Seeking to maximize efficiencies on the $1.35 billion (CA$1.7B) New St. Paul’s Hospital project in downtown Vancouver, PCL’s Integrated Construction Services (ICS) team is leveraging geographic information system (GIS) technology to optimize project delivery, reduce risk and meet client budget expectations. The innovative approach secured the project team an invitation to present at the Environmental Systems Research Institute (Esri) User Conference 2023. More than 18,000 of the leading minds in GIS mapping, software and location intelligence were in attendance.
(Left) A “bird’s-eye view” of the New St. Paul’s Hospitals Project during the excavation phase — with supervision from Seymour the Seagull. (Right) An updated drone image of the project taken November 2023.
“Working hand-in-hand with a progressive owner in a design-build project setting where the team evolves the design together, we are collectively pushing the boundaries of a traditional construction approach and elevating our efficiency, precision and accuracy of construction to another level,” says Lina Stinnett, PCL’s senior manager of integrated construction technology, during the presentation. Stinnett, together with Aaron Akehurst and Bilal Yasir from PCL’s ICS team in British Columbia, provided an overview of how drones transformed millions of data points into a 3D model of the job site, helping to increase project quality and reduce risk.
Starting with the project groundbreaking, drones flew every week during the excavation phase for the new St. Paul’s Hospital, capturing an average of 300 site photos every week. Each flight was able to convert over 1 million data points using photogrammetry. PCL’s ICS team then applied that information to create high-resolution 3D point clouds for every inch of the two-million-square-foot construction site.
By feeding these point clouds into Site Scan for ArcGIS — the end-to-end, cloud-based drone mapping software from Esri — and combining it with Building Information Modeling (BIM) for both permanent and temporary systems, PCL was able to identify potential risks early and pivot at critical points in the construction process to avoid expensive delays.
“While excavating this site, we needed to build a ramp to get in and out of the excavation area. By overlaying the digital design with the real-time excavation, we found that the ramp and crane foundation were in the same location. Setting up the crane is the most critical activity on a construction site, so the ramp had to move,” explains Yasir. “We shared the coordinates with the field team, and they started building the ramp in its new location, away from the crane foundation. As a result of the continuous drone survey, we used this information to pivot and adjust the ramp before it caused expensive delays.”
By layering drone imagery (left) over the BIM layer (right), it was made clear that the location of the excavation ramp would impede with the crane’s foundation.
This is only one of many examples where the integration of GIS with BIM optimizes the delivery of complex large-scale projects. As clients expect more value, quality control and transparency for their investment, PCL is responding by leveraging advanced technologies to help meet and exceed expectations.
“While excavating the site, we found some giant boulders as big as an F150 truck,” Yasir says. “We marked all these boulders in Site Scan to see them in site context. Using this data, we were able to refine the scope of work anticipated by the contractor hired to remove the boulders, saving the project close to $25,000 and avoiding any disputes over the scope of work.”
During the excavation process, it was found that the site contained a mixture of truck-sized boulders and backfill material that were impacting critical areas. By entering this boulder graveyard into Site Scan, PCL’s ICS team confirmed the exact volume and cost of removal with the subcontractor.
And when it came time to coordinate the arrival and placement of 520 concrete trucks to pour concrete in a 13-hour period, drone footage from the job site helped optimize the ideal site access and concrete pump locations using Site Scan. The result facilitated a streamlined operation with 520 trucks arriving to site at roughly 75-second intervals and successfully pouring approximately 4,580 cubic meters (150,000 cubic feet) of concrete over a continuous 13-hour period.
Using Site Scan, PCL’s ICS team optimized the location of each concrete pump station to ensure all 520 concrete trucks could arrive on site in 75-second intervals to successfully pour 4,580 cubic meters of concrete in a 13-hour period.
Since introducing drones into the field, PCL has reduced its cost of site inspections by up to 80% compared to using traditional 3D laser scans. Drones are being used at multiple phases throughout projects, as a single flight is sufficient to ensure quality requirements are being maintained; compared to the previous approach of sending a worker to manually walk through the site and document progress. In the case of the New St. Paul’s Hospital, drones analyzed every square inch of the concrete retaining walls, ultimately identifying out of tolerance areas for rectification before they impacted the next stage of construction.
The use of these innovative technologies doesn’t end when the project is finished.
“I can remember spending many late nights putting operations and maintenance binders like this one together, often delivering them months after construction was completed. At PCL we are working with clients to provide a more meaningful digital handover that pulls design, construction and commissioning data through to operations,” says Akehurst. “These progressive owners are empowering their facilities maintenance teams with data, leveraging BIM to create GIS indoor opportunities and ultimately setting the foundation for city-scale digital twins.”
The significant value found by combining accurate location data and other critical digital information in the construction process is still in the early stages of adoption. However, projects like the New St. Paul’s Hospital are showcasing exactly what is possible when clients, architects and builders all come to the table with a plan to find efficiencies and optimize every phase of the construction process. Leveraging advanced GIS technologies such as Site Scan and integrating the data collected with BIM means that project planning, quality, safety and risk management are significantly enhanced and accelerated — ultimately driving greater value to clients and their bottom line.