Please join us for an in person lunch and learn about SEM Tunnel Design! FREE food for in person!

This seminar will present the recent application of Sequential Excavation Method (SEM) tunneling techniques used for construction of the Courthouse Commons (COCO) Tunnel in downtown San Diego. The COCO Tunnel is a component of the larger Courthouse Commons Development Project and involved construction of a 300-foot long, 28-foot diameter tunnel located directly beneath an existing multi-story building. Tunneling required strict controls on excavation methods to minimize the potential for ground settlement, and flexibility to adapt to variable conditions which are common to underground construction in congested urban settings. The tunnel was further challenged by crossing of an active fault zone which required an innovative design approach utilizing seismic joints to accommodate up to 18 inches of potential fault displacement. This presentation will discuss design and construction challenges for the project and will include a short video (“tunnel tour”) that will provide an in-depth look at the project’s construction.