Base shear, one story no roof.

[Ceaugu]

What dead weight or which walls do you account for the base shear in a masonry enclosure.(eg for a cooling tower) that basically is four walls 12ft height +/- and no roof at all?

 

[DaveAtkins]

If this is on the ground, the base shear is zero--there is no diaphragm to accept any base shear. Each wall transfers its own seismic force directly to its foundation.

If this is up on a roof, all the masonry weight contributes to the base shear.

DaveAtkins

 

[whyun]

For four sided masonry structure with no roof, wall parallel to the seismic load direction has seismic effect from its own weight in addition to the seismic effect from the perpendicular walls.

Alternately, all walls may be designed as a cantilevered fence wall.