Sixth Street Viaduct Replacement,the visualization journey from preliminary proposal to winning the design competition for this signature Los Angeles icon

摘要

The Sixth Street Viaduct, completed in 1932 as part of the series of significant bridges over the Los Angeles River, has been featured in several media. Unfortunately, the Sixth Street Viaduct was constructed with a poor concrete mix, resulting in concrete deteriorating due to ongoing alkali-silica reaction. The entire structure needs replacement. The City Engineer of Los Angeles and the Bureau of Engineering PM team initiated an international design competition for replacing the Sixth Street Viaduct. On April 12, 2012, Los Angeles Mayor Antonio Villaraigosa and Councilmember Jose Huizar announced a bridge design competition for the $190 million construction project, with three shortlisted design teams tasked to develop a design concept, requiring community presentations at neighborhood locations before announcing the winner. The RFQ asked for an aesthetically distinctive viaduct to transform the neighborhoods, considered the public’s perception of the bridge, responded to complex project constraints, and be constructed within a fixed construction budget. The HNTB teamed up with Michael Maltzan Architecture, A.C. Martin Partners, and Dissing + Weitling Architects, and developed a winning design consisting of extraordinary concrete networked tied arches spanning the LA River, railroad tracks, industrial properties and US Hwy 101. The HNTB team proposed three sizes of arches to span the ground, the river and largest arches spanning the railroad tracks. The concrete arch design provides pedestrian access from the bridge to the ground below, consisting of new urban spaces. The visualization created for their scheme included the various renderings, plus an animation flythrough of the bridge