SoilTEM - Characterization of soil bearing capacity with non-invasive, high-resolution transient electromagnetic imaging
Abstract
Detailed knowledge of near surface soil structure is critical for a wide range of applications, including development and maintenance of runways. This project addresses an urgent need for a tool well-suited to efficient imaging of the top 3m of the soil, in order to quantify the soil bearing capacity to ensure for instance safe landing and take-off of aircrafts. Current practice for these purposes is to conduct on-ground manual measurements of the soil bearing capacity using for instance a cone penetrometer. This approach requires boots on the ground to execute a time-consuming measurement protocol often in a hostile environment. Hence, a fast, and cost-effective instrument to evaluate the soil bearing capacity would be of very high value.The transient electromagnetic method (TEM) is very promising for this problem. It is a rapid, non-invasive technique well-suited to roving systems, both terrestrial and airborne, allowing vast areas to be imaged cost-efficiently. TEM produces images of the electrical conductivity of the soil as a function of depth. The soil resistivity is correlated to the subsurface properties and with grid-like data collection one can construct 2D and-or 3D maps of the sub-surface, which can then inform the maps of high or low load bearing capacity.However, state-of-the-art TEM instruments cannot resolve structures and layers with sub-meter scale resolution in the top 3m of the soil, which is needed in load-bearing assessments. If TEM is to address soil-load bearing questions, it must deliver sub-meter resolution of the top 3 meters. We believe that this goal can now be realized given recent breakthroughs in the miniaturization of roving TEM systems and advanced data acquisition strategies, pioneered by the Hydrogeophysics Group (HGG) at Aarhus University. To achieve this goal they will- 1) develop a roving, ground-based TEM instrument with multiple coil orientations to enhance the resolution of the top layers to the sub-meter scale, and 2) explore novel acquisition strategies that will focus the sensitivity of the instrument further at the most shallow depths.The goal of the project is the rapid delivery of reliable, high-resolution 3D models of the soil layers. Beyond infrastructure projects, these developments will also be of great value in many other shallow-focused applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 22, 2024
- Source ID
- FA86552317019
Entities
People
- Anders Christiansen
Organizations
- Aarhus University
- Air Force Office of Scientific Research
- United States Air Force