OSUCivlEng
Civil/Environmental
- Jan 12, 2009
- 275
Has anyone compared the results of using the simplified method, the general procedure equations and the method in Appendix B5?
I recently did this with a pier cap and noticed that the simplified method and general procedure equations produced similar results. The results of the method in Appendix B5 required an area of shear reinforcing that was 40% less. That is not insignificant.
I came across this in the TXDOT Bridge Design Guide dated March 2022. Article 5.7.3.4.2 is the general procedure equations. Note the underlined sentence.
Why are we using still using <Appendix B5> for shear capacities of reinforced concrete members?
The shear design method in <Article 5.7.3.4.2> General Procedure is a valid shear design procedure. The development of this article was based on simplifying the iterative method now found in <Appendix B5> General Procedure For Shear Design With Tables. In simplifying the <Appendix B5> procedure, some assumptions needed to be made that made <Article 5.7.3.4.2> a closer solution for some cases and further for others. For mildly reinforced design <Article 5.7.3.4.2> is often conservative, sometimes excessively conservative. For prestressed sections this is not the case.
I recently did this with a pier cap and noticed that the simplified method and general procedure equations produced similar results. The results of the method in Appendix B5 required an area of shear reinforcing that was 40% less. That is not insignificant.
I came across this in the TXDOT Bridge Design Guide dated March 2022. Article 5.7.3.4.2 is the general procedure equations. Note the underlined sentence.
Why are we using still using <Appendix B5> for shear capacities of reinforced concrete members?
The shear design method in <Article 5.7.3.4.2> General Procedure is a valid shear design procedure. The development of this article was based on simplifying the iterative method now found in <Appendix B5> General Procedure For Shear Design With Tables. In simplifying the <Appendix B5> procedure, some assumptions needed to be made that made <Article 5.7.3.4.2> a closer solution for some cases and further for others. For mildly reinforced design <Article 5.7.3.4.2> is often conservative, sometimes excessively conservative. For prestressed sections this is not the case.