North Carolina Department of Transportation Experience with Predesign Load Testing

Load test programs performed in the predesign stage provide the greatest potential for savings in more economical foundation designs. The North Carolina Department of Transportation’s (NCDOT) first experience with predesign load testing was on the Neuse River Bridge project in 1994. The practice was used on all major bridges thereafter. This paper presents a case history of those projects detailing the load testing, outcome, and estimated cost savings. Through the case history, the paper discusses both the successful application of load test programs and the results that were achieved. A description of the NCDOT’s experience and practice of predesign load testing of deep foundations is presented. The philosophy and considerations used by the NCDOT to evaluate and develop load test programs are discussed. The effects on design and construction practices that have resulted from load testing and experiences in mitigating constructibility problems and construction claims through the use of load test programs are described. The progression of the NCDOT’s load test experiences and integration of new load test technologies are also presented.