Shearwall Modeling

[CTSeng]

Been modeling a group of walls, basically a square tower, in both STAAD and RAM and am not satisfied with the reactions from a lateral wind load applied at the centroid of the top of the wall group. The reactions in the direction of the applied load are correct it’s the perpendicular direction; they are equal but in opposite directions at each side of the square. They cancel each other out but why are there any at all? Also why would they differ from STAAD to RAM?

Any help is appreciated.

 

[kephamy]

The reason those equal but opposite loads are there is because the individual members in the wall will have that force imposed on them as well as the components and cladding. While this is not important to your base reactions, it is important to the structure. The two programs are probably giving you different results because of the number of area elements you are breaking your shear walls into.

 

[blihp]

without knowing the geometry this is difficult to answer, but are the walls with the equal & opposite reactions resolving a torsion induced from eccentricity between the point of load application and the centre of stiffness?