26 june 2012 korea rural research institute gun heo
TRANSCRIPT
26 June 2012
Korea Rural Research Institute
Gun Heo
Piezometer Installation
IntroductionII
ConclusionsVV
ContentsContents
In-situ ExperimentsIIII
Results and Discussion
IIIIII
IVIV
- Borehole Image Processing System (BIPS)
- In-Situ permeability test
Background & PurposeBackground & Purpose
• Seawater Blocking
• Securing fresh water
• Development Internal
Purpose of Seadike
• The riprap-bottom layer connects
both
seaside and lakeside, so permeable
• Reclaimed with dredged sands
Construction Condition ofthe Final Closing Section
• Piping and Erosion Embankment
• Desalination delay due to
excessive infiltration
were Concerned
Evaluate the status of riprap layer
Establish a long-term monitoring plan
Evaluate the status of riprap layer
Establish a long-term monitoring plan
Determine whether need reinforcement
Effective Safety management seadike
Determine whether need reinforcement
Effective Safety management seadike
Dredged SandsDredged Sands
Riprap Bottom LayerRiprap Bottom Layer
Outline
To evaluate the Filling Status
Filling Status
To evaluate the Permeation
Permeation
To measure the Pore Pressure
Installation PiezometerItems
Borehole Image Processing System (BIPS)
In-situ Permeability test Installation Piezometers and Building Monitoring System(Automated)
Visually check the Filling Status of the Bottom Layer.
Comparison the degree of
permeability
(General / Final closing)
Long-term Monitoring ⇒ Evaluate the temporal variation of Filling Status ⇒Propose Criteria for Monitoring
Purpose
Detailed Task
Utilization
• Determine whether need
reinforcement
• Safety Management
• Determine whether need
reinforcement
• Safety Management
Field test results + Data measured
• Evaluated Current state of the filling
& temporal variation of Filling Status
• Proposed Criteria for Monitoring
Bottom Protection Layer of the Final Closing SectionBottom Protection Layer of the Final Closing Section
< General Section > < Final Closing Section L = 1.8 km > < General Section>
To find the most vulnerable sections…
Electrical Resistivity ResultsElectrical Resistivity Results
electrical resistivity results of No. 59+60~No. 62+35 (5m electrode gap)electrical resistivity results of No. 59+60~No. 62+35 (5m electrode gap)
BelowBelow
Above Above
No. 60+25 Relatively low resistivity and showing the continuity sections No. 60+25 Relatively low resistivity and showing the continuity sections
Selected Sections(3 Final Closing Sections, 1 General Section)Selected Sections(3 Final Closing Sections, 1 General Section)
<Final Closing> No. 60 + 25
<Final Closing> No. 65 + 00
<Final Closing> No. 69 + 80
<General> No. 82 + 00
BIPS (Borehole Image Processing System)BIPS (Borehole Image Processing System)
BIPSBIPS
• To decipher the filling degree of the bottom layer
No of
HallsLocation Focused
4Near the
PiezometerRiprap
Bottom Layer
•Top (13.9m)
•Dredged Sands
•Riprap
• Riprap
• Dredged Sands
• Bottom (17.1m)
Results
In-situ Permeability testIn-situ Permeability test
Permeability TestPermeability Test ResultsResults
To compare the differences in permeability coefficients Number Location Test Section
Permeability
Coefficient k(cm/s)Remarks
BH-1 60+25Embankment 1.48×10-3
Final Closing Section
Bottom Layer 3.25×10-3
BH-2 65+00Embankment 2.38×10-3
Bottom Layer 2.29×10-3
BH-3 69+80Embankment 9.41×10-4
Bottom Layer 2.09×10-3
BH-4 82+00Embankment 1.25×10-4
General SectionBottom Layer 9.17×10-4
<Embankment/Bottom Layer> <General/Final Closing>
The differences are not significant
No of
HallsLocation Focused
4Near the
PiezometerRiprap Bottom
Layer
Casing
Installation PiezometersInstallation Piezometers
10
PiezometerPiezometer Cross-SectionalCross-Sectional
I General Section
3 Final Sections
Location
Piezometer
Items
• Automated measurement system
has been built for four-sections
• By measuring the pore pressure,
Compare those between general
section and Final closing sections,
evaluate the filling status of the
bottom layer
• In addition, by conducting long-term
monitoring , evaluate the safety of
seadike with hydraulic head loss ratio
• Arranged piezometers to compare the pore pressure of each
section
(between the final closing section and normal section)
• Arranged piezometers to compare the pore pressure of each point
• (between P1 and P3, P3 and P7)
• 4 piezometers in bottom protection layer (P-1,3,5,7)
• 4 piezometers in embankment (P-2,4,6,8)
CL
18.60
4.50
14.10
18.50
4.00
14.50
13.60
5.00
8.60
13.00
4.00
9.00
21.20
4.50
16.70
15.00
5.00
10.00
CLCL
CLCL
20.00 20.00 21.50
16.40
5.10
9.07
4.70
13.80P- 2
EL(+)5.25EL(+)3.88
EL(-)10.06
EL(-)5.56
EL(-)8.86
EL(-)10.64
EL(-)5.54
EL(-)9.14 EL(-)9.75 EL(-)9.89
EL(-)4.75 EL(-)5.19
EL(+)11.18 EL(+)10.91
EL(+)5.47EL(+)3.73
EL(-)7.42 EL(-)7.59EL(-)8.13 EL(-)9.27
EL(-)2.92 EL(-)3.59 EL(-)3.13
EL(-)5.27
W- 1 W- 2
P- 1P- 3
P- 3
P- 4
P- 4
P- 5
P- 5
P- 6
P- 6
P- 7
P- 7
P- 8
P- 8
P- 1
P- 2
Monitoring ProgramMonitoring Program
방조제평면도
상단메뉴
계측단면도
최근계측데이터실시간표시
수두손실율그래프 간극수압그래프
경고표출범례
범례 및계측요약
Floor plan
Menu Bar
Cross-section
Hydraulic Head Loss Ratio Pore pressure
Legend
Measured Value
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
센서 측정 테스트
Measurement Results No.60+25(Final Closing section)Measurement Results No.60+25(Final Closing section)
P1P1 P3P3
P5P5 P7P7
• Pore pressure changes due to tidal fluctuations that are quite stable
• From sea side to the lake side, the changes in pore pressure gradually decreases
Time(day) Time(day)
Time(day) Time(day)
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
Measurement Results No.65+00(Final Closing section)Measurement Results No.65+00(Final Closing section)
P1P1 P3P3
P5P5 P7P7
• Pore pressure changes due to tidal fluctuations that are stable
• From the sea side to the lake side, the changes in pore pressure gradually decreases
Time(day) Time(day)
Time(day) Time(day)
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
Measurement Results No.69+80(Final Closing section)Measurement Results No.69+80(Final Closing section)
P1P1 P3P3
P5P5 P7P7
• Pore pressure changes due to tidal fluctuations that are stable
• From the sea side to the lake side, the changes in pore pressure gradually decreases
Time(day) Time(day)
Time(day) Time(day)
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.2
0.4
0.6
0.8
1.0
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
간극수압
(kg
/)
간극
수압
㎠
0.0
0.3
0.6
0.9
1.2
1.5
2011-09-10 2011-09-17 2011-09-24 2011-10-01 2011-10-08 2011-10-15
Measurement Results No.82+00(General section)Measurement Results No.82+00(General section)
P1P1 P3P3
P5P5 P7P7
• Pore pressure changes due to tidal fluctuations that are stable
• From the sea side to the lake side, the changes in pore pressure gradually decreases
• General section shows a smaller value than final closing section.
Time(day) Time(day)
Time(day) Time(day)
Building Monitoring SystemBuilding Monitoring System
• Installation Piezometer
- 3 on the final closing sections(No.60+25, No.65+00, No.69+80)
- 1 on the general section(No.82+00)
- 8 Piezometers are installed on each section
• Monitoring Program
- Express the results and Monitor for long-term
• Installation Piezometer
- 3 on the final closing sections(No.60+25, No.65+00, No.69+80)
- 1 on the general section(No.82+00)
- 8 Piezometers are installed on each section
• Monitoring Program
- Express the results and Monitor for long-term
SummarySummary
• Every piezometer is operating properly
• Reliable pore pressure data are being collected
• Sea-side : Large Fluctuation, Lake-side : Small Fluctuation
• Every piezometer is operating properly
• Reliable pore pressure data are being collected
• Sea-side : Large Fluctuation, Lake-side : Small Fluctuation
Hydraulic Head Loss RatioHydraulic Head Loss Ratio
Hydraulic Head Loss RatioHydraulic Head Loss RatioTide/Pore pressure HeadTide/Pore pressure Head
1
21
P
PP
H
HHa
• a : Hydraulic Head Loss Ratio
• ΔHp1,2 : changes of pore pressure head at P1, P2
• “a” has the value of 0~1
• when a=0, ΔHp1 = ΔHp2,
• a=1, ΔHp2 = 0 ← NOT affected by tide at all
P1=tide level EL(m)
P1
-P2
EL(
m)
R2=Coefficient of determination
• The value of 0~1
• Closer to 0, Unstable
• Closer to 1, stable
Time (day)
Tide (m)Pore pressure head (m)
• Overlapped two graphs.
• Gray : tide level
• Black : Pore pressure Head of somewhere inside the structure which is affected by tide
• but, depends on the position and the time, the ranges of pore pressure will be changed
• Hard to set a criteria
Criteria(?)Criteria(?)
P1 P2
해측
내측내측제체
Sea-side
inner-sideembankment
Hydraulic Head Loss RatioHydraulic Head Loss Ratio
Hydraulic Head Loss RatioHydraulic Head Loss Ratio
Changes of TrendsChanges of Trends
Upward(Enlarged Head Difference)
Downward(Lessened Head Difference)
degree of dispersion(Change of the Infiltration Path)
Changes of inclination
Evaluation by Hydraulic Head Loss Ratio (No.60+25)Evaluation by Hydraulic Head Loss Ratio (No.60+25)
Bottom Protection LayerBottom Protection Layer EmbankmentEmbankment
• At P1, a = 0.228 R2= 0.931,
Blocking the water looks worse,
but the behavior is stable
• At P7, a = 0.972 R2= 0.997
Closer to the Lake-side, values
getting higher
•At P2, a = 0.289 R2= 0.935,
Blocking the water looks worse,
but the behavior is stable
• At P8, a = 0.972 R2= 0.993
Closer to Lake-side, a value
becomes higher
a R2 a R2
With the Hydraulic Head Loss RatioWith the Hydraulic Head Loss Ratio
Evaluation by Hydraulic Head Loss Ratio (No.65+00)Evaluation by Hydraulic Head Loss Ratio (No.65+00)
Bottom Protection LayerBottom Protection Layer EmbankmentEmbankment
• At P1, a = 0.312 R2= 0.950,
Blocking the water looks worse,
but the behavior is stable
• At P7, a = 0.917 R2= 0.997
Closer to Lake-side, a value
becomes higher
• At P2, a = 0.508 R2= 0.974,
Blocking the water looks worse,
but the behavior is stable
• At P8, a = 0.961 R2= 0.998
Closer to Lake-side, a value
becomes higher
aR2 a R2
Evaluation by Hydraulic Head Loss Ratio (No.69+80)Evaluation by Hydraulic Head Loss Ratio (No.69+80)
Bottom Protection LayerBottom Protection Layer EmbankmentEmbankment
• At P1, a = 0.203 R2= 0.873
Closer to sea-side, Blocking the
water looks worse, but the
behavior is stable
• At P7, a = 0.855 R2= 0.991
Closer to Lake-side, a value
becomes higher
• At P2, a = 0.267 R2= 0.867
Closer to sea-side, Blocking the
water looks worse, but the
behavior is stable
• At P8, a = 0.957 R2= 0.997
Closer to Lake-side, a value
becomes higher
aR2 a R2
Evaluation by Hydraulic Head Loss Ratio (No.82+00)Evaluation by Hydraulic Head Loss Ratio (No.82+00)
Bottom Protection LayerBottom Protection Layer EmbankmentEmbankment
• At P1, a = 0.295 R2= 0.937
Closer to sea-side, Blocking the
water looks worse, but the
behavior is stable
• At P7, a = 0.979 R2= 0.997
Closer to Lake-side, a value
becomes higher
• At P2, a = 0.671 R2=0.993
Even though it closes to sea-side
“a” value is relatively higher than
the Final closing section’s
• At P8, a = 0.984 R2= 0.999
Closer to Lake-side, a value
becomes higher
a R2a
R2
SummarySummary
LocationP1 P3 P5 P7
a R2 a R2 a R2 a R2
No.60+25 0.2279 0.931 0.6899 0.978 0.9211 0.998 0.9722 0.997
No.65+00 0.3121 0.950 0.5111 0.924 0.6348 0.988 0.9169 0.997
No.69+80 0.2033 0.873 0.4448 0.924 0.7081 0.989 0.8549 0.991
No.82+00 0.2945 0.937 0.7458 0.993 0.9314 0.999 0.9788 0.997
- Sea-side (P-1,3) : Blocking the water looks Bad, but the behavior is stable - Lake-side(P-5,7)
: Blocking the water looks Good, and the behavior is stable
- Blocking the water of the general section is Good, but the final closing sections also
show a stable behavior
- Reinforcement does not require now at the final closing section, however, need to
monitor constantly
- Sea-side (P-1,3) : Blocking the water looks Bad, but the behavior is stable - Lake-side(P-5,7)
: Blocking the water looks Good, and the behavior is stable
- Blocking the water of the general section is Good, but the final closing sections also
show a stable behavior
- Reinforcement does not require now at the final closing section, however, need to
monitor constantly
Criteria(Ⅰ)Criteria(Ⅰ)
Statistical MethodsStatistical Methods
• Three times the standard deviation
were set to the criteria
• By setting the criteria,
we could measure
- Abnormal data
- Upward mobility of trend lines
- Downward mobility of trend lines
- Changes of trend line inclination
• After long-term monitoring, we will
- Review the adequacy of 3σ
as criteria
- Set the check-list in case of
odd behavior
Regression and 3-sigma Graph
Tide(m)
Criteria (-3σ)
Criteria (+3σ)
P1-P2(m)
Criteria suitable for long-term MonitoringCriteria suitable for long-term Monitoring
Examples of setting Criteria(Ⅰ) No.60+25Examples of setting Criteria(Ⅰ) No.60+25
P1P1 P3P3
P5P5 P7P7
Criteria(Ⅱ)Criteria(Ⅱ)
Criteria based on the change of Hydraulic Head Loss RatioCriteria based on the change of Hydraulic Head Loss Ratio
Criteria(Ⅱ)Criteria(Ⅱ)
• By plotting the daily values,
can predict changes of hydraulic
head loss ratio
Suitable for
long-term monitoring
Criteria based on the change of Hydraulic Head Loss RatioCriteria based on the change of Hydraulic Head Loss Ratio
Hydraulic H
ead Loss Ratio
Section SelectSection Select
• 3 on the Final Closing Section (No. 60+25, No. 65+00, No. 69+80)
• 1 on the General Section (No. 82+00)
• 3 on the Final Closing Section (No. 60+25, No. 65+00, No. 69+80)
• 1 on the General Section (No. 82+00)
In-situ ExperimentsIn-situ Experiments
• BIPS
: The gap was deemed to have been filled with the dredged sands
• In-situ permeability test : comparison of the permeability coefficient - Bottom protection layer / Embankment - General / Final Closing Section Difference is not large
• BIPS
: The gap was deemed to have been filled with the dredged sands
• In-situ permeability test : comparison of the permeability coefficient - Bottom protection layer / Embankment - General / Final Closing Section Difference is not large
ConclusionsConclusions
Building the Monitoring SystemBuilding the Monitoring System
• Every piezometer is operating properly
• Evaluated the infiltration charcteristic by Hydraulic Head Loss Ratio
- Sea-side (P-1,3) : Blocking the water looks Bad, but the behavior is stable - Lake-side(P-5,7)
: Blocking the water looks Good, and the behavior is stable until now, evaluated need not reinforcement, but we will follow up the trend
• Suggested 2 Methods for Long-term Monitoring
- Criteria Based on Statistical Method
(Review the adequacy of 3σ by long-term monitoring) - Criteria based on the change of Hydraulic Head Loss Ratio (By the regression equation of trend line)
• Every piezometer is operating properly
• Evaluated the infiltration charcteristic by Hydraulic Head Loss Ratio
- Sea-side (P-1,3) : Blocking the water looks Bad, but the behavior is stable - Lake-side(P-5,7)
: Blocking the water looks Good, and the behavior is stable until now, evaluated need not reinforcement, but we will follow up the trend
• Suggested 2 Methods for Long-term Monitoring
- Criteria Based on Statistical Method
(Review the adequacy of 3σ by long-term monitoring) - Criteria based on the change of Hydraulic Head Loss Ratio (By the regression equation of trend line)
ApplicationsApplications
• Verify the stability of the sea-dike of the final closing section
• Monitoring technology for seawater intrusion were secured
• Methods for the structures affected by the tide were presented
• Verify the stability of the sea-dike of the final closing section
• Monitoring technology for seawater intrusion were secured
• Methods for the structures affected by the tide were presented
Thank you very much!!