Structural evaluation of a GFRP truss girder for a deployable bridge

Lightweight for transport facility and reduced assembling and erection time are the main requirements to deployable bridges for emergency purposes which can be easily satisfied by using GFRP profiles. A reduced scale model of the truss girder component of a thirty meters span bridge has been tested in laboratory. The prototype bridge is composed of a GFRP grid floor deck supported by prestressed truss girders which are mounted by assembling GFRP tubular profiles and steel joints with bearing type connections. Structural tests first focused on the behavior of a 13 m span simply supported truss girder model fabricated in the reduced geometric scale 1:2.3. This paper presents the description and the results obtained from numerical modeling and from experimental tests performed on the truss girder assembled with three distinct connection details between GFRP tubes and steel joints. The experimental results showed that improved performance of the connections make the proposed conceptual design plainly appropriate to be used as truss girders of a new concept of composite deployable bridge that can carry heavy vehicle loading.