TRUSS BRIDGE DYNAMIC LOAD ALLOWANCE AND DISTRIBUTION FACTORS

Truss bridge floor systems are complex and highly statically indeterminate systems where the static and dynamic response interacts with the main load carrying truss system through an often unanticipated mechanism. This paper reports on field tests of older truss bridge floor systems, including a single span 1937 pony truss, a single span 1937 through-truss, and a multispan 1935 pony truss. All tested bridges have similar arrangements of floor beams connected to the main truss and supporting nominally simple span stringers. Results of the dynamic load allowance (IM) investigation reveals that North American bridge codes overestimate impact for these types of bridges. The dynamic response was characterized by unexpected high vibrations resulting in large IM values in the stringers away from the load and relatively low IM values experienced in the floor beams under heavy load. In all cases the static response of the structure was characterized by load sharing of the stringers under concentrated wheel loads that is not accounted for by approximate methods specified by codes, resulting in lower than specified transverse distribution factors. For the covering abstract see ITRD E111699.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0947644320
• Corporate Authors:

  ENGINEERING TECHNICS PRESS

  46 CLUNY GARDENS
  EDINBURGH,   United Kingdom  EH10 6BN
• Authors:
  • LAMAN, J A
  • Boothby, T E
• Conference:
  • PROCEEDINGS OF THE SEVENTH INTERNATIONAL CONFERENCE ON STRUCTURAL FAULTS AND REPAIR, HELD THE ASSEMBLY ROOMS, EDINBURGH, UK, 8 JULY 1997. VOL 1: EXTENDING THE LIFE OF BRIDGES
• Publication Date: 1997

Language

• English

Media Info

• Features: References;
• Pagination: p. 487-93

Subject/Index Terms

• TRT Terms: Beams; Bearing capacity; Bridges; Conferences; Design; Maintenance; Test procedures
• ITRD Terms: 3472: Beam; 3085: Bearing capacity; 3455: Bridge; 8525: Conference; 9011: Design (overall design); 3847: Maintenance; 6288: Test method
• Subject Areas: Bridges and other structures; Design; Maintenance and Preservation;

Filing Info

• Accession Number: 00824065
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 0-947644-32-0
• Files: ITRD
• Created Date: Feb 6 2002 12:00AM