Objective: Improvement of dynamic analysis method of simple beam spans in the process of high-speed trains impact. Methods: Mathematical modeling with numerical and analytical methods of building mechanics was applied. Results: The parameters of high-speed trains influence on simple beam spans of bridges were analyzed. The method of dynamic factor to live load determination was introduced. The reliability of the method in question was corroborated by the results of numerical simulation of high-speed trains’ movement by beam spans with different speeds. The introduced algorithm of dynamic analysis was based on the connection between maximum acceleration of a beam span in resonance vibration mode and the basic factors of stress-strain state. The method in question makes it possible to determine both maximum and bottom values of main loading in a construction, which determines the possibility of endurance tests. It was noted that dynamic additions for the components of stress-strain state (bending moments, shear force, vertical deflections) were different. The fact in question determines the necessity of differential approach application to identify dynamic factors in the process of calculation testing on the first and the second groups of limit states. Practical importance: The method of dynamic factors’ determination presented in the study makes it possible to perform dynamic analysis and determine the main loading in simple beam spans without application of numerical modeling and direct analytical analysis, which considerably reduces labor costs on engineering.

Objective: To analyze calculation and construction peculiarities of bridgework at high-speed networks (VSM). Methods: Mathematical simulation, as well as numerical and analytical methods of structural engineering was applied. Results: The main peculiarities of bridge construction at high-speed networks (VSM) were analyzed in the given study. It was proved that artificial constructions at VSM operate in the conditions which differ considerably from the conditions at common railroad lines. The former include the need in continuous welded rail design along the whole length of a bridge, requirement for high stiffness of a structure; consideration of aerodynamic influence of a rolling stock, moving with high speed, on structures, consideration of “train-bridge” system’s elements interaction in order to identify resonant modes of train operation, which result in increased dynamic impact on a bridge, railway vehicles, etc. Calculation results of a “bridge- continuous welded rail” system interaction under temperature and train influence for specific types of bridgeworks multi-span beam discontinuous and continuous elevated structures were presented in the article. The influence of length, flow diagram and longitudinal stiffness of intermediate structures on force value, occurring in the rails of a rolling stock was stated. Practical importance: The description of some peculiarities of train operation at VSM bridges, which are to be considered during design engineering, were presented as well as certain measures, providing operation security and comfort of train passengers, were suggested.