Page 228 - Advanced Design Examples of Seismic Retrofit of Structures

Example of a Steel Frame Building With Masonry Infill Walls Chapter 4 221

TABLE 4.8 Live Loads

kg
Load
Item m 2
Classrooms 3500
Corridors 500
Office rooms 250
Public rooms without fixed chairs 500
Roof 150

(A) (B)
FIG. 4.13 Cradle-type connection. (A) An example (Permission from DRES). (B) Details.

Connections
The beam-to-column connections in example building are cradle-type as shown
in Fig. 4.13, which is considered as a simple connection. In order to determine
the stiffness of the connection, the method according to Karami [15] is used.
Based on the recommendation of Moghaddam [16], the torsional stiffness of
the cradle-type connections is approximately 900tonm/rad. For modeling the
connections, an arbitrary 10cm beam element with circular section is used.
The diameter of these elements is determined based on the aforementioned
assumed torsional stiffness.
s ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
r
ffiffiffiffiffiffiffiffiffiffiffiffi
5
GJ πd 4 4 32k θ L 4 32 900 10 10
k θ ¼ ,J ¼ ! d ¼ ¼ ffi 10:5cm
L 32 πG π 0:4 2 10 6
Infill Panels
In-Plane Direction In the model of the example building, the effects of infill
walls are considered as compressive-only diagonal strut as per ASCE 41 [1].