Good Day,
I have been experiencing some difficulty as it relates to the design of some shear walls I wish to use for a staircase I am currently modelling in staad. I have attached the staircase model, in which I have utilized plates (to represent the waist and steps of the stairs and the roof of the structure) and surfaces (to represent the walls). I used Staad concrete design to complete the shear wall design, however, the walls are not being designed with one layer of steel due to the 'large' out of plane moments as reported by Staad; if I use two layers then the design can be done using the same ACI code. This is strange as my hand calculation have indicated that 1 layer is sufficient as the forces (shear, in-plane moment, out-of-plane moment, axial loads) experienced by the walls is small. It is also strange as I have used STAAD to complete other wall designs with one layer of steel and the same wall thickness which were subjected to considerably greater force demands than this wall. Any assistance on this matter would be greatly appreciated.
communities.bentley.com/.../Shear-wall-design-_2D00_-ACI.zip