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2013SprShotcreteEMag

Theoregon City Bridge, Part II By Marcus H. von der Hofen This is the second of two articles discussing the Oregon City Bridge. The first article, “The Oregon City Bridge, Part I,” was published in the Fall 2012 issue of Shotcrete and discussed the historical background of the bridge. This article covers the recently completed rehabilitation project. tOctober 31, 2012, by the Wildish Standard a structure made entirely of concrete. In all actuality,The shotcrete covering had caused many abridge expert to be deceived into thinking this washe Oregon City Arch Bridge Rehabilitationproject was officially completed on Paving Company. Dedication to quality and it is a steel structural arch design encased in shotcrete professionalism, along with a true partnering to protect it from the emissions from industries between owners, contractors, and suppliers, located in close proximity. Originally placed using helped find ways to solve problems that could the dry-mix method nearly a century before, the have easily turned the project into overwhelming protective concrete would need to be removed confrontation and failure. This article is dedicated and replaced to the original lines and grades (refer to those who pride themselves on working toward to Fig. 2 and 3). the best solutions. One of the first questions to contemplate was: Wildish was tasked with renovating a historic Should it be done wet or dry? Should it be both? bridge that is 90 years old, replacing structurally Today’s shotcrete technology offers efficient site deficient components and accurately replicating batching of material in small amounts both wet the details and architectural features of this Conde and dry; state-of-the-art batch plants and testing McCullough through-arch bridge. McCullough’s facilities also allow ready mix producers to signature detailing is evident in the arches, obelisk perform various adjustments and quality control pylons with sconce light fixtures, ornate railings, that simply was not available 90 years ago. The and art deco piers. It is believed to be the only project has areas that really lend themselves to bridge of its kind in the entire United States—a either method. The bottom line in this case came through-deck steel arch covered with shotcrete down to what the personnel felt the most comfortable that incorporates concrete spandrel columns, with. I don’t find this reason brought up in the corbels, a sidewalk, deck approach spans, and a discussion very often, but it really should be part bridge rail (refer to Fig. 1). of the process. Many contract specifications are Fig. 1: Oregon City Bridge—multiple access methods Fig. 2 and 3: Shotcrete placement inside the arches 22 Shotcrete • Spring 2013


2013SprShotcreteEMag
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