Bldg design for 4 stories. 1 was built. Can I rotate colmn. on 2nd?

[dassouki]

Sorry for the short title as it is limited in Number of Characters.

I do some building design on the side, here is the situation:

* According to the design plans, the building was built for 4 stories (1+3).
* I'm designing the second floor right now, however, I'd like to rotate some of the columns from the Main floor
* Actual floor plan and proposed second can be found under

http://97.107.136.148/plan_1_and_2.pdf

The columns, I'd like to rotate are the ones within the zigzag circle. On the plan is the beam layout as well

Is this possible? Any other solutions I can look into?

cheers, and thanks in advance

 

[BAretired]

The fact that it is being reduced from four storeys to two reduces the lateral forces and moments substantially. The upper columns need to resist only one storey instead of three.

But I agree that we don't have enough information to provide an accurate answer. It must be assessed properly by a local engineer.

BA

 

[dik]

BARetired raises a good point. How are the lateral loads resisted? If shear walls or stair/elevator cores, then it may be a matter of simply transferring the load through the floor plate into the column below.

Can you contact the original engineer... should be a simple fix.

Dik

 

[TXStructural]

The cost of a good structural engineer will probably be well worth it in reduction of structure required for only one more floor, or rather, roof. As a reference, look at the original top floor to understand how the top level was to be framed. That should provide an excellent start, and will likely make sure that the lateral loads are placed properly. It's all about the load path.