Crack coefficients.........Sway and Non sway studies

[Murali27]

I am doing a multi storey building of 20 stories as per ACI. In finding out sway or non sway stories as per aci chapter 10 we are checking that stability index is less than or equal to 0.05. Please any one confirm me that is it right to use crack coeffcients as per 10.11.1 and ultimate loads???...
Even in the study of lateral displacements, are crack coefficients used to study the same with service loads????
Any input or references would be appreciated.

 

[JAE]

10.11.1 states that Pu and delta o should be based on the reduced Ig values. This is the same Pu and delta o used in the sway/non-sway check in 10.11.4.2 (Q = (Sigma Pu x delta o) / (Vu x lc))

Pu is an ultimate load
Vu is an ultimate load
delta o is the deflection due to Vu from a first order elastic frame analysis with stiffness values per 10.11.1

 

[Murali27]

Thank Q JAE.

 

[Murali27]

JAE

What is the limit of drift ratio and drift.

say stability index value is 0.059 say and drift ratio is less than 0.0013. Can this be ascertained as non sway story. Please suggest me exactly on this situation.