Page 384 - Advanced Design Examples of Seismic Retrofit of Structures

Example of a Steel Frame Building Retrofitted Chapter 5 349

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FIG. 5.26 Soil pressure in the retrofitted sports building by concentric braces (kg/cm ).
(A) 0.75DL+0.75LL+0.75EX+0.225EY. (B) 0.75DL+0.75LL+0.75EX 0.225EY. (C) 0.75DL
+0.75LL+0.75EY+0.225EX. (D) 0.75DL+0.75LL+0.75EY 0.225EX.

of the main building are vulnerable. The required reinforcement of the founda-
tion is higher than that in the buildings retrofitted with concentric braces.

5.10.3 Crossed Braces

The behavior factor of the buildings with crossed braces is the same as for
the buildings with concentric braces. However, according to Standard 2800
[2], the buildings with crossed braces should be designed against 1.5 times
of the designed seismic actions. This causes larger brace profiles compared with
concentric braces. In this method, the columns of the building adjacent to the
braces need to be retrofitted; however, other columns of the building are not