Digital models will soon include time (4D) and costs (5D).
(Image courtesy: Walter P. Moore)
For larger structural engineers, the transition to digital, three-dimensional building information modeling is perplexing, awkward and demanding. For smaller firms with fewer resources, the switch is downright angst-ridden. But no matter the size, BIM experts at the 2007 Structures Conference advised firms that they need to gear up for the transition or they will be left out in the cold.
"I would start now," said Howard W. Ashcraft, a construction technology lawyer with Hanson Bridgett Marcus Vlahos Rudy LLP, San Francisco. Firms that cannot offer BIM deliverables will [soon] be at a competitive disadvantage, he warned.
Few engineers attending the May 16-19 meeting in Long Beach, Calif., disputed that BIM and even collaborative BIM, which includes sharing of the BIM model with other firms on a project, are coming. But they feel trapped in the transition. That's partly because "designers are at the wrong end of the BIM reward stick," said Ashcraft. "Contractors get an immediate bang for the buck; designers don't," he said, pointing out that "Making an investment to increase your efficiency will not benefit you in the short term."
BIM start-up and continuation costs are an especially big concern for small firms. Sources report that for a firm of 20 employees, the initial cost could easily reach beyond $100,000 for upgrading computer hardware, buying software licenses and training. Initial cost does not include soft costs such as time away from "real" work during training, the learning curve, time spent reorganizing the work flow, revamping contracts and fixing problems with the systems.
BIM puts more effort up front, when changes cost less.
( Image courtesy : Construction Users Roundtable, A/E Productivity Committee)
That aside, when large-firm structural engineer Walter P. Moore and Associates Inc. introduced BIM, it was the firm's best year, said Doug Ashcraft, a principal and operations manager of the Houston-based firm. "The productivity of trained engineers is frightening," he said. Currently, WPM has more than 70 projects designed using BIM, he added.
For those structural engineers afraid to take the leap, help is coming soon. The Structural Engineering Institute (SEI) of the American Society of Civil Engineers, which organized the Long Beach conference attended by more than 1,000 engineers, has just formed a BIM committee. Its purpose is to explore, document and disseminate benefits, risks and practical and contractual implications of implementing building information modeling as it affects the structural engineering profession.
"The AEC industry has really hit the tipping point regarding BIM, and we did not see that the structural engineering community was represented in any real sense," said Joseph M. Ales Jr., a principal in WPM's Tampa office and the BIM committee's chairman.
Information will be provided in the SEI e-newsletter, articles in Structure Magazine and through sessions at the annual Structures Congress. "I think a BIM guideline will be expected at some point in time," said Ales. "I don't see our committee doing this on our own," but rather in collaboration with other structural engineers' associations, he added.
Though the committee of 12 is made up of structural engineers, Ales expects to add members from outside the profession, such as an architect, a mechanical engineer and a contractor, "to have the full range of disciplines represented." The idea is to ease the transition to the sharing of electronic data and documents among members of a project team, which is known as collaborative BIM or integrated project delivery (IPD).
Howard Ashcraft calls BIM, by itself, "CAD on steroids." Collaborative BIM, he said, is the real paradigm shift because it offers the potential to improve construction quality and productivity. In the near term, however, it raises big issues about insurance, liability and interoperability. "Delegating design to software raises questions of who is in responsible charge," he said. "What our intelligent models are doing is unlicensed practice of engineering. The registration rules have to change."
Though many groups have IPD initiatives, Howard Ashcraft says one group a bit ahead of the curve is the American Institute of Architects California Council, which this month released Integrated Project Delivery: A Working Definition. The document defines not only IPD but lays out "essential" principles and new business models. It also describes the stages of the process, including how to build an integrated team. AIACC and McGraw-Hill Construction-publisher of ENR and ENR.com-are holding an IPD conference, June 25-26, in San Francisco. Information is available on www.AIACC.org/.
Performance-based design is another hot topic for structural engineers, especially in seismic zones. On May 31 in San Francisco, the Applied Technology Council will be rolling out the 35%-complete draft of its Performance-Based Seismic Design Guidelines for new and existing buildings-the ATC-58 Project. The 10-year project is four years away from completion.
The project "introduces methods of structural reliability," said Ronald O. Hamburger, a principal in the San Francisco office of Simpson Gumpertz & Heger and the project's technical director. "If you make the effort [to follow ATC-58], you will see advantages and it will change the way you practice," he added.
At the core of the work are "fragility functions." Hamburger describes them as the probability that some component will reach or exceed a damage state as a function of a demand parameter.
Performance-based seismic design for tall buildings is another area of great interest to western U.S. structural engineers. To come to their aid, the Pacific Earthquake Engineering Research Center (PEER) at the University of California, Berkeley, last year formed a Tall Buildings Initiative. TBI, a consortium of several groups, is a focused effort aimed at clarifying performance objectives, model and analysis protocols, design frameworks and building-department administrative processes, including peer review, said Jack P. Moehle, PEER's director and TBI's organizer. The long-term goal is to develop a framework for seismic design of tall buildings, summarized in a guidelines document. Work on that is about to begin, he said.