Fraco Involved in the Tallest Dam Raise in the United States
Canadian manufacturer offered an efficient solution to inclined face
dam raise in the United States.
Preparing the inclined concrete face of the San Vicente Dam located in Lakeside, CA to create a good bonding surface for new concrete was never going to be straightforward matter, with gaining access to the work area being one of the main challenges. However, the past experience of Canadian mast climber Fraco Products Ltd and American Hydro, a leading company in hydrodemolition, have one more time created an efficient access solution.
The ProjectThese works are the first steps of a $568 million project that consists of raising the height of San Vicente Dam, which is owned and operated by the City of San Diego. Currently stands at 220 feet, the dam will be raised of an additional 117 feet – the tallest dam raise in the United States and the tallest of this type in the world. Construction works are scheduled from 2009 to 2012 and will be split into several distinct construction phases. This first phase consisted of removing two to three inches of the dry side of the dam to create a good bonding surface for the 800,000 cubic yard of roller-compacted concrete plus a significant amount of conventional concrete that will raise the dam to 337 feet high.
Past ExperienceFrom 2004 to 2006, both Fraco Products and American Hydro were involved in the renovation project of the Robert Moses Dam on the US/Canadian border at Niagara Falls, NY. At that time, access difficulties facing the contractors were because of the inclines of the dam face. For that project, major modifications were made by Fraco to its elevating units and specials wedge bolts were designed to ensure mast sections grip to the walls. On its side, because of the unique layout of the structure, American Hydro had to design and build a robot from a regular Fraco platform. That new system allowed American Hydro to remove concrete from virtually any height.
The ChallengeThe first installations of Fraco mast sections on the inclined concrete face of the San Vicente Dam required few adjustments. As stated by Tim Riley, Fraco representative of Southern California branch: "The first mast section placement to the far left took four (4) days as the Dam is not quite flat as it was suppose to be; conditions changed as each 30 foot of mast was flown into place. The second layout of mast took about two (2) days with some fine tuning of the custom shims. We installed the 3rd mast section in one day as we built the mast on the ground and copied the shim and spacer brackets to match the 2nd install."
Once the first three rails were installed, American Hydro came up and fit its robot on the first mast section and the concrete removal works began. As the works progressed, each mast section was moved to another area of the wall. The whole surface was completed by the end of April 2010.
About the Author
Fraco Products Ltd is a Canadian-based manufacturer of mast climbing access systems. The company offers solutions to specific construction markets such as infrastructure, glazing, power generation and masonry. For more information visit www.fraco.com.