Automated Station for Monitoring Seasonal Ground Movements in Expansive Clay

This paper summarizes the design, installation, and data collection from an autonomous field station located close to a new toll highway south of Austin, TX, that is underlain by more than 10 m of expansive clay. Given the remoteness of the site, the system was designed to be fully automated, requiring very low maintenance. The field station combines a novel string pot system for measuring vertical deformations at five depths in a central borehole, together with volumetric water content, and temperature data from multi-parameter reflectometer probes installed at similar depths in a series of surrounding boreholes. In addition, there is a conventional surface weather station, which records air pressure, temperature, rainfall, relative humidity, and solar radiation. The system has been active for more than 1 year, and the data collected over this period shows its robustness.