• composite bridges
• erection techniques
• incremental launching
• launching nose
• linear buckling analysis
• nose-deck interaction
• patch loading
• RTM method
• steel tub girder bridges

This thesis deals with the erection project of a composite girder bridge, by means of the incremental launching technique. After a detailed description of the main erection techniques regarding girder bridges (prestressed concrete, steel and composite bridges), the attention is focused on incremental launching, describing the most typical features and problems of this construction method, especially for composite bridges. Afterwards, a practical example is analysed, concerning a 310m-long steel tub girder bridge, with a varying depth concrete slab, incrementally launched from one abutment towards the opposite one (consisting in the construction of deck segments behind the abutment alternating with the launch of the whole deck section), using a steel trussed launching nose. The optimization of the nose-deck interaction is carried out, and the calculation of stresses in the superstructure during launching is performed by means of a special spreadsheet developed for this purpose, based on the reduced transfer matrix method. Finally, strength and stability verifications of the superstructure are accomplished, using a linear buckling FEM analysis, and the patch loading problem is described and discussed.