When can I design a boundary element of a shear wall as a column? Is there a link to a solved example? Help please.
We usually design boundary elements of concrete shear walls in multi- story buildings as columns.
The stirrups and ties in the end of the wall allow strengths and ductility past the plastic limit of rebars. they do this task in two ways.
They hold the concrete together even after great lateral forces have caused huge hammering strikes causing large cracks in concrete, thus giving the occupants more time to exit the building before collapse.
They also define a clear path for earthquake vibration sparing the vulnerable parts of the structure.
It is all about the stress limits of the wall material - compression, shear, and tension, as shown in the sketch below. Another particular concern, for a short wall, is the limit on the lateral displacement (wall rigidity/flexibility), which is a crucial concern in tall buildings. (Note, for a slender wall, buckling may occur prior to compression failure)
Depends on the wall material (wood, masonry, reinforced concrete), each structural design code has its own requirements/guidelines on the design of the shear wall (with or without the boundary elements) that you shall familiar with. You can google the subject "xxx shear wall design" to bring up quite a lot of examples on the design of walls under the specified material (XXX).