Framework for Assessment of Canada's Core Public Infrastructure Performance

1. Meeting of the National Round Table on Sustainable InfrastructureMarch 26, 2008, Toronto Framework for Assessment of State Performance and Management of Canada’s Core Public Infrastructure (CPI) Review of State- of- Art

2. Outline • Background • Review of performance assessment of CPI • Knowledge “deficit” in performance assessment • Approach

3. Background • CPI: roads, bridges, transit, water and wastewater systems • Canada’s CPI enable: • personal mobility • transport of people and goods, • provide safe drinking water • remove wastes • critical to competitiveness of economy and quality of life • NRC Cross-Canada Tour- Concerns of decision-makers: • aging infrastructure • lack of reliable performance data • ill-defined acceptable minimum levels of performance • few management tools • PSAB 3150 requirements • ineffective communications to decision makers • closing small towns, concerns of northern communities • Environment now on agenda- Sustainability concerns

4. Aging CPI Systems Increasing Demand Aggressive Environment Climate Change Deterioration of Core Public Infrastructure + Inadequate Performance Assessment Decreasing Capacity / Increasing Risk of Failure • Consequences: • Health & Safety problems • Economic & Social impacts • Environmental impact Background

5. Background Challenges • Life cycle management of CPI = challenging problem • Optimize allocation of funds for maintenance, rehabilitation & renewal for different CPI systems, given: • large network of CPI systems and components • CPI systems/components deteriorate with time • risk of failure increases with time • lack of reliable data on current and future state of systems • different assets with different consequences of failure • limited funds

6. CPI Performance Assessment Performance Indicators – Bridges • Safety • load rating, load carrying capacity, reliability index • condition rating, sufficiency rating, appraisal rating, health index • Serviceability • condition rating • excessive stresses, cracking, deformation, vibration • Fatigue • Functionality • condition rating, sufficiency rating • bridge width, vertical/horizontal clearances

7. CPI Performance Assessment Performance Indicators - Bridges Agency Condition rating system Performance Indicator FHWA AASHTO (CoRe elements) Canada (e.g. MTO)

8. CPI Performance Assessment Performance Indicators - Roads • Riding comfort index • Surface distress index • Structural adequacy index • Pavement condition index • International roughness index • Pavement quality index

9. CPI Performance Assessment Performance Indicators - Roads

10. CPI Performance Assessment Performance Indicators – Water Systems Failure Criteria Performance Indicator Sub Criteria Water Quality Hydraulic and Quantity of flow System Integrity

11. CPI Performance Assessment Performance Indicators – Wastewater Systems Performance Indicator Failure Criteria Sub Criteria Quality Sanitary/Storm Hydraulic and Quantity of flow System Integrity

12. CPI Performance Assessment Performance Indicators – Water & Wastewater Systems Water Sanitary and Storm Water

13. CPI Performance Assessment Deterioration Prediction Models • State-of-art deterioration prediction models are based on Markov chain models : • qualitative prediction of future performance based on ratings • modeling of cumulative damage only – No “shock” modeling • assumption of constant rate of deterioration - Not realistic at all ! • no information on residual capacity and safety • predicted service life is a rough approximation • ‘true” condition can be seriously overestimated – disaster! • examples of decision support systems: “Pontis”, “Bridgit”, etc.

14. CPI Performance Assessment Reliability of Performance Indicators- Examples • Same bridges rated by different inspectors : • up to 5 rating points difference! (FHWA 2000) • unacceptable for such critical structures! • predicted remaining life is arbitrary and may lead to unsafe estimates- disasters (loss of life, injuries, economic impacts, etc.) • Same bridge can be rated by 3 different inspectors as either: • Serious condition – Probability of collapse could be 0.01 • Fair condition - Probability of collapse could be 0.05 • Critical condition - Probability of collapse could be 0.1 Unacceptable for safety-critical systems

15. Condition Rating Probability of failure Poor ? 4 ? Serious 3 2 Critical ? 1 Imminent failure ? 0 Failed 1 ? CPI Performance Assessment Reliability of Performance Indicators- Examples • I35 bridge superstructure: • bridge opened to traffic in 1967 • rated “Poor” not “Critical” • scheduled for reconstruction in 2020-25 • estimated Remaining Life 12-15 years • bridge collapsed 2 years after evaluation !

16. CPI Performance Assessment Summary • Current performance assessment is mainly qualitative • Focus on material distresses instead of system distresses • Based on “visual” inspection + some non-destructive techniques • mapping observed material distresses to subjective rating scales • Arbitrary definition of minimum performance or failure criteria • No differentiation between safety-critical and secondary systems • Limited or no quantitative data on: • residual capacity, safety • probability of failure and risk of failure • remaining life

17. Cumulative damage “wear & tear” Random shock- induced damage Repair/Rehab/Replace Limit state/ acceptable minimum performance Performance Service life 1 Service life 3 Service life 2 Life cycle Time (years) Residual life “Knowledge Deficit” in CPI Performance Assessment

18. Time-varying probability of failure Time-decreasing capacity Initial capacity Capacity Load Load Time “Knowledge Deficit” in CPI Performance Assessment Quantitative Measures of CPI Performance - Examples • Performance= Capacity – Load • Performance= Capacity / Load • Performance= Probability that Capacity is higher than Load

19. “Knowledge Deficit” in CPI Performance Assessment Acceptable Minimum Levels of Performance • Develop rational and objective acceptable minimum levels of performance or limit states considering: • type of CPI system and component • consequences of failure/ importance/ criticality of CPI system: e.g. loss of life, health/ injury risks, property loss, environmental impact • type of failure mode: ductile / progressive or brittle / sudden • design life of CPI system/ component

20. Integrated CPI Management CPI Project Management CPI Network Management “Knowledge Deficit” in CPI Performance Assessment Quantifying Risk of Failure of CPI • Develop approaches to assess risk of failure of CPI systems: Risk of failure = Probability of Failure X Consequences of failure • Risk of failure enables decision makers to : • identify critical / high priority components of CPI • Integrate management of different CPI systems

21. Approach • Build on existing knowledge and best practices • Advance state of knowledge using sound scientific and engineering approaches and develop: • reliable and practical performance assessment of CPI systems • objective minimum performance levels • “unified” or “model” CPI performance indicators and measures • Promote adoption and implementation of developed approaches for CPI performance assessment and management

22. Approach • NRC and NRTSI will collaborate on research projects: • Phase 1: Development of a framework for assessment of state, performance and management of CPI • Phase 2: Development of approaches and tools for performance assessment and management of CPI • Benefits • ensure safety and health of Canadians • improve the performance of Canada’s CPI • support decision making at all levels of government • reduce economic, environmental, and social impacts of CPI • evaluate impact of funding on performance of CPI

23. Questions? Zoubir Lounis, Ph.D., P. Eng. Zoubir.Lounis@nrc.gc.ca Tel: (613) 993-5412