drag force on rigid diaphragm
drag force on rigid diaphragm
(OP)
I am working on a single story masonry building with concrete roof(see attached sketch) . I am wondering do I need to consider drag force when design the roof (e.g. for wall 3).






RE: drag force on rigid diaphragm
RE: drag force on rigid diaphragm
If the force transferred from the diaphragm to the Wall 3 can be connected within the length of Wall 3, then technically a collector/drag strut isn't needed. I might add additional reinforcing in the roof diaphragm along wall 3 just in case.
RE: drag force on rigid diaphragm
RE: drag force on rigid diaphragm
It is true and must be accounted for in design unless a means to prevent force transfer to these walls is made.
RE: drag force on rigid diaphragm
If you don't make such provision (for partitions - non bearing) in your design, the trouble is down the road. The wall colud be removed entirely without replacement for space recongiguration/re-utilization purposes . Now which member is to carry the add'l load after the removal? How you do retrofit under concrete roof (not impossible, but costly)?
Distingusish the terms - BEARING vs PARTITION (non-bearing, intend for removal).
RE: drag force on rigid diaphragm
Not all interior walls are automatically labelled "partitions", it is up to your design. So, it's good practice to label the bearing walls on the drawings.
RE: drag force on rigid diaphragm
JAE, if I add additional rebars for drag force, where should I add them, just the stripe of the roof aligned with wall 3 or 4 with the width of the wall? Do I need add stir up since the drag force could be compression?
RE: drag force on rigid diaphragm
Mike McCann
MMC Engineering
RE: drag force on rigid diaphragm