Preliminary Design of the Caldecott Fourth Bore
Abstract
This paper describes the preliminary design of the fourth bore of the Caldecott Tunnels along State Route 24 in Oakland, California. The paper focus is on two major aspects of the project: initial support system design and seismic design. The initial support system was designed based on the New Austrian Tunneling Method (NATM). NATM provides the required flexibility to accommodate the variable ground conditions in the weak, folded, and faulted rock along the alignment. The seismic design provides a final lining system that meets serviceability requirements for a 1,500 year seismic event with an estimated peak ground acceleration of 1.2g.
2007
Rapid Excavation and Tunneling Conference (RETC) Proceedings
Bhaskar B. Thapa
Jacobs Associates
Michael T. McRae
Jacobs Associates
Johannes V. Greunen
Jacobs Associates
