Abstract:
In the present study, a practical approach is proposed for geometric nonlinear analysis of existing
steel bridges. The approach is defined by finite element displacement direct rigidity procedure,
which is based on an iterative procedure. Tangent rigidity matrix is used for cable truss and/or
framed steel structures formed by finite elements. Hence, effects of prestressed cables in system
rigidity can be taken into account in the analyses. Moreover, stressing effects on cables are taken
into account with equivalent temperature change. The research has three main parts. In the first
part, prestressed cables are investigated for capacity increase for steel bridges. In the second part,
an iterative procedure is proposed for existing steel bridges that can be used for geometric
nonlinear analysis. In the third part, a representative bridge is modeled and analyzed. In the
model, first, the representative model is analyzed as it is existing form and then, it is analyzed
with prestressed cables in two different forms. So, three different results are investigated for their
structural behaviors. In the analyses, geometric nonlinear behavior is investigated and results are
evaluated. As a result of the study, capacity change by using stressed cables is defined for existing bridges.
