The Sunnydale CSO Tunnel—Dealing with Urban Infrastructure
Abstract
The Sunnydale Auxiliary Sewer Project is a CSO tunnel designed to prevent storm events from flooding residences near San Francisco Bay. Although this 2.44–3.35 m (8–11 ft) diameter sewer pipeline is less than 1,219 m (4,000 ft) long, its installation will require a single-pass, segmentally lined EPB drive, a microtunneled drive, a jacked-shield tunnel, and a short cut-and-cover section. Undercrossings include a major four-track commuter rail station, deeply buried gas and high-voltage electric utilities, and a culvert carrying ten-lane State Highway 101 that will require jet-grouting for support. In addition, the EPB tunneling will encounter a plume of contaminated soil and groundwater currently undergoing remediation. This paper discusses the reasons for the multiple construction methods, including variable subsurface conditions and infrastructure crossings.
2010
North American Tunneling (NAT) Conference Proceedings
Renée Fippin
Jacobs Associates
Heather Stewart
Jacobs Associates
Manfred Wong
San Francisco Public Utilities Commission
Richard Nolting, III
Jacobs Associates
