A comparative study on the seismic performances of typical five-story RC residential buildings designed with old and new Indian codes is presented. Accordingly, two three-dimensional models of a building designed with the old and new Indian codes are developed using STERA 3D software. The seismic performances are evaluated using the Capacity Spectrum Method (CSM) and non-linear Response History Analysis (RHA) for three input ground motions, in addition, the structural damage estimates given by damage indices are compared under scaled ground motions.

Results show that the building designed with the new Indian codes provide reduced structural responses when compared to that designed with old Indian codes. Furthermore, the assessment of the damage indices for the building designed using the new codes shows that the building has a more even damage dispersion over the floors and prevents collapse-level structural damage under the considered maximum scaled ground motion.

This article presents the results of experimental studies of bending moment redistribution in two-span continuous reinforced concrete beams reinforced with CFRP under load. Namely, fifteen beams of five series. The first series of beams (СB) are reference specimens without reinforcement. The second series of beams (MSB) included specimens reinforced with CFRP by gluing it to the tension zone in spans with U-shaped anchorage in the support sections without preliminary loading. The third (MSB C), fourth (MSB D) and fifth (MSB E) series of beams are specimens reinforced with CFRP at 30%, 50% and 70% of the expected breaking load of the reference specimens, similar to the second series of beams. To reveal static indeterminacy, readings of support dynamometers were taken at the beginning and end of each stage of the experimental study. Based on the data obtained, average experimental bending moment diagrams for each series were constructed. In addition, the study revealed that carbon fiber reinforcement affects the nature of the redistribution of bending moments in continuous beams, changing the ratio of the support Msu and span Msp moments. Thus, by using an external reinforcement system based on polymer composite materials, it is possible to adjust, if necessary, the nature of the redistribution of bending moments in continuous beams. In particular, by reinforcing the span zones, it is possible to relieve the support.

The sound insulation of complex enclosing structures, including small technical elements, including air ducts passing through internal structures and air exchange devices in external structures, was studied. Using the example of air exchange channels and the KIV 125 air exchange device, their effect on the sound insulation of multilayer glazing is shown. The results of measuring the sound insulation ability of single- and three-layer glazing with air exchange devices are presented. Standard methods for measuring the sound insulation of enclosing structures and small technical elements were used. The measurement of sound insulation of single- and multi-layer glazing with air exchange elements made it possible to identify the influence of the number of glazing elements and the air exchange channel on sound transmission through this type of structures and to develop a methodology for designing noiseproof windows in combination with ventilation ducts or air exchange devices.

Study of the influence of design and technological solutions for the construction of bulkheads of shipping hydraulic structures on filtration processes and the stability of the embankment of the dam core under operational impacts. The research method is a numerical modeling of the processes and analytical research methods made it possible to obtain the results of the set goal.

As a result of studying the influence of design and technological solutions for the construction of bulkheads, as temporary shipping hydraulic structures, on filtration processes and the stability of the embankment of the dam core under operational impacts, the following were completed: analysis of design and technological solutions for the construction of bulkheads of shipping hydraulic structures; analysis of the methods of blocking the river bed, as processes of gradual compression of the flow until the appearance of flow velocities that wash away the river bed and the backfill material. Criteria were identified that ensure the filtration strength of the soil for backfilling the core of the earth dam. A study was conducted of the potential destruction of the bulkhead when calculating for the main combination of loads using numerical modeling. Analysis of the filtration stability of the bulkhead using the finite element method under dynamic impacts has been carried out. Proposals have been developed to prevent the accumulation of filtered water through the bulkhead body. The filtration stability of the soil bulkhead as a temporary hydraulic structure is ensured by the current pressure gradient at the contact of two soils, which is significantly less than the permissible gradient, i.e., there is no erosion. The obtained results of numerical modeling allow us to observe a more accurate mechanism for the destruction of dam bulkheads. It is possible to carry out work on replacing the repair gates of the sluice under the protection of the soil bulkhead only in compliance with the requirements of regulatory and technical documentation and performing the necessary calculations.

The relationship between the strength of concrete and tangent modulus gets broken during its prolonged usage, so deformation curves matching the changes that occurred are required for the calculation of reinforced concrete structures. The formula based on the Arrenius equation enables the creation of concrete deformation model based on experimental data. Such model matches the criteria set. For validation of the model adequacy the results of comparing the model being proposed with the concrete deformation model used in the standards for different concrete classes are presented in graphical and tabular form. The results obtained confirm the adequacy of the deformation model proposed.

Taking into account the variable nature of load-bearing capacity and loads, checking the design reliability of building structures leads to ensuring that the probability of occurrence of the limit state should not exceed the target (permissible) value. This method is known as the probabilistic limit state verification method. There are simpler methods for checking limit states for engineering calculations, the most popular of which is the method of reliability factors. However, all existing methods for checking limit states and, accordingly, methods for ensuring the design reliability of building structures are based on the probabilistic method. For this reason, research and the normative consolidation of acceptable failure probabilities are one of the primary tasks of the scientific community and national authorities in the field of developing norms and rules. Based on an analytical review of the research, a description of the probability of failure and the reliability index as measures of design reliability is presented and provisions are fixed on the basis of which it is necessary to assign a target value for the probability of failure, including direct and indirect consequences of failure.

The conditions for assigning target failure probabilities in regulatory documents are systematized and the results of comparing the numerical values of reliability indices are presented. The most complete methodology for determining the target values of the probability of failure is set out in the international standard ISO 2394. This standard contains guidelines for determining target reliability indices based on economic optimization, analysis of individual or public risk, as well as the quality of life index. However, this methodology, and in particular the numerical values of reliability indices, require adaptation taking into account the economic characteristics of a particular country.

The paper presents a simple but effective method for assessing the dynamic response of a reinforced concrete structure under sudden removal of a load-bearing column. The local region above the failed column is modeled as a two-span beam with a concentrated mass m located in the middle of the beam. The removal process of the load-bearing middle column is modeled by reducing the value of the internal force R(t) in this column to zero in a certain short period of time tr. Based on the proposed model, we find the dynamic displacement in time of the point where the concentrated mass is located. The obtained results are of interest for solving applied problems related to the problem of survivability, protection of buildings and structures from progressive collapse, in particular in determining the criteria for the deformability of reinforced concrete structures under a special stress state.

Digital technologies and artificial intelligence are becoming increasingly relevant in various areas of human activity, in particular, in scientific research. If we talk about the history of architecture, then the technologies of extended reality (AR/VR) and 3D modeling are just beginning to be tested in this section of science. The focus is on 3D reconstruction of both individual historical monuments and larger objects. The article considers 3D reconstruction methods – manual modeling and various 3D scanning options, including the photogrammetric method. Artificial intelligence can also be used in different ways to advance technology. The article examines methods for recreating complex architectural objects, including cities, in a digital environment, in relation to different historical eras. As a separate area of research, a variant of reconstruction of unrealized architectural projects of famous authors is given. As working examples, digital 3D models of Moscow of the early 19th and 20th centuries, St. Petersburg of the early 18th century, Yaroslavl of the early 20th century and an alternative model of Moscow with implemented objects of the Russian avant-garde of the early 20th century and the general plan of 1935 are given. The prospects for further development of the described technology are assessed.

A technological solution of the production of composite building material based on waste cross-linked polyethylene and ceramic brick has been developed. The nature of the influence of cross-linked polyethylene on the strength and deformation characteristics of the composite is revealed. The nature of the destruction of composites based on polyethylene granules, waste of cross-linked polyethylene, hempcrete and traditional concrete is compared. It was revealed that the nature of the destruction of the proposed composites corresponds more to traditional concrete than to hempcrete, while the compressive strength is 20-40 MPa, depending on the content of crosslinked polyethylene. The adhesion of the aggregate in the form of cross-linked polyethylene to the cement matrix was evaluated. It was found that the aggregate in the form of cross-linked polyethylene has good adhesion to the cement matrix due to the irregular shape of the particles, surface roughness and the presence of carbon black in the composition of cross-linked polyethylene. The measured value of adhesion of the surface of cross linked polyethylene particles to the cement matrix was 0.98 MPa, which is comparable to the adhesion of the cement matrix to the polished surface of natural aggregates. An explanation for the formation of a heterogeneous durable structure due to the physical and chemical interaction of the components is given.

The article examines the influence of horizontal stationary sun protection devices on the illumination of rooms, taking into account their orientation relative to the cardinal directions and the angular height of the sun. Measurements were carried out under the natural sky on a transformable model of the room. The depth of the room and the dimensions of the stationary sun protection device were changed. Based on the obtained results, recommendations are given for the design of effective sun protection devices in order to ensure the best balance between protection from direct solar radiation and sufficient daylighting. Using the results of the work in the design will help improve the microclimate of the premises, reduce the heat load on heating and increase energy efficiency.

There is an overview of the intelligent systems use in different engineering systems of buildings which are designing in different countries. It has been presented the history of considered systems development and application for different sectors on national economy. Authors have described the results of practical application and control devices operation features in different engineering systems for providing microclimate (heating, ventilation and air conditioning). It has been detailed highlighted the options for regulating the building life support systems with modern controllers and integration them to joint unified system. Authors have determined the proposed key points of neural control systems development for engineering equipment in building and structures. Researchers have described possible options for introducing neurocontrollers to a building (including multi-stage introduction of single system neurocontroller to a global system neurocontroller with several engineering systems). The results of the research will be interested for the services operating engineering equipment of buildings and structures for different purposes. Also this information could be used by the planning services and developing companies which use modern automated control systems for engineering systems.