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[hemalmistry]

Structural system mentioned in clause 3.12.5 (core+outriggers) and 3.12.6 (core+outriggers+belt wall) have central core as LLRS only.

(1) Can we say these structural system confirms to "structural wall (located at core)" as per Table 1 & 2 for permissible height and aspect ratio requirement?

(2) Response reduction factor for such structural system with ductile central core is 4 as per IS:1893-1-2016?


Structural system mentioned in clause 3.12.7 (framed tube) have perimeter frame as LLRS only.

(1) Can we say such structural systems (though suitable for tall building as mentioned by code) are not allowed by code as no permissible height and aspect ratio requirements are mentioned in  Table 1 & 2?

(2) What could be Response reduction factor for such system?

Structural system mentioned in clause 3.12.8 (tube in tube), 3.12.9 (multiple tube) have perimeter frame and central core as LLRS.

(1) Can we say these structural system confirms to "structural wall+framed tube" as per Table 1 & 2 for permissible height and aspect ratio requirement?

(2)  Response reduction factor for such structural system with ductile central core+ductile perimeter frame is 5 (if dual system) and 4 (if not dual system) as per IS:1893-1-2016?

Structural system 3.12.7,3.12.8 & 3.12.9 consists closely spaced column connected by deep beams.

(1) Aspect ratio (b/d) and span/depth ratio requirement of IS:13920-2016 are also applicable to these deep beams connecting closely spaced column?

(2) Ductility requirement (design and detailing) for such deep beams shall be as per IS:13920-2016?

(3) Can we say if such frame with closely spaced column with deep beams are designed and detailed as per IS:13920-2016 then response reduction factor can be taken accordingly? Generally, short span deep beams are not ductile as per IS:1390-2016.

Regards
hemal