EET April 17 Depth vs Goswami Depth query

PEStructureAspirant · Apr 10, 2018

Hi,

I gave the EET April 2017 depth exam & also followed Goswami Book for Structure. I found a difference in which Goswami calculates Seismic Base shear v/s EET.

In Effective Seismic weight for Base shear calculation, should the exterior wall height be considered full height or half height for single story building or multi-storied?

In EET problem 4, they have considered half wall height for exterior wall. However, Goswami considers Full Height.

Can someone kindly advise.

PowerStroke79_PE · Apr 11, 2018

Which Goswami Book is it? Is it the all in one book? Anyways, ive always only calculated half the wall of the first floor( as in the top half for the second floor), if im not mistaken, PPI does so as well. I hope more come in and talk about this, but my understanding is you use the tributary width for the diaphragms of half the length of wall above and half below. In this approach you disregard the lower half of the wall, of the first floor, because you assume it bearing on the foundation and not contributing to the frame movement at the above level. This is my understanding, i am NOT a PE. I have the Goswami all in one but used it more for the Water Resources section in the past. I will look at the structural chapters tomorrow. Can you please confirm this is the book you speak of.

PEStructureAspirant · Apr 11, 2018

Thanks Hemi. Pl refer to Goswami All-in-One, Example 116.5, Pg 331.

others Kindly pour in.

In addition, ASCE 7-10 did not mention about excluding half the wall weight. What is the common practice

tj_PE · Apr 11, 2018

Common practice is to look at the wall seismic weight as distributed between two supports - the ground and the floor above. if you look at it as a simply supported beam, uniformly loaded, half of that load would go into the ground, and therefore not be included in a base shear calculation, and the other half would go up into the floor above, which would be included in the base shear calculation.

this understanding progresses in multistory buildings when you start doing vertical distribution calculations, but above is the important part of your inquiry.