base plate and anchor rod capacity checks

[ac0609]

Hi all,
I need to check the capacity of the base plate and anchors for a ground mounted sign w/ two posts and a sign panel area of 10'x5.5' that are attached to the existing concrete.
I am using the AISC steel design guide example for base plate and anchor rod but no direction with how to calculate with only moment. Steel base plate is 8"x8x3/8" with 4 anchor bolts 3/4" diameter 3.25" embedment length. I have wind load of .804 kips applied horizontally. How can i go about this?

 

[concepto.ed]

If you are using load combinations, you should have an axial load on the base plate. For your case axial load will be very small but it will allow you to calculate the eccentricity and everything else using large moment design criteria.

 

[BAretired]

What size are the posts? Is the bottom of sign at top of concrete or elevated? Is the height of sign 5.5' or 10'?

3/4" dia. anchor bolts should be 1.5" from the edge of plate, which means bolts are at 5" centers. An 8"x8" plate doesn't leave much room for a post plus clearance for a wrench. 804# wind force is only 14.6 psf pressure, which sounds light. 3/8" plate thickness will not develop much moment. 3.25" bolt embedment into existing concrete is inadequate.

BA

 

[JLNJ]

It’s about a 50-step process. None of the steps are particularly complicated or difficult, whether you use the AISC Design Guide or not. You start with the wind pressure and follow the load path into the dirt.

Which steps are you having trouble with? This forum is helpful with “I’m having trouble with this particular aspect” type of question and less interested in answering the “I have no idea what I’m doing please lay it all out for me in simple terms I can copy” requests.

 

[ac0609]

s

the height is 5.5'. its elevated 7' from the concrete.