Analyses and testing of annulus equipped pipe pile for the Sakonnet River Bridge project

The Sakonnet River Bridge replacement project refers to the design and construction of a 2265 ft long and 96 ft wide bridge along Routes 24 and 138 in Rhode Island, bridging the Sakonnet River close to its discharge into the ocean. The bridge was designated as the first major construction in New England for which the substructure is designed using the new AASHTO-LRFD specifications. The project is being carried out by the RI Department of Transportation with the lead engineering design by Commonwealth Engineering of Providence, RI and the Geotechnical consultant, Haley and Aldrich (H&A) of Boston, MA. Geosciences Testing and Research, Inc. (GTR) of N. Chelmsford, MA was retained by H & A as a special consultant for the foundations and LRFD implementation. The presented research was carried out as part of GTR's effort in this project.;The foundations for the Sakonnet River Bridge replacement project presented a challenge due to problematic deep silty and sandy glacial soils (with bedrock as deep as 400 ft. below the water line in the channel) and large central spans creating high loading demands of 2900 kips per pile at river pier 4 and 4100 kips per pile at river piers 5 and 6.;An alternative solution was developed by Prof. Paikowsky in the form of a 72 in. OEP equipped with an internal steel plate, referred to as the annulus pile.;A comparison of dynamic prediction methods to static load test capacities is presented. The comparison demonstrates how well the predictive methods work for pile 72-II and 72-III. The Case Method and CAPWAP last BOR result in conservative predictions; where as the Energy Approach at EOD overestimates pile capacity and better represents the ultimate pile resistance.;Lastly simulations using the Finite Element Analysis (FEA) software LS Dyna and HyperMesh were performed to investigate the dynamic loading conditions at the annulus. Where the annulus concept was new, section dimensions were conservatively designed. The FEA demonstrated the constructed annulus to be under-stressed, hence significantly over-designed for the loading conditions. Further analysis is required to investigate if section dimensions are to be reduced.;These presented analyses and testing were utilized in examining the annulus plug solution. The use of the annulus pile can provide an economical foundation solution for the Sakonnet River Bridge project by significantly reducing required pile lengths. Further evaluation of the annulus' pile behavior is planned to be carried out during construction.