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Structural Health Monitoring of Structural Health Monitoring of Huge Traditional Timber Structure Huge Traditional Timber Structure
in Japanin Japan
Kyoto Univ. (Japan)Kyoto Univ. (Japan) Yasuhiro HAYASHIYasuhiro HAYASHIGoei-do
Wooden Framed Structure of Wooden Framed Structure of GoeiGoei--dodo
http://www.tomo-net.or.jp/
2
Typical Beams of Typical Beams of GoeiGoei--dodo
http://www.tomo-net.or.jp/
http://www.tomo-net.or.jp/
3
Kyoto-net K-NETKyoto-net（Wood houses）
Seismic Seismic Observation Observation Network Network in Kyotoin Kyoto
(Kyoto(Kyoto--net)net)Hongan-ji
Kyoto
Goei-do Mon(12)
Goei-do(27)Amida-do(12)
Free field(6)
Observed StructuresObserved Structures（（No. of comp.No. of comp.））
4
Arrangement of SeismometersArrangement of Seismometers
NS69.7m
37.4m
Gojyu
Sanjyu
Ushibiki
Ashigatame
Kidan
59.1mWE
NS WENS WE
(b) Amida-do (c) Goei-do Mon
(a) Goei-do
・Strong motion・Ambient Vibration
（once a week）
SeismometersSeismometers
5
Fundamental Vibration Mode of Fundamental Vibration Mode of GoeiGoei--dodo
f=0.8Hz (Long. direction)f=0.8Hz (Trans. direction)
0.7
0.8
0.9Goei-do (Long.) Goei-do (Trans.)
03/11 04/1 04/3 04/5 04/7 04/9 04/11 05/1
Freq
uenc
y (H
z)
DATE
0.9
1
1.1
1.2Amida-do (Long.) Amida-do (Trans.)
03/11 04/1 04/3 04/5 04/7 04/9 04/11 05/1
Freq
uenc
y (H
z)
DATE
0.91
1.1
1.21.3
1.4Goei-do Mon (Long.) Goei-do Mon (Trans.)
03/11 04/1 04/3 04/5 04/7 04/9 04/11 05/1
Freq
uenc
y (H
z)
DATE
Seasonal Variation in Natural FrequencySeasonal Variation in Natural Frequency2003.112003.11--2004.122004.12
30
50
70
90Original data
03/11 04/1 04/3 04/5 04/7 04/9 04/11 05/1
Ave
rage
rela
tive
hum
idity
(o)
DATE
Smoothed data
0
20
40Original data
03/11 04/1 04/3 04/5 04/7 04/9 04/11 05/1Ave
rage
tem
pera
ture
(o)
DATE
Smoothed data
0
2
4
6 Original data
03/11 04/1 04/3 04/5 04/7 04/9 04/11 05/1
Ave
rage
win
d ve
loci
ty (m
/s)
DATE
Smoothed data
Temperature
Humidity
Wind velocity
Goei-do
Amida-do
Goei-do Mon
6
Observed Earthquake RecordsObserved Earthquake Records
No.5No.16
No.27
No.10
No.9
No.2
No.8
No.17No.18
No.20No.19
No.21
No.25
No.1
No.22-24
No.3,4No.6,7,11-15
Higashi Honganji templeEpicenter Mjma
(a) Hypocenters (b) Frequency of PGVs
0
5
10
15
0 5 10 15 20 25 30Fr
eque
ncy
PGV (mm/s)
Honganji The Tokai-do EQ.
-30
0
30
0 50 100 150 200 250 300Time (s)
Vel
ocity
(m
m/s
)
Ground velocity （Long. direction）
The TokaiThe Tokai--do earthquakedo earthquake（（2004/09/062004/09/06））
-3
0
3
0 50 100 150 200 250 300Time (s)
Rel
. dis
p. (
mm
)
Long. (NS)
Relative displacement
7
Fourier spectral ratio of Fourier spectral ratio of GoeiGoei--dodo
0
20
40
0 1 2 3
Long.Trans.
Spec
tral
rat
io
Frequency (Hz)
Goei-doPGV=0.7mm/s
22mm/s
The Tokai-do EQ.
Variation of natural frequency Variation of natural frequency during observed earthquakesduring observed earthquakes
0.5
0.6
0.7
0.8
0.9
0.001 0.01 0.1 1 10
Long.Trans.
Peak
freq
uenc
y (H
z)
Max relative displacement (mm)
8
(a) Natural frequency
(b) Relative displacement
Temporal Variation of Temporal Variation of natural frequency and vibration modenatural frequency and vibration mode
0.5
0.6
0.7
0.8
0 50 100 150 200 250 300
Translational Torsional
Time (s)N
atur
al f
req.
(H
z)
a
bc
d ef
gh
0
1
2
0 50 100 150 200 250 300
Translational Torsional
Time (s)
Rel
. dis
p. (m
m)
ab c d e f g h
ConclusionsConclusions
• The natural frequencies of the three timber structures are identified to be ranging from 0.8 to 1.3 Hz from ambient vibration measurements.
• The seasonal variation in the natural frequency average due to humidity is about 5% of the annual average.
• Natural frequency decreases drastically as the deformation increases but recovers to the original value as the deformation decreases.
• When considering the seismic safety of the Goei-do, torsionalresponse should be considered. Because torsional response will be dominant as the total response increases.
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