New York, NY, March 04, 2014 --(PR.com
)-- The American Council of Engineering Companies (ACEC) of New York has selected Weidlinger Associates, Inc., to receive Engineering Excellence Awards for the structural engineering and design of two projects—the Brooklyn Botanic Garden Visitor Center, which earned Diamond, and the Walt Whitman Bridge Jointless Floating Deck, which earned Platinum. The awards will be presented at the organization’s annual gala in New York City’s Waldorf Astoria Hotel on March 29, 2014.
The Brooklyn Botanic Garden Visitor Center, designed with architect Weiss/Manfredi, features a single-story retail pavilion and a double-height, leaf-shaped events pavilion, connected by a trellis-like glazed canopy. Nestled against a 25-foot-high berm (which was incorporated into the design to improve thermal efficiency), the 20,000-square-foot structure blends seamlessly into its verdant surroundings, providing an elegant passageway into the historic garden. The sinuous 320-foot-long building varies in width along its entire length, narrowing to a point at its western tip. Its nonrepetitive design features myriad curves and includes architecturally expressed steel and concrete. A living roof garden atop the events space boasts 40,000 seasonal plants and will capture an estimated 190,000 gallons of stormwater annually.
Weidlinger engineers worked with the architects to simplify the design and reduce costs without sacrificing architectural intent. “Because so much of the steel and concrete structure was exposed, many of our engineering solutions were directly related to improving the structure’s visual impression,” said Project Manager Cheng Gu. “But the project presented a number of other challenges as well. The loads supported by the green roof can vary widely, depending on the season and the weather. Construction was complicated by variations in the building’s height, width, and slope, and access was limited because the site was extremely narrow.”
The Center is a key component of “Campaign for the Next Century,” the Garden’s largest renewal effort since its founding a century ago. It houses exhibits, hosts events, and serves as a rest stop and orientation area for guests. The site is home to 28 geothermal wells, which reduce energy consumption. Its three bioinfiltration basins filter stormwater to the adjacent Japanese Garden, lessening demand on the city’s stormwater system and reducing water pollution. The project recently earned LEED Gold certification.
As a recipient of the New York Diamond Award, the Brooklyn Botanic Garden Visitor Center qualifies for entry in the ACEC National Engineering Excellence Awards competition.
The Walt Whitman Bridge Jointless, Floating Deck was constructed based on an innovative design developed by Weidlinger as a replacement for the bridge’s original concrete-filled steel grid deck. Operated by the Delaware River Port Authority (DRPA), the Walt Whitman Bridge spans the Delaware River between Philadelphia, Pennsylvania, and Gloucester, New Jersey, serving 120,000 vehicles per day. Its suspended portion comprises a 2,000-foot main span and two 770-foot side spans.
In 2005, the grid deck in the suspended spans was found to be in poor condition, with significant corrosion in its grid bars. Leakage at the transverse relief joints, spaced at 120-foot intervals to prevent the deck from bending with the stiffening trusses, had caused severe corrosion in the underlying stringers and floor trusses. These concerns, along with the advanced age of the bridge, prompted DRPA’s decision to replace the deck with a structure that was lightweight, entailed low initial construction costs, was less vulnerable to leakage and corrosion, and (unlike an orthotropic deck) could be fabricated domestically. Weidlinger was retained to explore replacement alternatives, and after a number of options were evaluated, a jointless “floating” steel grid deck was selected.
“The floating deck represents an entirely unprecedented concept, which evolved out of the search for an alternative that would retain the advantages of a conventional steel grid deck while eliminating the main source of its vulnerability—the transverse relief joints, which are prone to leakage, causing corrosion,” said Weidlinger Principal and Project Manager Qi Ye.
The design successfully eliminated all joints, making the deck continuous in each of the suspended spans. The deck sits on flexible elastomeric bearings, which allow it to move independently (float) relative to the supporting floor trusses. Because it is jointless, it is nonleaking.
Reduced corrosion means that the deck and the supporting steel are more sustainable, with greater longevity and lower maintenance costs over the life of the bridge. Since the floating deck is more rigid than a steel orthotropic deck, and the bonding between the asphalt overlay and concrete fill is more secure, the overlay is less susceptible to cracking and debonding, resulting in a longer service life. The flexible elastomeric bearings reduce deck vibrations, providing a smoother, quieter ride for motorists.
ACEC New York is the leading advocate in New York State for consulting engineers. The ACEC Engineering Excellence Award Program celebrates engineering achievements that demonstrate ingenuity and significant technical, economic, and social advancement. Entries are judged on five criteria: original or innovative application of new and existing techniques; future value to the engineering profession; social, economic, and sustainable design considerations; complexity; and exceeding client needs. For more information, visit http://www.acecny.org.
Weidlinger Associates, Inc., is a structural engineering firm that designs and rehabilitates buildings, bridges, and infrastructure and provides special services in applied science, forensics, and physical security. The firm, which employees about 300 full-time staff, celebrated its 60th year in 2009. It is recognized worldwide for its innovative and practical design solutions and for its long-term commitment to advancing the state of the art in engineering. Headquartered in New York City, the firm has branch offices in the United States and the United Kingdom. For more information, please see www.wai.com.