Design of cut-and-cover tunnel in seismically-active urban area: Presidio Parkway Replacement Project

摘要

Positioned alongside the north shoreline of San Francisco, the Battery Tunnel is one of thernstructures of Presidio Parkway which will connect the city streets through Presidio of San FranciscornNational Park to the iconic Golden Gate Bridge. The site is seismically active area and surroundedrnby the National Cemetery and historic battery structures. The design team came up with uniquerngeometry to accommodate geometric constraints and numerous utilities. The soldier piles werernselected as the temporary shoring system during construction to protect the marsh lands fromrninterruption of ground water. As a “recovery route” designated by the California Department ofrnTransportation, accurate evaluation of seismic performance of the tunnel was warranted. To that end,rnnonlinear soil-structure interaction analysis as well as linear analysis was performed. The analysesrnnot only confirmed that the structural design of the tunnel satisfies seismic design criteria for bothrntemporary and permanent condition, but also showed the differences between linear and nonlinearrnanalysis.