Development of safety methods on artificial structures of railway lines

Abstract

The numerous cases of deformation of technogenic objects in the transport industry under increasing axial loads and speeds of motion aggravate the need to solve the problems of early recognition of the nature and causes of deformations of structural elements. The need for this is due to the fact that destructions and accidents, resulting from deformation processes, cause enormous economic, social and environmental damage, incomparable with the funds spent on protective measures. The object of the study in the article is a railway trestle, consisting of two spans of a ribbed reinforced concrete beam. Determination of the residual resource in terms of bearing capacity and load-carrying capacity of the railway trestle is the main task. The authors have obtained bending deformations (stresses), frequencies of natural vibrations and operating modes of structures of railway trestle spans. The damage degree of the railway overpass spans structures may also be judged by the deviation of the calculated values of the amplitude-phase-frequency characteristics (AFFR) from the standard values. The peculiarity of this research is the fact, that the natural frequencies of railway overpass vibrations are determined either by «tails» of experimental vibrograms (oscillograms) after the load release from the span structure. During the express-diagnostics of railway overpasses, the relative deformations (stresses) of girder spans in the middle of the span, the first frequency (period) of natural vibrations of girder reinforced concrete spans of railway overpasses are used as parameters characterizing the technical condition of the spans. The results of tests and examinations of overpasses to ensure their safe operation have been given