Transit Bridge Fuses Art with Seismic Engineering
Best Highway/Bridge Project, Southern California: The I-210 Gold Line Bridge, Arcadia
A synthesis of art, architecture, innovative seismic engineering and construction, the $18.6-million rail-transit bridge spanning Interstate 210 is the centerpiece of the $735-million, 11.5-mile Gold Line Foothill Extension project.
The structural design for the three-span, 584-ft-long bridge marked the first use of Caltrans' methodology for analyzing bridges crossing active faults—in this case, the strike-slip Raymond Hills Fault. The cast-in-place, pre-stressed box-girder superstructure was chosen for its excellent performance under seismic loading, says Patrick Nicholson, AECOM design manager.
AECOM says the BIM-aided project is the first application of time domain reflectometry "smart column" technology, embedded in three, 11-ft-dia cast-in-drilled-hole piles to a depth of 110 ft below the freeway. Based on electrical impedance principles, the system immediately feeds engineers data regarding the bridge's structural integrity when an earthquake occurs.
The bridge celebrates local Native American crafts, incorporating two 25-ft-tall, 17-ft-dia sculptural baskets, designed by artist Andrew Leicester; these elements flank the serpentine superstructure.
Contractors used an aggregate mix specifically designed for the precast basket structures. The mix included black stone and three types of glass—clear, gray and mirrored—to provide a subtle reflective quality that responds to light and atmospheric conditions.
Three state agencies coordinated with the project team. "This was a truly collaborative process," says Habib Balian, the construction authority CEO. "It included the community that selected the artist; staff from multiple agencies that shared the vision of the sculptural design and allowed the artist to think outside the box girder; our board of directors who supported that vision; and the design-build team that made it happen."
Extensive falsework was erected to keep workers safe and protect the 255,000 motorists passing through the project site daily. There were no incidents during more than 94,000 hours worked, including 100 overnight shifts.
One judge said that "the innovation, coordination and design features of the structure are pretty amazing."
Contractor Skanska USA, Riverside
Owner Metro Gold Line Foothill Extension Construction Authority, Monrovia
Construction Manager Hill International, Irvine
Lead Design AECOM, Los Angeles
Consultants Group Delta Geotechnical Consultants, Torrance; The Culver Group Surveyors, Tustin; Brinkerhoff and Associates, Fallbrook; Lighting Design Alliance, Long Beach
Subcontractors National Ready Mix, Irwindale; Masonry Concepts, Santa Fe Springs; Dywidag Systems Intl., Long Beach; Paramount Metal & Supply Co., Paramount; American Sheet Metal, Anaheim; Fitzgerald Formliners, Santa Ana; Squires Lumber, Colton