About the Project
The objective of transportation asset management is to achieve life-cycle performance goals (safety, mobility, preservation, economics, and environmental aspects) by managing the physical assets in the most cost-effective manner. Traditionally, geotechnical asset management along the transportation environment is often neglected because it is vast and considered as laborious and costly (Stanley, 2011). Some of the key geotechnical assets that need to be monitored are the retaining walls, unstable slopes, rockfall sites, cut slopes, embankments, and tunnels. The current management practices for geotechnical assets along the transportation environment have been mostly restoring the asset after the failure rather than identifying and remediating hazardous conditions before its occurrence. Developing a financially sustainable Geotechnical Asset Management (GAM) system that can be used by transportation agencies as well as private firms to enable more proactive infrastructure risk assessment is critical for strategic investment and long-term management of United States’ transportation infrastructure. In this project, we propose to establish a framework for GAM using commercially available remote sensing that can be used by the various transportation agencies, as well as interested private infrastructure managers, such as railroad and pipeline companies.
Geotechnical Assets along the Transportation Environment
A survey of State DOTs, operators, and owners of different transportation networks will be performed to identify valuable geotechnical assets that need to be managed, available inventory of geotechnical assets, asset condition that needs to be monitored, measurement accuracies and precisions that need to be met to produce useful data, etc.
Geotechnical Asset Types
- Embankments and slopes (to include rock slopes, cut slopes, landslides, and rockfall sites)
- Earth retaining structures (retaining walls, reinforced soil slopes, and earth and rock buttresses)
- Culverts or drainage channels
- Pavement subgrade
- Subgrade and land within right-of-way
- Buried reinforcing elements (rock bolts, tieback anchors, and other buried elements)
- Material and quarry sites
- Horizontal drains
Example of Geotechnical Assets
Geotechnical Asset Management FrameworkThe key elements of any asset management framework are:
- Assessing the current state of asset
- Defining the required level of service and performance delivery
- Identification of the assets that are critical to performance
- Investment strategies for operation, maintenance, and improvement
Assessing the Current State of Geotechnical Asset Using Remote SensingRemote sensing techniques, such as Interferometric Synthetic Aperture Radar (InSAR), and Light Detection and Ranging (LiDAR) provide great opportunities to measure ground movements precisely. In addition, high resolution optical images complement observations from InSAR and LiDAR and can provide three-dimensional surface movement tracking capabilities. Applying the remote sensing techniques to the transportation environment would help to monitor the possibility of displacement associated with geotechnical assets and would significantly reduce the level of effort currently needed to survey and inspect these assets. A goal of this project would be to help understand which remote sensing method (in terms of sensor and platform) or fusion of methods would provide the most cost-effective solution for accessing the state of geotechnical assets. The following figure illustrates one of the InSAR techniques that are going to be used in the project.
Performance Modeling of Geotechnical AssetsOnce the displacement of a geotechnical asset is measured using remote sensing, it would be critical to be able to define a performance rating of the asset based on the measured displacement. In addition to the measured displacement, the rating system will have to account for other critical site variables such as the soil/rock type, geometry, asset type, geology, water table etc. This is because two geotechnical assets of the same type with similar measured displacements potentially have different performance ratings depending upon whether one is a soil site and the other is a rock site. Therefore, the research team would develop a rating system for geotechnical assets based on remotely measured displacement that also incorporates the site specific critical variables. The rating system will be developed and validated using historic displacement and geotechnical condition data obtained from the partner agencies (MDOT, AKDOT, UPRR, and Alyeska). Further, validation will be performed using numerical simulation of displacement using Finite Element Method (FEM).
Decision Support ToolDecision support is critical in this effort due to the need for synthesizing decision-making criteria from a number of disparate data sources, and in turn generated by a variety of sensor and inventory data. For this task, the project team will build on the work of the USDOT/OST-R Phase II project, "Bridge Condition Assessment Using Remote Sensors," in which a prototype Bridge Condition Decision Support System (DSS) was built for bridge infrastructure assessment and asset management. Specifically, the project team will use the experience gained and, to a lesser extent, the software produced during the Phase II project, in order to:
- Establish the requirements for a web-based application ("web app") supporting decision-makers in geotechnical asset management
- Identify development milestones, benchmarks, and testing methodologies
- Design the software architecture needed to share useful results for transportation infrastructure managers to make decisions on geotechnical issues
A schematic of the proposed project concept is illustrated in the following figure.
Technical ValidationTechnical validation of the proposed project will be performed in three different transportation environments: highways, railways, and pipelines. In consultation with partnering transportation agencies (MDOT, AKDOT, Alyeska, & UPRR), we have identified some potential sites that features various geotechnical assets. The potential sites are Glitter Gulch (AKDOT), Caliente Canyon subdivision (UPRR), Treasure Creek (Alyeska), and two Michigan sites that we are identifying with the help of MDOT. A summary of the potential sites are provided in the following table.
|Site Name||Transportation Environment||Geotechnical Assets at Site||Available Remote Sensing Data||Available Validation Data|
|MDOT sites Approx length= 3.5miles||Highway||Cut slope, embankment, & retaining structures||LiDAR (terrestrial & mobile)||Inclinometer data, & baseline survey|
|Treasure Creek, AK Approx length= 10.0miles||Pipeline & highway||Cut slope, embankments, rock slope, retaining structures, culverts, & pipelines||Airborne optical imagery (2001 & 2009), LiDAR (airborne & terrestrial), & InSAR||Annual field survey records from 1990, GPS survey, inclinometer data|
|Glitter Gulch, AK Approx length= 7.0miles||Highway & railway||Embankment, retaining walls & cut slope||LiDAR (airborne, mobile, & terrestrial), InSAR, & optical imagery||Field survey records & retaining wall data sheets|
|Caliente Canyon, NV Approx length= 25.0miles||Railway||Rockslide, slide fence, embankments, & retaining structures||Terrestrial LiDAR, InSAR||Slide fence events data & field survey records|
This project is funded by the US Department of Transportation, through the Office of the Assistant Secretary for Research and Technology.