

-30000

-20000

-10000

0

G03

Time (sec)

4m

8m

10m

12m

14m

16m

18m

20m

6m

0 0.2 0.4 0.6 0.8 1-200000

-190000

-180000

-170000

-160000

-150000

-140000

-130000

-120000

-110000

-100000

-90000

-80000

-70000

-60000

-50000

-40000

-30000

-20000

-10000

0

Dep

th (

m)

S-wave vel. (m/s)0 200 400 600

-60

-50

-40

-30

-20

-10

0

Ricker wavelet used in DWM (G03)

Ricker wavelet used in DWM (G03)

F-K spectraSource (Ricker wavelet 0.03s)

Dominant Period - 0.03s

0.4 0.45 0.5 0.55 0.6

-1

0

1

Frequency (Hz)

Po

we

r sp

ect

rum

Forage

Observation - offset 4m Ricker wave - 0.03s

1 10 1001e-06

1e-05

0.0001

0.001

0.01

0.1

ConclusionConclusion

• We determined the surface profiles in Grenoble area by the MASW method. Also, we made the distribution map of the engineering bedrock (Vs 400-500m/s) in Grenoble area.

• The dispersions of Rayleigh waves obtained by the MASW method are in agreement with those by microtremors.

• The S-wave velocity of 400-500m/sec is entirely appeared in Grenoble basin. On the other hand, the surface velocities higher than Vs 400m/s are quite various. Especially in the middle-west of Grenoble basin, the soft sediment (Vs < 400m/s) is deeply covered.

• We determined the S-wave velocity (Vs > 2km/sec) in rock sites.• The wave-length of Rayleigh waves in Grenoble area observed by

this study is slightly different from the previous model (ESG model).• We proposed the estimation method on quality factors of surface

layers using the waveforms excited by the hammer shot.

Individual dispersion(Sedimental basin)

Individual dispersion(Sedimental basin)

CampusCampus

Phase velocityF-K spectraFrequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Campus


0 10 20 30 40 50

100

200

300

400

500

Wave-length = 57.6m

Wave-length = 45.5m

TaillatTaillat

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Taillat


0 10 20 30 40 50

100

200

300

400

500


Wave-length = 66.5m

Wave-length = 84.7m

G03G03


Pha

se v

elo

city

(m

/se

c)

G03


0 10 20 30 40 50

100

200

300

400

500

Wave-length = 65.7m

Wave-length = 95.8m

ForageForage


Pha

se v

elo

city

(m

/se

c)

Forage


0 10 20 30 40 50

100

200

300

400

500

Wave-length = 53.4m

Wave-length = 26.6m

CaserneCaserne


Pha

se v

elo

city

(m

/se

c)

CASERNE


0 10 20 30 40 50

100

200

300

400

500

600

700

Wave-length = 25.7m

Wave-length = 43.8m

Kawase1Kawase1


Pha

se v

elo

city

(m

/se

c)

Kawase1


0 10 20 30 40 50

100

200

300

400

500

600

700

Wave-length = 33.4m

Wave-length = 23.9m

ImpotImpot


Wave-length = 44.5m

Wave-length = 48.8m

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)IMPOT


0 10 20 30 40 50

100

200

300

400

500

600

700

IllIll


Wave-length = 22.3m

Wave-length = 81.1m

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

ILL


0 10 20 30 40 50 60 70

100

200

300

400

500

Kawase2Kawase2


Pha

se v

elo

city

(m

/se

c)

KAWASE2


0 10 20 30 40 50

100

200

300

400

500

600

700

Wave-length = 44.3m

Wave-length = 41.1m

G12G12


Pha

se v

elo

city

(m

/se

c)

G12


0 10 20 30 40 50

100

200

300

400

500

600

700

Wave-length = 46.5m

Wave-length = 83.2m

MsportMsport


Wave-length = 47.4m

Wave-length = 52.7m

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

MSPORT


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

RailwayRailway


Pha

se v

elo

city

(m

/se

c)

RAILWAY


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Wave-length = 69.4m

Wave-length = 62.5m

G18G18


Pha

se v

elo

city

(m

/se

c)

G18


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Wave-length = 45.5m

Wave-length = 43.3m

MonsieurMonsieur


Pha

se v

elo

city

(m

/se

c)Monsieur


0 10 20 30 40 50

100

200

300

400

500

Wave-length = 41.2m

Wave-length = 39.9m

G15G15


Pha

se v

elo

city

(m

/se

c)

G15


0 10 20 30 40 50

100

200

300

400

500

Wave-length = 33.8m

Wave-length = 30.1m

StadeStade


Wave-length = 35.8m

Wave-length = 71.4m

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

STADE


0 10 20 30 40 50

100

200

300

400

500

Higher mode dispersion -1


Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Campus


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Taillat


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G03


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Forage


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

CASERNE


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

Kawase1


0 10 20 30 40 50

100

200

300

400

500

600

700

Higher mode dispersion -2Higher mode dispersion -2

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G12


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)ILL


0 10 20 30 40 50 60 70

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

MSPORT


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

IMPOT


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

KAWASE2


0 10 20 30 40 50

100

200

300

400

500

600

700

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

RAILWAY


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000



Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G18


0 10 20 30 40 50

100

200

300

400

500

600

700

800

900

1000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)Monsieur


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G15


0 10 20 30 40 50

100

200

300

400

500

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

STADE


0 10 20 30 40 50

100

200

300

400

500

F-K Power spectra -1F-K Power spectra -1F

-K S

pect

ra

Frequency (Hz)

Forage


0 10 20 30 40 50

0.005

0.01

0.015

0.02

F-K

Spe

ctra

Frequency (Hz)

Campus


0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

TAILLAT


0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

G03


0 10 20 30 40 50

0.1

0.2

0.3

0.4

F-K

Spe

ctra

Frequency (Hz)

CASERNE


0 10 20 30 40 50

0.01

0.02

0.03

0.04

F-K

Spe

ctra

Frequency (Hz)

KAWASE1


0 10 20 30 40 50

0.01

0.02

0.03

0.04


-K S

pect

ra

Frequency (Hz)

IMPOT


0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

ILL


0 10 20 30 40 50

0.005

0.01

0.015

0.02

F-K

Spe

ctra

Frequency (Hz)

KAWASE2


0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

MSPORT


0 10 20 30 40 50

0.01

0.02

0.03

0.04

F-K

Spe

ctra

Frequency (Hz)

RAILWAY


0 10 20 30 40 50

0.01

0.02

0.03

0.04

F-K

Spe

ctra

Frequency (Hz)

G12


0 10 20 30 40 50

0.05

0.1

0.15

0.2


-K S

pect

ra

Frequency (Hz)

G18


0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

MONSIEUR


0 10 20 30 40 50

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

G15


0 10 20 30 40 50

0.005

0.01

0.015

0.02

F-K

Spe

ctra

Frequency (Hz)

STADE


0 10 20 30 40 50

0.05

0.1

0.15

0.2

Individual dispersion(Rock sites)

Individual dispersion(Rock sites)

Bastile - Rayleigh waveBastile - Rayleigh wave


Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

Wave-length = 20.7m

Wave-length = 92.9m

G17 - Rayleigh waveG17 - Rayleigh wave


Wave-length = 32m

Wave-length = 94.2m

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

G10 - Rayleigh waveG10 - Rayleigh wave


Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Wave-length = 34.9m

Wave-length = 101.5m

Bastile - Love waveBastile - Love wave


Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

1000

2000

3000

4000

Wave-length = 29.4m


G17 - Love waveG17 - Love wave


Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50

500

1000

1500

2000

Wave-length = 31.3m

Wave-length = 53.4m

G10 - Love waveG10 - Love wave


Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Wave-length = 19.3m


Higher mode and Love wave dispersion

Higher mode and Love wave dispersion

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Love Wave

Rayleigh Wave

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

1000

2000

3000

4000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G17


0 10 20 30 40 50

500

1000

1500

2000

Frequency (Hz)

Pha

se v

elo

city

(m

/se

c)

G10


0 10 20 30 40 50 60 70 80 90 100

500

1000

1500

2000

2500

3000

3500

4000

F-K Power spectra - R. and L.

F-K Power spectra - R. and L.

F-K

Spe

ctra

Frequency (Hz)

G10


0 10 20 30 40 50 60 70 80 90 100

0.05

0.1

0.15

0.2

F-K

Spe

ctra

Frequency (Hz)

G17


0 10 20 30 40 50 60 70 80 90 100

0.2

0.4

0.6

0.8

F-K

Spe

ctra

Frequency (Hz)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

0.02

0.04

0.06

0.08

F-K

Spe

ctra

Frequency (Hz)

BASTILLE


0 10 20 30 40 50 60 70 80 90 100

0.02

0.04

0.06

0.08

F-K

Spe

ctra

Frequency (Hz)

G17


0 10 20 30 40 50 60 70 80 90 100

0.2

0.4

0.6

0.8

F-K

Spe

ctra

Frequency (Hz)

G10


0 10 20 30 40 50 60 70 80 90 100

0.05

0.1

0.15

0.2

Love Wave

Rayleigh Wave

Next stepNext step• Estimation of S-wave velocity structures at measurement sites• Categorization of surface structures in Grenoble Basin• Comparison of the geological data• Detecting of common minimum velocity layer in Grenoble - for 3D simulation• For this purpose, do we need to take into account the results of array microtremors ?• Do we need to make more MASW measurements in Grenoble basin, for detail categorization on surface structures ? • Comparison these results with the proposed model

• Confirmation of the estimated shallow structures by using earthquake recordings (which recordings do we select ?)• We would estimate the damping factor on surface by applying the waveform inversion with the discrete wave-number method.• We include the higher mode and/or Love wave dispersion, to invert the S-wave velocity structures.

InversionInversion

We have three steps to invert the basin structures.

• With the dispersion of Rayleigh wave estimated by MASW method

• Taking account of the dispersion estimated by Array Microtermors

→ To determine deeper structures

• Including of Higher modes and/or the dispersion of Love wave

→ To determine structures in detail

Measurement errorsMeasurement errors

Time (sec)dV

/V (

Per

.)

Error

T=0.05s

T=0.1s

0 0.02 0.04 0.06 0.08

0

10

20

30

40

50

Distance (m)

dV/V

(P

er.)

Error

D=3m

D=2m

0 0.2 0.4 0.6 0.8 1

0

10

20

30

40

50

Time errorDistance error

Spectral inversion using earthquake

recording

Spectral inversion using earthquake

recording

Documents

The surface profiles in Grenoble area determined by the MASW measurements