INTERACTIVE GRAPHICS TOOL FOR STRUCTURAL ANALYSIS AND DESIGN OF CONTINUOUS PRESTRESSED BEAMS ACCORDING TO NBR 6118/2014

Resumo

Nowadays, prestressed concrete structures have been increasingly used for covering long
spans due to several advantages over conventional reinforced concrete structures. In the design of such
structures, a fundamental step consists on the structural analysis to obtain the loads generated by the
prestressing. There are few commercial software, however, that allow the analysis of statically
indeterminate prestressed structures, such as continuous beams, widely used in bridges. In this sense,
the current work presents an interactive graphics software developed in MATLAB, which allows the
analysis of continuous beams for any cable layout. The analysis step is based on an association of the
force method, used to obtain the equivalent loads generated by prestressing, with the direct stiffness
method, used to obtain displacements, support reactions and diagrams, generated by the prestressing and
other user defined loads. The software also allows to obtain the stresses generated by different load
combinations over sections throughout the length of the beam, which can be used for performing
structural checks according to NBR 6118/2014. In order to verify its correct functioning, results of tests
carried out with several beams models are presented, varying the number of spans and the cable layout,
which were compared with values obtained with a commercial finite element software. The results were
satisfactory and show that the developed software is a useful and easy-to-use tool that can be used by
engineers, teachers and students of the area.