Presentation on theme: "Risk-Based Asset and Performance Management: A Geotechnical Perspective Scott A. Anderson FHWA - Resource Center."— Presentation transcript:
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
MAP-21 National Performance Goals 1.Safety 2.Infrastructure Conditions: State of Good Repair 3.Congestion Reduction 4.System Reliability- improve efficiency 5.Freight Movement and Economic Vitality 6.Environmental Sustainability 7.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.a summary listing of the pavement and bridge assets on the NHS in the State, including a description of the condition of those assets; 2.asset management objectives and measures; 3.performance gap identification; 4.lifecycle cost and risk management analysis; 5.a financial plan; and 6.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. 7 Really? 1.Safety 2.Infrastructure Conditions: State of Good Repair 3.Congestion Reduction 4.System Reliability- improve efficiency 5.Freight Movement and Economic Vitality 6.Environmental Sustainability 7.Reduced Project Delivery Delays
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)
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
Geotechnic al Asset Physical Asset Corridor and/or GAM Section ROW Feature Independent Feature SlopeRockSoilModifiedEmbankmentRockSoilModifiedSubgradeRockSoilModified Earth Retaining Structure Stabilized Earth Steel or Reinforced Concrete Element of other Structure Bridge Element Tunnel Element Pavement Element Outside- ROW Feature Slopes Water bodies Structure s (walls, etc.) Non- Corridor Material Sites Stockpiles or other Non- Physical Asset DataKnowledgeEquipment Proposed Geotechnical Asset Taxonomy – 1/8/14 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. Investigation and test results, lab and field equipment, key personnel High slopes, shorelines, and structures typically owned by others outside the ROW that are sources of risk because they can impact performance Established management systems for other structures that have (or should have) geotechnical elements. Others, could be added; for example – culverts. Predominant distinction in how feature is managed. Features with inclusions are “modified”.
Current Practice Implementation in States today They are all taking steps: some big, some small AlabamaGeorgiaFloridaKentuckyUtah North Carolina South Carolina Washington D.C. New Hampshire South Dakota TennesseeConnecticutMaineMarylandOregon New Jersey New YorkPennsylvaniaOhio North Dakota IndianaMichiganIllinoisMissouriNebraska IowaWisconsinMinnesotaArizonaMontana CaliforniaColoradoKansasWashingtonIdaho Alaska Vermont
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.a summary listing of the pavement and bridge assets on the NHS in the State, including a description of the condition of those assets; 2.asset management objectives and measures; 3.performance gap identification; 4.lifecycle cost and risk management analysis; 5.a financial plan; and 6.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
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 – Definition
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).
Deterioration models How are these levels related to Performance Goals?
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 Performance Goals SafetyInfrastructureCongestionEnvironmental Asset Classes Retaining WallsLOS RW,S LOS RW,I LOS RW,C LOS RW,E SlopesLOS SL,S LOS SL,I LOS SL,C LOS SL,E EmbankmentsLOS EM,S LOS EM,I LOS EM,C LOS EM,E SubgradeLOS SB,S LOS SB,I LOS SB,C LOS SB,E Asset Class Performance Goals Level of Service (LOS) describes condition with respect to Goals Linking Condition and Performance
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
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 All risks can be identified in a 3-D matrix: Risk Sources x Assets x Performance Goals TAM Guide (Section 5.4.1)
Definition of the Event (E) = “failure” Slipping below a condition state – a target LOS for a Performance Goal 30
GEOTECHNICAL RISK Performance Goals Risk Source Asset Class Natural Hazards External Agency Impacts Physical Failure Operational Risk Safety Subgrade Infrastructure Congestion Environmental Embankments Slopes Retaining Walls R RW,S,NH R EM,C,NH R SL,I,NH R RW,I,EAI R RW,E,OR R SB,E,NH R RW,S,NH R RW,C,PF Σ of ALL Risk Sources on GEOTECHNICAL Assets with respect to ALL Performance Goals Can be done for GAM Section, Corridor or entire inventory
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 Performance Goals Risk Source Asset Class Natural Hazards External Agency Impacts Physical Failure Operational Risk Safety Subgrade Infrastructure Congestion Environmental Embankments Slopes Retaining Walls R RW,S,NH R EM,C,NH R SL,I,NH R SB,E,NH R RW,S,NH R RW,C,PF
GAM Risks Performance Goals Risk Source Asset Class Natural Hazards Physical Failure Safety Subgrade Infrastructure Congestion Environmental Embankments Slopes Retaining Walls R RW,S,NH R EM,C,NH R SL,I,NH R SB,E,NH R RW,S,NH R RW,C,PF
Natural Hazard Risk Source Performance Goals Natural Hazards Safety Subgrade Infrastructure Congestion Environmental Embankments Slopes Retaining Walls R RW,S,NH R EM,C,NH R SL,I,NH R SB,E,NH R RW,S,NH
GAM Section, Corridor or Inventory LOS Risk Subgrade Embankments Slopes Retaining Walls Performance Goals 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