Preliminary Design for Shear Wall Buildings 1

[Olivaw]

I am designing a 10-story building with 2 basement levels. When running the model in ETABS, several walls are not functioning properly. They have shear stresses exceeding the maximum allowed by the code.

I haven't been able to obtain reliable results from the model. Some walls experience excessive shear, while others experience too little. I haven't been able to get the building to function properly, despite numerous iterations.

I want to know what preliminary design method can be used for this type of buildings. I would like to be able to calculate something by hand to validate the results of the model.

EDIT: I should have specificied that I care the most for shear load distribution produced by seismic loads.

 

[GErald123]

Rigid diaphragm analysis?

https://gab.wallawalla.edu/~louie.yaw/structuralanalysis/RigidDiaphragms.pdf

 

[Olivaw]

Thank you GErald123, I made an excel spreadsheet to calculate the shear distribution.

But I haven't been able to reproduce exactly the same results as ETABS.

 

[sticksandtriangles]

Post some screen shots Olivaw, maybe we can pinpoint some of the issues.

Some things that come to mind:

[ul]
[li]Shearwall stiffnesses, for a 10 story tall building, short skinny walls likely wont abide by just ratio'ing lengths of shearwalls to determine shear loads. Flexural stiffness will dominate on the upper levels and shorter walls will likely have little shear load in them [/li]
[/ul]
[ul]
[li]2 levels of basements can yield a large "backstay effect" where your shear can reverse at the basement levels and lead to a large increase in shear demands.

https://www.structuremag.org/wp-content/uploads/C-StructPractices-Tocci-June121.pdf

[/li]
[/ul]

S&T

 

[XR250]

Man, that is some terrible use of significant figures.

 

[lexpatrie]

That embedded graphic isn't from Tocci.