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Mission Valley East Extension

Mission Valley East Extension

Linking SDSU to the San Diego community
San Diego, California
San Diego Association of Governments
Zimmer Gunsul Frasca
Contract Value
$14 Million
Completion Date
Market Sector
Mass Transit

Atkinson, in conjunction with Clark Construction Group, LLC, performed underground tunnel excavation for the Mission Valley East trolley extension at the San Diego State University campus. Crews used a number of excavation methods including cut and cover and New Austrian Tunneling Method (NATM) during the construction of the train tunnel and 50,000-square-foot station.

Atkinson utilized multiple crews and worked 24 hours a day, seven days a week to excavate the 37-foot-wide, 29-foot-high tunnel. Atkinson performed a total of 2,915 linear feet of cut and cover excavation and an additional 1,085 linear feet of NATM underground tunnel excavation.

The tunnel and underground trolley station at SDSU was the most challenging element of a very challenging project. The quality and attention to detail of the project team's work are overwhelming factors in the station's recognition and success. They were an excellent partner. Even with its expanded scope, the team delivered this project on time. I was also impressed how they controlled costs and came to the table to negotiate changes.
Jim Linthicum, Director of Engineering and Construction, San Diego Association of Governments