Score another small victory for more-constructible high-rises, especially in seismic zones. Results of recent load tests on a "sandwich" shear-wall assembly, designed to simplify and speed construction of core shear walls surrounded by steel frames, are equal to or better than anticipated, say researchers.The sandwich, called a dual-plate composite shear wall because its steel- plate walls are filled with lightly reinforced concrete, is not for use only in seismic zones. "It is a great system for multihazard mitigation because it is good for seismic, wind and gravity loads as well as blast resistance," says Ron Klemencic, president of Seattle-based structural

Rendering courtesy of Related Cos The choice of a firm not based in New York City has angered some groups. Work on the $4-billion Hudson Yards project on Manhattan's West Side is set to start by late summer with the recently announced surprise choice of Tutor Perini, Sylmar, Calif., as prime contractor. New York City-based developers Related Cos. and Oxford Properties Group say they will form Hudson Yards Builders, a joint venture with Tishman Construction, to operate as owner-builder for the 26-acre site that is Manhattan's single-largest undeveloped property."[Tutor Perini] has an exemplary track record with complex, large-scale developments," says

Image courtesy FXFOWLE Work will soon begin on the 606-foot-tall Renaissance Tower in Istanbul, Turkey. Image courtesy FXFOWLE Located on the Asian side of Istanbul, the 44-story tower will be a highly visible landmark in this city of roughly 12 million people. A 606-ft-high chiseled obelisk designed by FXFOWLE, New York City, will delineate the eastern entrance to Istanbul when construction finishes in July 2014. Renaissance Tower, as the office building will be known, is being developed by Ankara-based Renaissance Construction Co., which plans to lease most of the 914,900-sq-ft high-rise.Located on the Asian side of Istanbul, the 44-story tower

The inventors and original supplier of a popular shear-stud reinforcement for two-way flat slabs in concrete frames are up in arms over charges, based on recent research, that the American Concrete Institute's model code governing use of the studs is flawed. The researchers claim that, consequently, there is potential for premature failure due to punching shear at slab-column connections, especially under earthquake loads.A. Ghali, professor emeritus of civil engineering, University of Calgary, Alberta, Canada, and the lead researcher for original studies on shear studs dating back to the 1970s, disagrees. Extensive testing shows that code-specified "equations and detailing for the

The Council on Tall Buildings & Urban Habitat is vigorously advancing its mission—to help upgrade skyscraper production by offering better design tools and standardizing practice worldwide. In a fundamental shift, the 42-year-old CTBUH is engaging in research, including a $2-million fire study that will culminate in a real building burn.Next year, CTBUH plans to publish five design guidelines on wind-tunnel testing, structural outriggers, performance-based seismic design, column shortening, foundations and natural ventilation. “There is a need for better tall buildings around the world,” said Antony Wood, CTBUH's executive director, at the CTBUH 2011 World Conference in Seoul. The Oct. 10-12

The American Society of Civil Engineers has decided that emergency changes to wind-load provisions in ASCE's 2010 building design standard are not needed. ASCE recently reviewed the provisions, prompted by a red flag raised by structural engineer-researcher Emil Simiu, who says the wind standard is flawed and needlessly complex.  SIMIUInconsistencies in chapters 26-31 of the 608-page “Minimum Design Loads for Buildings and Other Structures: ASCE/SEI 7-10” can result in “unconservative” designs, says Simiu, a member of the 2010 standard's subcommittee on wind loads. “Some buildings can be produced that do not meet the intended risk levels implicit in the standard,”

In the aftermath of Tuesday's 5.8-magnitude earthquake in Virginia, building owners in the Washington, D.C., region are accessing potential damage to buildings. Other industry voices are questioning whether the temblor, the largest Virginia has experienced on record, will lead to new discussions of Seismic codes for the East Coast.Several major facilities are closed while teams of engineers inspect  structures. Most notably, the National Parks Service closed the Washington Monument indefinitely after teams discovered cracks near the top of the 555-ft-tall obelisk, considered the world's tallest of its kind. Other closed facilities include the National Building Museum, the Dept. of Homeland

Photo by Gustavo J. Parra-Montesinos Orthogonal layouts of shear stud reinforcing at slab-column connections in flat-plate concrete frames do not perform well, says researcher. Photo by Gustavo J. Parra-Montesinos A researcher suggests radial layouts should replace orthogonal layouts of shear stud reinforcing at slab-column connections in flat-plate concrete frames. Related Links: Healthy Doses of Steel Fiber Clear Rebar Congestion Structural designers say there is cause for concern but no reason to panic over research that indicates potential for premature failure of flat-plate concrete frames reinforced at slab-column connections with a popular shear-studs-on-a-rail detail.Engineers estimate that in seismic zones alone there

Buildings Unfinished Chicago Condo Redeveloped as Apartments Capitalizing on new demand for apartment dwellings, Related Midwest, a unit of New York City-based Related Cos., plans to convert an unfinished Chicago condominium into a 65-story, 500-unit luxury apartment building. The Chicago-based developer Teng & Associates originally planned to construct a 90-story condominium-hotel on the site, but the company only completed a 27-story concrete shell before running out of money in 2008. Property records indicate Related Cos. paid $26 million in late July for the structure, which is located on Wacker Drive. Other area developers, including Michael Reschke and Mark Goodman, previously

Rendering Courtesy of Tishman/Turner Challenges ahead include fabricating the curving, sloping "bones" of the dove in heavy steel in Italy, transporting them to the site and stabilizing them during erection. The expressed steel framing for the grand-scale sculptural transit hall of the WTC’s Transportation Hub, designed by architect-engineer Santiago Calatrava to evoke a dove of peace, already has been simplified to keep it from literally flapping its wings. Yet it still is going to be “as challenging a steel project as it gets,” says Dan Payea, vice president of operations for Skanska Koch, a Carteret, N.J.-based division of Skanska Civil