When looking at the report for my anchoring to concrete design, it seems that Avc0 is being calculated incorrectly for my design conditions, which are shear applied perpendicular to an edge, with an edge distance Ca1 = 49", member thickness of 12", and Ca2 being infinity on either side. Please see the attached print out of the Hilti report.
On page 165 of the PROFIS Design Guide, it states that Avc0 is calculated using the following:
(1.5Ca1 1.5 Ca1)(1.5 Ca1) = (4.5Ca1)^2.
The problem with using this equation is its not considering the user-defined thickness of the concrete. In my case I defined the concrete to be 12" thick, which is far less than Ca1 (49").
So instead of Avc0 = ((1.5 x 49") (1.5 x 49"))(1.5 x 49") = 10,804 in^2, it should be Avc0 = ((1.5 x 49") (1.5 x 49"))(12") = 1,764 in^2.
The calculation of Avc appears to be correct when checked by hand and is 1,860 in^2. With the Avc0 calculated by the software, the group anchor capacity is being reduced significantly as compared to the single anchor, whereas the ratio between Avc and Avc0 is expected to be greater than 1.
Is there a setting in the software that I'm not aware of that would cause the thickness of the concrete to be ignored in the Avc0 calculation?
Hi Jonathan,
For further assistance, please email your ".pe" file to hnatechnicalservices@hilti.com.
Regards,
Ashley