ASCE members got to see a glimpse of the future of construction technology when Pete Melas, P.E. of the Office of Construction at NYSDOT's main office in Albany gave a presentation on "Electronic Engineering Data" at Cooper Union on March 13, 2008. The presentation was the start of a two-part lecture that also included a presentation of the Stewart International Airport Access Improvement Project, highlighting its use of innovative GPS-guided construction and inspection techniques. Mr. Melas' presentation focused on three major areas: Electronic Engineering Data (EED), Automated Machine Guidance (AMG), and automated stakeout and inspection.
Electronic Engineering Data includes coordinates, alignments, and Digital Terrain Model (DTM) surfaces. The benefits of using EED include the elimination of re-entry of field data (e.g., calculation of quantity items for payment), visualizing the designer's intent and early identification of potential conflicts, automation of calculations, immediate field access to project information (e.g., an inspector in the field carries project data on a handheld unit), and promoting the sharing of data between parties.
Automated Machine Guidance (AMG) involves an on-board computer linked to GPS and sensors that continually monitors direction, elevation, and slope information. These data provide directional guidance to an operator via on-screen guidance and graphics. Projects using AMG have achieved a 30-50 percent reduction in time delays, material rework, and labor costs as well as a 40 percent reduction in fuel consumption, resulting in lower bid quantities. AMG allows for a decreased need to stop construction equipment for grade checks and results in increased safety as fewer people are in range of operating equipment.
Automated stakeout and inspection employs the use of Real-Time Kinematic (RTK) GPS rovers for stakeout and the inspection of constructed elements. Mr. Melas described the NYSDOT Continuously Operating Reference Stations (CORS) positioned across New York State and how they can enable GPS rovers to obtain RTK corrections without the need to set up a base station near the site. With an automated stakeout system, one person can accomplish the work that formerly required the use of a two to three person survey party. Quality control checks are important with automated stakeout as satellite coverage and reliability varies throughout the day and can be affected by other factors such as tree cover. It is therefore important to test RTK GPS rovers against known benchmarks.