base plate with large moment

[senthil83]

i am designing a column base plate with large moment as per aisc design guide -1,

P = 2000 kn
Mu = 5000 kn-m

due to higher moment, i am getting very large base plate dimension to satisfy inequality eqn.

how to reduce it?

regards,

 

[clarke1973]

Your question is not very clear. Are you trying to reduce the base plate size (thickness?) or the moment itself?
adding stiffeners will help reduce the base plate thickness, depending on the arrangement. would recommend attaching a sketch to give a clearer picture

 

[klaus.]

5000 kNm is a very high Moment
guess you need a special base plate structure....not just a plate


best regards
Klaus

 

[JedClampett]

Still the best reference for this is Blodgett, "Design of Welded Structures."
But better than designing for it is changing your analysis so that the moment is reduced or goes away. Unless you have a cantilever, can you assume a pinned base and throw the moment elsewhere?

 

[Shu Jiang PEng SE]

If the lateral load on the column is 25% percent of the vertical load, that is 500kN. The connection between the column and the beam should be kind of moment connection. You can derive the column height of more than 10 meters. You are sure that the correct load on the column?

 

[Yao1989]

What is the application of this baseplate?

 

[BAretired]

Declare the joint to be hinged, then the moment is zero.

BA

 

[SM3225]

Is your column a regular wide flange shape column or a different one viz. cruciform column etc...?
You may please refer to the wide variety of suggested base plates appropriate for the mentioned range of heavy loading available in the Book titled "Design Of Welded Structures by Omer W. Blodgett" ...
Finally it should be a trade off between fabrication cost versus material cost, as adding stiffeners increases fabrication cost like anything.

Nevertheless, It would be prudent to perform one quick review of your analysis results, especially any feasible alternative which could have a bearing on your final joint reaction for instance adding a few braces here & there etc.

Regards,
SM