Accuracy of static capacity methods and calibration of resistance factors for driven piles in Rhode Island soils

Sean Davis, University of Rhode Island

Abstract

Currently the AASHTO (American Association of State Highway and Transportation Officials) bridge design code mandates the use of Load and Resistance Factor Design (LRFD) for structural and geotechnical design. The code incorporates static capacity methods and resistance factors for sand and clay calibrated from a national database. There is uncertainty when applying AASHTO methods in silts that are commonly encountered in the State of Rhode Island. To reduce this uncertainty static load test data from various construction projects were compiled and analyzed and used as a basis for assessing the accuracy of common static capacity methods including Nordlund, SPT and Effective Stress Methods. The data were also used to develop region-specific resistance factors. Comparison of resistance factors showed that the current AASHTO factors are sufficient for piles designed in Providence increasing resistance factors of some capacity methods by 33%. Results also showed that some static capacity methods for driven piles perform poorly in typical Rhode Island sub surface profiles with methods over predicting capacity by 60%. Regionally calibrated resistance factors are provided for different pile types, capacity methods and subsurface profiles.^

Subject Area

Engineering, Civil

Recommended Citation

Sean Davis, "Accuracy of static capacity methods and calibration of resistance factors for driven piles in Rhode Island soils" (2012). Dissertations and Master's Theses (Campus Access). Paper AAI1516550.
http://digitalcommons.uri.edu/dissertations/AAI1516550

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