Seismic Design -- Extreme event and Extreme event Seismic

Document Information

Document Type: FAQ

Product(s): LEAP RCPIER/Substructure

Version(s): All

Original Author: Bentley Technical Support Group -VM

QUESTION: While doing seismic design , what is the difference between Load groups Extreme event and Extreme event Seismic ?



Extreme Event  -- No plastic hinge condition is applied but still the EQ is applied .

Extreme Event Seismic --  EQ load is applied along with the Plastic hinge condition.

Seismic load group in LFD and Extreme Event Seismic in LRFD is a special group which should be defined and used in conjunction with EQ loads when the plastic hinge moments for column need to be computed and used for design of cap and footing.  When such a load group is defined and selected for analysis and design, program generates a separate envelope for it. When column design is done, program also determines the plastic hinge moment in columns. When cap and footing design is done, it considers the column plastic hinging moment into account and does a separate check for this special load group responses.