The substructure module built into OpenBridge seems to analyze an abutment wall stem as a column. A toggle would be useful to consider it more like a wall in some instances. The magnitude of vertical load on an abutment stem can often be insignificant, whereas reinforcing would primarily be designed for the bending moment caused by forces like earth pressure. Distributing main reinforcing around the perimeter and requiring minimum column reinforcement with ties is not a conventional scenario in many cases (often heavy reinforcement on the rear face and shrinkage reinforcement on the front face).