It's an exciting time to be involved in construction and building technology, says James T. Garret, a civil and environmental engineering professor and lab director at Carnegie Mellon University in Pittsburgh. He says there is a huge need for instrumentation and monitoring of infrastructure to better build, manage, protect and maintain it. "A $30,000 BMW has more sensors and monitors on it than a $10-million bridge," he notes.
|CROSSOVER Linking technology, such as vortex modeling and construction, yields insight. (Graphics courtesy of Flow Analysis Inc.)|
Yet the potential of technology only starts to be realized when people perceive possibilities and systematically examine them. That's the nature of research.
Stumbling blocks often appear on the long path ideas follow from concept, to prototype, to trial product, to the ultimate status of acceptance as a useful tool. But the one thing surviving ideas have in common is that they are championed by believers and are conveyed from mind to mind.
Backtracking the history of a tool being tested by New York City-based engineering firm Weidlinger Associates Inc. gives a good example of research evolution. The firm specializes in blast analysis, retrofits and blast hardening, as well as structural engineering. Weidlinger currently is testing software that began life a dozen years ago as research for the U.S. Army to study helicopter rotors. It models whirlwinds.
|BEGINNINGS Research into wireless networks at Carnegie Mellon starts with low-tech, push-in model and plan. (Photo by Tom Sawyer for ENR)|
"The vortex from one blade directly affects the other blades," explains Frank Marconi, whose job is "applied science" at Weidlinger. He says the thumping noise helicopters make is the sound of blades slicing through vortices. He thinks the vortex modeling software can be applied to the construction industry.
The tool uses an approach called vorticity confinement to study the swirls that shed from objects as wind passes. As anyone who has watched a wind devil or tornado knows, they can endure for a long time. They are also what makes clouds of smoke roil and define the dispersion of pollutants in the sky. The software can model that as well.
Vorticity confinement is just beginning to be marketed by a start-up company, Flow Analysis, Tullahoma, Tenn. Marconi is the person at Weidlinger whose mind is currently cradling the vorticity confinement idea.
Weidlinger is testing the software on a cable-stayed bridge project. The software's predictions are being compared to wind-tunnel analysis of alternative designs for fairings on new deck edges for the Bronx-Whitestone Bridge in New York City. The engineers need to understand how the designs affect the wind as it parts around the edge of the deck and sheds vortices downstream. The swirling air could affect deck oscillation and vehicles on the roadway.
Marconi says the software can predict turbulence generated by wind rushing past buildings and, because it works quickly, could be the basis for real-time emergency response to airborne contamination plumes. Weidlinger has used it to craft a proposal for a system to monitor urban landscapes and subway systems and to predict contamination paths of released biochemical agents. Such predictions could inform evacuations and advise strategies to contain and limit damage. "It could be used to compute how chemical agents will propagate in a building," Marconi says.
|FUNCTION The right software can make the difference between toys and tools. (Photo by Tom Sawyer for ENR)|
SCREEN TESTED. Before Marconi got hold of it, the only previous commercial application of the software had been to generate boiling clouds of computer-generated smoke for a few movies, including The Mummy. The movie industry learned of it at a computer trade show. John Steinhoff, the professor who developed the tool at the University of Tennessee Space Institute, Tullahoma, was demonstrating it to gauge commercial interest.
"It's a perfect example of something that has been tested against experience in a slightly different field," Steinhoff says. "Now we're trying to transfer the technology to the architectural and engineering world."
University researchers often build new tools to answer questions posed by industry and government. Both provide funding and support through grants and contracts. A look at just some of the projects under way at Carnegie Mellon offers a good example of the breadth of scientific inquiry across the U.S. today.
Researchers at the university's Advanced Infrastructure Systems Lab in the Institute of Complex Systems are trying to improve information technology in infrastructure construction and operation. They are blurring the lines between departments, such as civil engineering and computer science, to cross-pollinate ideas. "I see information technology as a stimulus for inter-disciplinary research," says John Anderson, dean of the college of engineering.
Improving software for use with wearable computers to take design data in the field is one area. "We always say it's a toy when you buy it, but by developing the right software for it, it becomes a tool," says researcher Christian Buergy.
Others are developing microsensors to embed in concrete and other materials that can detect changes in electromagnetic or chemical characteristics and infer levels of deterioration and corrosion. Some of this research builds on technology from the medical sciences, including magnetic resonance imaging.
|ROBO WARRIORS Hearty motors and gear-trains are the costly parts. (Photo by Tom Sawyer of ENR)|
MINI-BOTS. Another area of study at Carnegie Mellon with crossover potential is remote sensing using miniature robots. The idea driving the work, undertaken for the U.S. Marine Corps, is to create a series of "mini-bots" that can self-navigate and scurry through ventilation ducts or other confined spaces. They use lasers, video, thermal or acoustic sensors to navigate, peer through vents and map layouts to locate hostile characters and dangers, reporting back wirelessly to their operators.
The goal is to make them small, robust and cheap, and to endow them with a variety of modular sensors that can be snapped onto a common frame. They are designed to work in concert. Some versions assemble themselves end to end and climb over obstructions or stairs, then scatter again to reconnoiter. There is even a repair-bot in development that can find a damaged or trapped fellow and, using a built in fork-lift, free it or remove defective modules and replace them on the spot. "Once small robots catch on, there will be many places they could be used that nobody has ever thought of," says researcher Robert Grabowski.
Other researchers are testing laser scan monitoring of ongoing steel erection for early defect detection. Others are searching for ways to improve jobsite information flow. The work ranges from creating daily reporting systems to experimenting with wireless data networks. They want to better understand the weaknesses and strengths of such networks with an eye toward using them on construction sites. Chips on tools, people and equipment could use networks to automatically report real-time status of activity all over the site, opening up many new possibilities for productivity enhancement and quality control.
|APPLIED RESULTS Polytechnic researchers develop sequencing tools for complex work. (Graphics top left courtesy of Brooklyn Poly-technical University; Photo by Tom Sawyer of ENR)|
"There is a tremendous amount of technology we don't have to develop ourselves, but there is a lot of research needed on what is the most appropriate use," says Carnegie Mellon civil and environmental engineering professor James Garret, who directs the labs. "You have to really understand the problem that is being encountered in the field."
The picture at Carnegie Mellon is repeated at many other institutions. Researchers at Arizona State University's Del E. Webb School of Construction are studying cemented soils, green building, and the use of geographic information systems and satellite positioning technology to coordinate activities on complex, multiple-site construction projects, such as super housing-tract developments.
In most cases, research is conducted in partnership with government or industry. At Brooklyn, N.Y.'s Polytechnic University, which has a graduate-level program in construction engineering and management, one research partner is the agency that builds and manages New York City's subways.
A current project is to develop 3D and 4D models of a planned elevated subway platform renovation in a severely constrained, high-traffic site. Sequencing alternating phases of demolition and construction while keeping the station in use is a typical problem with subway renovations, although in this case it is exacerbated by the need to keep streets and sidewalks below unencumbered as well. Researchers expect to transfer technology directly to the Metropolitan Transit Authority for replication on future projects.
|TOP LAB NIST project pushes job quality control boundaries to achieve high standards for re-search. (Photo by Tom Sawyer for ENR|
Another research project pursued at Polytechnic by Eric Hsiao-Hua Chang, takes the 4D sequence scheduling problem even further by bringing multiple sequences into a single model. He calls his patented approach NDCON, for n-dimensional construction management information system. The goal is to provide a tool to help contractors adjust and re-balance complex schedules when the effects of delays ripple through other disciplines. Polytechnic has often found itself at the applied end of the research spectrum, as it is construction manager of the school's own multi-project, $95- million construction program.
But one of the most striking examples of putting your construction where your research is has to be a project to construct a new Advanced Measurement Laboratory at the National Institute of Standards and Technology in Gaithersburg, Md. Every aspect of the $235-million project is infused with the proceeds of research, from the distributed and collaborative design activities and project management, to the design features, quality control measures and construction techniques used to build the structures.
The facility is a cluster of linked buildings, more than half a million sq ft in total. It includes a clean room, two highly controlled instrument labs and two metrology labs buried underground to shelter them from vibrations and temperature changes. In one, temperatures will be held to a tolerance of +/-0.01°C. That is quality control.