The defensive structures of the Kazan yurt are unique in both historical and architecturally objects. The era of many peoples and ethnic groups intertwined in them. Their development was influenced by a large number of factors. Their detailed analysis is the purpose of this work.

Keywords: defensive structures, architecture, fortress, construction, architectural appearance, stages of development, Kazan yurt

The features of the functioning of steel structures in an aggressive environment are considered, the results of a qualitative and quantitative assessment of the nature of damage to a profiled sheet are given.

Keywords: steel structures, building structures, corrosion, aggressive environment, zinc coating, corrosion rate

The issues of developing a project for strengthening the building structures of a cable overpass after an emergency (accident) are discussed. On a real example, a description of the accident is given, the performance of work on the ghost of structures to the standard state is illustrated. The article was written on the basis of the completed research work No. 18-26.

Keywords: building structures, safety, cable trestle, emergency response, technical expertise, buildings and structures, metal structures, reinforcement project

The technology of organizing the construction of decentralized energy systems based on wind power plants is given. New design solutions for the structural elements of wind turbines and overhead lines (tower, collapsible ballast-type foundation, protective element) are proposed, taking into account the specifics of the technology of construction and installation works. Data are given on reducing the cost of construction production by optimizing the machines and mechanisms used.

Keywords: wind turbine structures, overhead lines, tower, collapsible ballast-type foundation, protective element, in-line method, decentralized system

The assumptions of mathematical models for calculating the crack resistance of reinforced concrete structures are considered. For each of them, an analysis was carried out to determine whether they correspond to reality throughout the entire life cycle of the structure: from the hardening of the concrete mix to destruction. Based on the results of the analysis, it was proposed to use only one single calculation at the level of standards to assess the crack resistance of structures - according to the crack opening width, acrc. So, for example, at a certain value of acrc, the structure will still remain airtight (the cracks will be non-through), and if this value is exceeded, it will not. At the same time, the calculations already available in the norms for limiting permeability and the safety of reinforcement will still remain in demand. At the junction of the theory of damage accumulation and nonlinear fracture mechanics, a compressed algorithm is proposed for possibly taking into account the influence of cracks at all scale levels of the concrete structure, the key for which is the normalization of the statistical parameters of the distribution of discontinuities by diameters, lengths, openings, depths, directions, distances between discontinuities, etc.

Keywords: reinforced concrete, crack resistance, cracking moment, crack width, plasticity coefficient, damageability, non-linear fracture mechanics

An example of a technical examination of a cultural heritage object of federal significance is given in order to identify the fact of violation of the Federal legislation during its restoration. Recommendations are given on the preparation of a technical conclusion of this examination. The article was written on the basis of the research carried out (at the request of law enforcement agencies).

Keywords: technical expertise, object of cultural heritage, violation of the law, building structures, temple, dome, restoration

The optimization of the taxable base of capital construction objects is considered, this is the desire of customers and operating organizations to manage the cost of ownership of one or another technical solution, which is certainly reasonable in modern conditions, when when making a technical solution, its full cost is estimated, including the so-called cost of ownership for the entire period of the life cycle of the object, from the formation of an idea for the creation of a future object to its decommissioning.

Keywords: collapsible foundation, protective element, flow method, wind power plant, building structures

The procedure for carrying out a set of works to preserve the object of cultural heritage of regional significance "The mass grave of Soviet soldiers who died of wounds" is given. All stages of carrying out such types of work are considered, recommendations are given for solving issues that arise in the process of carrying out work.

Keywords: repair, object of cultural significance, work technology, inspection, building structures, mass grave

The article considers an experimental study of the stress-strain state of radial beam domes. The maximum stress values are fixed in stretched flexible elements with a peak value of 363.6 MPa. With the calculated resistance of the wire material Bp-I Rs = 410 MPa, there is a 12% load-bearing capacity margin. Note the high level of stresses in other flexible elements with values in the range from 141.4 to 274.72 MPa.

Keywords: radial beam dome, experimental studies, loading, strain gages, deformation

The article proposes a technique for optimizing trihedral lattice tower structures according to the criterion of minimum mass, taking into account limitations in strength, ultimate slenderness of elements, stability, and the absence of resonant vortex excitation. A lattice tower with a cross section of elements in the form of round pipes, consisting of two sections, is considered. The variable parameters are the width of the tower, the height of the lower section, the outer diameters of the cross-section of the chords and gratings, the number of panels in the lower and upper sections. The solution of the nonlinear optimization problem is performed in the MATLAB environment using the Global Optimization Toolbox package. Determination of forces in the tower and frequencies of natural oscillations is performed by the finite element method using the subroutine for MATLAB developed by the authors. The influences on the tower are ice and wind loads, the dead weight of the tower, as well as the weight of the equipment. When calculating the effect of wind, the pulsation component is taken into account. The surrogate optimization method is used to solve the nonlinear optimization problem. In the initial approximation, the mass of the tower was 2 tons. As a result of optimization, the mass was reduced by more than 2 times.

Keywords: lattice towers, finite element method, surrogate optimization, resonant vortex excitation

The algorithm of the project development for the preservation of the cultural heritage object is considered. Recommendations are given for carrying out work on the preservation of the ruined temple for the possibility of its further restoration. A real example of a survey of an object of regional significance "Church of Archangel Michael" (Belgorod region, Valuysky district, village of Podgornoye) is given.

Keywords: conservation, object of cultural significance, survey, building structures, ruined temple

The procedure for performing pre-design work on cultural heritage objects of regional heritage is given (for example, the object "Former real school" in the city of Serdobsk, Penza region). An example of a survey of building structures, the compilation of a historical reference on the object, the collection of initial permits is given. The article is written on the basis of the completed research contract 22-146.

Keywords: the object of cultural heritage, pre-design work, technical expertise, building structures, historical information