INTRODUCTORY INTERVIEW

LINDA FIGG

Linda Figg is president and CEO of FIGG Bridge Group, an international family of companies founded in 1978 that designs and builds landmark bridges. With construction values totaling over $14 billion, FIGG bridges have been completed or are under way in forty-two states and six countries.

FIGG bridges have received 366 awards for their owners, including three Presidential Awards for Design Excellence: the Bob Graham Sunshine Skyway Bridge crossing Tampa Bay; the Blue Ridge Parkway Viaduct around Grandfather Mountain, North Carolina; and the Natchez Trace Parkway Arches in Tennessee. Only five bridges have been recognized with this honor. FIGG has set new industry standards in design, technology, materials, and ease of construction. To learn more, visit figgbridge.com.

Dedicated to expanding national dialogue about infrastructure, Linda pioneered the FIGG Bridge Design Charette, interactive community listening and learning sessions, and has facilitated more than three hundred public workshops to develop bridges. Linda was inducted into the Alabama Engineering Hall of Fame in 2010 and the National Academy of Construction in 2011. In 2011, she chaired the Construction Industry Round Table, the first woman to do so. The American Road & Transportation Builders Association awarded her the Ethel S. Birchland Lifetime Achievement Award in 2014. She served as president of the American Segmental Bridge Institute from 2012 through 2014. She holds a civil engineering degree from Auburn University.

Judith Dupré: Is functionality a bridge’s main role?

Linda Figg: Functionality is fundamental, but bridges are both structures and symbols. A bridge can join riverbanks or cross great distances, but most profoundly it connects people to each other and to their dreams. A beautiful bridge can become an enduring symbol of an area, enabling and deepening a community’s sense of itself.

JD: You’ve actively involved the public in your designs, a radical premise since many bridges are built without input from those who will use them on a daily basis.

LF: Given the sizable investment in a landmark bridge, it must stand the test of time physically as well as visually. The impression the structure leaves on those who live in the community and on those who visit remains for as long as the bridge does. For this reason, years ago, we began inviting area residents to have a say in the design of their bridges, realizing that this was the best way to ensure that the bridge would be welcomed and fully integrated. We pioneered the FIGG Bridge Design Charette, interactive workshops that provide the opportunity for people to express what they love about their communities and share their hopes for the new bridge.

JD: The charette’s most important function may be the invitation to participate itself.

LF: Agreed. Residents are engaged as decision makers. In effect, we are re-creating the village green where citizens once gathered to discuss their interests and concerns with others.

JD: You’re invested in the belief that communities know what’s best for them, and that a solution will arise from collaborating with them.

LF: Yes, because they’ve always lived there, they’re experts. From generation to generation, they pass down the spirit of community that translates into the particular dynamics of an area. It’s extraordinary to be able to tap into that, extract from it, and then translate that spirit into structure. It’s not about our name being on it. It’s about the community’s name being on it.

JD: It’s an unusual way of designing bridges.

LF: It would be presumptuous of us to go in and say, “This is the bridge you should have.” By embracing a community’s innate creativity, we can design a bridge that establishes an authentic sense of place. It’s really the soul of the community that we’re trying to capture. And I guess the question is then, What is the soul of the bridge? I hope it is the soul of the community.

JD: In the long run, it could be considered cost effective.

LF: From our perspective, it is always cost effective, and ultimately results in a better, more sustainable solution. And I think, more and more, bridge owners are seeing that.

The open interiors of the box girders used in precast segmental bridges serve multiple purposes. They can be used to access utilities, collect and redirect runoff water, and house smart technologies that aggregate data on deck activity, which is used to improve transit systems and increase safety.

The New I-35W St. Anthony Falls Bridge (2008), a ten-lane federal highway bridge across the Mississippi River in Minneapolis, replaced the bridge that collapsed on that spot in 2007. The superstructure of the 504-foot (154-meter)-long main span consists of four variable-depth precast concrete segmental box girders. It was designed and built in just eleven months, despite frigid winter conditions, complex design criteria, and multiple site challenges.

The Winona Bridge (2016) is a 2,300-foot (701-meter)-long Mississippi River crossing in Minnesota with a 450-foot (137-meter) main span. The concrete bridge features a pedestrian path, scenic overlooks, and a minimalist design that harmonizes with the older truss bridge seen just beyond it.

South Norfolk Jordan Bridge (2012) in Virginia’s Hampton Roads region is a 5,375-foot (1,638-meter)-long replacement bridge that was realized without local, state, or federal money. It features a 145-foot (44-meter) vertical clearance under its 385-foot (117-meter) main span. Built using local labor and materials, the bridge boosted the area’s economy and its future shipping capabilities. It was designed, built, and operated by United Bridge Partners.

“ If the community looks at their bridge and says, ’Wow! That’s who we are,’ then we’ve been successful.”

JD: What does the public expect from a bridge?

LF: They want bridges that are visually pleasing, reflective of their place, and ecologically sensitive. They want construction to be completed quickly while traffic keeps moving, expectations that parallel the owner’s desire for swift and economical construction.

JD: Given global interconnectivity, some think that “place” doesn’t matter anymore.

LF: Place always matters! Every bridge is a storyteller, telling the story of a particular place and the technology of its time. Since a bridge is always experienced in its totality, its design is inextricable from its location, which encompasses geological conditions, traffic patterns, and the natural and built environment. Its design cannot be separated from a region’s history, culture, and economy. Communities everywhere are beginning to say, “Wait a minute. Let’s dig deep and find out what’s special about us.” When they do, the bridge enjoys a memorable presence and gradually accrues symbolic meaning as well.

JD: How do you approach design?

LF: Whether a bridge is new or a replacement structure, it must conform to existing transportation networks, so the alignment has the first and most profound effect on the overall design approach. The alignment considers grades and elevations of existing and proposed roads and the terrain, which may include bodies of water, roadways, railroads, and other site constraints. The length of the structure, especially the length of the visually dominant main span, will dictate the most suitable type of bridge and how it will be constructed.

Citizens want to have a say in their bridges. FIGG holds interactive sessions that give residents, local leaders, and business owners the opportunity to actively participate in the design of their new bridge.

JD: FIGG is largely responsible for introducing medium- and long-span concrete segmental bridges to the United States, which once were constructed mostly with steel.

LF: That growth was aided by the Federal Highway Administration requiring the competitive use of materials, opening the door to better, more cost-efficient designs.

Raising environmental standards demands exploring the many efficiencies inherent in concrete segmental bridges. Segmental design encourages ecologically aware land use and preservation. Also, when you fabricate off-site and then assemble it quickly in its final location, you’re preserving sensitive ecosystems and allowing traffic to flow. Segments for the Selmon, I-35W, and Victory bridges, to name a few, were cast nearby and then assembled on-site.

The New I-35W Bridge has a minimal, sculptural presence in an area that is structurally and visually dense. Its main span forms a curved parabolic arch that frames the Mississippi and pays homage to two nearby historic arch bridges. Two illuminated pylons, seen here, show the range of LED lighting effects.

FIGG worked with a local Native American artist to develop the art program for the Four Bears Bridge (2005) on the Fort Berthold Reservation in North Dakota. The art incorporates the history, sacred symbols, and colors of the Three Affiliated Tribes—the Mandan, the Hidatsa, and the Arikara—who live there.

Weekly updates on a span’s progress, such as this one held at the New I-35W Bridge, keep the public informed and engaged.

A rendering shows the new Harbor Bridge in the port of Corpus Christi, Texas. With a 1,661-foot (506-meter) main span, it will be the longest cable-stayed span in the United States when completed in 2020. Its navigational clearance of 205 feet (62 meters) will allow larger ships to enter the port. Twin concrete pylons, 538 feet (164 meters) tall, soar over Whataburger Field, home of the Hooks baseball team.

Concrete proved an ideal solution for the U.S. 191 Colorado River Bridge (2010) in Moab, Utah, a place of pristine natural beauty near Arches National Park. Utilizing long spans and staining the concrete to blend seamlessly with the region’s famed red rock landscape yielded a bridge with a minimal profile that appears to emerge from the earth itself.

To protect the environment, the I-70 Hanging Lake Viaduct (1992) in Colorado’s Glenwood Canyon was built from above and over active traffic; once traffic moved to the new, elevated structure, permanent piers were centered under it.

The Blue Ridge Parkway Viaduct (1987), which hugs Grandfather Mountain in North Carolina, was built from the top down to preserve its natural setting. Bridge segments were placed progressively in a unidirectional cantilever that curves around the mountain; only one of the 153 segments is straight.

“ Concrete is a fluid, formidable communication tool. It can be sculpted, stained, and placed to meet a spectrum of technical and aesthetic criteria.”

JD: You’re a big proponent of concrete.

LF: The majority of our designs use concrete, because our customers recognize its benefits. Its durability and low maintenance are key, particularly in coastal environments and restrictive sites. Concrete is tremendously versatile, allowing modular fabrication, top-down construction, and multiple concurrent operations. Concrete segmental bridges have repeatedly proven their strength when tested by extreme weather events.

Enhancing the appearance of concrete with custom textures and colors is more economical and feasible than ever before. Color on a bridge surface adds visual interest and emphasizes its three-dimensionality. Using local aggregate and sand also ensures that the concrete will blend with its natural context.

JD: But doesn’t concrete have a large carbon footprint?

LF: That footprint is increasingly smaller, offset by high-performance mixes that impede corrosion and increase service life. Cost reduction through repetition is also a consideration; the new I-35W Bridge saw the placement of 120 concrete segments in forty-seven days and restored a vital transportation link over the Mississippi in just eleven months. Accelerated construction is matched by cost savings: the I-93 ramps and viaducts for the Zakim Bridge in Boston are just one instance where tens of millions were saved by eschewing steel. New concrete mixes, like those we used on the new I-35W Bridge, saved 3.5 tons of CO2 per truckload, and clean pollution from the air.

JD: What makes a bridge aesthetically pleasing?

LF: Aesthetic form arises from well-designed function. Structural aesthetics emerge from three distinct yet interdependent conditions: context, design, and connection. A bridge’s beauty, functionality, and identity arise from the ongoing interrelation between these three conditions and the people who use it.

JD: Are there design rules of thumb that you can share?

LF: Many factors contribute collectively to a bridge’s presence, but to distill it, I would say shapes, colors, textures, and lighting captured in a thematic family of details that reflect the natural and built environment. In a successful project, these parts come together in a way that satisfies the senses as well as the need for reliable transportation.

Harmonious forms, lines, and patterns draw the viewer’s eye from one element to the next, creating visual continuity and sensory satisfaction. To achieve this, we typically utilize the same superstructure cross-section over the bridge’s full length and also consistently use optimal span lengths.

Maintaining a constant box girder depth and constant cross-section will greatly simplify casting and erection operations. For longer spans, however, it is often more economical to vary the depth of the superstructure instead of maintaining a constant depth. A deeper box girder section is required to resist the higher forces close to the piers, while a shallower section at midspan is adequate to resist lower forces. In these instances, gradually decreasing the structural depth over the length of the span will minimize materials used and, by reducing the structure’s visual mass, will result in a more graceful structure. Determining an ideal span-to-depth ratio is also essential. Span-to-depth ratios ranging from 20 to 30 will result in superior aesthetics. On uniform spans, a span-to-depth ratio of 15 is also visually attractive but, as a rule, less than 15 is not preferred.