APPLICATION OF WELDED STUDS FOR FASTENING OF RAILWAY BRIDGE DECK

摘要

Proposed is a new structure of fastening of slabs of ballast-free bridge deck to T-girders of railway bridges, which provides for change of thread studs to welded ones. Arc-contact welding allows for stud positioning directly over vertical wall of T-girder that does not result to angular deformation of girder upper flange typical in application of thread studs. Aim of present work was evaluation of possibility of application of welded studs for fastening of slabs of ballast-free bridge deck in construction and repair of railway bridges. For that, fatigue tests of welded joints of stud to upper flange of girder from the most wide-spread steels St3sp (killed) and 09G2S were carried out at different ranges of loading, which are realized in stud preliminary tightened with. 6 tf force during rolling stock movement. It is determined that cyclic life of such joints exceeds 5·10 cycles of stress alternation at loading range ΔP ≤ 3 tf. Numerical simulation showed that application of oak board and rubber band as spacing layer between slab of ballast-free bridge deck provides for cyclic life of welded stud not less than 5·10 cycles of stress alternation, since loading range exceeds ΔP = 3 tf. However, application of fast hardening nonshrinking mixtures (cast-in-place concrete) as spacing layer allows reducing range of loading to ΔP = 1 tf, that guarantees welded stud life not less than 5·10 cycles of stress alternation.