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Civil Engineering/Stability & Shear Walls


I am busy reviewing a design for a large office block, approximately 6200m2 floor plates and 18 suspended floors. There are a number of shear/lift shaft walls that do not extend all the way down to the foundations and sit mid-span on a 300mm RC slab. The grid is 8.4m x 8.4m and the typical parking slabs a office slabs are 300mm thick. In SA we have wind loads of 40m/s and low seismic mining induced activity, with a peak horizontal ground acceleration of 0.2.

Can the designer assume that the lift shaft walls without foundations, that spring directly off a slab, will contribute to the overall stiffness of the building without having a reaction at the lowest level onto the slab supporting the wall.

Dear Micheael

The interstory stiffness is not governed by support situation especially in 2nd and upper story provided that good connections exist between slab and the shaft in each storey. Actually softwares like sap2000 and etabs calculate the shaft contribution automatically.


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Babak Esmailzadeh Hakimi


I can answer questions in Structural Engineering, Earthquake Engineering, Project Management and Project Control topics!


I am experienced in the area of earthquake engineering in electrical power industry, i.e. Lifeline Earthquake Engineering. My focus has been on structural seismic design of power installations. Recently I have got involved in project management in the category of constructional engineering.

Sinam Consulting Engineers Co.

Bs degree in Civil Engineering from Ferdowsi University ,1988, Mashhad Iran, Ms degree in Earthquake Engineering, Sharif University of Technology, 1993, Tehran, Iran

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