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[avnishpoddar88]

why Structurally, the best position for the shear walls is in the center of each half of the building?

[Dr. N. Subramanian]

Dear Er Avnish


The best position for shear walls are at the ends of the building and not at the center of buildings.

Best wishes,
NS

[avnishpoddar88]

Good Morning Sir,
     Thank you Sir,as per my knowledge , i know shear wall should be located at the ends of building. but  i studied few journals in which they written "structurally, the best position for the shear wall is the center of each half of the building". so i cant justify myself thats why i asked this question in this forum.

Best Regards
AvnisH

[Dr. N. Subramanian]

Dear Er. Avinash


Ours is a Democratic country. Everyone has a right to tell his opinion. But we must follow only the right one!

Regards
NS

[VPandya]

Dear  Dr.  Subramanian,  
This is a side issue but it is a common practice in USA to use High -Rise Building  Elevator  Core  Walls  as  SHEAR WALLS . I do not think that is a common practice in layout of High-Rise Building framing  in India, Why ?    


Regards.


Vasudeo  Pandya P.E.
Structural  Engineer  

[Dr. N. Subramanian]

Dear Er Pandyaji

Yes. The box type core walls around lifts and staircases can effectively function as shear walls. In India they are not designed as shear walls(not in all cases) and are having infill walls. They can also resist the lateral loads to some extent, provided they occupy a bigger area.

Warm regards
Subramanian

[arunangshu]

In my opinion, irrespective the demography of the structure, following points are kept in mind while placing the shear walls:

1. When placing at the the ends, one needs to ensure symmetry with respective to the plan geometry of the structure - else torsion will be a headache. Many times we do not have the privileges to provide the walls symmetrically due to various Architectural constraint.
By means of symmetry, one should not be very strict on the exactly same length and exactly similar position - can be distributed too.

2. While placing at the ends or periphery of the structure, it may impact the facade hence overall aesthetics - again architectural concerns are important here.

3. Both of above can be avoided when we place the shear walls  in the centrally located lift cores/stair cores. Least architectural concerns and reduces the torsional possibilities.

Dr. Subramanian, please rectify me if wrong. Many thanks.

Best regards
Arun

[Shahid Goundi]

I agree with Dr Subramanian Sir, Structurally it is advisable to provide shear wall at periphery of the building. However Inner core such as Staircase and lift cores can be treated as shear wall provided those are connected by slab.
I have seen in many  projects that the central cores have lots for opening around the walls for MEP services and those walls are not connected with the diaphragm. My senior advice me, walls which are not connected by diaphragm cannot be considered as shear walls.
Design of diaphragm is also equally important. While modeling the  structure in etabs we assign slab as rigid diaphragm, but not many people check whether the diaphragm is rigid or flexible. In IS 1893:2002 cl:7.7.2.2 mention the check for rigid and flexible diaphragm.

I deal with precast structure and we design diaphragm as per PCI and ACI guidelines , we provide chord and collector steels as per the diaphragm design around shear walls and at the periphery of the diaphragm.
I don't know whether this practise is followed for CIS design in india.
Many of my friends who are working in various consultancy say that they don't do diaphragm design and the simply develop the slab reinforcement in shear walls. But I feel there should be clause for Design of Diaphragm in IS codes