DYNAMIC LOAD SPECTRA FOR GIRDER BRIDGES

The dynamic load is an important component of bridge loads. The determination of the dynamic load factor (DLF), defined as the ratio of dynamic and static responses, is essential for the development of a new generation of reliability-based bridge design codes. Field measurements are performed to determine the actual variation of the DLF with various truck as well as bridge parameters and to verify the available analytical models. The effects of various parameters, such as truck gross weight, truck speed, truck type, girder static stress, and girder position, on the DLF are presented. The field tests are carried out on four steel girder bridges. Measurements are taken using a weigh-in-motion system with strain transducers. For each truck passage, the truck weight, speed, axle configuration, and lane occupancy are determined and recorded. A numerical procedure is developed to filter and process collected data. The DLF is determined under normal truck traffic of various load ranges and axle configurations. The field measurements confirm the results of the analytical study. In absolute terms, the response caused by dynamic load is practically constant and does not depend on truck weight. However, for exterior girders the static stress is small. Therefore, the DLF should be considered on the basis of girders of maximum stress values.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 69-83
  • Monograph Title: Steel, concrete, and wood bridges
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00711795
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 25 1995 12:00AM