Pavement and Bridge Deck Evaluation Projects in California
In 2020, Infrasense worked with NCE of Reno, Nevada, to evaluate the pavement structure under runway 28L at the San Francisco International Airport. This project materialized when airport engineers needed a quick and reliable method of evaluating the 11,000-foot-long, 200-foot-wide runway and identifying areas of thin asphalt cover. Because SFO is one of the busiest airports in the country, the runway closure was limited to just 6 hours; Infrasense had to be deliberate and efficient with our data collection in order to obtain all the necessary data within the prescribed timeframe.
Working within the time constraints set by the airport, Infrasense collected 4 channels of GPR data simultaneously using dual 1-GHz air-coupled antennas and dual 400-MHz ground-coupled antennas. By using two different frequencies, Infrasense was able to obtain multiple resolutions of data so that both the thin asphalt layers and deep asphalt base and supporting layers could be identified in the GPR analysis. Data was collected using GPS for positional accuracy, and allowed Infrasense to collected data at precise 6-foot intervals across the width of the runway.
In 2019, Infrasense worked with WSP and BDI to collect data on the Richmond-San Rafael bridge and 6 others in the Bay Area. Infrasense deployed a suite of complementary testing methods, including high-speed ground penetrating radar (GPR), infrared thermography (IR), high resolution visual imaging (HRV). The GPR and IR surveys were performed in order to identify and quantify areas of delaminated or deteriorated concrete within the 64 year old deck. GPR, IR, and HRV data was collected using a vehicle-based survey system at normal driving speeds with minimal disruption to traffic. For double decker bridges such as the Richmond-San Rafael Bridge, Infrasense also performed IR and HRV surveys of the soffits to identify and map defects on the bottom portion of the upper decks.
In addition to collecting and analyzing data on the Richmond-San Rafael Bridge, Infrasense also collected GPR, IR, and HRV data on six other major Bay Area bridges, including the West spans of the famous San Francisco-Oakland Bay Bridge. In total, Infrasense collected data on nearly 12 million square feet of bridge deck without any road closures or traffic delays.
