Metal Building / Pre-engineered Building Reactions
Metal Building / Pre-engineered Building Reactions
(OP)
Hello All,
Please see the following question, I am copying this from another thread (posted by Ciphere) where it was not answered. I have the same question and trying to find an answer.
"I am designing foundations for a PEMB designed with MBS software (Dr. Dean Jorgenson, et al). The MBS reactions data contains a table entitled "RIDGID FRAME: Basic Column Reactions" and another table entitled "ENDWALL COLUMN: Basic Column Reactions". A (small) separate table is entitled "Building Bracing Reactions". I am trying to determine if the bracing reactions are already included in the Basic Column Reactions, or if they should be added to the Basic Column Reactions to determine the loads imposed on the foundations. I would appreciate any insight / experience in this matter."
-Xam
Please see the following question, I am copying this from another thread (posted by Ciphere) where it was not answered. I have the same question and trying to find an answer.
"I am designing foundations for a PEMB designed with MBS software (Dr. Dean Jorgenson, et al). The MBS reactions data contains a table entitled "RIDGID FRAME: Basic Column Reactions" and another table entitled "ENDWALL COLUMN: Basic Column Reactions". A (small) separate table is entitled "Building Bracing Reactions". I am trying to determine if the bracing reactions are already included in the Basic Column Reactions, or if they should be added to the Basic Column Reactions to determine the loads imposed on the foundations. I would appreciate any insight / experience in this matter."
-Xam





RE: Metal Building / Pre-engineered Building Reactions
Longer answer: When not sure either ask the PEMB Designer (good luck) or just combine them in the most conservative way.
RE: Metal Building / Pre-engineered Building Reactions
Dave
Thaidavid
RE: Metal Building / Pre-engineered Building Reactions
Jim
RE: Metal Building / Pre-engineered Building Reactions
It makes logical sense that the bracing loads (likely coming from wind or seismic in one direction) and the portal uplift (coming from wind or seismic in the perpendicular direction) shouldn't need to be combined. But there's diagonal cases, direct uplift (on the roof) among others, so without any guidance I'd add them together.
RE: Metal Building / Pre-engineered Building Reactions
Thanks for your valuable suggestions. I did call the building manufacturer and talked to them. Turns out that they included the Bracing Reactions in the Basic Column Reactions table, and they suggested to use bracing reactions as Zero "0". The bracing provided in this case is X-Bracing.
There are multiple wind loads (WIND_LEFT1, WIND_RIGHT1, WIND_LEFT2......) given in this table, and I am trying to use Factored Load combinations (1.4D + .....) from ASCE 7-10. Can anyone provide some input or share their load combinations so that I can learn the acceptable design method? I am trying to accommodate only one wind load in a combination but not using multiple wind loads in a combination. Generally, do anyone use two or more wind loads adding into one combination? My foundation is a Shallow Foundation with a grade beam tying into it. Please let me know if this question is not clear to anyone.
Thanks!
RE: Metal Building / Pre-engineered Building Reactions
Foundation and Anchor Design Guide for Metal Building Systems 1st Edition - Alexander Newman