Abstract. Within the last decades, a considerable amount of experimental studies have been carried out by numerous researchers across the world with the purpose to study the carrying capacity of concrete-filled steel tubular (CFST) columns and evaluation of their stressed-strained state. The array of the obtained results have allowed designing a mathematical model to determine the maximum carrying capacity value of such constructions using the methods of mathematical statistics. The authors obtained three types of regression equations for short and long circular CFST columns with different geometrical and physical properties under axial compression. Statistical quality of the obtained models was verified by both regression equation quality in general and statistical significance of the equation parameters. The comparison of the obtained carrying capacity values with the results calculated by Eurocode 4 and AIJ methodologies allows making a conclusion on the sufficient calculation accuracy of the designed mathematical models.

The article analyzes in detail the results of the performed reconstruction works with the application of thermosetting polymers. The method of adhesive anchoring of reinforcement rods with fixing them in the concrete body with acrylic glue was carried out on transport infrastructure facilities (railway steam shop and railway itinerary post). It has been determined that strengthening the foundation with application of the thermosetting polymers (adhesive anchor joints) gives a significant reduction in the consumption of concrete, metal and labor costs. The advantage of such acrylic adhesives is the possibility of varying the ratio of monomeric and polymeric part (powder) containing redox system, within acceptable concentrations, without significant changes in adhesion and cohesion parameters. The obtained results are very important in practice, because in the conditions of preparation of the adhesive (especially in construction conditions) it is difficult to determine the exact number of components. The experimental research data can be used for attachment joints projecting and industrial technological lines development, as well as for further polymeric adhesive materials, widely applied in industrial and civil engineering, improvement.

Experimental studies of rectangular steel-concrete columns under centric compression with random eccentricity were conducted. The stress-strain state and the carrying capacity exhaustion have been assessed. The regression dependence is proposed to determine the maximum carrying capacity of such columns. The mathematical model takes into account the combined influence of the physical and geometric characteristics of the columns, such as their length, crosssectional area, casing thickness, prism strength of concrete, yield strength of steel, modulus of elasticity of both steel and concrete. The correspondence of the obtained model to the experimental data, as well as the significance of the regression parameters are confirmed by the Fisher and Student criteria.

In the current practice of construction and design of transport facilities, structures with external reinforcement are commonly used which effectively resist compression. The use of steel-concrete and composite structures enables us to reduce material consumption and cost of structures significantly. There are a few established approaches used to evaluate the load-bearing capacity of steel-concrete structures under axial and eccentric compression, each being based on the initial prerequisites, which underlie the calculation formulas. In this paper, the functional relationship of the value of the maximum load-bearing capacity of rectangular concrete-filled steel tubular (CFST) columns under axial compression with the random eccentricity is plotted. A regression model is proposed based on the methods of mathematical statistics, which allows for the evaluation of the impact of geometrical and physical characteristics of rectangular CFST columns on the value of their load-bearing capacity. The correspondence of the obtained model to the experimental data, as well as the significance of the regression parameters are confirmed by Fisher and Student criteria.

The article presents methodological approaches to determining the volume of passenger service in long-distance railway connections and intercity bus services in Ukraine, which are expected in the coming years. Goal. The purpose of the study is to increase the reliability of the information base for making informed management decisions on the further development of the transport passenger complex. Methodology. In the process of research there was used a set of methods of expert assessment and logical analysis of possible factors influencing; economic and mathematical modeling; formalized extrapolation methods to determine the predictive parameters of influencing factors. Results. The forecast values of the number of transported passengers and the values of passenger turnover in long-distance railway and intercity bus connections in the short-term period are obtained. Originality. To estimate the forecast values of passenger traffic there was used the combination of methods of correlation-regression analysis and forecasting the magnitude of factors by the method of variable average. Practical value. The study of the patterns of passenger traffic dynamics revealed that in the next two years no significant changes are expected in the volume of work of both kinds of transport. However, in long-distance railway transport it is possible to increase passenger traffic by 1.6% (0.74 million passengers) and, accordingly, the annual passenger turnover will increase by 2.2%. In the intercity bus service, a slight decrease in the volume of passenger traffic by 0.8% (0.93 million passengers) is possible, and the rate of decrease in annual passenger turnover will be 0.5%. In the conditions of constant reduction of the population of Ukraine the most effective mechanism of ensuring further sustainable development of both types of passenger transportation is constant adjustment of tariff policy on the principles of flexibility and bonus tariff formation under condition of continuous improvement of services quality.