Abstract
Bridge design often appears to be a technical endeavor, but a bridge is not just a crossing, it is a permanent fixture that shapes how people identify with the environment around them. The capstone project documents the design, fabrication and construction of a steel bridge for the AISC Student Steel Bridge Competition (SSBC). It was undertaken to gain hands-on experience applying structural engineering principles to the creation of a physical product. The accompanying STS paper examines how social forces shape aesthetic decision-making in bridge engineering. This was motivated by a belief that understanding how stakeholders negotiate a structure's appearance is essential for any engineer whose work will outlast them. The SSBC includes an aesthetic judging component, showing that even within a student competition, visual quality is treated as a serious design consideration, just as the STS paper argues. The competition was an experience that contributed to the STS paper's exploration of how engineering and aesthetic outcomes are often more intertwined than they appear.
The AISC Student Steel Bridge Competition challenges teams to design and build a bridge solution within strict constraints, this year’s case addressing the need for a pedestrian crossing over the Rio Grande River in El Paso, Texas. The project delivered a structurally efficient 1:10 scale steel bridge that safely supports required loads while minimizing weight and assembly time, the competition's primary scoring criteria. The team used SAP2000 for structural analysis, SolidWorks for 3D modeling and topology optimization, and Revit for fabrication drawings, before fabricating and constructing the bridge in Lacy Hall, the universities fabrication facility.
The project concluded at the AISC regional competition at Old Dominion University, where the bridge was assembled in 19 minutes and 4 seconds, a personal best and carried over 2,500 pounds with an aggregate deflection of 2.2 inches well within the allowable limit. The bridge placed third overall, third in structural efficiency and construction economy and earned second place in lightness, cost estimation and construction speed. Beyond the results, the process provided valuable experience in project management, iterative design, hands-on fabrication and teamwork, while also setting the framework for a resurgence in the university's participation in the annual competition.
The STS research paper examines how social forces shape aesthetic decision-making in bridge engineering and what conditions allow competing priorities to be negotiated productively. This question is significant because design decisions carry lasting consequences for communities, yet the processes through which aesthetic values are weighed against technical and financial ones are rarely examined with the same rigor as the engineering itself. The research employs the Social Construction of Technology (SCOT) as its primary framework, tracing how social groups within relevant case studies assign meanings to the same structure and negotiate those interpretations over time, with Actor-Network Theory as a secondary lens to surface the role of nonhuman forces like site conditions and engineering constraints.
The research draws on comparative case study and document analysis across four bridge projects. The Dresden Elbe Valley case shows how fragmented negotiation led to the loss of cultural designation. The San Francisco-Oakland Bay Bridge shows how financial pressure can unravel agreements even after communities have won them. The Tappan Zee replacement demonstrates how a Visual Quality Panel successfully embedded community values into a widely recognized regional landmark. The Millau Viaduct illustrates how engineering constraints can themselves generate aesthetic form independent of social negotiation. Together, the cases suggest that structured collaboration produces better aesthetic outcomes, and that its absence carries real costs to the communities that live alongside these structures.
