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[nishants.iitk]

IS 16700 ammendment (2019) Table 1 states two types of combined systems:
1. Structural Wall + Perimeter Frame
2. Structural Wall + Moment Frame

For Structural Wall + Moment Frame IS 16700 Clause 8.4.2 states, it needs to be designed as dual system. The code specifically does not mentions the same for Structural Wall+Perimeter Frame. A research paper also highlights this issue Link Here
Please suggest your opinion if Structural Wall +Perimeter frame should be designed as dual system or not?

[hemalmistry]

Clause 8.4.2 does not require structural wall+moment frame system to be designed as dual system.

Structural wall+moment frame system or structural wall+perimeter frame (without flat slab/slab-column frame) system may or may not be dual system and response reduction factor "R" shall be selected accordingly.

However, if structural wall+perimeter frame system is having flat slab/slab-column frames, structural walls and perimeter frames shall be designed for 100% and 25% of base shear respectively with seismic drift of building limited to 0.1%.

Regards,
Hemal Mistry

[pvgraju]

In structural wall and moment frame system both structural wall and moment frame both contribute  moment shear axial load etc. so both active. so dual syatem.

in structural wall and perimeter frame generally structural wall contributes more. Perimeter frame for holding the member only. So designing as a dual system is not required. If perimeter frame is also contributing more it is to be designed as a dual system.