Strut and Tie Model – Width of all compressive struts

Document Information

Document Type: FAQ

Product(s): LEAP RCPier

Version(s): All

Original Author: Bentley Technical Support Group -VM

QUESTION: What is the required input value for Width of all Compressive Struts?

ANSWER:

“Width of all compressive struts” has no fixed value.

Width of compressive strut should be based on some calculation logic and on user experience and judgment.

 It is suggested to check Tutor 3 from RCP and to check Arizona DOT example.

 Based on the 3 reference examples it was found out that different approach was used to figure out the width of compressive struts. 

• Portland cement association example suggest using the truss member thickness as the bearing block dimension which is 30”.
• In the Tutor 3 example it clearly mentions to “Assume that the truss member thickness is 0.4 ft (4.8 in.) and the member width equals the pier cap width, 4ft (48 in.)”.
• In the Arizona DOT example, the thickness is taken as the width of Hammer head which is 66”. 

For some additional information on how RCpier handles Strut and tie model, please check the Bentley communities link.

http://communities.bentley.com/products/bridge_design___engineering/w/bridge_design_and_engineering__wiki/15678.analysis-of-strut-and-tie-model

http://communities.bentley.com/products/bridge_design___engineering/w/bridge_design_and_engineering__wiki/15679.input-of-strut-and-tie-model-in-rcpier