was much worse than the geotechnical report indicated. Just below the grassy surface lay decades of debris from abandoned and demolished buildings previously located on the site. To address this issue, we created a large area onsite for evaluating and sorting the existing subgrade material into soil that could be reused and rubble that was transported offsite. Specialized skeleton buckets and screeners helped us complete this sorting process and retain as much geotechnical material as possible. Though labor intensive, this double handling of soil material was a vi- tal step for implementing the overall landscape design, which involved replacing the 800 existingAsh trees on the grounds’ processional allées with London Plane trees. A considerable portion of the site consisted of a vegetation protection zone (VPZ) that was not permitted to be compressed or compacted by installations because of its fragile root systems. All work in those areas had to be completed by hand or by directionally boring below the surface using trenchless technology. Over the decades, the urban site had undergone significant construc- tion activity, yet the available records of buried utility lines and other hazards were incomplete and potentially inaccurate. Our team used a combination of leading-edge subsurface utility mapping technologies to ensure the Arch and existing subterranean museum remained fully operational during construction, with no inter- ruption to critical utility systems. Ground penetrating radar and other electronic locating devices helped us supplement historical data and other traditional approaches to underground surveying. This data now provides an accurate record of the site for future use. Expanding the museum The project’s second phase involved a 50,000-square-foot subter- ranean addition to the existing 100,000-square-foot museum, includ- ing creation of a dramatic new entrance and upper-level lobby facing downtown St. Louis. Constructed with cantilevered solid steel beams and custom glazing, the reinforced roof deck features 2,400 cubic yards of post-tensioned concrete, as well as 189,000 cubic feet of geofoam blocks to eliminate additional excessive weight on the roof deck. Mass excavation for the museum involved a fully shored hole approxi- mately 30 feet deep. We used a resonant breaking machine to limit vibration in the removal of concrete pavement and specialty conveyors for installation of the reinforced soil slopes along the east bank of the Arch grounds and around the museum. This specialty slope is stabi- lized with layers of geogrid and fiber-infused soil. Overall, this ambitious project required extensive coordination among a large team of consultants, architects, archeologists, governmental agen- cies, and subcontractors working on the project — often simultaneously. In total, the project involved moving 300,000 cubic yards of earth,
Museum at the Gateway Arch As part of Michael Van Valkenburgh Associates (MVVA) team that won the 2010 City+Arch+River international design competition, Cooper Robertson and James Carpenter Design Associates (JCDA) with Trivers Associates designed the significant expansion and renovation of the Eero Saarinen-designed Museum of Westward Expansion, located directly below the iconic Gateway Arch. The museum is scheduled to open July 3, 2018. The museum improvements are one part of MVVA’s comprehensive expansion and renewal of the National Park’s Dan Kiley- designed 91-acre landscape with dramatically improved connections to downtown St. Louis. JCDA’s work has primarily focused on planning and design of the museum expansion’s new West Entry and public spaces. JCDA applied its design approach founded on the experience of light in the built environment, to the entry sequence and the new main public spaces of the Museum Arrivals Hall, which lead down to and connect with renewed exhibitions and the renovated Saarinen museum below the Arch. Beyond transforming, modernizing, and improving the museum, the project goal was to better integrate the new and original museum within the National Park Service’s Gateway Arch landscape and improve connectivity between the park to the Old Courthouse and into downtown St. Louis. JCDA and Cooper Robertson created a new civic space that engages with and reinforces the presence of the international icon of the Arch, while directly supporting the revitalization of downtown St. Louis.
Watch a time lapse video of museum construction at https://vimeo.com/268616120.
Information provide by v2com (www.v2com-newswire.com), an international newswire specializing in design, architecture, and lifestyle.
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