Importance factor for wind loads Asce-7-10 Etabs2013

[ayelamayem77]

Dear all,

[highlight #FCE94F]The wind speed in ASCE-7-10 is given at the strength level value. This differs from previous editions
of the ASCE Standard where service level values were used. ASCE 7-05 design wind
speeds are multiplied by (1.6)^0.5 to convert to ASCE 7-10 design wind speeds. ASCE 7
Table C26.5-6 provides a listing of design wind speeds and their converted values.
Also, previous editions of the ASCE Standard used an importance factor to provide
enhanced performance for those facilities assigned to a high risk category. ASCE 7-10
achieves the same objective by using a probabilistic approach with three wind speed
maps provided for buildings with different risk categories. An increased return period
provides enhanced performance for those facilities that constitute a substantial public
hazard because of high levels of occupancy or because of the essential nature of their
function. The design wind speed return period for each map is based on the risk category
assigned to the building and the importance factor is eliminated[/highlight]

My question:

Why Etabs2013 requires an importance factor in auto lateral wind load when selecting ASCE-7-10 code???????

 

[ayelamayem77]

Dear all
please help me to find an answer to my question , maybe i miss-understand something.

 

[ayelamayem77]

i found the answer, referring to ASCE-7-10 Table 1.5-2 Importance Factors by Risk Category of Buildings and Other Structures for Snow, Ice, and
Earthquake Loads
Iw FOR WIND = 1 FOR ALL RISK CATEGORIES