Embedding reality capture in the construction of NYC’s East Side Access Project
Lennart Andersson, the director of LiRo’s Virtual Design, Construction, & Operations (VDCO) group, and his team use reality capture and BIM tools like ReCap, Revit, Navisworks, and InfraWorks to power their scan-to-BIM processes on a Manhattan megaproject.
LiRo and East Side Access
When completed, NYC’s East Side Access project will connect trains from Long Island and Queens to Manhattan’s Grand Central Station. The project includes over 8 miles of new tunnels and an 8 city-block long concourse with multiple train platforms below Grand Central Station. Construction began in 2002 and is scheduled for completion in 2022.
LiRo is providing construction management services as part of a joint venture. In addition, LiRo’s Virtual Design, Construction, & Operations (VDCO) group helped implement BIM throughout the project while the project was midway through construction and now provides ongoing BIM services and support.
The project’s design was completed in early 2000s using 2D CAD tools—the standard approach at the time. But building the project based on 100,000+ individual drawings became so unwieldly that in 2012, LiRo’s VDCO group was hired to transition the project to 3D modeling and BIM.
LiRo used Revit to model the entire project based on the original construction drawings. During that effort, LiRo scanned the as-is surrounding conditions, particularly in congested or poorly documented areas such as the existing Madison Yard located under Grand Central Station, to maximize the accuracy of their models and improve pre-construction project coordination.
Scanning during construction
Reality capture has also become a vital part of the project’s construction. “Teams routinely scan critical construction—structural columns for example—and we import that data into Revit to compare the as-built work to the as-designed model,” explains Naveen Lazar, BIM Manager in Liro’S VDCO group. “We can check clearances and ensure that any deviations are within tolerance. And the Revit model is updated to reflect as-built conditions for ongoing construction coordination.”
As-built scans are also used to track and document construction progress. In addition, congested areas are scanned before they are covered by walls or ceilings to document as-built conditions for future coordination or maintenance.
“Nowadays, we routinely include scan-to-BIM requirements in the BIM contracts we develop for our clients. But the East Side Access construction contracts predated affordable scanning technology. Nevertheless, reality capture is still an important part of the project…not because it’s required, but because the constructions team recognize its value.”—Lennart Andersson, Director of VDCO, The LiRo Group
East Side Access scanning
- 950-1000 scans during design, linked together in Revit as a master project point cloud
- 3000+ scans to date for construction
- Leica ScanStation PX0 used during design & preconstruction phases
- Leica BLK360 and Matterport Pro2 3D Camera for during construction
- Leica scanning used for exteriors or where higher accuracy is needed
- Matterport photogrammetry used for quick captures of small areas or to provide 3D project walkthroughs
In the works…
This project also involves major renovations of Harold Interlocking, a railroad junction in Queens and the busiest railway junction in the country. Due to its size, ground-based laser scanning of the area is not practical. But once drone operations are approved, LiRo plans to use drones to regularly capture the area from air to record site activity. These scans will become a form of time-lapse documentation and be used to verify as-built progress, validate contractor payments, and inform logistics planning.
LiRo also recently introduced its first mobile scanner on wheels, which exceeds the capability of traditional scanners by scanning much larger areas of up to 250,000 square feet per day. The mobile scanner improves the speed of scanning ten-fold. As an example, the team is already using it on large outdoor campuses and civil projects, both indoors and outdoors.
This is only the beginning. It will be exciting to see how these mobile scanners will be used with stationary models and how these tools will revolutionize documentation and surveying processes.
“Reality capture should be an integral part of all phases of a project,” says Andersson. “On East Side Access, it’s been critical for coordination and clash detection for both design and construction. And I’m sure it will play an equally important role throughout the project’s operation and maintenance.”