A Dynamic Stress Study of the Aluminum Bridge over the Appomattox River at Petersburg

摘要

The report describes a dynamic stress study of the only aluminum highway bridge in the Virginia system of highways. This structure is a 97' simple span with composite action between the aluminum girders and the lightweight concrete deck slab and is located on Route 36 at the north city limits of Petersburg. Girder strains and deflections were measured and recorded at midspan, and additional strains were measured and recorded at bearing pedestals, secondary bracing members and on the webs of the girder modules for 120 crossings of a test vehicle (H20-S16 loading) at a variety of speeds and lateral positions. Data included in the report and commented upon are double amplitudes of oscillation, logarithmic decrements and fundamental frequencies, in addition to the stresses (from the strains) and deflections mentioned above. From both the study of the test data and close observation of the structure during and after the dynamic tests, it is concluded that this aluminum structure was designed in accordance with good structural engineering practice and performs its function in an adequate manner. (Author)