CHIEN-WEN HUANG DOCTORAL STUDENT TOKYO METROPOLITAN UNIVERSITY

MESUREMENT OF PORE WATER PRESSURE IN A GROUND, TEMPERATURE AND RAINFALL AT SLOPE FAILURE　 IN

MOUNTAINOUS AREA

CHIEN-WEN HUANGDOCTORAL STUDENTTOKYO METROPOLITAN UNIVERSITY首　都　大　学　東　京

TOKYO METROPOLITAN UNIVERSITY

INTRODUCTION

MONITORING SYSTEM INSTALLATION

MONITORING RESUTLS

FUTURE SCOPES

首　都　大　学　東　京TOKYO METROPOLITAN UNIVERSITY

INTRODUCTION


INTRODUCTION

August 2011

October 2012

Fudo Sawa, Takase River ,Nagano Prefecture, Japan

Loss of Storage capacity and subsequent effect:

Specific Sedimentation Rate of Reservoir at Takase Dam :5,020m3/km2/year

Fudosawa contributed 35,000m3/km2/year of sedimentation

Predict the phenomena and propose effective countermeasures and simulate a model to against slope failure.


RESEARCH PURPOSE

Wetting Front

Slip Surface

Unsaturated Zone

Saturated Zone

Ground Water Table

10/1

811

/111

/15

11/2

912

/13

12/2

71/

101/

24 2/7

2/21 3/7

3/21 4/4

4/18 5/2

5/16

5/30

6/13

6/27

7/11

7/25 8/8

8/22 9/5

9/19

10/3

10/1

710

/31

11/1

411

/28

12/1

212

/26

1/9

1/23 2/6

2/20 3/5

3/19 4/2

4/16

4/30

5/14

5/28

6/11

6/25 7/9

7/23 8/6

8/20-15

-10

-5

0

5

10

15

20

25

30

CH4CH1CH3

CH5

CH2 CH1 CH2 CH3 CH4 CH5 CH6

Tem

pera

ture

(cen

tigra

de)

Day (2010 - 2012)

CH6

2010 2011 2012

CH5

Snow Season

CH6 Damaged

e f

Snow Season

a b c

Phase 1 Phase 2

d

-40

-30

-20

-10

0

10

20

30

40

50

10/1

811

/111

/15

11/2

912

/13

12/2

71/

101/

24 2/7

2/21 3/7

3/21 4/4

4/18 5/2

5/16

5/30

6/13

6/27

7/11

7/25 8/8

8/22 9/5

9/19

10/3

10/1

710

/31

11/1

411

/28

12/1

212

/26

1/9

1/23 2/6

2/20 3/5

3/19 4/2

4/16

4/30

5/14

5/28

6/11

6/25 7/9

7/23 8/6

8/20 9/3

9/17

10/1

10/1

510

/29-60

-50

-40

-30

-20

-10

0

10

20

30

CH5

CH3

CH1 CH2 CH3 CH4

Por

e w

ater

pre

ssur

e (c

m H

2O)

Day (2010 - 2012)

CH4CH1

Tem

pera

ture

at g

roun

d su

rface

(cen

tigra

de)

CH2

2010 2011 2012

　　Snow Season Snow Season

Phase 1 Phase 20

10

20

30

40

50

60

70

80

90

100

10/1

811

/111

/15

11/2

912

/13

12/2

71/

101/

24 2/7

2/21 3/

73/

21 4/4

4/18 5/

25/

165/

306/

136/

277/

117/

25 8/8

8/22 9/

59/

1910

/310

/17

10/3

111

/14

11/2

812

/12

12/2

61/

91/

23 2/6

2/20 3/

53/

19 4/2

4/16

4/30

5/14

5/28

6/11

6/25 7/

97/

23 8/6

8/20 9/

39/

1710

/110

/15

10/2

9-70

-60

-50

-40

-30

-20

-10

0

10

20

30

CH1 CH2 CH3 CH4

Por

e w

ater

pre

ssur

e (c

m H

2O)

Day (2010 - 2012)

CH2CH3

CH4

Rai

nfal

l (m

m/d

ay) a

t F

udos

awa an

d Om

achi

CH1

2010 2011 2012

Snow Season Snow Season

Phase 1 Phase 2

Daily Monitoring

Hazard PredictionMeasurement Results


GEOLOGICAL CONDITION Altitude:1,550m~1,600m Ave. Temperature:-16ºC~30ºC Ave. Precipitation:2,100mm/year Late Cretaceous – Paleogene Granite Rocks

Nagano Prefecture

Nagano City

Lake Suwa

OmachiFudo SawaTalus Cone Deposit


LOCATION OVERVIEW

~33m

~65m~ 99m

Rain GaugePore power pressure Gauges


A

B

C

GRAIN SIZE DISTRIBUTION

0.001 0.01 0.1 1 10 1000

20

40

60

80

100

通過質量百分率

(％)

粒径 (mm)

赤色 No.1緑色 No.2青色 No.3黄色 No.4△ ふるい分け試験1□ ふるい分け試験2○ 沈降試験

• Granular Soil with D50=4.5mm


Grain Size (mm)

Perc

ent F

iner

by

Wei

ght (

%)

134

5 6 7 8

2

124

5

6

7

8

Fudo Sawa

Takase Dam

Observation Point

3

By Google

Comparison

October 27, 2012

November 11, 2010 July 31, 2012

July 31, 2012 October 27, 2012

Comparison

MONITORING SYSTEM INSTALLATION AND MEASUREMENT


MONITORING SYSTEM COMPONETS

z

Pore Water Pressure Gauges

Data Logger Rain Gauge

Thermometer

Camera


A B

MONITORING SYSTEM LAYOUT


Monitoring System Installation Process

1 2 3

4 5 6

Drilling Borehole Borehole Depth

Measurement Placement of Pore Water

Pressure Gauge Rain Gauge Installation Thermometer Installation Data Logger Setup Camera Setup

MONITORING SYSTEM COMPONETS

7


WHO DOES THE BEST JOBS FOR THE FIELD TRIP IN THE WORLD

MONITORING RESULTS


PORE WATER PRESSURE IN THE SLOPE ANDTEMPERATURE AT GOURND SURFACE

-40

-30

-20

-10

0

10

20

30

40

50

10/1

811

/111

/15

11/2

912

/13

12/2

71/

101/

24 2/7

2/21 3/

73/

21 4/4

4/18 5/2

5/16

5/30

6/13

6/27

7/11

7/25 8/8

8/22 9/5

9/19

10/3

10/1

710

/31

11/1

411

/28

12/1

212

/26

1/9

1/23 2/

62/

20 3/5

3/19 4/

24/

164/

305/

145/

286/

116/

25 7/9

7/23 8/6

8/20 9/3

9/17

10/1

10/1

510

/29-60

-50

-40

-30

-20

-10

0

10

20

30

CH5

CH3

CH1 CH2 CH3 CH4

Por

e w

ater

pre

ssur

e (c

m H

2O)

Day (2010 - 2012)

CH4CH1

Tem

pera

ture

at g

roun

d su

rface

(cen

tigra

de)

CH2

2010 2011 2012

　　Snow Season Snow Season

Phase 1 Phase 2

Typhoon Jelawat


Pore water pressure decreased

INTERACTION BETWEEN PORE WATER PRESSURE IN THE SLOPE AND INTENSITY OF RAINFALL

0

10

20

30

40

50

60

70

80

90

100

10/1

811

/111

/15

11/2

912

/13

12/2

71/

101/

24 2/7

2/21 3/7

3/21 4/4

4/18 5/2

5/16

5/30

6/13

6/27

7/11

7/25 8/8

8/22 9/5

9/19

10/3

10/1

710

/31

11/1

411

/28

12/1

212

/26

1/9

1/23 2/6

2/20 3/5

3/19 4/2

4/16

4/30

5/14

5/28

6/11

6/25 7/9

7/23 8/6

8/20 9/3

9/17

10/1

10/1

510

/29-70

-60

-50

-40

-30

-20

-10

0

10

20

30

CH1 CH2 CH3 CH4

Por

e w

ater

pre

ssur

e (c

m H

2O)

Day (2010 - 2012)

CH2CH3

CH4

Rai

nfal

l (m

m/d

ay) a

t Fud

osaw

a an

d O

mac

hi

CH1

2010 2011 2012

Snow Season Snow Season

Phase 1 Phase 2 Typhoon JelawatTyphoon Onyok


Heavy Rain Warning

INTERACTION BETWEEN PORE WATER PRESSURE IN THE SLOPE AND INTENSITY OF RAINFALL

0

10

20

30

40

50

60

70

80

90

100

8/1

8/3

8/5

8/7

8/9

8/11

8/13

8/15

8/17

8/19

8/21

8/23

8/25

8/27

8/29

8/31 9/2

9/4

9/6

9/8

9/10

9/12

9/14

9/16

9/18

9/20

9/22

9/24

9/26

9/28

9/30

10/2

10/4

10/6

10/8

10/1

010

/12

10/1

410

/16

10/1

810

/20

10/2

210

/24

10/2

610

/28

10/3

0-70

-60

-50

-40

-30

-20

-10

0

10

20

30

CH1 CH2 CH3 CH4

Por

e w

ater

pre

ssur

e (c

m H

2O)

Day (2012)

CH2

CH3

CH4

Rai

nfal

l (m

m/d

ay) a

t Fud

osaw

a an

d O

mac

hi

CH1

Typhoon Jelawat

Typhoon Jelawat台風 17号　ジェラワット

Rock

Flood

Soil Washed out

FUTURE SCOPES

Simulating the real time pore water pressure and rainfall distribution in time history after rainfall events based on the data collected through monitoring system.

MODEL SIMULATION

The fist step of the slope monitoring for modeling of changes in pore water pressure response in ground due to rain fall.

SLOPE MONITORING

1 21

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CHIEN-WEN HUANG DOCTORAL STUDENT TOKYO METROPOLITAN UNIVERSITY