T-walls are pile-supported concrete floodwalls that are part of the New Orleans flood protection system. They are typically founded on long concrete or steel battered piles and include a sheet pile cut off for seepage and gradient control. The lack of sufficient lateral support from the compressible foundation soil, accompanied by relatively large expected lateral loads from storm surge, require that these support piles be battered. Since the soils in Southern Louisiana contain soft and compressible silt and clay, these floodwalls need to be designed to resist not only flood loads but also loads produced by consolidation of soft foundation soil under the weight of new fill placed on or near a T-wall during construction. This is commonly referred to as downdrag and induces additional bending moments on the piles. Currently, the effects of settlement and flood loads are analyzed separately and the maximum bending moments developed on the battered piles are superimposed, without accounting for the nonlinearities associated with the analysis of the system.;It is important that the settlement induced bending moments are assessed and understood to ensure that they do not exceed allowable limits. In an attempt to develop a comprehensive T-wall design procedure that appropriately considers field conditions, the United States Army Corps of Engineers (USACE) New Orleans District partnered with Rensselaer Polytechnic Institute (RPI) and Virginia Polytechnic Institute and State University and jointly developed a research program. The first step of the program included a series of centrifuge tests that would provide insight into the mechanisms and magnitudes of settlement-induced bending moments and would produce reliable data sets for validation of numerical models. In addition, the validated numerical models would be used to investigate the combined and separate effects of flood and settlement loading for a wide range of T-wall and soil conditions.;This dissertation focuses on the experimental program and describes the modeling of a scaled version of a typical T-wall and the simulation of consolidation of soft foundation soil under fill loading for several prototype years. Different pile configurations and loading scenarios were tested at the RPI Centrifuge Facility in order to isolate the key parameters to the response of the system to settlement loading. The centrifuge tests provided information about the location and magnitude of the maximum settlement induced bending moments on the battered piles. The effects of pile configuration, pile spacing and fill loading geometry were explored and are discussed in this dissertation.
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