Lynnyk G. Recovery of Exploitation Resource and Increasing Bearing Capacity Span of Railway Bridges

The object of the investigation is metal span constructions of railway bridges. The subject of the research is restoring operational life and increasing bearing capacity of metal span constructions of railway bridges. For solving the problem there were used the experimental methods with using up-to-date tensiometric complex, diagnostic complex of acoustic emission, analytical methods of building mechanics and elasticity theory, methods of numeral mathematic modeling mode of deformation of the explored constructions with using the method of final elements. In the dissertation there were researched the reasons of degradation of metal span constructions of railway bridges and there was accomplished the scientific search of ways to increase their operational life and load-carrying ability. There was defined the influence of bridge floor on load-carrying ability, durability, operational life of metal span constructions of railway bridges; there was theoretically and experimentally researched the effectiveness of bridge floor construction on reinforced-concrete slabs combined into cooperation with beams of carriage way of the span constructions. By results of laboratory and full-scale explorations of ways of retardation of splits it was established that the most effective way to restore the operational life is the way of welding the splits with later high-frequency mechanic forging. By results of the theoretic investigations of mode of deformation of the system “slab-padding layer-beam”, there was substantiated the optimum tension force of studs that effectively increases work in terms of cycle loadings and increases operational life of the constructions. The results of the dissertational work were used in the development of sectoral normative documents of the Ukrainan Railway. The field of application of the work results is the capital repairs and reconstruction of metal span constructions. In experimental research there were used the devices of defectoscope acoustic-emission complex “GALS-1” ZAT UkrNDINK № 022-041; multichannel complex MGCPlus №801093116; tension testing machine R-5 and hydro pulsating machine CM-10pu.