Applying mathematical modeling to determine the efficiency of reinforcing brick columns in the built-in civil defense structures with steel cages

This study’s object is brick structures for multi-story residential construction. In such buildings it is necessary to arrange built-in protective structures for civil defense. As a result of prolonged temperature and humidity exposure, wetting and destruction of brickwork may occur. Solving this problem requires devising measures to isolate brickwork from external influences, as well as, if necessary, options for strengthening damaged structures. One of the results of this work is the identification of principal damage based on analysis of the consequences of prolonged temperature and humidity exposure to complexly loaded brick structures (walls, partitions, columns) of a public facility. This is frost-related damage up to 40% of the initial cross-section, which is mainly associated with different porosity of the brick and the influence of atmospheric precipitation. The next result of the work is proposals for increasing the bearing capacity of damaged brickwork using tie clips from rolled steel elements. A qualitative feature of the proposal is the recommendations for installing these clips, which allow them to be included in joint work with existing brick elements. This qualitative distinctive feature was confirmed by mathematical numerical modeling of the increase in the bearing capacity of reinforcement brick structures. From a scientific perspective, different initial stress-strain states of brick structures and steel elements at the time of ensuring their joint operation were taken into account. After the installation of steel clips, the maximum compressive stresses in the brickwork decreased by 28.6%. The results could be applied when installing reinforcements with steel clips for damaged compressed brick structures