Date of Award
Master of Science
Civil, Construction, and Environmental Engineering
Jeramy C. Ashlock
Granular-surfaced roadways, one of the most significant public road systems in the U.S., are highly vulnerable to be severely affected by the seasonal freeze-thaw cycles in cold regions. The state of Iowa is located in a cold region and experiences severe winter weather each year. To minimize the damage, seasonal load restrictions (SLRs) are applied, for typically 8 to 9 weeks from February to May. In addition, the Road Weather Information System is used to monitor the winter weather conditions, which consists of equipment to collect and transfer observations from roads. To help local transportation agencies with the organization of SLRs and resource planning, the development of a prediction model for different soil conditions around the state would be very useful. A great deal of cost savings could be achieved with a prediction model that captures the characteristics of the freeze-thaw cycles well and is updated with real-time weather and soil data. To develop such a model, an appropriate sensor network and data acquisition system must be planned and installed rigorously. In this study, the development and installation of the monitoring system are described, which is located in Hamilton County in central Iowa. The system consists of a weather station to collect atmospheric information and 80 sensors to measure soil water content, matric potential, and soil temperature properties from the subgrade of the roadway. This thesis presents the preparations that were done beforehand, installation procedures, and various post-installation problems and troubleshooting measures. The suitable sensors and data acquisition system were selected and coordinated to ensure successful installation and operation. Furthermore, laboratory and field trials were performed to minimize any installation or connection problems. This study also includes further details such as soil-specific calibration and grounding practices as well as a preliminary discussion about the obtained field data. A brief comparison between the weather station data and measurements of the nearest active RWIS stations was made to determine whether the RWIS stations could replace the weather stations for future application of the prediction models in other locations.
Genc, Derya, "Development, installation and preliminary data collection of an environmental sensor system for freeze–thaw monitoring under granular-surfaced roadways" (2019). Graduate Theses and Dissertations. 17450.