Building the Unbuildable: Breaking Through the Wall of ‘No’
At first glance, the scope of the Arizona State University Health Futures Center (ASU HFC) canopy project seemed straightforward. Originally included in the buildout of the new medical learning center, the giant shade covering was designed to offer shelter from the desert over the facility’s courtyard and main entrance and was to be erected over an unoccupied environment. Budget constraints arose and the canopy project was indefinitely put on hold. Meanwhile, the team progressed, fully completing the building sans canopy in early spring 2020.
Just as students, teachers, medical professionals, and staff started to flow into the new facility in April of 2020, so did the delayed funding allocations for the canopy. Collaborators from DPR Construction, designers CO Architects and DFDG Architects, steel fabricator Able Steel, and steel erectors Pro Steel Erectors Inc. and ASE Steel Erectors now faced a major challenge: building this major component over what was now a bustling main entry, congregation space, and thoroughfare.
“For so many logistical reasons and objections from external partners, we heard over and over that the canopy would be impossible to build,” said project manager Casey Helburg. “The 'Wall of No' grew higher as our list of challenges got longer.”
In the now-occupied environment, building the canopy as originally designed looked increasingly unfeasible. The original custom-made structural steel members were not only extremely expensive but also, because of the delay, now faced procurement challenges. And at an estimated 500 tons, the canopy was essentially too heavy to manage in the tightly constricted courtyard now that the HFC had been fully built and occupied. Use of the necessary machinery by workers elevated on a complex scaffolding 40-60 feet in the air, over an open foundation with exposed rebar seemed all but impossible – and dangerous – in the constrained space. The team considered altering the canopy design itself to accommodate the mounting list of challenges in order to incorporate structurally acceptable yet aesthetically pleasing solutions. Alternative options, however, proved to be too far removed from the original design and didn’t address the issues presented on-site.
Closing the courtyard wouldn’t solve every issue, either. The risk that flying massive steel beams by crane over the specially designed hardscape below would cause damage to the intricately sandblasted concrete was too great.
The team was also careful to consider that if they closed the courtyard and redirected newly ingrained wayfinding and flows of traffic around the side of the building through covered walkways to a loading dock, the shift would create not only an irritating and confusing obstacle but an ugly pathway for the HFC tenants and visitors. And those inside during working hours would still be subject to noise and fumes from welding and paint, right at their front door.
To continue the canopy build as originally planned, not only were there multiple logistical non-starters to overcome, but those challenges pushed the canopy buildout to roughly $200,000 over budget and an estimated additional 10-month timeline – not an option for this team.
“When it really came down to it, we realized we were going to have to do this using prefabrication,” said project engineer Ben DeBorde. “But what pieces are we going to assemble? And where are we going to assemble them?” While their solution wasn’t exactly right in front of them… it was in the greenfield adjacent to the HFC.
At first mention of prefabrication of the canopy in conversation with Able Steel, there was a collective chuckle at the tongue-in-cheek suggestion.
“We all thought, ‘no one is going to agree to this,’” DeBorde said. Yet despite the bold idea, wheels were immediately turning, and in response to the off-the-cuff comment the subject matter experts began considering if this innovative option could actually make sense. After two weeks in conversation and contemplation, Able Steel told the DPR team, “We think we can prefab this. Let’s take the next step.” Soon thereafter it was time to put pen to paper and bring together the design teams, trade partners and structural engineer to have open, honest discussions about exploring realistic options for making the prospect of prefab a reality.
While it seemed that the team was finding ways up, over and around the initial Wall of No, they still faced barriers to success on the other side, as prefabrication alone wasn’t the simple solution to every problem. Where would prefabrication take place? If they prefabricated the entire canopy, could they find an adequate and available crane to intricately rig and properly pick just one piece on such a short haul job? Furthermore, there was still the issue of the customized steel members. For the sake of its immense weight, would the team need to prefabricate the canopy in sections and complete construction over the courtyard?
“Every partner on the team had to explore our comfort zones and knew we needed to push the envelope with our design decisions,” said Helburg. The teams got deep into working sessions, talking about limiting factors of equipment and negotiable and non-negotiable design components, as well as brainstorming ways they could reduce cost, weight, and schedule. In these discussions, it came up that ACE Steel Erectors had been using a proprietary carbon fiber application system mostly in the aeronautical industry in making repairs and weighing connections, and the design teams had used previously carbon fiber on large industrial complexes. Again, the wheels were in motion.
“We depended on ACE to inform us of how the carbon fiber system could actually work in this application,” said DeBorde. “We asked tons of questions. Where else has it been used? How do we need to apply and treat carbon fiber? What kind of timing will it need and how long does it take to dry? What kind of weather can it withstand?” The team asked question after question, learning about expectations, finishes, protection, environmental requirements, treatments, distinguishing features, and more.
“In all of my years in construction, I’ve never seen this done before,” said Helburg. The carbon fiber solution that ACE had suggested would allow the team to procure more readily available, standard-sized structural steel members, cutting procurement time exponentially, thereby reducing schedule, securing a major cost savings, and significantly lowering the tonnage of steel while maintaining its integrity and tensile strength through use of the supplemental carbon fiber.
With weight, cost, and timeline challenges addressed, the team began to overcome the rest of the challenges as well, one by one. The greenfield area adjacent to the HFC was approved for prefabrication space by ASU. The steel embed plates to attach the canopy columns in the courtyard concrete were chalk-lined and reproduced in entirety in the greenfield. Prefabrication virtually eliminated high-elevation work and allowed the team to use ladders and tie-offs, come-alongs, scissor lifts, and pieces of essential machinery that would have been impossible to maneuver in the courtyard, let alone from scaffolding 40-60 feet in the air. Working on solid earth rather than an elevated platform allowed them to focus on the job and achieve quality welds and installation.
The prefabricated solution proved to be a success. There were zero safety incidents on the project. The team achieved an approximately 50 percent reduction in project lifecycle from 10 months to approximately five months. And despite a limited availability of specialty equipment in the area, the team secured a crane to handle the pick of the entire canopy structure, which took approximately 30 minutes. The HFC courtyard was only closed for one day while the canopy was picked and placed, and the project was completed to the satisfaction of every stakeholder. The Wall of No had become the canopy the team had hoped for.
“What we learned here is to keep digging and asking, to be relentless. Don't give up on finding solutions and don’t be deterred by hearing ‘no,’” said DeBorde. “With so much technology and the opportunity to innovate and incorporate out-of-the-box-ideas, we really can give it a shot and make something successful. It’s all about leading and moving forward and being able to provide a safe work environment and the right solutions to help our clients achieve their goals.”
Posted on March 18, 2022
Last Updated August 23, 2022