1. Do not
underestimate the importance of the loading shape
function.
•The loading or deformation shape function is selected to
represent the predominant dynamic mode
shape of the building.
•Quite often, an inverted triangular shape is used
consistent with the codified static lateral
force distribution.
•It is most common to keep the load shape constant during the push.
•Use of adaptive load shapes is on
the increase.
•No consistent guidelines exist for definition and
application of adaptive load functions
exist.
•Loading shape importance increases for tall buildings
whose earthquake response is not dominated
by a single mode shape.
•For these buildings, a loading shape function based on
the first mode shape may seriously
underestimate the seismic demand on the intermediate
floor levels.
•
