SLOW GROUND MOTION STUDIES IN KEK · Slow Ground Motion Studies in KEK Frequency Dependence of...
Transcript of SLOW GROUND MOTION STUDIES IN KEK · Slow Ground Motion Studies in KEK Frequency Dependence of...
Yamamoto and Takeda
Slow Ground Motion Studies in KEK
SLOW GROUND MOTION STUDIES IN KEK Geology DependenceGeology DependenceGeology DependenceGeology Dependence
Noboru Yamamoto and Shigeru Takeda
KEK, High Energy Accelerator Research Organization
Power Spectrum Density and Coherence Slow Ground Motion and Geology Slow Ground Motion and Excavation MethodsSlow Ground Motion and Excavation MethodsSlow Ground Motion and Excavation MethodsSlow Ground Motion and Excavation Methods
Slow Ground Motion Studies in KEK Typical Parameters of JLC
Typical Parameters of Linear Collider
XXXX----bandbandbandband CCCC----bandbandbandband Beam Energy Entrance/Exit Beam Energy Entrance/Exit Beam Energy Entrance/Exit Beam Energy Entrance/Exit E0/E1E0/E1E0/E1E0/E1 10/50010/50010/50010/500 10/50010/50010/50010/500 GeVGeVGeVGeV Particles/bunch Particles/bunch Particles/bunch Particles/bunch N N N N 0.8 0.8 0.8 0.8 1.0 1.0 1.0 1.0 10 10 10 1010101010
Invariant Emittance Invariant Emittance Invariant Emittance Invariant Emittance ε N y 30 30 30 30 30 30 30 30 nm nm nm nm Bunch length Bunch length Bunch length Bunch length σ z 80 80 80 80 200 200 200 200 µµµµmmmm β at entrance at entrance at entrance at entrance β 0 4 4 4 4 4 4 4 4 m m m m Rf Rf Rf Rf frequencyfrequencyfrequencyfrequency ffff 11.4 11.4 11.4 11.4 5.7 5.7 5.7 5.7 G G G GHHHHzzzz Accel. gradient Accel. gradient Accel. gradient Accel. gradient dE/dsdE/dsdE/dsdE/ds 45 45 45 45 32 32 32 32 MeV/mMeV/mMeV/mMeV/m Iris radius/wavelength Iris radius/wavelength Iris radius/wavelength Iris radius/wavelength a / λ 0.16 0.16 0.16 0.16 0.14 0.14 0.14 0.14
ATL coefficient ATL coefficient ATL coefficient ATL coefficient A A A A 1 1 1 1 1 1 1 1 nm nm nm nm2222/s/m/s/m/s/m/s/m Stable time for Stable time for Stable time for Stable time for ∈ =0.1 =0.1 =0.1 =0.1 tttt 3 3 3 3 24 24 24 24 hours hours hours hours
Yamamoto and Takeda
Slow Ground Motion Studies in KEK Sensors for Ground Motion Studies
Yamamoto and Takeda
ATL COEFFICIENT in JAPAN
No Site Name A (nm2/m/sec) Geology of the Place1 Tunnel of KEKB 4.0E+01 Clay and Gravel2 Rokkoh-1 3.6E+01 Granite (near Fault)3 Rokkoh-2 3.3E+01 Granite4 Miyazaki 1.5E+01 Diorite5 Kamaishi-1 1.4E-01 Granite (Crack and Water)6 Kamaishi-2 5.7E-02 Granite7 Sazare 5.0E-02 Green Schist8 Esashi-1 5.7E-03 Granite (Floating Stone)9 Esashi-2 2.0E-03 Granite
Geological Map of Japan and the Present Data Taking Site.
Described numbers are the same in figures and Table.
No. 1
No. 2, 3
No. 4
No. 5, 6
No. 7
No. 8, 9
GRANITE GOOD for LC
Sedimentary Layer
Volcanic Rock
Slow Ground Motion Studies in KEK Geological Map and Sites for Data Taking
Yamamoto and Takeda
Yamamoto and Takeda
Slow Ground Motion Studies in KEK Frequency Dependence of Ground Motion
1E-71E-61E-5 1E-41E-31E-2 1E-1 1 1E1 1E21E-161E-151E-141E-131E-121E-111E-10
1E-91E-81E-71E-61E-51E-41E-31E-21E-11E01E11E21E31E41E51E61E71E81E9
1/f4
1/f 2
OCEAN SWELL
SAZARE
EARTH-TIDESPo
wer
Spe
ctru
m D
ensi
ty ( µ µµµ
m2 /H
z)
frequency (Hz)
frequency range f<0.1 Hz: The measured power spectrum of ground motion can be characterized by 2/ fk . This coefficient k has site dependence and changes from 1 to 102 nm2/Hz. The earth-tide, one of the elastic motions in this low frequency range, becomes cause of inelastic motion through its dissipation. One of the models describing this inelastic ground motion is the ATL model.
frequency range f>0.1 Hz: The power spectrum density decreases very rapidly with frequency being proportional to 4/1 f .
Slow Ground Motion Studies in KEK What Happen in the Noisy Site (f>0.01Hz)
1E-2 1E-1 1 10 1E21E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
1
10
1E2
Quiet Site: Sazare
Traf
fic N
oise
s
Pow
er S
pect
ral D
ensi
ty ( µ µµµ
m2 /H
z)
frequency (Hz)
Noisy Site: KEK
Earth
quak
e an
d Ar
tific
ial N
oise
s
Ocean Swell
Ground motion in the noisy site (KEK). Coherence between two points at a distance of 48 m. Power spectra for the two points are the same. Incoherent spectrum is given by the equation shown in the figure. A big bump spectrum, around 0.2 Hz, corresponds to the ocean swell. The incoherent spectrum around 3 Hz comes from traffic noises. This incoherent vibration gives an amplitude of 83 nm. That is, the tunnel in KEK should have a depth of 900 m, providing we want the amplitude of 1 nm.
1E-2 1E-1 1 101E-5
1E-4
1E-3
1E-2
1E-1
1
10
Pow
er S
pect
rum
Den
sity
(µ µµµm
2 /Hz)
frequency (Hz)
1E-3
1E-2
1E-1
1
(1-Coherence) x (RAW SPECTRUM)
RAW SPECTRUM
Coh
eren
ce
Yamamoto and Takeda
Slow Ground Motion Studies in KEK What Happen in the Noisy Site (f>0.1 Hz)
1 10 1E21E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
1E-2
1E-1
QUIET SITE No. 4
NOISY SITE No. 3
Spec
trum
(µ µµµm
2 /Hz)
frequency (Hz)
1E-2 1E-1 1 10
1E-1
1No 3
No 2
CO
HER
ENC
E
frequency (Hz)
Coherence in the Granite tunnel. Two sensors at a
distance of 60 meters are used to get coherence. No. 3
shows that both sensors stand on the good granite rocks.
No. 2 shows that there is a fault, about 10 m wide, among
the sensors. The amplitude of No. 2 is rapidly decrease in
the frequency range higher than 0.4 Hz. No. 2 also shows
the amplitude is about 0.85 in the frequency range lower
than 0.3 Hz. But A is not so different each other as shown
in the table of ATL COEFFICIENT.
Yamamoto and Takeda
Slow Ground Motion Studies in KEK What Happen in the Tidal Frequency Region
2627282930313233343536
0 2880 5760 8640 11520 14400 17280 20160 23040-33-32-31-30-29-28-27-26-25-24-23
-3-2-101234567
#2
time (min)
Ground Motion at Esashi (by LSHF)
#1
#3Ve
rtica
l Pos
ition
(µ µµµm
)
The time series data on the vertical ground motions observed at three points being 14 m apart between one another.
Yamamoto and Takeda
Yamamoto and Takeda
Slow Ground Motion Studies in KEK What Happen in the Tidal Frequency Region
1E-6 1E-5 1E-4 1E-3 1E-21E-4
1E-3
1E-2
1E-1
1
10
1E2
1E3
1E4
1E5Ground Motion at Esashi (by LSHF)
#2
#1
Pow
er S
pect
rum
Den
sity
( µ µµµm
2 /Hz)
frequency (Hz)
1E-6 1E-5 1E-4 1E-3 1E-2
1E-1
1
1E-1
1
#1-#2
CO
HER
ENCE
frequency (Hz)
#2-#3
Coherence in the Granite Tunnel Having a Floating Lumped Rock.
Except the #1 lumped rock position, we get good coherence.
#1 shows no earth-tide spectrum. ATL coefficient in this point is a little bad as shown in the previous ATL Table.
Slow Ground Motion Studies in KEK What Happen in the Tidal Frequency Region
Yamamoto and Takeda
N
3 km from the Entrance
<Dam>:Controls the Ground Water Level
Excavated by Slow Blasting Method
#1~#4:Geodetic Platform Tiltmeter (Resolution: 0.05μrad)Auxiliary Sensor: 3D Velocity Vibration Meter
Granite Flat Base, on which the sensor is setting up.
#1 17 m#2 17 m
#3 17 m#4
1E-6 1E-5 1E-4 1E-3 1E-2
1E-1
1
1E-1
1
1E-1
1
COH
EREN
CE
9910frequency (Hz)
X1-X2
X1-X3
X2-X3
EFFECT of BLASTING CREVICE:
We executed several experiments to get detailed information
about the surface layer of the granite tunnel cut by SBM.
The coherence shows very complex changes without the dam.
Slow Ground Motion Studies in KEK What Happen in the Tidal Frequency Region
Yamamoto and Takeda
1E-5 1E-4 1E-3 1E-21E-4
1E-3
1E-2
1E-1
1
10
1E2
1E3
1E4
1E5
EARTH-TIDES
2 mHz
X1
X2
X4
Tilt
( µ µµµra
d2 /Hz)
Frequency (Hz)
1E-1
1
1E-1
1
1E-6 1E-5 1E-4 1E-3 1E-2
1E-1
1
X1-X2
X3-X2
X4-X2
CO
HER
ENC
E
Frequency (Hz)
In order to check the activity of underground water, we built
a dam across the flow to control the water level in the crevice.
• #2 was mostly suffered by the reaction between the crevice and
the water.
• #4 is another effect, such as lumped rock like Esashi.