above and below the opening portions. Aluminum mullions
150 mm deep and 75 mm wide will be spaced at 1. 4 m intervals, and the design also includes movement joints that
will range in width from 50 to 75 mm to accommodate the
potential wind and seismic loads. A series of flat, cantilevered
structures referred to as ribbons will project from the curtain
wall system in such a way as to follow the curves in the outline of each section and merge into the connecting bridges
between the sections, De Gaetano says. These aluminum
ribbons will be approximately 1 m high and 500 mm deep
and will extend along the curtain wall for most of the length
of each section.
The Hongqiao SOHO building is being designed with
a so-called fire compartmentation isolation system that will
operate both vertically between the floor slabs and horizontally at the facades to provide three hours of fire safety. A facade system is usually designed to provide only about one
hour of fire safety, De Gaetano adds, but the requirements
in Shanghai have become more stringent in recent years.
The project design team also includes the international
engineering firms Parsons Brinckerhoff and AECOM, which
are responsible for respectively the mechanical systems and
the sustainability aspects of the structure. The project is expected to be completed in 2013. —ROBERT L. REID
Rhode Island City Awards 20-Year
D/B/O Contract to CH2M HILL
IN LATE JUNE the City of Woonsocket, Rhode Island, selected CH2M HILL, of Englewood, Colorado, to upgrade and operate
the 16 mgd Woonsocket Regional Wastewater Treatment Facility under the terms of a 20-year, nearly $80-million design/build/
operate (D/B/O) contract. An integral part of the planned upgrades
involves equipping the plant to ensure its future compliance with
strict nutrient requirements scheduled to take effect in the com-ing years.
Besides Woonsocket and North Smithfield, Rhode Island, the
treatment facility serves the Massachusetts towns of Bellingham
and Blackstone, and it discharges to the Blackstone River, a major
tributary of Narragansett Bay. In recent years, the bay has become
a key focus of restoration efforts, prompting stricter limits on nutrients from such point-source dischargers as the Woonsocket facility.
Constructed in the 1930s, the Woonsocket plant underwent
major upgrades in the 1960s, 1970s, and 1990s. However, the aging facility requires additional improvements, particularly relating
to nutrient removal. Under the terms of a consent agreement with
the Rhode Island Department of Environmental Management, the
City of Woonsocket must drastically reduce nutrient discharges
from the facility beginning no later than May 1, 2017. As a result,
the city “required a significant upgrade” to the treatment plant,
says Sheila McGauvran, P.E., the city’s director of public works.
Supporting Roadway Infrastructure for over 100 years.
 Civil Engineering SEPTEMBER 2012