Risk-Based Asset and Performance Management: A Geotechnical Perspective Scott A. Anderson FHWA - Resource Center Risk-Based Asset and Performance Management Can’t do all we would like Need to Optimize Can’t do it all at once Need to Prioritize This is the motivation for “management” There is also a catalyst Catalysts for management Bridge – safety Pavement – cost Geotechnical – performance MAP-21 National Performance Goals 1. 2. 3. 4. 5. 6. 7. Safety Infrastructure Conditions: State of Good Repair Congestion Reduction System Reliability- improve efficiency Freight Movement and Economic Vitality Environmental Sustainability Reduced Project Delivery Delays 4 FAQ on MAP-21 • • • Question 2: What requirements does MAP-21 have pertaining to asset management? Answer 2: Each State is required to develop a risk-based asset management plan for the National Highway System (NHS) to improve or preserve the condition of the assets and the performance of the system. (23 U.S.C. 119(e)(1), MAP-21 § 1106) The Secretary is required to issue a regulation not later than 18 months after date of enactment, after consultation with the States, which will establish the process to develop the State asset management plan for the NHS. (23 U.S.C. § 119(e)(8), MAP-21 § 1106) Source: FHWA website 5 • • • Question 3: What are the scope and content of a risk-based asset management plan? Answer 3: In general, a State risk-based asset management plan includes strategies that lead to a program of projects that would make progress toward achievement of the State targets for asset condition and performance of the NHS in accordance with 23 U.S.C. 150(d) and supporting progress toward the achievement of the national goals identified in 23 U.S.C. 150(b). (23 U.S.C. 119(e)(2), MAP-21 § 1106) States must address pavements and bridges but are encouraged to include all infrastructure assets within the highway right-of-way in their risk-based asset management plan. 23 U.S.C. 119(e)(4) (MAP-21 § 1106) requires that a State asset management plan be in a form that the Secretary determines to be appropriate. It also requires that the plan include: 1. 2. 3. 4. 5. 6. a summary listing of the pavement and bridge assets on the NHS in the State, including a description of the condition of those assets; asset management objectives and measures; performance gap identification; lifecycle cost and risk management analysis; a financial plan; and investment strategies. 6 • • Question 4: What other infrastructure assets within the highway right-of-way can be included in a risk-based asset management plan? Answer 4: While the MAP-21 risk-based asset management plan specifies pavements and bridges on the NHS in 23 U.S.C. § 119(e)(4), 23 U.S.C. 119(e)(3) (MAP-21 § 1106) requires the Secretary to encourage States to include all infrastructure assets within the highway right-of-way. Examples of such infrastructure assets include: pavement markings, culverts, guardrail, signs, traffic signals, lighting, Intelligent Transportation Systems (ITS) infrastructure, rest areas, etc., in the asset management plan. 1. 2. Really? 3. 4. 5. 6. 7. Safety Infrastructure Conditions: State of Good Repair Congestion Reduction System Reliability- improve efficiency Freight Movement and Economic Vitality Environmental Sustainability Reduced Project Delivery Delays 7 Geotechnical Impacts on System Performance Though the pavement and bridges are in excellent condition, the performance here is poor. The Geotechnical Role We can address many performance goals The intent of the law may fail if we don’t manage our assets to support performance goals The language we speak will become less relevant if we aren’t ‘managing our assets’ We are responsible for certain links in a transportation corridor (The System) Asset management Performance management Risk-based Asset management Risk-based Performance management Some Practical Definitions 1. Asset Management 2. Performance Management 3. Geotechnical Asset Next slides 11 Physical assets along a corridor 12 Independent features, not elements of others 13 Comprised of earth or performance achieved through earth interaction with structure or inclusion 14 Proposed Geotechnical Asset Taxonomy – 1/8/14 Rock Slope The adjective “Geotechnical” means the asset is comprised of earth, pertains to earth, or its performance is achieved through earth interaction with a structure or inclusion. Inclusions are any and all non-earth modifications: pipes, anchors, grids, fabrics, grouts, etc. Soil Modified Rock Embankment Soil Modified Independent Feature Rock Subgrade Soil Modified ROW Feature Earth Retaining Structure Corridor and/or GAM Section Element of other Structure Bridge Element Tunnel Element Stabilized Earth Steel or Reinforced Concrete Predominant distinction in how feature is managed. Features with inclusions are “modified”. Pavement Element Physical Asset OutsideROW Feature Water bodies NonCorridor Geotechnical Asset Data NonPhysical Asset Equipment Knowledge Slopes Material Sites Stockpiles or other Established management systems for other structures that have (or should have) geotechnical elements. Others, could be added; for example – culverts. Structures (walls, etc.) High slopes, shorelines, and structures typically owned by others outside the ROW that are sources of risk because they can impact performance Investigation and test results, lab and field equipment, key personnel Current Practice Implementation in States today Alabama North Carolina Tennessee New Jersey Indiana Iowa California Alaska Georgia South Carolina Connecticut New York Florida Washington D.C. Maine Pennsylvania Kentucky New Hampshire Maryland Ohio Michigan Wisconsin Colorado Vermont Illinois Minnesota Kansas Missouri Arizona Washington Utah South Dakota Oregon North Dakota Nebraska Montana Idaho They are all taking steps: some big, some small Remember the fine print? 23 U.S.C. 119(e)(4) (MAP-21 § 1106) requires that a State asset management plan be in a form that the Secretary determines to be appropriate. It also requires that the plan include: 1. 2. 3. 4. 5. 6. a summary listing of the pavement and bridge assets on the NHS in the State, including a description of the condition of those assets; asset management objectives and measures; performance gap identification; lifecycle cost and risk management analysis; a financial plan; and investment strategies. That’s what these states are doing, all in their own ways. Let’s look at linking Condition, Performance and Risk Management - and define “Condition” and “Risk Management” as we do so Two diversions to show breadth of the revolution Performance Based Practical Design (PBPD) SHRP2 - R19B: BRIDGE FOR SERVICE LIFE BEYOND 100 YEARS: SERVICE LIMIT STATE DESIGN …Then on to some new ideas PBPD – Definition The PBPD approach: • grounded in performance management • exercise engineering judgment to build up the improvements from existing conditions to address purpose and need • uses appropriate performance-analysis tools • considers both short- and long-term project and system goals PBPD – Overlapping Value Engineering Road Diets Livability Context Sensitive Solutions SHRP2 R19B – Bridges for Service Life beyond 100 Years: Executive Summary The objectives of SHRP 2 Project R19B were to develop design and detailing guidance and calibrated Service Limit States (SLSs) to provide 100 year life, and to develop a framework for further development of calibrated SLSs. Generally, it has been assumed that maintenance activities will be sufficient to prevent significant loss of the strength and stiffness that would result in unsatisfactory service level performance. Consideration of SLSs requires different input data than the previously calibrated Strength Limit State I (ULSs). In ULSs, the limit state function is defined with two variables, resistance, which was considered constant in time, and loads. For SLSs , a different approach is needed: • As exceeding service limit states does not lead to a clear, immediate, loss of functionality, defining the resistance is very subjective. • Acceptable performance can be subjective (full life-cycle analysis is required). • Resistance and load effects can be and often are correlated. • Load must be considered to be a function of time, described by magnitude and frequency of occurrence. • Resistance may be strongly affected by quality of workmanship, operation procedures and maintenance. • Resistance is subject to changes in time, mostly but not only deterioration, with difficulty predicting initiation time and time-varying rate of deterioration (e.g. corrosion, accumulation of debris, cracking). • Resistance can depend on geographical location (climate, exposure to industrial pollution, exposure to deicing agents or proximity to the ocean). Pavement Deterioration Curve PCI = Condition Galehouse et al., 2006 ROCK SLOPE REMAINING SERVICE INTERVAL (To Change of State - yrs) Deterioration models How are these levels related to Performance Goals? Time in Condition State 18 1 11 6 100% C O N D I T I O N A - Excellent 80% B - Good 60% C - Fair 40% D - Poor 20% F - Failed 5 10 15 20 25 TIME (yrs) Theoretical Deterioration Curve Uncertainty limits Rock Slope Condition 30 35 40 0% Example: With four Performance Goals and four Asset Classes, these are the components of Level of Service (LOS). A description of condition with respect to different goals Asset Class Linking Condition and Performance Performance Goals Asset Classes Performance Goals Safety Infrastructure Congestion Environmental Retaining Walls LOSRW,S LOSRW,I LOSRW,C LOSRW,E Slopes LOSSL,S LOSSL,I LOSSL,C LOSSL,E Embankments LOSEM,S LOSEM,I LOSEM,C LOSEM,E Subgrade LOSSB,S LOSSB,I LOSSB,C LOSSB,E Level of Service (LOS) describes condition with respect to Goals Risk Management Risk(E) = Probability(E) x Consequence(E) (Vulnerability included here with Consequence) “Risk management is an important part of asset management …” (AASHTO TAM Guide and ES) MAP 21 reads as follows: “IN GENERAL—A State shall develop a risk-based asset management plan for the National Highway System to improve or preserve the condition of the assets and the performance of the system.” Challenge • Risk is treated as though it is an additional Performance Measure or Goal (TAMG 5.1.3) as though it were additional to Safety, Congestion, Reliability, etc. • This leaves open a question (See TAMG 5.4): “Risk of what; what event is failure?” • This contributes to an imprecise use of the word, and confusion… Proposed Solution • Explicitly do not consider risk as an additional Performance Measure or Goal • Treat risk as related to each and every Performance Goal, and whether or not it will be met (= “failure”) Safety, Congestion, Reliability, etc. • Define “Level of Service” (LOS) as also related to the same Performance Goals Key Point • LOS is static at a point in time, whereas Risk is related to the potential rate of change of LOS LOS is “today”, what condition and service is the asset providing through today; it is not uncertain Risk is “tomorrow”; all else is the same, but of course it is uncertain Risk is related to a prediction, a forecast of LOS change through action or inaction (To Change of State - yrs) Time in Condition State C O N D I T I O N 18 1 11 6 A - Excellent 80% B - Good 60% C - Fair 40% D - Poor 20% F - Failed 5 100% 10 15 20 25 TIME (yrs) 30 35 40 0% Risk Sources – sources of the event (E) Natural Hazards • e.g. extreme/rare events External Agency Impacts • e.g. poor materials or construction Physical Failure • e.g. deterioration Operational Risk • e.g. poor design, operation, or business decision TAM Guide (Section 5.4.1) All risks can be identified in a 3-D matrix: Risk Sources x Assets x Performance Goals Definition of the Event (E) = “failure” • Slipping below a condition state – a target LOS for a Performance Goal (To Change of State - yrs) Time in Condition State 18 1 11 6 100% C O N D I T I O N A - Excellent 80% B - Good 60% C - Fair 40% D - Poor 20% F - Failed 5 10 15 20 25 30 35 40 0% TIME (yrs) 30 Risk Cube GEOTECHNICAL RISK RRW,E,OR Operational Risk Physical Failure External Agency Impacts Σ of ALL Risk Sources on GEOTECHNICAL Assets with respect to ALL Performance Goals Can be done for GAM Section, Corridor or entire Retaining Walls Slopes Embankments Subgrade RRW,I,EAI RRW,S,NH Asset Class Natural Hazards RRW,C,PF RRW,S,NH RSL,I,NH REM,C,NH RSB,E,NH Performance Goals Simplification • 64 cells (this example) is too many. – MAP-21 has 7 Goals … 112 cells • Eliminate or categorize secondary contributors • Address Operational Risk and External Agency Impacts differently through – Established business practices – Implementation of QC/QA Plans 2 Sources are managed separate from GAM Operational Risk Physical Failure External Agency Impacts Retaining Walls Slopes Embankments Subgrade RRW,S,NH Asset Class Natural Hazards RRW,C,PF RRW,S,NH RSL,I,NH REM,C,NH RSB,E,NH Performance Goals GAM Risks RRW,C,PF Physical Failure Retaining Walls Slopes Embankments Subgrade RRW,S,NH Asset Class Natural Hazards RRW,S,NH RSL,I,NH REM,C,NH RSB,E,NH Performance Goals Physical Failure Risk Source Physical Failure RRW,C,PF Retaining Walls Slopes Embankments Subgrade Performance Goals Natural Hazard Risk Source Natural Hazards Retaining Walls Slopes Embankments Subgrade RRW,S,NH RRW,S,NH RSL,I,NH REM,C,NH RSB,E,NH Performance Goals GAM Section, Corridor or Inventory Retaining Walls Slopes Embankments LOS Risk Performance Goals Performance Goals Subgrade TAM Guide Maturity Achieve minimum LOS before looking at Risk of falling below it (might already be there) US 2, Crookston, MN 4 months of monitoring Could more have been done? Risk-Based Asset and Performance Management Can’t do all we would like Need to Optimize Can’t do it all at once Need to Prioritize What do you think? Conclusions There is an evolution in practice It is multidisciplinary Decisions are based on performance and risk These are not new ideas for geotechs but there is lots of opportunity Questions