摘要: |
The current Arkansas State Highway and Transportation Department (AHTD) design practice of using shear strength measurements obtained from correlations with standard penetration blow count data contains uncertainty and bias. This uncertainty requires the use of conservative resistance factors in geotechnical engineering design to compensate for the reduced reliability of this testing method. These conservative resistance factors, as accounted for in the implementation of load and resistance factor design (LRFD) under the LRFD Bridge Design Specifications (2007), may result in overly conservative designs. Cost savings may be obtained from designs based on data obtained from conducting advanced sampling (hydraulic fixed piston Osterberg and Pitcher barrel sampling techniques), advanced in-situ testing (cone penetration in sands and clays or in situ vane shear in clays), advanced laboratory testing (direct simple shear, consolidated undrained triaxial compression/extension, and constant-rate-of-strain consolidation), and advanced full-scale load tests (Osterberg load cell tests). |