Geotechnical Asset Management: Environmental Sustainability and Resilience
Federal rules in encourage transportation
agencies to incorporate in their Transportation Asset Management (TAM) Plans
all infrastructure assets within the highway right of way (23 Code of Federal Regulations R 515.9). The focus is on National
Highway System (NHS) bridges and pavements, but an agency may include
geotechnical assets such as retaining walls, unstable slopes, embankments, and
other asset classes whose functionality may affect the whole life cost and/or
performance of the highway network. For the assets that a State voluntarily includes in its asset management plan, the State
will not have to adhere to the asset management plan processes the State adopts
for bridges and pavements.
Agencies with large investments in geotechnical assets, or
with whose highway networks that are especially vulnerable to geotechnical
hazards, may want to include in their TAM Plans a risk management strategy that
analyzes geotechnical assets in a quantitative manner similar to what is often done
with bridges and pavements. Such analysis could include quantitative
performance measures for sustainability and resilience to measure project
benefits and assist in prioritization and resource allocation of geotechnical
asset investments such as risk mitigation, slope stabilization, reconstruction,
and maintaining access to sustainable quantities of soil and rock for projects.
Projects with positive impacts on environmental values or maintaining
continuity of service would then be evaluated on a basis consistent with other
For the purpose of this research needs statement, the term
“sustainability” refers to the effect of geotechnical assets, and of projects
affecting such assets, on environmental values such as air quality, water
quality, and cultural resources. The term “resilience” refers to the capability
of a geotechnical asset to maintain its functions and structure in the face of
internal and external change and to degrade gracefully when it must, avoiding
the disruption of transportation service on a highway corridor.
In order to support this type of analysis, there is a need
for performance measures and analysis tools to characterize the sustainability
and resilience of geotechnical assets. These would need to be simple and
consistent, able to be assessed visually in the field, supplemented with modern
remote sensing techniques, sensitive to common agency actions, and clearly
relatable to agency goals such as those enumerated in 23 US Code 150(b). Tools
would be necessary to associate changes in these measures with quantitative
benefits compatible with life cycle cost analysis and suitable for benefit/cost
The objective of this research is to develop a clear, standardized
set of definitions of sustainability and resilience performance that can
characterize geotechnical assets. Methods will be developed and documented to
perform field assessment, to forecast deterioration or other changes as
applicable, to estimate the effects of common agency actions, and to estimate
economic benefits of actions. The measures and tools will need to be
field-tested by means of pilot studies, preferably with state DOT cooperation
and the potential to implement the projects thus defined.
The definitions and methods shall be evaluated for
consistency with existing databases or inventories, agency project
prioritization methods, and existing or proposed level of service standards.
Using these measures and tools, agencies will have a
consistent basis for site-based risk management that is fully-integrated with
ongoing TAM business processes. Systematic and objective methods will ensure
that geotechnical risks are managed consistently and fully considered in
planning and programming.
NCHRP 24-46 Development of an Implementation Manual for Geotechnical Asset Management for Transportation Agencies is developing implementation guidance for
geotechnical asset management, but is not expected to perform the research
necessary to develop the quantitative measures and methods described here.
NCHRP Project 20-07/Task 378 (Assessing Risk for Bridge Management) has prepared a concept of resilience applicable to
bridges, and a related set of analytical tools to assess the likelihood and
consequences of service disruption scenarios. The framework may be adaptable to
geotechnical assets, particularly the resilience and sustainability concepts
and the structure of analysis tools, which tie the methodology to other
standard resources such as the AASHTO Guide for User and Non-User Benefit
Analysis for Highways (Red Book). Considering the apparent increase in unstable
slopes causing service disruptions in steep terrain, tools to apply these
concepts would be timely.
FHWA is developing a framework for implementing cross-asset
tradeoff analysis that can integrate geotechnical assets into existing
frameworks and systems for pavements and bridges. This can be used by agencies
to implement a TAM Plan that includes geotechnical assets.
NCHRP Report 590 describes an approach for multi-objective
optimization for bridge management that can integrate hazards and risk analysis
into life cycle cost analysis, priority-setting, and resource allocation. This
can provide one possible model, using the concept of utility functions, that
may be applicable.
Many agencies have independently developed rockfall hazard
rating systems, retaining wall inventories and assessments, and unstable slope
management systems that build on visual assessments to characterize the
vulnerability of geotechnical assets, but there is currently not a standard of
practice for integrating this data into an asset management plan. Information
that is collected is largely still managed with worst first or emergency
reactive prioritization rather than evaluating life-cycle costs and economic
It is envisioned that the research will involve at least the
Review and synthesize the relevant literature
including the sources listed above and any other ongoing or completed work in
Develop at least three alternative definitions
of resilience and sustainability performance measures that can characterize
existing geotechnical assets and the potential effects of agency actions,
particularly maintenance, risk mitigation, preservation, reconstruction.
Prepare a Preliminary Report describing existing
or developed definitions of resilience performance measures, including a case
for and against each candidate performance measure. Solicit comments from the project Panel.
Conduct a webinar with the Panel to decide the top two most viable definitions
to proceed with more in-depth work.
For each of the top two viable alternative
definitions of resilience and sustainability, develop a draft set of field
assessment procedures, and calculation methods. Show how each possible measure
might be tracked over time if it changes, how project benefits might be calculated
in terms of the 23 USC 150(b) national goals and in terms of dollars of social
benefit (to the agency, road users, and non-users).
Prepare an Interim Report describing the
findings and recommendations of the preceding tasks. Solicit comments from the
project Panel. Meet face-to-face with the Panel for one day to discuss the
comments and proposed recommendations. Prepare a presentation for the Panel and
lead discussions leading to final recommendations. Select one recommended
measure for sustainability and one for resilience to advance.
Based on the Panel discussion and
recommendations, develop a draft Guidelines document fully describing
recommended measures, field procedures, assessment timelines and cycles, and
Pilot test the draft Guidelines document using a
set of sites identified by cooperating agencies. This will require site visits
and professional geological visual surveys similar to what agencies would be
expected to perform routinely on their geotechnical assets. Gather necessary
data and perform the calculations recommended in the draft Guidelines. Assess
the usefulness of the results for all intended purposes including performance
tracking, communication of project benefits, prioritization, resource
allocation, performance target setting, and project programming.
Revise the draft Guidelines document based on
what is learned in the pilot tests. Develop metrics to enable agencies to
estimate and manage resource requirements for a routine field survey. Discuss
the added benefits of the measures to transportation asset management. Provide
recommendations on how to incorporate the measures into existing processes and
systems including cross-asset decision making.
Prepare a draft Final Report describing the work
that was done over the project. Submit the new draft Guidelines and draft Final
Report to the Panel for review and comment. Conduct a webinar to discuss the
final documents with the Panel.
Finalize and submit the Guidelines and Final
Report based on Panel discussion.
Prepare and conduct a webinar to help federal,
state, and local agencies to implement the Guidelines.
This research is envisioned to feed directly into TAM Plans
and management systems for geotechnical assets. Continued FHWA and AASHTO
support for asset management and performance management will help to ensure
successful and widespread implementation.
With increasing focus of transportation agencies on the related concepts of resilience and sustainability as a result of climatic changes occurring world-wide, research into how climate affects transportation assets. Our transportation systems continue to grow and some of the necessary resources are becoming more and more obviously non-renewable. Geotechnical assets are not immune to these difficulties. Resilience of geotechnical assets when impacted by evermore increasing environmental pressures becomes more relevant each year. Impacts on the environment by geotechnical assets in terms of air and water quality and cultural resources must be assessed in a standardized manner, consistent with existing agency protocols and levels of service. Every transportation agency must consider these issues. Coastal zones have an especially high stake in these matters.
|Sponsoring Committee:||AKG00, Section – Geology and Geotechnical Engineering
|Research Period:||24 - 36 months|
|RNS Developer:||David Stanley and Scott Anderson|
|Source Info:||RNS developed by the Geotechnical Asset Management, AFP00(1), Joint Subcommittee of AFP00 and AFS00. Primary sources for questions on the research are David Stanley and Scott Anderson, co-chairs of AFP00(1). Note: Alaska DOT&PF has agreed to co-sponsor the research.|
|Index Terms:||Asset management, Highway bridges, Geotechnical engineering, Pavement performance, Resilience (Materials), Embankments, Sustainable development, |
Administration and Management
Maintenance and Preservation
Planning and Forecasting