A historic park area and a ground cover of only 10 – 32 feet (3 – 9.8 meters) above the proposed Fort Canning Tunnel posed significant design and construction challenges. Both the owner and the contractor sought an alternative tunnel construction method to avoid extensive surface disruption in the area.
Gall Zeidler Consultants provided an alternative New Austrian Tunneling Method (NATM) design, utilizing continuous grouted steel pipe, pre-support, and a two-pass lining system for the mined portion of the proposed tunnel. The design earned a Merit Award at the 2008 Design & Engineering Safety Excellence Awards.
2004 – 2006
Three-Lane Highway Tunnel
525 feet (160 meters)
Width: 48.2 feet (14.7 meters)
Height: 38 feet (11.6 meters)
Fill, Fort Canning Boulder Bed (FCBB) Formation and Residual Soil, Jurong Formation (Below Tunnel Invert); Groundwater is Only 3 – 7 feet (1 – 2 meters) Below Existing Grade
Approximately $22 Million
T.Y. Lin International, Principal Designer; Sato Kogyo, Contractor
Singapore Land Transport Authority (LTA)