bruinboy
Structural
- Jun 15, 2004
- 15
Hi,
I'm trying to design the column base plate for a residential moment frame. The foundation is an 8" by 29" grade beam with 3-#5's top and bottom on piers. The column is subjected to a 13 kip axial force and a 17 kip moment which seems to have a pretty high eccentricity of 15 inches (this is from a lateral EQ load using a 1.0 factor). I'm using an example from page 22 of the Errata for AISC Design Guide 1: Column Base Plates that I downloaded for free off the internet. Unfortunately, I couldn't get access to the whole thing. My question is, to find the length "A" in that example, what do the different numbers in that equation refer to (specifically the 4(2.1 x 14)/6 and also the (2.1 x 14)/3))? I'm getting some wierd numbers for my tension force. If increasing the size of the grade beam width is not an option, is shaping the base plate into an upside down "u" and bolting through the grade beam acceptable? Problem with that is there still may not be enough concrete area for bearing. Does everyone use UBC Table 19-D for the bolt strengths? Thanks for all the help.
I'm trying to design the column base plate for a residential moment frame. The foundation is an 8" by 29" grade beam with 3-#5's top and bottom on piers. The column is subjected to a 13 kip axial force and a 17 kip moment which seems to have a pretty high eccentricity of 15 inches (this is from a lateral EQ load using a 1.0 factor). I'm using an example from page 22 of the Errata for AISC Design Guide 1: Column Base Plates that I downloaded for free off the internet. Unfortunately, I couldn't get access to the whole thing. My question is, to find the length "A" in that example, what do the different numbers in that equation refer to (specifically the 4(2.1 x 14)/6 and also the (2.1 x 14)/3))? I'm getting some wierd numbers for my tension force. If increasing the size of the grade beam width is not an option, is shaping the base plate into an upside down "u" and bolting through the grade beam acceptable? Problem with that is there still may not be enough concrete area for bearing. Does everyone use UBC Table 19-D for the bolt strengths? Thanks for all the help.
