Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 149887

149887 - Embedded Passive Radio Frequency Sensing System for Pavement Subsurface Displacement and Moisture Monitoring 

Pavements are widely used on roads and airport runways, which constitute a critical infrastructure of modern transportation systems. However, factors such as aging, overuse, water infiltration, and landslides can damage pavements, ultimately leading distress and failure. Damage in subsurface courses (which support road stability and load-bearing capacity of the pavement system) is difficult to detect by manual/visual inspection, while delays in maintenance and repairs could lead to catastrophic events. Although structural health monitoring systems (SHM) have been used to address the challenge of manual inspection, the existing systems primarily focus on the surface course rather than the subsurface courses. Therefore, it is of paramount interest to develop a subsurface course monitoring system to effectively inspect and assess the pavement structural conditions based on long-term and large-scale implementation.

This poster presentation focuses on demonstrating the proof of concept of the applicability of the novel embeddable, passive radio frequency (RF) based sensing system in subsurface course monitoring. These RF sensors leverage backscatter techniques to obtain RF channel information for the purpose of estimating the distance and detecting the presence of moisture between the sensors, based on which deformation and water content in the pavement could be detected, respectively. Controlled 1-D displacement experiments were conducted in air and sand substrates, in laboratory settings, to examine the capability of displacement monitoring. In addition, an experiment on detection of water infiltration into dry sand was conducted to examine the feasibility of moisture monitoring. The main challenge of the latter includes replicating the subsurface conditions in laboratory settings and identifying the relationship between subsurface materials as a function of different water content and sensed RF channel information.

The results show that the embedded passive RF sensing system captures the displacement changes and the presence of water in the controlled subsurface course conditions. The results of the experiment in the air show that the system performance has a 10% difference from the theoretical model, which is potentially caused by the noise from the laboratory settings. The results of the experiment in the sand demonstrate that the system has 95% confidence in detecting a 2 cm scale displacement change. Finally, the results of the water presence experiment demonstrate that the system has 99% confidence in detecting the penetration of water into dry sand. These results successfully provide proof of concept for embedded passive RF sensing applicability in subsurface course health monitoring. By further investigating the source, and addressing the effects, of noise, the proposed sensing system could be deployed in practical, real-world scenarios.

Presenting Author: Kent Eng Princeton University

Presenting Author Biography: Kent X. Eng is a Ph.D. student of civil and environmental engineering at Princeton University. He obtained his B.S. from the University of Illinois Urbana Champaign (2019), and M.S. from Stanford University (2021). From 2021-2023, he worked as a structural engineering designer at Skidmore, Owings & Merrill (SOM). In the summer of 2024, he worked as a fellowship student at Los Alamos National Laboratory. His focus is on advanced sensing technologies and universal SHM methods. Current research focuses on infrastructure sensing and monitoring using radio frequency sensing technologies.

Authors:

Kent Eng Princeton University
Zygmunt Haas The University of Texas at Dallas
Petar Djuric Stony Brook University
Samir Das Stony Brook University
Milutin Stanacevic Stony Brook University
Branko Glisic Princeton University