The paper presents data on the prevalence and service life of solid piers of railroad bridges of the Russian Railways. The dynamics of solid pier damages, the development of normative documents on assessing their technical conditions and durability, and methods of assessing the residual life of bridge structures are shown herein. Information on the threshold values of failure is also given. The residual life of the intermediate masonry support is analyzed and estimated using two standard techniques. Their similarities and differences are determined and their limitations are compared. Proposals are made to clarify the damage parameters described in the current normative document for assessing the technical condition of railway structures. For statistical data processing in relation to bridge damages and prediction of their development, a model is proposed on the basis of semi- Markovian process. Possible data sources for constructing such a model are indicated. An alternative model for estimating the reliability of bridge structures is shown.

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The purpose of this article is to create a methodology for determining the design strength of rubble masonry of bridge supports meeting the modern safety requirements for transport structures. The article contains data on the use of the rubble masonry in solid supports of railway bridges. Development of methodology of determining the permissible stresses on the rubble masonry, and the practice of applying the design strength of the rubble masonry in regulatory documents are considered. Analysis of the research works is carried out, according to which the design strength of the rubble masonry of solid supports is determined when calculating the load-bearing capacity. The experimental data of European scientists in the field of determining the strength characteristics of stone masonries are considered. A domestic method for determining the design values of strength characteristics for building materials used in transport construction is presented. The main deficiencies of the existing method for determining the design strength of rubble masonry are defined and suggestions are made for its clarification. The article concludes with the formulation of tasks required to be solved for clarification of strength characteristics of the operated railway supports made of rubble masonry.

The article discusses the interaction issue between the track and the rolling stock to determine the forces working on the track during the passage of a rolling load, and their further distribution through the ballast bed. The study aims to determine the vertical pressure profile working on the orthotropic metal ballast bed slab of the railway superstructure. To determine the load share from the rolling stock transferred from the rails to the cross-sleepers, the rail is represented as a beam of infinite length with one or several concentrated forces. To determine the cross-sleeper stress-strain state, it is considered as a short beam on a cushion course. The article presents the substantiation of the flow mechanics formulas application possibility to the ballast bed. Based on the Boussinesq problem solution, calculation formulas are obtained for determining the pressure along with the ballast bed plate. The results obtained by the proposed method were compared with other authors’ experimental data and the finite element modeling results in the Midas FEA software package. The analysis took into account the design features of the ballast bed plates and the track superstructure on the existing superstructures. A theoretical study of the influence of the sheet of the covering bending stiffness on the pressure profile northing is carried out. The proposed method is applicable for various superstructure and the ballast bed slab, and also takes into account the uneven pressure distribution on the inner and outer rails from the trainload, changes in eccentricity along the length of the structure, different thickness of the ballast bed under the cross-sleepers ends, as well as the effect of centrifugal force.