The relevance of the study is due to the need to assess the seismic resistance of buildings with defects caused by reinforcement corrosion to prevent their destruction under seismic impacts. The most common defect in reinforced concrete structures is corrosion damage of the working reinforcement, which not only reduces the bearing capacity but also changes the dynamic characteristics of structures. The aim of the work is to develop a method for calculating the bearing capacity of corrosion-damaged compressed reinforced concrete elements under alternating low-cycle loading. Materials and methods include an analytical review, experimental studies of column samples with varying degrees of reinforcement corrosion, and numerical simulation in the LSDYNA software package. The results include a developed method for calculating the hysteresis envelope, experimental data on the reduction of strength, stiffness, and dissipative properties of columns, as well as verification of the proposed method. The conclusions confirm that reinforcement corrosion leads to a significant decrease in the dynamic and strength characteristics of elements, and the proposed method makes it possible to assess their bearing capacity under seismic actions with sufficient accuracy.

Substructures of reinforced concrete building frames in a zone of potential local collapse are considered. To assess their resistance in special limit states, an analytical calculation model is proposed. The validation of the presented computational resistance model is based on the results of 22 tests of typical substructures of monolithic and precast building frames, as reported in the works of various researchers. Using the proposed analytical model, a parametric study was performed on the influence of the following factors on the resistance in special limit states: the ratio of the beam cross-sectional height to the span, and the ratio of the effective section depth to the total depth.

A brief review of foreign and domestic theories or criteria for concrete strength, modern proprietary and “heavy” software and computing systems for solving reinforced concrete problems in a 3D solid nonlinear formulation is provided. The concrete strength criteria used in these systems are listed. The Menetrey-Willam plastic flow theory of concrete is examined in detail, taking into account the possibility of nonlinear hardening under compression and linear and nonlinear softening under tension and dilation (HSD).

Numerical modeling of three different fragments of slab reinforced concrete structures was carried out using the finite element method (FEM) in the ANSYS 2024 R2 software package with variations in the following: FE dimensions, strength criteria, reinforcement method and HSD parameters, and reinforcement area. The results of slab calculations are described in detail, with quantitative and qualitative characteristics of the calculation models indicated. Ways to improve the FEM for calculating slab reinforced concrete structures are proposed.

The article presents options for strengthening and restoring load-bearing reinforced concrete structures of buildings damaged during operation. The effectiveness of using steel-fiber concrete to strengthen structures is due to the increased strength and deformation characteristics of the material compared to reinforced concrete. In addition, numerous theoretical and experimental studies have confirmed a 3–5-fold increased crack resistance of steel-fiber-reinforced concrete structures compared to reinforced concrete ones. The optimal characteristics of steel fiber concrete for use as reinforcement have been determined. Based on theoretical and experimental studies, the prerequisites and methodology for calculating bendable, compressed-curved and compressed reinforced concrete structures with zone reinforcement made of steel fiber operating under static and short-term dynamic loads are formulated. The developed method for calculating the strength of normal and inclined sections implements a nonlinear deformation model based on real diagrams of deformation of materials. For the possibility of practical application of these studies, an algorithm and a computer calculation program have been developed that allow the engineer to select the optimal parameters of steel fiber reinforcement, concrete and reinforcement for strengthening and restoring damaged reinforced concrete structures by variant calculation. During the calculation process, the percentage of overload of the structure is determined, the required gain level is determined taking into account the required margin factor, and a gain option with the necessary parameters is selected.

The paper proposes methods for calculating the mechanical safety of structures and structural systems of buildings and structures in emergency situations, special and out-of-design impacts. The proposed damping system is aimed at developing and implementing technological innovations — active and passive control systems for vibration damping — and ensuring the technological leadership of the Russian Federation in the field of guaranteed safety of buildings and structures under critical natural and man-made impacts. It is proposed to improve the safety of buildings and structures through the development and development of effective vibration damping methods as a result of the use of three cable coupling systems equipped with single-acting hydraulic cylinders. These three separate damping systems add up to form an integrated system for reducing the vibration level of the spatial reinforced concrete frame of the production building. An algorithm for finding the safe inclusion of columns and beams (trusses) in the operation of a damped frame communication system is being built and numerically tested by reducing the vibration range of the frame. From the cycle of solutions to the differential equations of motion of the damped system with variations in resistance to movement and/or column parameters, optimal damper parameters, mechanical characteristics of columns and beams, as well as pre-tension parameters are selected for these disturbances. Cross-rope (flexible) coupling systems with single-acting hydraulic cylinders damping horizontal vibrations and hydraulic cable couplings damping vertical vibrations of the bearing structures of the coating are investigated. Based on numerical experiments, the parameters of cross-band-rope horizontal and vertical hydraulic coupling systems for single-story industrial building frames are determined: pre-tensioning, cable characteristics, hydraulic cylinder characteristics, as well as refined mechanical characteristics of the reinforced concrete frame. A mathematical model of vibration damping of reinforced concrete frames with cable ties equipped with single-acting hydraulic cylinders, as well as methods, algorithms and a software package are developed and investigated.

The article presents a justification of the values for refined safety factors used in the design of buildings and structures made of large reinforced concrete modules. The relevance of the study is determined by the need to account for the specific features of industrial production of reinforced concrete structures, the high accuracy of factory manufacturing, the reduced variability of concrete strength characteristics, and the capabilities of modern numerical calculation methods. Numerical studies were carried out for individual large reinforced concrete modules, as well as for buildings with frame-wall and wall structural systems. The analyses were performed in linear, nonlinear dynamic, and probabilistic formulations using the LIRA-SAPR and ANSYS/LS-DYNA software packages, as well as the Python programming language. The strength of concrete and reinforcement, snow load, wind load, and uniformly distributed imposed load were considered as random variables. Based on the Monte Carlo simulation method, values of the probability of failure and the reliability index were obtained for buildings made of large reinforced concrete modules. It is shown that, for the structural systems under consideration, the calculated reliability indices exceed the target levels established in regulatory documents on the reliability of building structures. The obtained results make it possible to justify the refinement of individual partial safety factors while maintaining the required safety level of buildings made of large rein-forced.

In this review, the current state of research on the use of machine learning for the design of reinforced concrete structures has been systematized and critically analyzed. The paper examines the main types of machine learning models used, analyzes quantitative metrics for assessing the quality of their predictions, and discusses issues related to the interpretability of results, error estimation, and the identification of nonlinear relationships. Special attention is given to existing gaps in scientific knowledge, regulatory conflicts, and limitations that hinder the practical implementation of AI technologies in design. Based on the analysis, promising directions for future research have been identified.