Quincy Engineering, Inc. provided the preliminary and final design of the 5th and 6th Street Overcrossings over the Union Pacific Railroad in the historic Sacramento Railyards. Additional design work included a viaduct structure and a bridge over future Sacramento Regional Transit (RT) light rail tracks. This project is part of an urban in-fill redevelopment plan located on 240 acres of the old Southern Pacific Railyards Locomotive Shop Area.
The redeveloped railyards will be occupied by a number of users including the Union Pacific Railroad, Amtrak, and RT, so close coordination was required to ensure all user needs would be met.
Considerations for access, future access, maintenance and operations, and plans for future expansion have all been factored into the design of the initial transportation network in the area. Extensive context sensitive design solutions have been incorporated into the design through the use of textured and stamped concretes, pedestrian lookouts, lighting and custom fencing. The use of planters and landscaping as aesthetic features has also been included. These structures were built in the early phase of the development to provide circulation in the area, while at the same time providing for the ultimate shift of the mainline railroad tracks.
Two of the more challenging issues of the project were unusual subsurface conditions and the close proximity to old and historic buildings. First, the site is located on a former lagoon of the Sacramento River that was filled in 1800’s. Due to the loose nature of the fill, a pile demonstration test was conducted that allowed the use of higher capacity piling for the bridges that resulted in more than $1M in cost savings. Secondly, vibration monitoring was conducted in the old buildings during pile driving to ensure that these structures were not damaged during construction of the bridges.