Los Angeles, CA

Arroyo Bridge


The Arroyo Bridge spans a large, steep-sided canyon, opening up previously unavailable space and breathtaking views. The 80 ft pedestrian bridge blends with the Southern California landscape, only becoming visible upon approach. The multispan bridge was conceptualized by architecture students from the University of Southern California, in partnership with The Martin Architecture and Design Workshop. The students collaborated with Gigante AG to develop the architectural design and worked with a team of engineers, architects, contractors, and fabricators to make the design a reality. SGH served as the structural engineer for the project.

SGH designed the trussed structure for the bridge comprising a twisting network of steel tube components that mimic how a leaf’s primary stem supports its smaller veins with every member supporting or bracing the others to maintain the global structural integrity.  Highlights of our work include:

  • Helping the project team achieve architectural vision while optimizing steel tonnage
  • Performing linear and nonlinear finite element analyses with frame elements to evaluate global buckling failure modes, considering the structure’s slender elements, complex load path, weight eccentricity, narrow and asymmetric pier supports, and significant span-to-depth ratio of the bridge
  • Designing hundreds of connections where multiple steel members connect at varying angles, creating a unique geometry at each node
  • Consulting on fabrication processes and construction sequences, allowing the construction team to shop fabricate the bridge in segments, ship them to the site, and assemble with extremely tight construction tolerances

Project Summary



New Construction
Structures | Advanced Analysis
Infrastructure & Transportation
Specialized Capabilities
Marine & Civil Works | Computational Mechanics

Key team members

James Parker
James Parker
Chief Executive Officer