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1 Even though bridge and pavement conditions receive much of the media attention and legislative directives for state departments of transportation (DOTs), the value and perfor- mance of other assets also are important to the effective operation of the transportation system throughout its life-cycle. One such asset category is geotechnical assets, which are the walls, slopes, embankments, and subgrades that contribute to the ability of a transportation agency to perform its strategic mission. According to the FHWA (2018), âtransportation asset management [TAM] plans are an essential management tool which bring[s] together all related business processes and stakeholders, internal and external, to achieve a common understanding and commitment to improve performance.â To truly drive performance, transportation agencies therefore need to look beyond the two legacy asset categories named in federal authorization and better understand the impact of all assetsâincluding geotech- nical assetsâwithin the system that they must manage as responsibly and cost-effectively as they are able. Implementing asset management practices for geotechnical assets enables an infrastruc- ture owner to measure and manage the life-cycle investment considering performance expectations and tolerance for risk. Although geotechnical asset management (GAM) is not typically mandated through legislative processes, the reasons for adopting this practice are comparable to those that justify any other business practice that is directed at making smart investments with limited funds. Without employing GAM, organizations are accepting unknown magnitudes of undue risk to traveler safety, mobility, and economic vitality, while potentially making unfavorable life-cycle investment decisions. Fortunately, for an owner of geotechnical assets, risk-based GAM implementation can build on the practices developed by successful programs. Two such programs in the United Kingdom have more than 15 years of implementation experience: Highways England manages 4,400 miles of roadways with 49,000 slope and embankment earthwork assets that are similar in age to many DOT geotechnical assets in the United States, and the UKâs Network Rail system has more than 9,800 miles of railway with 191,000 earthwork assets, most of which are well over 125 years old. When combined with other international and domestic geotechnical asset and natural hazard management programs, these examples provide valuable information on the need for and benefits of GAM regardless of asset age, as well as implementation concepts that can enable rapid return on investment (ROI). An early benefit of GAM implementation is the efficient use of taxpayer funds through leveraging existing practices that minimize the need for significant investment in new pro- grams or re-allocation of resources. Drawing from existing risk-based asset management practices, Volume 2 of NCHRP Report 903 (the GAM Implementation Manual) incorporates the use of a spreadsheet-based (Microsoft Excel) software tool, the GAM Planner. Together, S U M M A R Y Geotechnical Asset Management for Transportation Agencies, Volume 1: Research Overview
2 Geotechnical Asset Management for Transportation Agencies, Volume 1: Research Overview the GAM Implementation Manual and the Gam Planner tool can enable an agency to imple- ment a risk-based asset management program quickly and without requiring significant start-up costs or efforts. Once asset management has started, evidence from across the asset management spectrum indicates that a program will mature through justified process improvements that support ROI. Therefore, an implementation workflow for GAM can start simply and with an incomplete inventory that advances with time. The goal of any asset management system is to logically align asset design, operations, maintenance, and upgrade decisions with agency goals and objectives. For GAM implemen- tation to succeed across an organization, the program should relate how asset performance affects both customers and the decisions made by executives who focus on agency goals and objectives. For this to occur, asset performance measures should relate to high-level agency objectives such as common safety and system performance objectives. The GAM imple- mentation process and the accompanying GAM Planner developed through this research center on performance objectives related to asset condition, safety impacts, mobility, and economic consequences, which are common objectives across DOTs and offer a means for connecting geotechnical asset performance to stakeholder goals and objectives. In addition to alignment with stakeholder objectives, consistent use of definitions within a GAM taxonomy that is aligned with other asset management systems can enable communi- cation across disciplines within the organization and among different agencies. Definitions of asset provided by both AASHTO and the International Organization for Standardization (ISO) support the recommended geotechnical asset taxonomy consisting of walls, slopes, embankments, and subgrades as physical assets within the right-of-way (ROW). Further, the basis for this taxonomy is validated by several years of applied GAM for transportation systems in the United Kingdom. Some geotechnical assets involve ground improvements or inclusions such as steel anchorages and reinforcement, concrete materials, culverts, and geosynthetic grids and fab- rics. Although these improvements and inclusions have geotechnical performance charac- teristics, their function is to enable the performance of the specific asset as a design element or component. As a result, management of these geotechnical improvements or inclusions is best handled within a framework, such as an emerging GAM program, that manages the overall asset performance in terms of higher-level agency objectives and goals. Historically, many agencies in the United States have assumed management responsibil- ity for geotechnical or geologic hazard events that originate beyond the agency ROW or other boundary. This practice can provide value to the agency performance objectives and to the greater economic region. Management programs provide an opportunity to distin- guish between geotechnical assets constructed within the ROW and geotechnical features or sites beyond the ROW. This distinction should be discussed with executives and planning staff to achieve consensus on inclusion in the GAM program or defer to other agency risk management programs. For example, geotechnical features beyond the ROW boundary could be candidates for agency-wide resilience strategies that address other external agency hazards such as flooding, earthquake, or terror events. The topic of features beyond the ROW has been identified as an area for future study, as the information about GAM imple- mentation and benefits gained from long-standing GAM programs in the United Kingdom focuses primarily on management of assets within the ROW. Whether an agency formally implements a risk-based GAM program or defers to exist- ing legacy approaches, asset treatments such as âdo minimum,â âmaintain,â ârehabilitate (rehab),â âreconstruct (or renew),â and ârestoreâ will be executed by the agency on each asset. The GAM Planner provided with the GAM Implementation Manual provides initial
Summary 3 recommendations for asset treatment as the inventory is developed, enabling an agency to develop long-term financial plans for the geotechnical asset category. As with existing asset management programs for pavements and bridges, the estimated program-level investment needs for geotechnical assets across an agency will likely exceed the available funds. Using a GAM program can improve the likelihood for successful implementation by incorporating additional risk management, risk prioritization, and life-cycle cost-investment prioritization approaches. These varying prioritization approaches can enable an agency to satisfy the most pressing investment needs in a framework that also is flexible to the objectives of executive and planning staff. Through GAM processes, a geotechnical asset manager can collaborate with stakeholders across an agency to develop a âshelf,â or candidate list, of beneficial geotechnical asset treat- ment projects that can be selected depending on investment level and risk tolerance.