Infrasense recently performed a subsurface utility engineering (SUE) survey for an interstate in Massachusetts. All four industry standard quality levels were employed for this project from a comprehensive as-built records search (QL-D) to targeted test pitting for visual verification and direct measurements (QL-A). The geophysical survey (QL-B) utilized a high-resolution 3D ground-penetrating radar (3DGPR) system, and a thorough electromagnetic induction (EMI) investigation carried out by experienced utility locators.
SALEM, Mass., Nov. 29, 2024 /PRNewswire-PRWeb/ -- Infrasense was tasked with completing a SUE survey to designate and locate underground utilities along a state highway road in Essex County, Massachusetts as part of rehab planning of an overpass. The survey included a QL-C level investigation using the record drawings, a QL-B investigation of all potential utilities and subsurface obstructions using geophysical methods (GPR and EMI), followed up by Level A potholing at 7 locations to measure precise depths of the individually mapped utilities at the clients' specified locations.
The GPR data collection for the QL-B component was completed using our Impulse Radar Raptor-45 multichannel array GPR system. The Raptor system was deployed using the 18-channel vehicle mount setup for the roadway collection, and then with the 8-channel cart-based setup for sidewalk and shoulder collection. The 3-D array uses RTK GPS for location tracking and a total of eight 450-MHz GPR antennas simultaneously collecting subsurface information along 5.5-foot-wide swaths at traffic speed down to depths of approximately 10 feet for this project. As part of the ASCE 38-22 specification, the GPR data collection was completed in conjunction with an electromagnetic induction (EMI) pipe and cable locator tool (RD8200) to trace out the position of any utilities that were accessible from manholes, utility poles, water meters, hydrants, etc., and any active electrical lines which are detectable without direct access. Utilities identified by way of EMI were marked on the surface using paint and then recorded using RTK GPS.
The results of the project were compiled into a digital map integrating the GPR and EMI datasets. The array GPR data was assembled into a representative 3D model of the project for analysis using depth slice review, and advanced mapping toolsets in the Impulse Radar Condor software package. The GPR results are transferred into CAD software and then integrated with the EMI results to confirm service types and finalize target identification. Using these results, we coordinated with the client to determine the 7-test pit locations for full QL-A location information of the desired utilities, including communication, water, and gas lines. The test pit elevation information was used to calibrate the depth results before final submittal.
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, Inc., 781-281-1686, [email protected], http://www.infrasense.com
SOURCE Infrasense, Inc.
Share this article