Seismic Analysis and Design of Berth 14 Extension: Balboa, Panama

Berth 14 is located near the Pacific end of the Panama Canal and is part of a marginal wharf system built by the U.S. Army Corps of Engineers in the early 1900s. It consists of a hybrid concrete-steel superstructure supported on large and brittle concrete shafts of up to 2.4 meters (7.9 feet) in diameter. This paper describes the challenges encountered in the construction of a finger pier extension 85 meters (279 feet) long by 50 meters (164 feet) wide to Berth 14. The extension was designed for repairable damage under a contingency level earthquake and minor damage and disruption to operations under an operating level earthquake. A flexible structural system consisting of 700-millimeter (28-inch) octagonal precast, prestressed concrete plumb piles was chosen as the most practical and cost efficient solution to construct the extension. Careful detailing of a full force-transfer mechanism from the new structure into existing Berth 14 was required as part of the design. Potentially imposing large inertial forces on the drilled shafts of the existing berth—an initial concern—was proved to be irrelevant through analytical modeling of the connected new and existing structures. The paper addresses the analytical tools and techniques employed to evaluate possible substructure alternatives as well as the seismic assessment of the existing Berth 14.