LRFD Calibration

LRFD has been used increasingly and has become mandatory for all bridge projects funded by the Federal Highway Administration (FHWA). Compared with the allowable-stress design (ASD) method, LRFD can achieve a compatible reliability between the bridge superstructure and substructure. The uncertainty of load and resistance are quantified separately and are reasonably incorporated into the design process.

An example histogram of collected bias of drilled shaft resistance and fitted statistical distributions