posted 2nd May 2025
The Project
AECOM was tasked with capturing and modeling architectural and MEP elements for an expansive wastewater treatment facility located in a challenging urban environment. The facility spans both aboveground and underground structures, with a complex layout spread across multiple levels, 150 feet below the surface. This intricate setting demanded an accurate and efficient scan-to-BIM workflow to meet the project’s tight timeline and LOA 200 accuracy requirements.
The Challenge
This project was an ideal test for AECOM’s Digital Practice Innovation group to demonstrate a faster, more efficient workflow. The wastewater facility’s multi-level layout and extensive MEP systems demanded both high accuracy and speed. Aligning data from SLAM and TLS technologies, each with different accuracy levels, was critical to delivering a cohesive, reliable model.
The Workflow
Capture and modeling in parallel:
- AECOM placed an extensive network of control points to ensure alignment of data from different scanning methodologies.
- Control points were placed outside and throughout the interior of the facility, including vertical control in stairways.
- Each level of the facility was captured separately using the NavVis VLX, locking scans to control points to reduce drift and improve accuracy.
- Stairs were captured next, followed by TLS scanning.
- Meanwhile, the modeling team began building the Revit model using PDF plans to model levels, doors, windows, and other basic elements.
- NavVis VLX data was inserted into the Revit model to adjust for existing conditions.
- EdgeWise was used to process the NavVis VLX data, extracting larger MEP elements to provide an early overview.
- This parallel workflow enabled significant modemodellinggress before terrestrial scanning was completed.