City-Wide Scanning Helps Tulsa With ADA Compliance Push
Local engineering firm’s 3D scanning effort eliminates daunting manual process.
A technology can be seen as being truly revolutionary and impactful when new uses for it continually arise. So when Sisemore-Weisz & Associates (SWA) landed a contract to help the city of Tulsa verify compliance to the Americans with Disabilities Act (ADA), the strengths of 3D scanning immediately came to mind.
“The scope of the project was certainly on the larger side,” said Shawn Collins, SWA’s chief of parties. “The city compiled a list of 20 municipal locations that could possibly be out of compliance with the ADA. That list included a number of municipal buildings, several fire houses, a court building, the Tulsa Animal Shelter, the city’s oldest cemetery, the 9-1-1 call center, the Tulsa Police Department’s headquarters, Tulsa City Hall, the Oxley Nature Center the Bank of Oklahoma Center (our civic arena), and the Tulsa Zoo.”
"Given the size of the overall project, if we were to take a hand topo shot every six inches, it would have literally taken us forever."
Tiny Deviation, Big Challenge
The challenge of the compliance survey project was not only in the number of structures needing verification work, but also in the detail to which those surveys had to conform. Collins said that really drove the direction in which they chose to go.
He said, “Given the size of the overall project, if we were to take a hand topo shot every six inches, it would have literally taken us forever. However, we already owned a Topcon GLS-2000 scanner and felt that it could provide the solution we needed — we could not have been more right.”
According to Jimmie Hendrickson, SWA project manager, the number of scans per structure varied — anywhere from 10 to 300 — as did the data generated from them.
“Our goal was to capture data that could then be used to assess whether or not a particular area of a structure — a sidewalk or an entryway, for example — complied with the directives set out in the ADA,” he said.
Topcon GLS-2000 is a full-featured scanner that has proven ideal for capturing existing, as-built conditions in a host of applications. Compact and lightweight, the dual mode instrument (selectable for Class 3R or Class 1M operation) can accurately capture a full 360° scan — including images — in less than three minutes. Providing both speed and versatility, the GLS-2000 offers a range of 350 meters.
For each site, Hendrickson said they started by bringing in Tulsa state plane control, then running a closed level loop though all scan positions, and importing the control file (.CSV) into the scanner.
“After creating the line work and the outline of the building face, we generated our grid and saved the file as a .DWG (CAD) file.” He added. “At that point, we opened the file using Civil3D. Once opened, we brought in the items created in TopoDOT — the line work, points, etc. — then used our template in Civil3D to label and contour the project, and sent the completed CAD file to the architect.”
With that file in hand, architects working with the City of Tulsa will review the scans, examine the surfaces in question, determine where any ADA conflicts might be.
“This is an effort that is high on the city’s ‘to-do list,’ if you will,” said Shawn Collins. “It was a massive undertaking and, given the tight parameters, one that really could not have been done using traditional survey techniques. Fortunately, we have technology like the GLS-2000 to make a project like this happen and everyone involved is pleased with the results.”