LONG SPAN BRIDGE DEFLECTIONS

This report discusses an investigation of the immediate and long term deflection of simple span and continuous prestressed concrete bridges. The study examines the design assumptions and construction methods used to plan and build the superstructure with respect to its deflections. Factors affecting bridge deflection such as concrete strength, modulus of elasticity, aggregate shrinkage, structure shortening, length of time the structure is on falsework, skew, and end condiiton of the abutments are also analyzed. Falsework load distribution is studied. Conclusions are as follows: Judgement differences in design assumptions can cause substantial variations in calculated deflections. Maximum falsework loads occur several days after the top deck is cast. Most structures deflect elastically and continue to deflect plastically after the falsework is released. Occasionally as structure will rise significantly after a long period of constant deflection. (Author)

• Corporate Authors:

  California Department of Transportation

  Division of Structures Design, 1120 N Street
  Sacramento, CA  United States  95814

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Nelsen, B H
  • Jurach, P J
• Publication Date: 1983-12

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 160 p.

Subject/Index Terms

• TRT Terms: Aggregates; Bridge superstructures; Concrete; Deflection; Falsework; Load transfer; Long span bridges; Modulus of elasticity; Shrinkage; Strength of materials
• Uncontrolled Terms: Concrete strength
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00390390
• Record Type: Publication
• Report/Paper Numbers: FHWA-CA-SD-82-01 Final Rpt.
• Contract Numbers: D-4-43
• Files: TRIS, USDOT, STATEDOT
• Created Date: Nov 30 1984 12:00AM