KDOT Column Expert: Ultimate Shear Capacity of Circular Columns using the Modified Compression Field Theory

The extreme event requirement as a limit state set by AASHTO LRFD makes it necessary to develop the actual capacity of concrete sections to accurately design them to withstand the extreme load events. For confined sections subjected to combined axial force and uniaxial bending moment, the actual ultimate flexural capacity is found using the earlier versions of Kansas Department of Transportation (KDOT) Column Expert. Accordingly, it is necessary to develop a computer program that evaluates the section capacity in shear by generating accurate shear-moment interaction diagrams for each level of axial force and compares them to the available experimental results. This analysis can prove useful to estimate the existing capacity of damaged bridge piers when subjected to truck impacts. It is also desirable to have a reliable analysis tool that can be used to assess the actual shear capacity of the pier when developing a repair action. Experimental evidences have shown that the modified compression field theory can capture the actual shear capacity of the section very accurately. In addition, the dowel action of the longitudinal bars acting in tension can contribute to increasing the shear capacity, a factor often neglected by design codes of practice. The nonlinear axial load-strain and uniaxial moment-curvature response of reinforced concrete circular section combined with shear forces is very involved. It is important to note that accurate results are guaranteed when the axial load and bending moments are proportional since loading path dependence is avoided. Rasheed and Abd El Fattah have developed a framework for columns that imposes proportional axial force and uniaxial bending moment on circular sections and iterates to obtain the corresponding deformation parameters. However, this procedure needs to be extended to the general case of shear-moment-axial force interaction.

Language

• English

Project

• Status: Completed
• Funding: $59720.00
• Contract Numbers:

  DTRT12-G-UTC07

• Sponsor Organizations:

  Research and Innovative Technology Administration

  University Transportation Centers Program
  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Performing Organizations:

  Kansas State University

  Department of Civil Engineering
  Manhattan, KS  United States  66506-5000
• Principal Investigators:

  Rasheed, Hayder

• Start Date: 20130701
• Expected Completion Date: 0
• Actual Completion Date: 20141231
• Source Data: RiP Project 35130

Subject/Index Terms

• TRT Terms: Bearing capacity; Bridge design; Bridge piers; Columns; Flexural strength; Trucks
• Identifier Terms: AASHTO Guide Specifications for LRFD Seismic Bridge Design
• Subject Areas: Bridges and other structures; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01503732
• Record Type: Research project
• Source Agency: Mid-America Transportation Center
• Contract Numbers: DTRT12-G-UTC07
• Files: UTC, RIP
• Created Date: Jan 16 2014 1:00AM