Seismic Design of the Uniform Wharf in Guam

This paper reviews the seismic design performed for the replacement of a 373-meter-long (1,224-foot-long) naval wharf located in Apra Harbor in the U.S. Territory of Guam. Design challenges included in the paper are associated with eliminating the interference between the structural components of the new and existing walls, accommodating the uneven alignment of the existing wall, and incorporating the limited soil improvement possible at the corner region. The existing wall, constructed originally in 1948, consists of a sheet pile wall anchored to a sheet pile tieback wall. The wharf has not been in use since 1993 because of the significant damage it suffered after the magnitude 8.0 earthquake. Extensive liquefaction was deemed the main reason for the structural damage observed. The replacement wharf, currently under construction way, consists of a new anchored sheet pile wall outboard of the existing face of the wall while leaving the existing structure in place. The new structure includes soil improvement behind the sheet pile wall to mitigate the effects of probable liquefaction during future seismic events.