North Carolina Department of Transportation's Experience with LRFD

North Carolina Department of Transportation (NCDOT) has been wrestling with the implementation of AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications since the late 1990s. NCDOT’s concerns include the following: North Carolina’s local geology was not accounted for in the code; NCDOT’s Vesic driven pile design method was not included in the AASHTO code; and the proposed resistance factors in the AASHTO specifications appeared to be too low. As a consequence, NCDOT decided to award a research contract to North Carolina State University (NCSU) to develop local calibrations based on NCDOT’s practice. This research was conducted by professors M. S. Rahman and M. A. Gabr, who were assisted by K. J. Kim of NCDOT, and R. Z. Sarica and M. S. Hossain of NCSU. Some of the recommendations of this research will be incorporated with the AASHTO LRFD code to become the department's LRFD practice. This paper presents a brief case study of NCDOT's implementation of the AASHTO LRFD Bridge Design Specifications.