Ice-Structure Interaction at the Confederation Bridge Pier Dhruba - - PowerPoint PPT Presentation

▶
ice structure interaction at the
SMART_READER_LITE
LIVE PREVIEW

Ice-Structure Interaction at the Confederation Bridge Pier Dhruba - - PowerPoint PPT Presentation

Nov 14, 2023 166 likes •565 views

Ice-Structure Interaction at the Confederation Bridge Pier Dhruba Tripathi Department of Civil Engineering, University of Calgary Calgary, Canada Overview Confederation Bridge Introduction Monitoring Direct, indirect, and

slide-1
SLIDE 1

Ice-Structure Interaction at the Confederation Bridge Pier

Dhruba Tripathi Department of Civil Engineering, University of Calgary Calgary, Canada

slide-2
SLIDE 2

5/18/2010 Tripathi 2

Overview

 Confederation Bridge Introduction  Monitoring – Direct, indirect, and observations  Pressure panels  Data analysis

 Activation Analysis  Detailed Pressure Distribution Analysis  Correlation Analysis

 Conclusion

slide-3
SLIDE 3

5/18/2010 Tripathi 3

Confederation Bridge

slide-4
SLIDE 4

5/18/2010 Tripathi 4

Confederation Bridge

 12.9 km long  100 years design life  40 m above water

(typical)

 4.5m to14m deep precast

concrete box girder

 Bridge Footings- Gravity

foundation on bedrock

slide-5
SLIDE 5

5/18/2010 Tripathi 5

Ice Force Monitoring

 Direct measurement

  • f ice pressure

 Indirect measurement

  • f the global ice force

 Observation of ice

kinematics

slide-6
SLIDE 6

Indirect measurement

  • f ice force

 Tilt meters measure

displacements

 Stiffness of the pier

determined by a pull test

5/18/2010 Tripathi 6

slide-7
SLIDE 7

5/18/2010 Tripathi 7

Ice load on the Bridge

 Limit stress (ice failure)

 Vertical structures – Crushing failure of ice  Conical ice shield – flexural failure –

causes lower load

 Limit force (ice driving force)

slide-8
SLIDE 8

Ice Load History

5/18/2010 Tripathi 8

slide-9
SLIDE 9

Real-Time Monitoring

 Computers at the bridge can

be accessed through internet

 Ice load – live chart at

website updated every 15 minutes (http://ice.ucalgary.ca)

 Real-time access - videos

from four cameras for the

  • bservation of ice-structure

interaction

5/18/2010 9 Tripathi

slide-10
SLIDE 10

Direct measurement of ice pressure

5/18/2010 Tripathi 10

20 panels Covering 40m2

slide-11
SLIDE 11

5/18/2010 Tripathi 11

Ice Force Panels (IFPs)

20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1  A total of 160

sectors in 20 panels on the cone

slide-12
SLIDE 12

5/18/2010 Tripathi 12

Typical Panel

 8 sectors

(~500 x 500 mm)

 ~ 30 button on

each sector

 2 buttons

instrumented

 Best represents

average pressure

slide-13
SLIDE 13

Data

 120 channels – upper cone (level ice and

rubble)

 40 channels – lower cone (Thick ice)  64 channels – pier shaft (Large keels)  Tiltmeter data – Global ice force

(comparison)

 4 time-lapse video data, upward-looking

sonar

5/18/2010 Tripathi 13

slide-14
SLIDE 14

5/18/2010 Tripathi 14

Ice Structure Interaction

?

STRUCTURE ICE Pressure zones (hpz)

What happens at the ice structure interface? Spatial and temporal pressure distribution ?

slide-15
SLIDE 15

5/18/2010 Tripathi 15

Data

 Electrical signals

 Average data- every 17 seconds

 Full Ice season – continuous

recording

 Triggered data- every 34

milliseconds  For Events only

slide-16
SLIDE 16

Typical data header (120 data channels)

5/18/2010 Tripathi 16

slide-17
SLIDE 17

Panel Reliability

 4 panels and 10 sectors  42 sectors bad in

1998

 7 panels and 16 sectors  72 sectors bad in

2003

5/18/2010 Tripathi 17

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

slide-18
SLIDE 18

Events selection and Panels

 Events selection

 Ice forces – (tiltmeter data)  Availability of pressure panel data  Video analysis, when available

 Panels

 Panels on cone for interaction of level ice  Waterline panels – level ice impact  Panels above water-line – Rubble piles

5/18/2010 Tripathi 18

slide-19
SLIDE 19

5/18/2010 Tripathi 19

Data Conversion

89 90 109 110 93 94 113 114

  • 1
  • 0.5

0.5 1 1.5 2 2.5 09:04.3 09:13.0 09:21.6 09:30.2 09:38.9 09:47.5 09:56.2 10:04.8

Time stamp (min.) Pressure, yip (MPa)

89 90 109 110 93 94 113 114 LEGEND

slide-20
SLIDE 20

Baseline

 Unrealistic negative pressure  Baselines differ in different channels  Clear pressure peaks (sustained

pressure for longer duration – very rare)

 Baselines changed over time

5/18/2010 Tripathi 20

slide-21
SLIDE 21

Baseline Correction- Trimmed

5/18/2010 Tripathi 21

slide-22
SLIDE 22

5/18/2010 Tripathi 22

slide-23
SLIDE 23

5/18/2010 Tripathi 23

slide-24
SLIDE 24

5/18/2010 Tripathi 24

slide-25
SLIDE 25

5/18/2010 Tripathi 25

Ice pressure and ice force

slide-26
SLIDE 26

Data Analysis

Activation Analysis

 Sector considered active  [pressure peak] > [a

threshold]

Detailed Pressure Distribution Analysis

 Peaks – supported by at least 5 adjacent peaks in

each side

5/18/2010 Tripathi 26

slide-27
SLIDE 27

Horizontal and vertical pressure distribution

5/18/2010 Tripathi 28

89 90 109 110 93 94 113 114

slide-28
SLIDE 28

5/18/2010 Tripathi 29

Activation, Integrated load

1 2 3 4 5 09:09.3 09:11.9 09:14.4 09:17.0 09:19.6 09:22.2 09:24.8 09:27.4 09:30.0 09:32.5 09:35.1 09:37.7 09:40.3 09:42.9 09:45.5 09:48.0 09:50.6 09:53.2 Panel Activation (No.) 0.1 0.2 0.3 0.4 0.5 0.6 Integrated Load (MN) Panel Activation Integrated Load

Integrated load =∑[ yi ai cos(αi)]

89 90 109 110 93 94 113 114

slide-29
SLIDE 29

Horizontal Pressure Distribution

5/18/2010 Tripathi 30

slide-30
SLIDE 30

Horizontal Distribution

5/18/2010 Tripathi 31

slide-31
SLIDE 31

Vertical pressure distribution

5/18/2010 Tripathi 32

slide-32
SLIDE 32

Tripathi 33 89 90 109 110 93 94 113 114

Detailed Pressure Distribution Analysis

  • 2
  • 1

1 2

12:09

Sector Pressure (MPa) Time (HH:MM) Sector 89

  • 2
  • 1

1 2 12:09

Time (HH:MM) Sector Pressure (MPa)

Sector 90

  • 2
  • 1

1 2 12:09

Sector Pressure (MPa) Time (HH:MM)

Sector 93

Sector 94

  • 2
  • 1

1 2 12:09

Time (HH:MM) Sector Pressure (MPa)

5/18/2010

slide-33
SLIDE 33

Probability of exceedance

5/18/2010 Tripathi 34

slide-34
SLIDE 34

5/18/2010 Tripathi 35

Correlation Analysis

  • Strength and direction of a linear relationship of

pressure between different sectors

  • Activation correlation
  • Time-series corrleation
slide-35
SLIDE 35

5/18/2010 Tripathi 36

Time-series correleation

81 82 83 84 85 86 89 90 81 82 83 84 85 86 89 90

  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 1

Correlation Coefficient S e c t

  • r

s

81 82 83 84 85 86 89 90

slide-36
SLIDE 36

5/18/2010 Tripathi 37

Limitations

 Pressure panels readings -

representation of absolute pressure

 Many of the sectors were

damaged

 Availability of video data at

night (apparently, the largest events occur at night)

slide-37
SLIDE 37

5/18/2010 Tripathi 38

Further works

 Test the results by using

numerical methods like finite element method.

 Process limit driving

force events

 Add some more events

to refine the result.

slide-38
SLIDE 38

Acknowledgements

May 29, 2009 39

  • Dr. Tom Brown

Noorma Shrestha Susan Tibbo Kelly Obert Mohamed El-Seify Derek Myane Dambar Tiwari

slide-39
SLIDE 39

Thank You !

Questions ?