Innovation That Matters

The students designed the bridge using 3D software, creating a bird’s nest-like structure | Photo source

Novel bridge design slashes construction waste

Architecture & Design

A bridge built in California has demonstrated the utility and sustainability of a construction technique that blends human design with robotic fabrication and construction

Spotted: A new bridge over an arroyo in the mountains of Los Angeles uses innovative fabrication methods that reduce waste and streamlines construction. The bridge was initially designed as a speculative exercise by students at the University of Southern California’s School of Architecture. Seven years later, the bridge has now been completed. 

The students designed the bridge using 3D software, creating a bird’s nest-like structure. However, the most innovative aspects of the bridge are the methods used to construct it. The 500 hundred steel tubes making up the bridge were fabricated using an advanced six-axis robotic arm and then assembled into large sections which welded together on-site. 

The team designing the bridge found that using the robotic construction and welding techniques eliminated most of the construction waste involved in similar types of construction. A large part of this waste is generated by the use of a temporary formwork to position parts for mounting and welding. This framework is not needed when using the robots. 

According to R. Scott Mitchell, an associate professor at the USC School of Architecture who led the studio that designed, and later constructed, the project, the bridge is made up of 9,000 kgs of steel, and produced just 500 kgs of waste material, all of which was recycled. Mitchell said: “While the final steel design was feasible, the geometric complexity and asymmetry would have required impractical amounts of fixturing to hold structural members in position prior to welding … I began thinking about the prospect of placing and holding structural members with little or no fixturing. An industrial robotic arm proved to be the best, if not only, solution.” 

Blending automated fabrication and construction technique is proving fertile ground for sustainability in construction. At Springwise, we have also seen this in recent innovations such as the use of robots to 3D-print a housing community and a house made of clay

Written By: Lisa Magloff



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