Problem 86 Seismic Design of Building Structures Lindeburg 8th

[tenguy23]

In question 86(b) for the "East-west earthquake," why doesn't the solution consider the participating weight of he 25ft portion of wall between points A1 and A2? This wall is perpendicular to the direction of earthquake and I would imagine it would be similar to the "North-South" and how they included half of the perpendicular wall on line 2.

 

[tenguy23]

To clarify, This question is in regards to the 11th edition of the SDBS (not 8th)