Rowes Wharf: A Case Study in Substructure Innovation

Abstract This case study examines the decision-making aspects of the below-grade portions of a major mixed-use project located adjacent tot he site of the historic Boston Sconce (South Battery). The initial development guidelines in this project led the development team to identify the need for major subsurface and marine construction. The necessary subsurface and marine construction represented both unusual cost premiums and risks relative to standard development enterprises. The initial subsurface construction strategy called for the use of a slurry wall and tieback support system for excavation. Although conventional excavation techniques were contemplated, an evaluation of the complexity of the below-grade construction problems led to the consideration of an Up/Down construction procedure, involving the installation of caisson foundations followed by the simultaneous erection of the superstructure and excavation of the below-grade portions of the project. This case study reviews the process by which the Up/Down decision was reached, and briefly presents the Up/Down procedure as implemented in this project.