Post Frame Building Design
Post Frame Building Design
(OP)
Have designed post framed building before using the NFBA Post-Frame manual. All prior applications have used embedded posts so following the manual was rather straight forward. A recent job has come up with the request to have the posts attached to the concrete at grade without a fixed connection. This would result in diaphragm action being the sole resistance for frame side sway. This is very common practice as noted by many constructed projects. My question is with regards to modeling and analyzing the frames. Since the frames have no horizontal resistance (pinned at base and at top of column), what is used to keep the frame stable during analysis? The NFBA manual uses a program called DAFI that gives the diaphragm load and horizontal displacement for each frame. My only thought is to provide a spring force at the eave of the frame model which could be established based on the diaphragm load and horizontal displacement. Does this seem like a reasonable approach for design?






RE: Post Frame Building Design
Although typically one or both of the end walls have such large doors in them that they can't be counted on for shearwalls.
RE: Post Frame Building Design
Flexible diaphragms transfer load based on trib area, so shear walls are required at each wall, hence jayrod's point.
Also, the frames must be braced during construction because they are unstable without sheathing.
RE: Post Frame Building Design