Underground shear walls

[Mastropower]

Hello everyone,

I am currently designing a building with an elevator core acting as the LFRS (Lateral Force Resisting System). The core goes from the foundation level, which is 5-6 stories below ground level up to the roof of the building, which is also 5-6 stories above ground level. The height of the shear wall sis taken from ground level to the roof of the building.

Here is my question: when designing the shear wall, the stories that are below the ground level, must we consider the slabs at the underground levels as supports, transferring shear in the wall, or should we ignore the floor levels?

I hope this is somewhat clear.

Thanks in advance everyone.