Service Performed Tunnel inspection, structural analysis and assessment, recommendations and concepts for tunnel repair and retrofit.
Geology description
The bedrock in the project area primarily comprises intact metamorphosed sandstone (i.e. graywacke) of the Franciscan Melange and contains few discontinuities. The bedrock is typically overlain by stiff to hard lean clay.
Description
The Puerto Suello Tunnel is a 400 m long single-track rail tunnel in San Rafael, California and was constructed in 1879. The 4.9 m wide and 6.8 m high tunnel was partially destroyed by a fire in 1961, was rebuilt for freight service in 1967 and closed in the mid-1980s. The tunnel was acquired by SMART in 2003, who retrofitted and then reopened it for commuter rail service in 2017.
The ground overburden above the tunnel reaches a maximum of 45 m and the tunnel was constructed using cut-and-cover and mined construction methodologies.