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O86 Provisions
Section 11.8 of the O86 is somewhat convoluted. 11.8.1 "General" gives some specific seismic requirements regarding ductility, then it says for the higher seismic design categories, clauses 11.8.2-11.8.6 apply, otherwise 11.8.7 for low seismic design categories applies. However 11.8.7 says that 11.8.6 applies to these structures as well, and 11.4 and 11.5 apply with modifications. Furthermore 11.8.8 is not referred to by 11.8.1 so it applies to all structures.
Definition of High Seismic Category
11.8.1 says is SC3 or SC4 rather than SC1 or SC2, these categories being determined from IES(0.2) and IES(1.0) in NBC 2020 4.1.8.5.
These seismic categories are new to NBC 2020, and Shearwalls implements NDS 2015. In O86-14, these provisions applied if the value of IEFaSa(0.2) is equal to or greater than 0.35. Until NBC 2020 is implemented, Shearwalls will continue to use the NBC 2015 value as the limit.
Refer to NBC Provisions for the meaning of the IE, Fa, and Sa values from the NBC.
Shearwalls Implementation
Shearwalls applies the following to all seismic design
11.8.1 - Non-ductile design modes
11.8.6 - Design of force transfer elements
11.8.8 - Maximum Percentage Gypsum Wallboard
When IEFaSa(0.2) is equal to or greater than 0.35, Shearwalls applies
11.8.2 - Hold-down force amplification
11.8.3 - Overcapacity of seismic force resisting system
The following are beyond the scope of Shearwalls and not applied
11.8.4 - Light frame diaphragms on light frame shearwalls
11.8.5 - Light frame diaphragms with other than light frame shearwalls