Presence of a Plinth (Subasman) in the Building

If the building to be examined or designed has a plinth (subasman), it is recommended to enter the plinth as a separate floor.

You can rename the lowest floor as the plinth floor; for example, you can set the story height to 1 m.

If you do not continue some upper floor walls into the plinth, the upper wall may crack if its base does not rest on a foundation or wall.

If you are using Version 7, you can enter reinforced concrete plinth shear walls as reinforced concrete basement shear walls.

If you are a Version 5 or 6 user:

If the walls are reinforced concrete shear walls: in the wall properties, set the wall unit weight = 2500, modulus of elasticity = concrete modulus of elasticity, fk = fck, safety factor = 1.5, fvko = 0.65*fctk, and check the reinforced wall checkbox in wall properties. You can let the program select the reinforcement or you can specify the reinforcement you want and consider sufficient. If the reinforcement is specified by the user, the adequacy of the provided reinforcement is checked in the calculation reports.

On the plinth floor (and other floors), the tie beam height above the wall must always be less than the story height. Otherwise, wall stiffnesses will become undefined, which may cause errors during analysis.

Plinth shear walls should be entered as wall elements, either reinforced or unreinforced.