HiLo pile driving - Topsector Energie op Z… · 15 february 2017 HiLo pile driving 9 Results...
Transcript of HiLo pile driving - Topsector Energie op Z… · 15 february 2017 HiLo pile driving 9 Results...
HiLo pile drivingKoen Hermans
ECN
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1. Introducing HiLo pile driving
2. Research goals
3. Results
Content
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HiLo pile drivingHigh frequency Low energy
• Minimize noise emissions
• Reduced fatigue damage
• Limited penalty on installation time
Introducing HiLo
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HiLo experiments
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HiLo project – goal
‘Develop a fatigue model, based on the experimental data, that can estimate the fatigue damage at the PDA location, using only the calendar data as an input.’
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HiLo project – model approach
Hammer Calendar- Energy/blow- Penetration
Plan penetration(driveability study)
Transferred- Energy- Force
Stresses in pile- Travelling wave
Fatigue- Stress cycle- Damage
Model
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Data available
Hammer Calendar- Energy/blow- Penetration- and many more...
Plan penetration(driveability study)
Transferred- velocity- Force
Stresses in pile- Travelling wave
Fatigue- Stress cycle- Damage
PDA: time series per blow
Calendar: per 0.25 m penetration
17 mei 2013 Titel 8
Results
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Results
Calendar energy [kJ]
Blow count [bl/25 cm]
Number of blows
Description Fatigue damage D
VP01 200-250 40 373 IHC recommended 0.0723 %
VP04 480-550 22 179 Industry standard 0.17 %
VP05 150-180 95 883 HiLo 0.0188 %
0
0,05
0,1
0,15
0,2
Fatigue damage [%]
IHC recommended Industry standard HiLo
-89 %
-74%
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Correlation methodology • i.e. model not directly applicable to other sites
• Calendar resolution is main source of error
Fatigue damage during installation was much smaller than expected• 0.17 % for conventional driving
• Stress concentration factor of 3.3 16 % damage (conventional driving)
Comparison piling strategies• Up to 89% reduction fatigue damage (‘HiLo’ vs ‘Conventional driving’)
Conclusion HiLo pile driving significantly lowers fatigue damage
Project results
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• Offshorewind.biz
• Cobouw
• Piledrivers magazine
• Deep Foundations magazine
News item
Koen HermansResearcher Support Structures, ECN
[email protected] +31 625714364
Thanks for your attention
Questions?
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Concerning the low fatigue damage
Backup slide
• Stress concentrations cause a much higher damage• Up to 40 fold the fatigue damage for SCF = 3.3