Economic Analysis Tools for Geotechnical Asset Management
"The term ‘asset management’ means a strategic and
systematic process of operating, maintaining, and improving physical assets,
with a focus on both engineering and economic analysis based upon quality
information, to identify a structured sequence of maintenance, preservation,
repair, rehabilitation, and replacement actions that will achieve and sustain a
desired state of good repair over the lifecycle of the assets at minimum practicable
cost.’’ (23 US Code 101(a)(2))
Federal rules 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 515.9). This 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 network. Federal rules mandate that pavement and bridge
management systems be used to support the development and implementation of the
TAM Plan for those assets.
Agencies wishing to implement geotechnical asset management
will need to develop reliable quantitative tools, similar to those provided in
pavement and bridge management systems, to implement asset management
procedures for slopes, embankments, and retaining walls. The business processes
to be supported would include:
Summarizing asset conditions and performance
Estimating the cost and effectiveness of risk mitigation,
preservation, and reconstruction;
Estimating risk, including the likelihood and
consequences of service disruptions;
Estimating life cycle costs;
Selecting treatments for specific assets;
Setting priorities and allocating resources
within budget constraints;
Setting performance targets in relation to
The analytical needs of geotechnical assets are simpler than
those of pavements or bridges, and might be satisfied with a simple tool, such
as a suitably configured spreadsheet and accompanying documentation.
The objective of this research is to develop a simple model
and documentation to support the business processes listed above, using
appropriate methods and drawing on existing tools and research as much as
possible. Agencies using the tool will populate it from their existing
inventories and condition surveys for geotechnical assets. The tool is not
intended for supporting inventory maintenance, inspection processes, or
geographic analysis: it is to focus on economic analysis and planning of
infrastructure investments. The tool developed in this project shall not
contain any proprietary software or restrictions on end user rights. The
spreadsheet files shall be compatible with Microsoft Excel 2013 or above.
tools will enable agencies to leverage their existing databases and geographic
information systems to conduct the economic analysis required in support of
developing and implementing TAM Plans for geotechnical assets. Most agencies do
not have the capability to develop such tools, but often do have the capability
to adopt and customize spreadsheets developed by others.
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 models described here. Many agencies have
developed Rockfall Hazard Rating Systems that build on a visual assessment of
slope characteristics to characterize the vulnerability of rock slopes. Similar
methods have been used, less commonly, for soil slopes and for retaining walls.
A number of agencies incorporate retaining walls within their bridge management
systems and use deterioration and cost models developed for those systems. Some
commercial software developers are marketing systems for management of asset
inventories and condition surveys, and for mapping and other geographic
analysis. These systems do not contain the required economic analysis, but
might be interfaced with a spreadsheet tool having the required functionality.
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 publicly-available ongoing or
completed work in the area.
Prepare a functional design document for the
tool. The document will provide a first draft of worksheet formats (input data,
calculations, and displays of results); a description of the methods to be used
(including justification and mathematical formulas) and their capabilities and
limitations; data requirements; and an outline of proposed documentation.
Solicit comments from the project Panel on the
functional design document. Meet with the Panel to discuss the comments and
Based on Panel comments, refine and carry out
the functional design, producing a draft spreadsheet tool. A draft of the
documentation will also be included.
Provide telephone and email support as needed to
enable the project Panel members to evaluate and comment on the draft
Based on Panel comments, revise the tool and
documentation. Solicit feedback from the Panel and make further changes as
needed to ensure that the Panel comments are fully incorporated.
Finalize and submit the Final Spreadsheet and
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. Depending on the quality of data and
models obtained, the Panel may elect to conduct a follow up study to gather
additional data for incorporation into the model. In the longer term agencies
should be able to repeat the methodology with data collected over longer
timeframes to improve and further customize the models.
All transportation agencies have responsibility for geotechnical assets. At all levels from local to state to federal, management of geotechnical assets is becoming more critical as agency funding levels continue to dip. Alaska DOT&PF has indicated they are interested enough to be co-sponsors. Alaska is in the process of completing a years-long research program to develop a start-up Geotechnical Asset Management program, but they (and other transportation agencies) will need immediately usable deterioration models and economic analysis tools for geotechnical assets. This research will provide the economic analysis tools agencies will need to manage geotechnical assets to the best effect.
|Sponsoring Committee:||AFP00, Geological and Geoenvironmental Engineering Section
|Research Period:||12 - 24 months|
|RNS Developer:||David Stanley and Scott Anderson|
|Source Info:||RNS developed by the Geotechnical Asset Management, AFP00(1), Joint Section 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 has agreed to co-sponsor the research.|
|Index Terms:||Geotechnical engineering, Asset management, Life cycle costing, Bridge management systems, Retaining walls, Deterioration, Embankments, Rehabilitation (Maintenance), |
|Cosponsoring Committees:||AFS00, Geotechnical Engineering Section|
Administration and Management
Maintenance and Preservation
Planning and Forecasting