Conspan Vertical Shear Capacity

To calculate the Phi Vn/Vu ratio you need Vu , Vc and Vs Provided value .

Vu & Vc can be obtained from the above table .

Since the Conspan file is not available I don't know the stirrups information like Stirrups size , legs and spacing and it will be difficult for me to calculate Vs Provd.

So please calculate Vs Provided value using formula = ((Av *Fy * d )/ S ) (Eq 9-30 AASHTO LFD Code)

Then calculate Phi Vn = ( 0.9 x (Vs prvd + Vc) )

Ratio Phi Vn/Vu = (0.9 x (Vs prvd + Vc) ) / Vu

I was able to calculate these values; however when computing the load rating using these values, it does not match what is provided in the Conspan Load Rating output. After reviewing the updates information and "fixes" for the version I am running, I believe that it is due to having the toggle on for the FLDOT option to count the shear stirrups across failure plane while simultaneously using the simplified shear design procedure. Once I uncheck this toggle, the Conspan load rating matches what I hand calculate.

I'm glad the issue was resolved.

Hi Vinay, why is the option given to consider the shear across failure plane when the simplified shear design procedure is used for analysis? Shouldn't it be greyed out? What is the program doing when you select simplified shear design AND check the box to include shear across failure plane in the rating tab? From my understanding the analysis and the rating (Beam) tab are doing different things. 

Thanks

Hi ,

If the user has selected one of the 2 Vertical Shear Method in the Analysis TAB then the program will design the girder as per that method.

Then while rating the girder, if the user selects the FDOT alternative , then the program calculates the shear capacity as per FDOT requirements.

Program calculates the shear capacity based on what option is being selected in Analysis TAB and Rating Parameter Dialog box.

Please let me know if you need any additional information.

Yeah that is the option I am referring to. When using LRFD 7th Ed. (or any edition) for analysis with the Simplified Shear Method (Vci Vcw, 5.8.3.4.3 7th ed) NOT the MCFT General Procedure (Beta Theta Eq, 5.8.3.4, 7th ed), why is the option to consider shear reinf across failure plane still there? It should not be an option when using the Simplified shear method, right? Even if you look at the FDOT Load Rating Manual that refers to the use of shear reinf. across failure plane, it refers to using it with the MCFT and so does the Manual for Bridge Eval. 3rd ed. 

from FDOT LRM ^.

Thanks

User can uncheck the FDOT alternative option as it is not mandatory to check this option, then the program will not consider the 

shear reinf. across failure plane.

User can uncheck the FDOT alternative option as it is not mandatory to check this option, then the program will not consider the 

shear reinf. across failure plane.