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Frictional resistance between base plate and concrete/grout

Posted by ARSalmost 4 years ago
Frictional resistance between base plate and concrete/grout

Does PROFIS have the capability to account for frictional resistance between a base plate and the underlying concrete/grout? If a simultaneous downward compressive load is applied along with a shear load, there should be a frictional resistance that can reduce the shear capacity demand on the anchors.

In the generated calc report, there doesn't appear to be any consideration for the frictional resistance. I'm just wondering if there is a setting or something that I missed. Alternatively, I assume that I can manually account for this by only inputting the net factored shear after friction is considered, but I'm hoping PROFIS is more intuitive than that.

On a related note - AISC Design Guide 1 (2nd ed.) cites ACI 349-06, which allowed the use of a coefficient of friction value of 0.4 for LRFD loads and included provisions for estimating the frictional resistance.

shear,friction

1 Reply
Posted by Emily almost 4 years ago
Hilti Verified

Hello,

The software takes a more conservative design approach and thus the frictional force between the base plate and concrete or grout is not considered for shear transfer within PROFIS Engineering. The entire shear load is transferred to the anchor(s) via the base plate.

Cordially,
Emily


1 comment on this reply
Posted by ARSalmost 4 years ago
That assumption could be substantially over-conservative if you have a situation where a large sustained downward load exists. So at this point, if I wanted to consider frictional resistance, I'd have to manually reduce the shear load input. Hopefully that feature is considered in future upgrades to the software, even if it's a selectable on/off option.