Key Concepts in Dynamic Signal Processing from Instrumented Pavement Sections

Abstract

Accelerated pavement test facilities have often featured dynamic pavement response instrumentation, such as strain gauges, pressure plates and multi-depth deflectometers since the 1960s. While the instrumentation and data acquisition systems have rapidly evolved since then, researchers still face the fundamental problem of converting raw dynamic signals gathered at high sampling rates into meaningful information. These signals are inevitably infused with electronic noise that complicates extraction of useful information. Furthermore, the resources to collect and store raw data often far outpaces the capabilities to process and analyze the signals efficiently. The National Center for Asphalt Technology (NCAT) Pavement Test Track has utilized dynamic strain gauges and earth pressure cells since 2003 within structural pavement research studies and NCAT has also been involved in live-traffic instrumented test sites in China, Oklahoma and New Mexico. Each test site experienced the problems described above and also faced unique challenges related to site-specific conditions. This paper provides lessons-learned from the past 14 years of dynamic signal processing at each of these test sites. A common set of practices is described and applied to two of the sites that demonstrates the effectiveness and efficiency of the developed processing schemes. Emphasis is placed on speed of data processing and visual inspection for quality control.