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

The article deals with the issues of vehicle traffic safety on artificial constructions. Ensuring safety in the field of rail transport is an essential element in the activities of all subjects of the market of railway services, including passenger carriers. To fully study the issues of the deformed state of beam superstructures, it is necessary to conduct static and dynamic tests. Before the start of the tests, it is mandatory to check the technical condition of the artificial structure: 1) visual inspection, special checks with verification of necessary parameters; 2) carrying out control linear measurements; 3) selective determination of concrete strength by non-destructive methods. First, the static tests is conducted to determine the total deformations of each beam of the superstructure at the control point with maximum deformations of ½ L. Then dynamic tests with determination of periods of natural oscillations and deformations (stresses). Processing of the results of surveys and tests of the overpass with an assessment of the possibility of passing design loads on the road bridge, after which a dynamic passport of the transport structure is compiled. The study of the stressed state of vehicles gives a clear idea of the causes of deformations in the structural elements when analyzing the work of the span of the automobile bridge in conditions of increasing axial loads and traffic flow speeds. Deformation processes lead to defects, structural failures and accidents on the vehicle, which leads to premature wear, material damage and environmental damage. Periodic measurements of deformations (stresses) of the superstructure structure over several years will make it possible to predict changes in its condition over time and determine the remaining resource in terms of load-bearing capacity and load capacity. As a result of experimental studies, it was proved that the presented technique, developed in the classical version for detecting structural defects between a single-layer coating and a base of various types, can also work effectively in the case of non-destructive testing of multilayer structures