Log Wall Out-of-Plane Design

[wel-eng.]

Does anyone have experience with designing log homes/log cabins? I understand the in-plane behavior of the shearwalls, but how should one go about analyzing and designing for out-of-plane loads on log walls? ICC 400-2017 offers little guidance on this.

Do you design the walls to span horizontally from perpendicular wall to perpendicular wall, thus not requiring out-of-plane support from the diaphragm? Or do you design it to span vertically from foundation to 2nd level diaphragm/roof, similar to a typical stud wall? I imagine the true behavior will be somewhere in between the two, but what is the standard approach here? The logs will be interlocked throughout, but I imagine the type of construction is susceptible to hinging under high wind pressures or in high seismic regions.

Let me know if anyone has any ideas.

 

[DaveAtkins]

I designed some log home walls many years ago. If the logs are continuous and can span horizontally, that is the easiest way to check them. If not , you need to check the walls in bending vertically, checking the tension in the long lag screws which are used to connect each log to the log below.

Once the load is into the roof diaphragm, you use the log walls as shear walls. They are heavy, which helps with overturning.

DaveAtkins