A fiber optic cable buried in this roadside trench records vibration from passing cars and trucks on Farmer’s Loop Road. These seismic surface waves carry information about subsurface soil and permafrost. Fairbanks AK, June 2015, credit Nate Lindsey.
LBNL-ESD and the U.S. Army Core of Engineers—Cold Regions Research and Engineering Laboratory (USACE—CRREL) are collaborating to explore the use of distributed fiber-optic sensors to monitor the state of permafrost underlying transportation infrastructure, such as roads, runways, and rail lines.
Permafrost environments are a unique setting for built infrastructure, an environment in which small thermal perturbations can have dramatic impacts on structural stability, ranging from foundation settling to catastrophic failure of roads, bridges, and runways due to thermokarst generation. A substantial global temperature change is expected within the next century, with a higher degree of variability predicted in Arctic regions (approximately 4°C), where substantial Department of Defense (DoD) resources are currently located. The nonlinear coupling of future changes in air temperature, surface insolation, and surface/subsurface hydrology to soil mechanics generates a high degree of uncertainty as to the environmental changes that built infrastructure will actually experience.
The objective of this project is to develop and validate a fiber-optic geophysical sensing package capable of providing real-time information on subsurface conditions relevant to infrastructure performance and failure in permafrost environments. The system will consist of a combination of three fiber-based distributed sensing methods—distributed temperature sensing (DTS), distributed strain sensing (DSS), and distributed acoustic sensing (DAS)—designed to be embedded in, or near, built infrastructure and to detect regions of progressive permafrost thaw induced by subsurface flow, surface water accumulation, or changes in system thermal behavior.
This is a Department of Defense (DoD) Strategic Environmental Research and Development (SERDP) project.