Structures with Basement (4.3.2.3)
In buildings with basements surrounded by rigid bulkheads as required by 4.3.2.3 , (R / I) = 2.5 and D = 1.5 are taken automatically for the lower section.
ICONS
D = Strength Redundancy Coefficient
I = Building Priority Coefficient
R = Structural System Behavior Coefficient
As shown in the example below, in buildings with basements surrounded by rigid walls from the outside, (R / I) = 2.5 and D = 1.5 in the sub-sections with basement floors.
![](../__attachments/1088062024/image-20200619-082538.png?inst-v=f19fc7cc-758e-4997-b5f0-444a3286777e)
Modal Response Spectrum Analysis of Structures with Basement Internal Design Force of Elements of Building with Basement