ASCE Los Angeles Section

Irvine, CA

Sand Canyon Avenue is a major east/west arterial highway link for the City of Irvine. The Sand Canyon Avenue Grade Separation undercrossing project intersects the LOSSAN rail corridor between Interstate 5 and Oak Canyon/ Laguna Canyon Avenue.  The project lowers Sand Canyon Avenue under the railroad tracks and widens the roadway from four lanes to six lanes. The grade separation will relieve traffic delays and accommodate future traffic demands. The Sand Canyon exit ramp off of Interstate 5 Southbound received upgrading to improve traffic conditions and accommodate the new Sand Canyon Avenue. The new roadway provides access for vehicles, pedestrians, and bicyclist to travel safely under the railroad tracks and avoid delays from crossing trains. Project improvements include: new rail bridge structure, walls, landscaped median and parkways, storm water pump station and water quality retention basin, class I and III bicycle facility, and utility corridors.

The difficulty in the design of this grade separation was the complexity of the stage construction. As a requirement by the City, access had to be maintained at all times to the Old Town Business district at Burt Road. To accomplish this feat, a multi-stage construction approach was developed. The first stage consisted of combining dual shoo-fly construction of rail track to maintain accessibility for the 60+ daily trains passing alongside the site, removal of the original track to begin bridge construction and one of two weekend closures. Stage two included the installation of temporary shoring, grading on the east end of the project, new bridge construction and new permanent rail track, and providing detour access routes. The third stage consisted of connecting the permanent rail with the existing line, removing the temporary shoo-fly, grading on the west end of the bridge structure, and construction of the pumping station. The final stage included asphalt installation for the new Sand Canyon Avenue and connecting adjacent streets.

The traveling distance along Sand Canyon Avenue between the LOSSAN Rail corridor and the I-5 Freeway is approximately 600 feet. The Burt Road intersection at Sand Canyon is approximately half the distance or 300 feet separation from the LOSSAN Rail Corridor and 300 feet separation from the I-5 Freeway.  Sand Canyon Avenue roadway surface would be lowered at its maximum depth of approximately 20 feet below the at-grade condition.  Temporary water and oil line facilities were constructed to mitigate construction of the rail shoo-fly system, and utility relocation corridors were developed to facilitate utility construction in advance of the grade separation work.

A strong working relationship with the utility agencies, the Irvine Company, Metro link, Caltrans, OCTA and the City of Irvine was forged to facilitate the development and coordination of the design effort.  Environmental, Funding Regulatory, and Multi-Agency coordination was required to obtain the regulatory requirements for the project.

The Sand Canyon Grade Separation project was the first of the OC-Bridges group of grade separation projects overseen by OCTA.

Rail

The Sand Canyon Avenue Grade Separation undercrossing project intersects the LOSSAN rail corridor between Interstate 5 and Oak Canyon/ Laguna Canyon Avenue.  The project lowers Sand Canyon Avenue under the railroad tracks and widens the roadway from four lanes to six lanes. The grade separation will relieve traffic delays and accommodate future traffic demands.

Sand Canyon Avenue is a major east/west arterial highway link for the City of Irvine. The Sand Canyon Avenue Grade Separation undercrossing project intersects the LOSSAN rail corridor between Interstate 5 and Oak Canyon/ Laguna Canyon Avenue.  The project lowers Sand Canyon Avenue under the railroad tracks and widens the roadway from four lanes to six lanes. The grade separation will relieve traffic delays and accommodate future traffic demands. The new roadway provides access for vehicles, pedestrians, and bicyclist to travel safely under the railroad tracks and avoid delays from crossing trains. Project improvements include: new rail bridge structure, walls, landscaped median and parkways, storm water pump station and water quality retention basin, class I and III bicycle facility, and utility corridors.

The difficulty in the design of this grade separation was the complexity of the stage construction.  The traveling distance along Sand Canyon Avenue between the LOSSAN Rail corridor and the I-5 Freeway is approximately 600 feet. The Burt Road intersection at Sand Canyon is approximately half the distance or 300 feet separation from the LOSSAN Rail Corridor and 300 feet separation from the I-5 Freeway.  Sand Canyon Avenue roadway surface would be lowered at its maximum depth of approximately 20 feet below the at-grade condition. As a requirement by the City, access had to be maintained at all times to the Old Town Business district at Burt Road. To accomplish this feat, a multi-stage construction approach was developed: combining dual shoo-fly construction, temporary shoring, detour access routes, and two phased week-end closures to facilitate rail mainline connection.  Temporary water and oil line facilities were constructed to mitigate construction of the rail shoo-fly system, and utility relocation corridors were developed to facilitate utility construction in advance of the grade separation work.