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IT’S IN THE EYE OF THE INSPECTOR Overview of visual inspection methods in four countries and lessons learned ISFD4, Toronto 6 May 2008 Jaap Flikweert. Background. Based on study for NL Research programme ‘Inspection of flood defences’ (VIW) (STOWA & Rijkswaterstaat)
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IT’S IN THE EYE OF THE INSPECTOR • Overview of visual inspection methods in four countries and lessons learned • ISFD4, Toronto • 6 May 2008 • Jaap Flikweert
Background • Based on study for NL Research programme • ‘Inspection of flood defences’ (VIW) • (STOWA & Rijkswaterstaat) • Co-author: Gerard Moser • Sources: • Personal involvement in NL & UK • Literature study & interviews for FR & DE
Lay out of presentation • Why inspect? • Role of visual inspection • Local context • Methods • Conclusions on effective use of visual inspection
Asset management • Flood risk management Risk-based asset management • Balancing risk, cost and performance • Why inspect? • To measure deterioration • To steer intervention • To improve performance • To reduce risk graphic: Advantica Ltd.
Asset Inspection • Parallel with human health
Asset inspection Visual, intrusive, remote Tradition, performance based Judgement, guidance, calculation
Role of visual inspection • Drivers for developments: • Defences protect more • More complicated structures • Professionalisation • Technological development • Why still visual inspection? • Use of local knowledge • Cost • Human factor • Emergency staff available
Local context Netherlands: Flood risk dominant, defences vital, long history Strict legal framework, flexible application Focus on meeting standards Assets managed by professionals Germany (Federal waterways): Flood risk significant, defences very important Strict procedures Focus on preventing damage Assets managed by professionals England: Flood risk significant, increasing profile, defences locally important Permissive powers, strict procedures Focus on cost-effectiveness and risk Assets managed by professionals France: Flood risk significant, defences locally important Guidance Focus on introducing defence management Varying but improving quality of asset management Scale of flood risk Rules Focus Organi-sation
Methods • Long tradition of visual inspection • Recent years: less embedded in asset management
Methods • Why: • Identify & repair small defectsLimited link with asset management under development • How: • No detailed rules, left to local judgementGuidance under development • Who: • Operational staff • Recent development: training available
Methods • Focus on Federal waterways • Framework: • DIN flood embankments • Specific internal directive for inspection • Clear hierarchical structure: • Inspector: inspect and inform • Field officer: check, respond and inform • Asset manager: check and respond • Indicators are asset specific & failure mode related
Methods • Why: • Identify defects, prevent breach • How: • Detailed roles • Asset specific indicators • Who: • Specialist full-time inspectors • Backed by experts
Methods • Since mid 90s: Condition Assessment Manual: • Condition grade (1-5) • Nationally consistent • Indicator for performance • Developments: • Improve link with failure modes
Methods • Why: • Keep track of deterioration • Measure maintenance quality • How: • Detailed prescribed roles • Systematic technical guidance • Who: • Operational staff with specific training
Methods • Longer tradition of dam management, but flood defence management just starting • Opportunity for integrated approach: • Performance based • Inspection embedded in asset management • Guide pratique (Cémagref): • Procedures • Set of forms
Methods • Why: • Identify defences and determine starting point • Move toward keeping track of deterioration • How: • General guidance on approach • Can be applied to set local indicators • Who: • Variable, depends on asset management organisation
Conclusions • Each country / culture its own method • Visual inspection can have different purposes • General move toward performance based inspection • Specific role for visual inspection within overall inspection, given technological developments: • Taking the pulse • Trigger for expert inspection • Input for modelling