Dam Safety Instrumentation with Case Study · Dam Safety Instrumentation with Case Study Dr. Rajbal...
Transcript of Dam Safety Instrumentation with Case Study · Dam Safety Instrumentation with Case Study Dr. Rajbal...
Dam Safety Instrumentation with Case Study
Dr. Rajbal SinghJoint Director
Rock Mechanics DisciplineCentral Soil and Materials
Research Station (CSMRS), New Delhi
Dam Instrumentation
• Safety of Dam• Construction• First Filling• Operation
• Refinement of Design• Back Analysis
Status of Dam Instrumentation in India
• 4800 Dams + 475 under construction• 200 Instrumented Dam (< 5 %)• About 50 years ago, instruments were not
usually specified in Water ResourcesProject Proposals and instruments wereinstalled only when problems wereencountered during construction andoperation of the project.
• Instrumentation is generally specified ineach Project Proposal: Tala, Tehri, NJP,SSP, Indira Sagar.
TO THIMPHU
DAMPOWER HOUSE
TAIL RACE TUNNELKM 7.5
ROAD TO MIRICHINGCHU ADIT NO. 4
ROAD TO POWER HOUSE
ADIT NO.5
ADIT NO.3
ADIT NO.2
ADIT NO.1
ADIT NO.4
HEAD RACE TUNNEL
KM 45
ROAD TO GEDUCHUADIT NO. 3
ROAD TO PADECHUADIT NO. 2
ROAD TO DAM SITE & ADIT NO. 1
KM 80 P.T. ROAD
89O 40' 89O 40'
R OAD TO KALIKHOLAADIT NO. 5
TO PHUENTSHOLING
C1
C2
C3
C4
C5
MONITAR
Tala Hydroelectric Project, Bhutan
Layout of Head Race Tunnel
RD 0RD 3456
RD 9399
RD 13355
RD 18094
RD 21470
RD 23032
Thiyomachu (101m)
Padechu (268m)
Geduchu (963m) Mirchingchu
(320m)
Kalikhola (520m)
C1 C2 C3 C4 C5
HRT 6.483 km HRT 4.997 km HRT 4.400 km HRT 7.183 km
D/s - 3027mU/s - 1212m
D/s - 2081mU/s - 2916m
D/s - 2525mU/s - 1875m
Mirchingchu Kalikhola
Thiyomachu
TakctchuD/s – 2244m
Dam Complex Powerhouse
Complex
D/s - 2201mU/s - 2214m
D/s – 1592.6mU/s - 1175m
Excavation of HRT from 11 Faces
AGO Reach
By Pass of HRT
PROJECT FEATURESDam on River Wangchu
Concrete Dam - 92 m height 130 m length (Located 3 km d/s of Chukha Power House)Diversion Tunnel - 6.8 m diameter 356 m length
Instrumentation Programme at THEP
•Planning•Technical Specifications•Contractual Arrangement
•Calibration of Instruments•Supply•Installation•Monitoring
Instrumentation Programme at THEP
• Accuracy of Data• Analysis• Documentation/Report• DAS• Attitude/Interest of Project
Management• Instrumentation Responsibility• Cost of Instrumentation [3%]
Cost and Power Generation
• Cost to Completion – Rs. 43210 million• Project Fully financed by the Govt. of India• Indian Technology• Instrumentation Cost
• Annual Generation - 4865 million units• Cost per unit - Rs. 1.80 per unit (India)
- Rs. 0.30 per unit (Bhutan)
Instrumentation at Tala ProjectQuality Control and Instrumentation• Contractual Arrangements
– EnCardio Rite Electronics Ltd., Lucknow
• Calibration of Instruments• Supply• Installation• Monitoring • Reporting of Monitoring
• Documentation
RemarksInstalledProposed
Monitoring22Automatic Water Level Recorder
11
Monitoring44Strong Motion Accelerograph10Monitoring2020Up Lift Pressure Pipe9
Monitoring12621 Sets
12621 Sets
Vibrating Wire Strain Meter8Monitoring2121Concrete Pressure Cell7
Monitoring11Inverted Plumb Line6
Monitoring22Normal Plumb Line5Monitoring79MPBX4Monitoring1823Joint Meter/ Crack Meter3Monitoring3037Pore Pressure Meter2Monitoring5151Temperature Meter1
Total No. of InstrumentsName of InstrumentS.No
Instruments Installed in Dam
Instruments Installed in Dam
• Instruments Installed = 282 Nos.
• Instruments Working = 277 Nos.
• Instruments Not Working = 5 NOs.
2 3 4 5 6 71
U/S View of Dam, Intake Structures Coffer Dam, Diversion Tunnel
TYPE: CONCRETE GRAVITYHEIGHT: 92 MNO. OF BLOCKS: 7UNDERSLUICES: 5OVER SPILLWAY: 1
Concrete Placement in Tala DamConcrete Completed- March 2006
EL. 1354.50
ELEVATOR SHAFT2500X2400
1NO. OVERFLOW SPILLWAY1000 PARAPET
7
EL. 1338.50
EL. 1310.50
EL. 1354.502000
EL. 1320.00
EL. 1309.50
EL. 1306.50
EL. 1280.50
FOUNDATION GALLERY
CROSS
7000
5250
EL. 1306.50
5 NOS.
(6500 X 13150)
EL. 1283.50EL. 1281.50
SUMP WELL EL. 1277.50
3 5 6 74
EL. 1296.50
GALLERY
EL.1366.00
EL. 1340.50
EL.1367.00 EL.1366.00
12 SLUICE
SPILLWAY
OBSERVATION OF TEMPERATURE METERS
15
20
25
30
351/
3/20
01
1/4/
2001
5/5/
2001
17/1
1/01
1/1/
2002
1/2/
2002
7/3/
2002
2/4/
2002
29/1
1/02
7/1/
2003
9/2/
2003
9/3/
2003
10/4
/200
3
9/5/
2003
Date
Tem
pera
ture
(o C)
B2T2 B2T3 B5T3 B5T7 B5T8
30.90C
220C
OBSERVATION OF TEMPERATURE METERS
TEMPERATURE METER BLOCK 5
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
DATE Figure 6A: Observation of Temperature meters B5T16 to B5T22
B5T16 B5T17 B5T18 B5T19 B5T20 B5T21 B5T22
16.1
OBSERVATION OF TEMPERATURE METERS
New Temperature M eters Of Block-2
0.01.02.03.04.05.06.07.08.09.0
10.011.012.013.014.015.0
DATE Figure 5B : Observat ion of Temperat ure Met ers B2T19 t o B2T24
B2T19 B2T20 B2T21 B2T22 B2T23 B2T24
Temperature Meters in Block 2
22.6
30.9
19.0
10.3
16.8
9.0
6
11
16
21
26
31
03/0
1/20
01
06/0
4/20
01
23/0
5/20
01
25/1
2/20
01
02/0
1/20
02
16/0
3/20
02
16/0
4/20
02
01/0
1/20
03
09/0
2/20
03
16/0
3/20
03
24/0
4/20
03
26/0
1/20
04
27/0
2/20
04
06/0
4/20
04
12/0
5/20
04
11/0
9/20
04
21/1
0/20
04
04/1
2/20
04
11/0
1/20
05
23/0
2/20
05
06/0
4/20
05
09/0
5/20
05
28/0
6/20
05
22/0
8/20
05
28/0
9/20
05
02/1
1/20
05
05/1
2/20
05
11/0
1/20
06
Monitoring Time (Date)
Tem
prat
ure
(deg
ree
c)
B2T1 B2T2 B2T3 B2T4 B2T5 B2T6B2T7 B2T8 B2T9 B2T10 B2T11 B2T12B2T13 B2T14 B2T15 B2T16 B2T17 B2T18B2T19 B2T20 B2T21 B2T22 B2T23 B2T24B2T25 B2T26 B2T27 B2T28 B2T29
Cement Content & Concrete Temperature
Cement Content kg/m3
Temperature of Mass Concrete
Remarks
210 25.4 (10-30.9) Cracking
200 22.5 (10-28.8) Cracking
190 19.0 (10-27.7) Cracking
180 14.9 (10-15.6) No Cracking
170 14.3 (10-14.3) No Cracking
160 13.6 (10-13.6) No Cracking
140 12.4 (10-5.2-12.4) No Cracking
Strength of In-situ Cores with Age and Cement Content
25.41 27.18
43.77 42.82
33.58
21.18
90
362410
467
750
1016
0
10
20
30
40
50
60
160 170 180 190 200 210Cement Content, Kg/m3
Com
pres
sive
Stre
ngth
, MPa
0
200
400
600
800
1000
1200
Test
ing
Age
, day
s
Compressive Strength Testing Age
Cube Compressive Strength at Different Testing Age
13.95
20.73
23.925.33
27.12
11.43
20.33
25.44
28.67
31.46
6.28
14.48
22.90
26.83
28.35
6.04
14.83
21.41
29.45 29.71
7.35
17.42
24.45
0
5
10
15
20
25
30
35
7 28 90 180 365Testing Age (Days)
Com
pres
sive
Str
engt
h (M
Pa)
Cement Content = 200 kg/m3Cement Content = 190 kg/m3Cement Content = 180 kg/m3Cement Content = 170 kg/m3Cement Content = 160 kg/m3Comp. Strength = 15 MPa after 365 daysComp. Strength = 12.5 MPa after 28 days
Pore Pressure Meters in Block 5
5.6
2.8
3.8
2.321.8
1.3
3.6
2.5
4.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
15/0
3/20
01
26/0
4/20
01
17/1
1/20
01
01/0
9/20
02
17/0
2/20
02
30/0
3/20
02
29/1
1/20
02
16/0
1/20
03
27/0
2/20
03
04/0
4/20
03
05/0
9/20
03
26/1
0/20
03
26/0
1/20
04
27/0
2/20
04
04/0
6/20
04
05/1
2/20
04
09/1
1/20
04
21/1
0/20
04
12/0
4/20
04
01/1
1/20
05
19/0
2/20
05
28/0
3/20
05
06/0
5/20
05
16/0
6/20
05
10/0
8/20
05
22/0
9/20
05
26/1
0/20
05
03/1
2/20
05
05/0
1/20
06
Monitoring Time (Date)
Pore
Pre
ssur
e (k
g/cm
2)
B5P1 B5P2 B5P3 B5P4 B5P5 B5P6
B5P7 B5P8 B5P9 B5P10 B5P11 B5P12
B5P13 B5P14 B5P15 B5P16
Stress Meters in Block 2
5.5
4.74.2
1.0
0
1
2
3
4
5
6
03/0
1/20
01
26/0
4/20
01
14/1
2/20
01
09/0
2/20
02
02/0
4/20
02
01/0
1/20
03
27/0
2/20
03
16/0
4/20
03
24/0
6/20
03
17/0
7/20
03
31/0
8/20
03
21/1
0/20
03
11/1
2/20
03
26/0
1/20
04
10/0
3/20
04
05/0
5/20
04
23/0
9/20
04
17/1
1/20
04
11/0
1/20
05
03/0
5/20
05
25/0
4/20
05
28/6
/200
5
05/0
9/20
05
26/1
0/20
05
12/1
2/20
05
Monitoring Time (Date)
Stre
ss (k
g/cm
2)
B2S1 B2S2 B2S3 B2S4 B2S5
B2S6 B2S7 B2S8 B2S9 B2S10
Strain Meters in Dam Block 2
-30.0
-20.0
-10.0
0.0
10.0
20.0
30.0
40.0
11/0
2/20
04
10/0
3/20
04
19/0
4/20
04
24/0
5/20
04
01/1
0/20
04
14/1
1/20
04
18/1
2/20
04
25/0
1/20
05
23/0
2/20
05
04/0
6/20
05
05/0
9/20
05
28/0
6/20
05
22/0
8/20
05
28/0
9/20
05
02/1
1/20
05
05/1
2/20
05
11/0
1/20
06
Monitoring Time (Date)
Stra
in (m
icro
met
er)
B2SN9A B2SN9B B2SN9CB2SN9D B2SN9E B2SN9F
Report on Reprt # 6Quality Control and Instrumentation for
Concrete Gravity Dam of 1020 MW Tala Hydroelectric Project in Bhutan
Volume II: Instrumentation
Dr. Rajbal SinghChief Research Officer, Quality Control
Engineer-In-Charge, InstrumentationQuality Control Department
Tala Hydroelectric Project AuthorityGedu, BhutanOctober 2006
INDEXS. NO. CONTENTS PAGE NO.
PREFACE ILIST OF TABLES v-vi
LIST OF FIGURES vii-viii
1.0 INTRODUCTION 12.0 DETAILS OF INSTRUMENTS 23.0 INSTALLATION OF INSTRUMENTS 74.0 MONITORING OF INSTRUMENTS 95.0 CONCLUSIONS 17
ACKNOWLEDGEMENTS 18REFERENCES 19TABLES 21-166FIGURES 167-213ANNEXURES 214-235
CONCLUSIONS Mass concrete temperature, which was about 100C
at the time of placement, has risen up to 30.90Cand finally settled down between 21.60C to 22.50C.
Due to low ambient temperature (40C) in the monthof January, temperature of mass concrete droppedduring 3 days from 9.90C to 5.20C and increasedagain up to 12.60C.
• Cement content in mass concrete should beoptimized to achieve required strength. Highcement content leads to cracking in massconcrete.
• Temperature readings should be monitored fromthe time of placement of concrete.
• Instrument should be calibrated with placementtemperature of mass concrete.
CONCLUSIONS … contd.
The pore pressure meters installed haveshown pore pressures in the range of 3.2kg/cm2 to 4.0 kg/cm2, in Blocks 2 and 5respectively.
Three joint meters/crack meters installed inblocks 3 and 5 at the cracks, show theincrease in crack width in the order of 0.01mmto 0.11 mm.
The joint meters installed between two blocksjoint have shown insignificant displacement inthe range of 0.01mm to 5.40mm.
CONCLUSIONS … contd. The concrete pressure cells installed in Blocks 2
and 5 have shown pressures in the massconcrete varying from 5.5 kg/cm2 to 4.4 kg/cm2
which is 3.8 to 4.76 time lower than theoreticallyexpected stresses of 20.16 kg/cm2 and 20.95kg/cm2 based on mass concrete density of 2400kg/cm2 and height of blocks 84 m and 87.30 mabove the pressure cells, respectively. However,the pressure cells have shown increasing trendduring observations.
9.2 kg/cm2 & 12.6 kg/cm2 from FEM The safe design parameters must be made
available and may be attached with dataacquisition system as alarm for furthermonitoring the safety of dam.
CONCLUSIONS …contd.In general, behaviour of all instruments installed in Tala dam was in order with respect to increasing/decreasing trends in observations.
A record number of 277 instruments were in working order out of 282.
This was possible due to awarding a contract for supply, installation, maintenance and monitoring of instruments before commencement of dam construction.
Temperature Meter
Pore Pressure Meter Joint Meter/Crack Meter
Instruments InstalledConcrete Pressure Cell
Strain MeterSpider For Strain Rosettes
INSTRUMENTS INSTALLED
• Uplift pressure Meters
• Water Level Indicators
• Surveying Points or Targets