Shear Capacity of Texas Standard Prestressed Beams from Strut & Tie Models of Beam Ends

Article 5.7.3.2 of AASHTO LRFD includes design guidance for sections near supports. This AASHTO design provision, i.e., the 0.18 f 'c limit, has been put in place to ensure that the complicated nature of stresses are accounted for while transferring the forces in the B-region to the simply supported ends of pretensioned girders. The 0.18 f 'c shear stress limit can be exceeded if load transfer into the supports can be justified by appropriate strut and tie models (STMs). Bridge designers find these STMs to be difficult to create. For Tx-Girders near their span limit, the bottom flange is nearly full of prestressing steel, and the web will have harped strands over a significant height. For U-beams, X-beams, slab beams, decked slab beams, and box beams, there will be many debonded strands to different lengths in addition to strands bonded over the entire beam length.This project aims to create a series of strut-and-tie models (STMs) for the end regions of Tx-Girders, U-beams, box beams, X-beams, slab beams, and decked slab beams. These STMs will be used to study the interaction between shear, flexure, and the anchorage of longitudinal tie(s) with the ultimate goal of deriving simplified shear stress limits.

• Record URL:
  https://library.ctr.utexas.edu/Presto/project=7015

Language

• English

Project

• Status: Active
• Funding: $399,736
• Contract Numbers:

  0-7015

• Sponsor Organizations:

  Texas Department of Transportation

  11th and Brazos Streets
  Austin, TX  United States  78701

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Managing Organizations:

  Texas Department of Transportation

  11th and Brazos Streets
  Austin, TX  United States  78701
• Project Managers:

  Steele, Joanne

• Performing Organizations:

  Center for Transportation Research

  3925 W. Braker Lane
  Austin, TX  United States  78759
• Principal Investigators:

  Bayrak, Oguzhan

• Start Date: 20190717
• Expected Completion Date: 20211031
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Beams; Bridge design; Strut and tie method
• Subject Areas: Bridges and other structures; Design;

Filing Info

• Accession Number: 01714850
• Record Type: Research project
• Source Agency: Texas Department of Transportation
• Contract Numbers: 0-7015
• Files: RIP, STATEDOT
• Created Date: Aug 26 2019 3:27PM