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
As the U.S. Army Corps of Engineers’ Chicago District considers possible scenarios for closing Chicago’s locks to keep predatory Asian carp from entering Lake Michigan, the U.S. Supreme Court is set to decide if it will hear a lawsuit that could force the locks’ closure. Lynne Whelan, Corps-Chicago District public affairs officer, says the agency is studying several options, including closing the locks to boat traffic as many as three or four days a week. Michigan Attorney General Mike Cox filed a lawsuit with the high court in December to force closure of the locks. The court is expected to
The New York State Dept. of Environmental Conservation (DEC) on April 2 denied a water-quality standards certification for Units 2 and 3 of Entergy Corp.’s Westchester County-based Indian Point nuclear powerplant. The certification, under Clean Water Act guidelines, is required by the U.S. Nuclear Regulatory Commission to renew the units’ operating licenses for the next 20 years. The current licenses expire in 2013 and 2015, respectively. DEC says the units, which generate 1078 MW and 1080 MW, respectively, daily take in 2.5 billion gallons of water from the Hudson River and discharge the untreated water back into the river. DEC
California’s High Speed Rail Authority is reconsidering plans for a new leg, which would run from Los Angeles to San Diego, of a $42-billion, 800-mile system; instead, it now is weighing a shared-track arrangement with Amtrak. The proposal was put forth on April 8 by Richard Katz, an authority board member. He says that the measure could save an estimated $2 billion and would eliminate the need to demolish hundreds of homes and businesses. The project has been awarded $2.25 billion in federal stimulus funding and could begin construction as early as fall 2012.
By the end of April, a joint venture called Audubon Bridge Constructors plans to begin pulling cable on the John James Audubon Bridge at St. Francisville, La., the longest cable-stayed bridge in North America. The JV has been on the project since April 2006, contending with a vast, wet site and water levels that vary as much as 40 ft. The bridge is expected to be completed in mid-2011. Photo: Angelle Bergeron Complex horizontal beams joining the pylon columns began taking shape in March. They are nearing completion now as towers head to 520 ft. Cable-pulling is expected to begin
The Ontario government on April 8 approved renewable energy projects—worth nearly $9 billion to U.S. and Canadian firms—to produce 2,500 MW. The 184 projects fall under the province’s feed-in tariff (FIT) program, which gives solar power developers a premium fixed price of up to 80 cents per kWh for 20 years. Seventy-six of the projects are for ground-mounted solar photovoltaic technology, 47 involve onshore wind and 46 are smaller hydroelectric projects. The remaining projects involve biogas, biomass, landfill-gas, rooftop-solar and offshore wind applications. U.S. contract winners include Chicago-based Invenergy LLC, Recurrent Energy, San Francisco, and Nextera Energy, Juno Beach, Fla.
Construction on the Sunrise Powerlink—a $1.88-billion, 118-mile, 1,000-MW-capacity power line that would connect urban San Diego with alternative energy sources in the Imperial Valley—could begin in June if the U.S. Forest Service grants final approval. The owner, San Diego Gas and Electric Co., says the line is a key part of California’s mandated goal of deriving a third of its power from alternative sources by 2020. SDG&E could expedite the decision by meeting two conditions based on environmental considerations: shifting right-of-way to a northern route to avoid crossing designated wilderness areas and completing some construction using helicopters to protect the
The first new steel mill in Youngstown, Ohio, in decades is being built to supply small-diameter steel pipe for robust activity in Marcellus Shale gas-and-oil exploration. The plant is conveniently located within the geologic formation’s perimeter. Marcellus Shale is a Devonian formation situated within North America’s Allegheny Plateau. The $650-million V&M Star mill, to be sited next to an existing V&M mill, will enable the owner to fill rising demand for smaller tubes ranging in size from 23⁄8 in. to 7 in. “It’s got to be the first new steel-making facility [in the area] in at least 40 years,” says
The Tennessee Valley Authority, Knoxville, Tenn., has awarded San Francisco-based URS Corp. a five-year, $20- million contract to provide engineering and construction management services for conversion of wet coal-ash storage facilities at five coal plants to dry storage systems. The upgrade follows the 2008 storage pond failure at a TVA plant in Kingston, Tenn. Under the contract, URS will handle conversion of storage systems at the Colbert, Widows Creek, Gallatin, Bull Run and John Sevier power plants, located elsewhere in Tennessee and in Alabama. TVA agreed to move to dry coal-ash storage systems after the Kingston coal-ash impoundment collapsed, contaminating
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