In a refurbished steel mill, the crane girder itself is used as the top cho
rd of a supporting Pratt truss. Subsequent to rehabilitation the crane load
s are increased and, to assess the capacity of the truss, non-linear increm
ental finite element analyses are carried out. These show that all members
are satisfactory, attaining safety ratios greater than 1.00. The safety rat
io is the load in a member, at any step of the analysis, multiplied by the
resistance factor for steel members and divided by the factored load the me
mber must sustain. The inelastic analysis shows that the truss action domin
ates and that the only bending moments to be considered are those introduce
d by joint and out-of-plane eccentricities. At the limit point, a particula
r member, without eccentric moments, can be taken to be axially loaded with
pin ends. Failure of a shear diagonal in a panel does not lead to collapse
of the truss because the surrounding panel members carry shear by vierende
el action. Code analyses are quite conservative. (C) 1999 Elsevier Science
Ltd. All rights reserved.