A significant number of long-span public buildings with spatial steel structures are designed, erected and exploited in our country. One of the main areas of their application are unique sports objects. In the article experience of dye penetrant inspection of the Gorki Gorod Mall's long-span steel dome's welded joints is analyzed. The shopping and entertainment center was built in Sochi for the 2014 Olympic Games. Methodology, advantages and disadvantages of dye penetrant inspection are given. Typical defects of welded joints in spatial metal structures identified by this method are described. The data obtained from the experience of use of such structures allows to actualize and expand the developing normative documents.

Keywords: defect, dome, dye penetrant inspection, grid shell, inspection, long-span structure, non-destructive testing, spatial rod structure, steel structure, welded joint

The article presents the calculation of reinforced concrete column reinforcement using a metal cage made of angles, taking into account the physical nonlinearity of materials within the framework of the Lira CAD software package. The use of a nonlinear approach is due to the inability of linear methods to adequately reflect the real behavior of concrete and steel under load, in particular, their destruction and gradual loss of rigidity. This paper presents a model that takes into account the nonlinear stiffness characteristics of concrete and steel in accordance with regulatory documents. Taking into account the physical nonlinearity of materials when calculating column reinforcement is critically important for reliable modeling of the structure's behavior and preventing underestimation of the risks of destruction. It is necessary to check the structure for local destruction at each stage of loading to ensure the reliability of calculations and the safety of the structure. The use of specialized software with the ability to stage-by-stage loading and checking for local destruction allows you to obtain accurate results and justify optimal design solutions.

Keywords: columns, reinforced concrete, steel, strengthening, jacket, calculation, physical nonlinearity, software package, stresses, strains