R&M provided geotechnical engineering for the design and reconstruction of the Water Street Viaduct (Trestle No. 2). The goal of the project was to replace the aging 1,000′ long mountainside viaduct with a modern structure. The project challenges include complicated foundation and utility conditions, complex right-of-way issues and challenging site access. R&M performed geotechnical investigations, including vertical borings through the existing viaduct surface and horizontal borings beneath the deck surface. Foundation design included both shallow footings anchored to bedrock and deep foundations in areas of thick soil deposits. R&M also provided geotechnical support during construction.
Located parallel to a steep slope, Trestle No. 2 provides access to adjacent homes and serves as a critical link between north and south Ketchikan. Construction was phased to allow for access to homes during construction.
Services for this Project
