Infrasense collected data to map the location of underground utilities and buried trolley tracks, analyze asphalt thickness, and identify the limits and depth to the top of the Red Line tunnel. Ground Penetrating Radar (GPR) and Electromagnetic Induction (EMI) tools were used as primary detection instruments, along with GPS for location referencing.
CAMBRIDGE, Mass., June 25, 2024 /PRNewswire-PRWeb/ -- Infrasense conducted a subsurface survey along approximately 2000 feet of Massachusetts Avenue through Harvard Square in Cambridge, Massachusetts. A combination of vehicle-based and pushcart Ground Penetrating Radar (GPR) data collection, Electromagnetic Induction (EMI) cable locating, and Real-Time Kinematic Global Positioning System (RTK GPS) location referencing were used. These testing methods provided the data needed to identify and map utilities and subsurface obstructions, asphalt thickness, and Red Line tunnel structure limits. GPR and EMI were the primary methods for the subsurface survey.
The GPR survey was completed in two stages. The first part of the collection used a 400-MHz antenna system, including a GSSI SIR-4000 data acquisition unit, a survey cart, GPS, and an electronic distance measuring instrument (DMI). This type of survey can achieve penetration depths of 10 to 12 feet if conditions are favorable. Even with the presence of asphalt, brick, and concrete across the site, subsurface features were detected from the data at a depth of approximately eight feet. Additional GPR data were collected using a vehicle-mounted 1-GHz horn antenna system which provided high resolution, and near-surface information for pavement structure evaluation.
The team employed two EMI systems, a Dyantel 2573M and Subsite Electronics 750 R/T, to locate and trace utilities accessible from utility holes, utility poles, gas meters, hydrants, etc. Each tool has both active and passive modes that allow for unique methods of identifying frequencies associated with utilities. Each utility identified and traced using the EMI method was marked on the ground's surface using service-specific paint colors.
The GPR utility results were then compared to the EMI and as-built information to confirm the service type when possible, and to avoid double reporting of same service lines. In addition to utilities, the extent of existing buried trolly tracks and the top of the Red Line tunnel were also mapped.
About Infrasense, Inc.
Since 1987, Infrasense, Inc. has applied advanced technologies to address the most difficult challenges in subsurface scanning. Infrasense's engineers nondestructively extract critical information from a diverse range of structures. In addition to providing ongoing subsurface evaluation services to clients across the country, the firm has also conducted numerous research programs to advance the field of subsurface detection and nondestructive evaluation. To learn more about Infrasense and the services we provide, visit our website: http://www.infrasense.com.
Media Contact
Lily Strickler, Infrasense, 7812811686, [email protected], www.infrasense.com
SOURCE Infrasense
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