The article is devoted to the question of defining own frequencies of trailing pipeline passages with the use of calculation model as a multi-span regular beam (pipe) on elastic supports (suspension brackets together with a cable). The example of calculation is given in comparison with calculations by other methods.

It is a review of several systems, previously tested on bridges of other design models, to determine frequencies and periods of own horizontal and vertical wavering (vibration) of floating bridges , which are extremely sensitive to dynamic effects. This publication shows the optimal method of calculations.

Purpose. The publication presents the results of calculations of spans for floating bridges with open double T beams. The purpose of research is to analyze the suitability of spans from open double T beams for floating bridges with minimum weight under loads, which is provided by standards for modern floating bridges designing. Methodology. Comparative method, analytical calculation methods (influence lines methodology), strength calculations, endurance, maximum shear stress are used in this paper. Findings. Current loads for bridges calculations are 75% more than those, for which the spans of floating bridge from NZhM-56 property are designed. The use of open double T beams that is formed with double T beam no. 70 (the height of the open one is 104 cm) reduces the cross sectional area in a weakened spot, but virtually it does not influence the strength and durability of the material. The use of open double T beams for spans of floating bridges saves up to 22 % of metal that means one in five spans will made of saved metal. Savings on each spans, such as CRP, will be 33.6 - 263 thous. grn. (considering the price of 1 ton of final product 29 thous. grn.). Originality. Research allows making next step in material saving and use of open double T beams for spans in the whole. Practical value. The obtained results give us possibility to make a number of conclusions that allow us to become more familiar and more practical with the use of open double T beams for spans of floating bridges.

Purpose. This work presents using carbon fiber as composite rebar by way of rods of fittings for reinforcement armored concrete span 13,5 meter length compared to same-length span with usual fixture. Methodology. The calculation is carried out as described in the methodological guidelines for the design and calculation of concrete span with frame-welded fittings. Findings. On the basis of the above study was to determine how the use of composite reinforcement as working for the reinforcement of its span. Originality. The possibility of using composite rebar as an element that works in tension in the span was proved. Practical value. Install valves of this type will reduce the cost of the span and increase its operating period.

In this paper, we studied the natural oscillations in the vertical and horizontal surface of viaduct of Ivanci. A number of schemes which allow determining the frequency on a more simple dependencies are given