The result of defining a point spring is a single spring at a finite element node. The result of defining a line spring is one or more line springs that are each located at a finite element edge. RAM Concept uses the thickness of the lowest numbered element in determining the spring elevation. For this reason, it is not advisable to locate springs at slab steps.

All springs that have a horizontal stiffness should be placed at the mid-depth of the slab or they may cause an unintended arch action in addition to their horizontal stiffness (mid-depth placement is done by setting the "Elevation above slab soffit" to be one-half of the slab depth). For slabs with varying centroid elevations, it can be difficult to avoid adding a rotational restraint to the slab when using lateral springs and supports.

Normally there is no need to use horizontal springs, as RAM Concept automatically stabilizes the structure in the x- and y-directions (you can turn this automatic stabilization off in the General tab of the Calc Options dialog box). One situation where you might use a horizontal spring is a structure braced against sidesway but modeled without bracing members (perhaps soil friction provides the bracing).

Be very careful about specifying anything but a z-force constant. R- and s-force constants could result in membrane action.