The South Capitol Street Corridor Project is one of the District Department of Transportation’s (DDOT) largest projects, and is currently under construction. This case study will focus on the design of the foundation piles for the main spans of the iconic Frederick Douglass Memorial (FDM) Bridge, and will include a discussion of the foundation design evolution from an originally designed alternative foundation system (i.e. coffer dams and drilled shafts), to the current use of driven Large Diameter Open End Pipe (LDOEP) Piles. The paper will provide a discussion of the design methodology used during preliminary engineering and final design, and will highlight insight gained from the extensive load testing program completed to date. The load testing program consists of a combination of high strain dynamic testing (PDA), as well as Statnamic Load Testing on select sacrificial, pre-production test piles. Specifically, data gathered during the nearly-completed load testing program suggests the development of significant internal shaft frictional resistance within the tested LDOEP Piles. This paper will also discuss limitations of currently accepted industry design methods for predicting the capacity of LDOEP piles, a subject that is also currently being researched by FHWA. The data from this test pile program will help design assumptions for future projects.
Subjects: driven piles, large diameter open end pipe piles
Author: Michael D. Venezia, P.E., and Karl A. Higgins III, P.E., D.GE