...
Answer: While a true integral bent is fully fixed, Software CSI software allows the connection to have free DOF. The software connects fixed bearings to the top and bottom of a girder to model fully integral bents and abutments.
Some special cases exist, however, where behavior is more closely simulated with bearings which are not fully fixed. An example may be a steel box girder connected to superstructure girders through shear-only connections. This allows longitudinal girders to rotate relative to the cross girder, necessitating free DOF assignment within the support condition. The links used to model an integral-girder support condition for a steel-girder deck section composed of shell elements are shown in Figure 1:
