Friendly debate in our structural design group:
Do you consider roof ballast as part of the Effective Seismic Weight?
-some say yes, since it IS a dead load and their are no caveats/exclusions for it per code.
-some say "maybe not" since it may act like ball bearings (i.e. not stay put in their original location) during a seismic event and thus not fully contribute to the pendulum/oscillating momentum of the structure.
Anybody seen any texts refer to this or have an opinion of their own?
Thx.
Do you consider roof ballast as part of the Effective Seismic Weight?
-some say yes, since it IS a dead load and their are no caveats/exclusions for it per code.
-some say "maybe not" since it may act like ball bearings (i.e. not stay put in their original location) during a seismic event and thus not fully contribute to the pendulum/oscillating momentum of the structure.
Anybody seen any texts refer to this or have an opinion of their own?
Thx.