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AutoCAD Helps Drive Infrastructure Design
6 Apr, 2011 By: David CohnParsons Brinckerhoff uses AutoCAD to help design and visualize the Presidio Parkway project in San Francisco.
Editor's note: Through a sponsorship by Autodesk, Cadalyst editors bring you this feature, part of a special series of articles that highlight the role of AutoCAD and 2D design in today's demanding CAD work flows. Watch for the next installment next month.
To say that Parsons Brinckerhoff is a large architecture, engineering, and construction management firm certainly would be an understatement. Founded in 1885 and headquartered in New York City, the firm employs more than 14,000 people and has 150 offices worldwide. One of the company's earliest projects was the original Interborough Rapid Transit (IRT) line of the New York City subway. Today, Parsons Brinckerhoff is a leader in the design and operation of infrastructure, and its list of projects is huge — both in number and scope — and includes transit systems in Atlanta, San Francisco, and New Delhi; airports in Hong Kong and Washington, D.C.; the North American Air Defense Command (NORAD) in Colorado; the H-3 highway in Hawaii; and the Detroit–Windsor Tunnel. Parsons Brinckerhoff also is a major Autodesk customer and runs its own in-house authorized training center.
To say that AutoCAD is a major factor in most Parsons Brinckerhoff projects, therefore, also would be an understatement. According to Rebecca Arsham, training manager at Parsons Brinckerhoff's CAD services group in San Francisco, Parsons Brinckerhoff uses "just about any and every product that we can in the Autodesk suite to get the job done." Nowhere is this integration of the wide array of Autodesk software more evident than it is in the Presidio Parkway project.
The Presidio Parkway project involves the replacement of the existing south access road to the Golden Gate Bridge. Originally built in 1938, the roadway known as Doyle Drive and Route 101 has reached the end of its useful life. (Image courtesy of the Presidio Parkway project.)
The Presidio Parkway project involves the replacement of the existing south access road to the iconic Golden Gate Bridge in San Francisco. The existing roadway, presently known as both Doyle Drive and Route 101, is structurally and seismically deficient and must be replaced. Each weekday, more than 100,000 vehicles travel between Marin County and San Francisco over the Golden Gate Bridge along the 1.5-mile-long Doyle Drive. The roadway is facing the same problem that threatens other parts of our nation's infrastructure — the ravages of time and continual use. Originally built in 1936, Doyle Drive has reached the end of its useful life.
Massive Project also a Design Opportunity
Replacing this aging roadway is critical for seismic and traffic safety reasons, and it also provides an opportunity for major design improvements. Doyle Drive was designed originally to funnel traffic over the Presidio military base using an elevated roadway. But today, the adjacent area is home to residents and businesses and provides open space for events and outdoor recreation. The former base now is part of the Golden Gate National Recreational Area. In addition to bridge access, Doyle Drive links to the Golden Gate National Recreation Area and the Palace of Fine Arts.
The new project design called for a parkway, not just a freeway. The partnership of agencies responsible for the project — including the San Francisco County Transportation Authority (SFCTA) and the California Department of Transportation (Caltrans) — turned to Parsons Brinckerhoff to design and manage its construction and to create design visualizations that could be shared with the public, both to help them understand aspects of the design and to plan for the continued flow of traffic and periodic closures of Doyle Drive.
Before (left) and after (right) visualizations such as these, developed using Autodesk software, help the public understand aspects of the Presidio Parkway design. (Images courtesy of the Presidio Parkway project.)
"It's a massive project," explained Tristan Randall, a virtual design and construction (VDC) engineer at Parsons Brinckerhoff. "It involves four tunnels, 10 bridges, and 15 major retaining walls," and will cost $1 billion. A new high viaduct will vary in height from 66 to 115 feet above the ground. Six of the columns supporting that viaduct are 12 feet in diameter, requiring a special oscillator rig to excavate holes as wide as 130 feet. The larger, deeper columns result in longer spans between columns, opening up views from the Presidio to San Francisco Bay. Construction on the parkway began in 2009 and is scheduled to be completed in 2014.
Six of the columns supporting a new high viaduct are 12 feet in diameter, enabling longer spans, which in turn open up views from the Presidio to San Francisco Bay. (Image courtesy of the Presidio Parkway project.)
Two-dimensional production drawings for the project are being developed using Bentley MicroStation in conjunction with Arup, another large architecture and engineering firm whose structural projects have included the Sydney Opera House and the Centre Pompidou in Paris. To create the design visualizations, however, Randall and the VDC team at Parsons Brinckerhoff, aided by contractor R&L Brosamer and its subcontractors, work in 3D with an assortment of Autodesk software.
Engineers at Parsons Brinckerhoff use AutoCAD Civil 3D and other Autodesk software to model Presidio Parkway project. This model of an electrical substation — developed using Revit — shows duct banks (in green) with embedded electrical, drainage, and fire protection systems. (Image courtesy of SFCTA and Parsons Brinckerhoff.)
"We're using several different tools to do that, in order to evaluate potential clashes, to coordinate several different systems on site, and to evaluate the constructability of the designs," said Randall. Their tools include AutoCAD, AutoCAD Civil 3D, and all three flavors of Autodesk Revit, as well as Bentley MicroStation and InRoads. They use the AutoCAD DWG file format to pass information between these different packages.
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