An inadvertent meeting of the minds during planning for a 484,000-sq-ft hospital in Dayton, Ohio, turned into an effort that has propelled multitrade prefabrication of hospital components to a new level. In the most ambitious U.S. implementation of the strategy, the construction manager estimates that prefabbing the 178 identical patient rooms and 120 overhead corridor utility racks sliced more than two months from construction and 1% to 2% off the cost of the $152-million building, which is 90% complete. The first effort is seen as just a beginning. “I want to change the design of hospitals with this process,” says
A series of guides written by leading building organizations to advance energy efficiency are on target, helping designers achieve 30% energy savings over the minimum code requirements of Standard 90.1-1999, developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers and others, according to a market assessment released on May 20 by ASHRAE. The assessment, which focused on ASHRAE members, was conducted by the Energy Center of Wisconsin and showed that 70% of ASHRAE members who have used the guides find them credible and useful design resources. The guides were developed in conjunction with the American Institute of Architects,
Writers of standards—both for general structural design and, in particular, structural steel design—rolled out their 2010 versions this month, completed in time to be referenced in the upcoming 2012 edition of the model “International Building Code.” An overriding goal, say the engineers responsible for the revisions, is to make the standards simpler to understand and use. Illustration: AISC Weld-access-hole geometry is included in steel standard, despite a patent issue. The major editorial change to ASCE/SEI 7-10 “Minimum Design Loads for Buildings and Other Structures” from the 2005 standard is a “complete” reorganization into a multiple-chapter format—first introduced for seismic loads
With cracks as sharp as the frozen Arctic air, a 1,357-ft steel communications tower in Port Clarence, Alaska, tumbled to the ground on April 28, the first step in the U.S. Coast Guard�s decommissioning of its network of LORAN radio navigation facilities across the country. Photo: Controlled Demolition Inc. Tower demolition is start of Coast Guard decommissioning of aging navigation signal network. The 400-ton, 45-segment triangular steel tower is the largest man-made structure to be felled by explosives, according to Controlled Demolition Inc. (CDI), Phoenix, Md., which performed the operation as a subcontractor to Jacobs Field Services North America. For
On April 15, opposing sides in a debate over the fate of a deteriorating, nine-year-old Seattle apartment tower presented their positions regarding the building’s future safety to Seattle’s Dept. of Planning and Development (DPD). McCarthy Building Cos. maintains the 26-story McGuire Apartments, with its corroding post-tensioned slab system, can be economically fixed. The owner disagrees. Photo: Kennedy Associates Contractor and owner at odds about ‘sick’ tower’s cure. + Image Source: Post-Tensioning Institute Post-tensioned slab The steps to post-tensioning are as follows: Place the tendons and nail anchors to the formwork, cast the concrete slab, remove the formwork, stress and anchor
A recent successful load test on a steel-fiber-reinforced-concrete beam, free of congestion-causing diagonal reinforcing steel, promises to positively impact constructibility of tall, moment-resisting frames in seismic zones. Using SFRC, engineers can reinforce high-aspect-ratio link beams, which span openings in shear walls, as regular beams, say the test’s researchers. Photo: Gustavo J. Parra-Montesinos Steel-fiber-reinforced-concrete beam (above, rotated 90°) needs no diagonal reinforcement. “We have a design for which you do not need diagonal bars, and you can still achieve large drift capacity under very high shear forces,” says Gustavo J. Parra-Montesinos, the test’s lead researcher and a Dept. of Civil and
The contractor for an occupied, 26-story apartment building in Seattle that has corroding post-tensioning cables disagrees with the owner’s assertion that the nine-year-old high-rise will become unsafe. McCarthy Building Cos. also disputes the cause and scope of the damage to McGuire Apartments, built for $33 million, stated by the local owner, Carpenter’s Tower LLC. Photo: Ken Lambert, The Seattle Times Problems of Seattle high-rise are too costly to fix, says owner. The contractor disagrees. On April 10, the owner announced plans to vacate the building over several months “due to extensive construction defects, which are financially impractical” to repair. A
The University of Nevada, Las Vegas, claims that a three-year-old student recreation facility at its main campus fails to meet some seismic requirements under the 2002 Uniform Building Code. The structure remains open, but a warning notice is posted. Photo: Luetta Callaway Investigator alleges differences between flexible and rigid components cause problems. Related Links: Engineer�s Report on UNLV Building Designed by the Phoenix office of DMJM Design, a unit of AECOM, with St. Louis-based Hastings+Chivetta Architects Inc., the building is likely to end up in court. Bennett & Jimenez Inc., Las Vegas, which has since shut down, was the structural
Design and construction of Minneapolis’s Target Field, a $545-million ballpark for baseball’s Minnesota Twins, was like stuffing 12 lb of potatoes into an 8-lb bag. The eight-acre site not only was hemmed in on all sides by roads and rails, it really needed 12 acres to comfortably accommodate the program for a 40,000-seat ballpark. Because the neighbors were so close, there was no lay-down area or viable crane path outside the bowl’s footprint. Thus, the ballpark had to be constructed from the inside out, which builders consider far from ideal. Slide Show Photo: Mortenson Construction The many restrictions, including up
Poor quality, often homemade concrete led to widespread building damage in Port-au-Prince following last month’s earthquake in Haiti, says Ken Hover, an engineering professor at Cornell University who had recently returned from the devastated city. Slide Show Photo: Ken Hover Some buildings suffered cracks rather than total failure from Haiti's devastating 7.0 magnitude earthquake on Jan. 12. Hover made his remarks Feb. 3 at the World of Concrete tradeshow in Las Vegas. He had performed structural assessments for two university-backed Port-au-Prince health clinics from Jan. 20-25. The clinics consisted of 15 separate structures. Hover says he used California's post-earthquake investigation