CAL PARK TUNNEL REHABILITATION PROJECT

摘要

The Cal Park Tunnel is a significant public works rehabilitation project in Marin County, California. The existing tunnel was built in the 1880s as a single-track railroad tunnel, widened in 1924 to double tracks, and closed in the mid-1970s. In the early 1990s it suffered vandalism, fire, tunnel timber support decay, and multiple collapses. This paper discusses rehabilitation of the tunnel into a multimodal transportation facility for passenger rail and a pedestrian-bicycle pathway. Because of uncertainty surrounding the tunnel’s condition and its proximity to a major freeway, and in order to achieve a final product safe for public use, the project required a variety of support and ground modification schemes, final lining approaches, and risk management strategies by the owner and contractor.