Wheel Loads From Bridge Strains: Laboratory Studies

Abstract

Laboratory tests are described that explore the validity of using bridge measurements to determine not only equivalent static wheel loads but also their dynamic variation with time. A 12.2‐m span composite girder was loaded with one to four dynamic loads fixed in location. Acceptable load predictions were obtained from measured strains and computed bending moments at the one‐eighth points of the span. Estimates of dynamic load at a reduced accuracy were also obtained from measured deflections. Accurate dynamic calibration tests were necessary to find the equivalent beam‐bending stiffness used in the dynamic interpretive analysis and also the strain‐bending moment relationships.