Conceptual Approaches to Solving the Issue of Reinforcing the Rock - Cut Structures of Geghard Monastery Complex

The article presents a visual and instrumental research of the technical condition of the main rock-cut structures and their masonry additions, the documentation of their damages (cracks, crevices, destructions and erosions) and deformations, thorough complete laboratory studies of rock samples and their physical and mechanical characteristics, conceptual approaches to preventive and reinforcing measures necessary for the further safe survival of structures, as well as the comprehensive development and implementation of measures to prevent further damages (elimination of causes) and ensure the long-term existence of structures. Based on the analyses carried out, it is recommended to use a ready-made dry mixture mortar of the “Mapegrout'' brand produced by the Italian company “Mapei” to fill cracks if necessary. It is available in the market of the country and is successfully used in the reconstruction of tunnels and other underground structures. The issues of compatibility of reinforcing materials with sandstone rock are also considered on the basis of some averaged data of the main decisive physical and mechanical characteristics of the strength and deformation of sandstone.

Analysis of Structure Displacement Formed as a Result of Torsion in Case of Using Rubber-Metal Seismic Isolators

The study of a building with a complex planning solution, rubber-metal laminated seismic isolation supports (hereinafter referred to a RMLSIS) placed at the foundation level and with a reinforced concrete frame-braced system is presented, taking into account the displacement of the structure formed as a result of torsion. The analyses were conducted with the finite element method. The calculation schemes were modeled using the "Lira-SAPR" software. The displacement of the structure formed as a result of torsion of buildings having the same planning solution, different number of floors as well as with and without RMLSIS is estimated. The results obtained show that the displacement values of the structure formed as a result of torsion increased about 40% in buildings without RMLSIS and 25% in buildings with RMLSIS.

The Basics of Developing an Alternative Concept for Commercial and Military Vehicle Operation (Random Strategy)

The efficiency of commercial automobiles and wheeled military vehicles mainly depends on the choice of maintenance (M) and current repair (CR) concept. In the paper the difficulties of adapting the (M) and (CR) planning strategies to the structural characteristics of modern transport facilities are pointed out. The advantages of using the (M) and (CR) random strategy for transport facilities based on the stochastic nature of failures and malfunctions are substantiated. Considering the failures and malfunctions as random values and identifying the patterns of their distribution based on γ percentage resources, it is proposed to develop a list of regulated maintenance and repair work, periodicity and labor intensity based on a random strategy, which will increase the efficiency of preserving the technical resource of the rolling stock throughout the entire life cycle of the vehicle.

The Dependence of Durability and Deformation of Elements of Soil Cement Composite with Carbonate White Soil Mixture on Age

The results of an experimental study of changes in strength and deformability during the period of time subjected to short-term loading of elements made of a soil-cement composite based on white soil (belozems) of carbonate composition are discussed. Research was carried out in accordance with current standards, as well as a well-known method that has been repeatedly tested earlier. To assess the experimentally established data, the results of similar studies by other authors, carried out applying elements from soil-cement based on clay soils, as well as from lightweight concrete on lithoid pumice (volcanic rock), are also presented. On the basis of the comparative analyzes of the experimentally established data, conclusions are formulated. The consideration of those may be useful both for the estimation of optimal schedules of the construction of buildings from a soil-cement composite, and for the assessment of their stress-strain state.

Stiffness of Post-Tensioned Girderless Floor With Different Column Grids

The paper considers models of monolithic flat floor slabs with five spans in both directions. The cell sizes are 6×6m, 6×9m, and 6×12m. The calculation method is based on the application of temperature load and rope modeling of rod elements. It is shown that post-stressing should be used for slab side lengths over 7 m, as the installation of pre-stressed reinforcement for shorter lengths is less feasible and causes high economic costs.

Study on the New Method of Constructing Shear Walls in Multi-Storey Buildings With Site Cast Reinforced Concrete Frame System

The article touches upon the comparative analysis of bearing system calculations of a multi-storey residential building with site cast reinforced concrete frame and shear wall constructed by two different methods. In the calculation models, the shear walls are constructed from site cast reinforced concrete in the first case, and from three-layer sound and thermal insulating bearing panels in the second. The calculations have been made considering the impact of the seismic force. According to the calculation results, the dynamic parameters of the bearing systems of the buildings and the economic efficiency indicators have been compared. Considering the fact that in the recent years three-layer sound and thermal insulating panels have been widely used in the world, the study attempted to reveal the efficiency of using such panels in the Republic of Armenia.

The Impact of the Constructive Solution on the Formation of the Portal in the Architecture of Armenian Churches of 4th-7th Centuries

The article refers to the issues of decorative elements in architecture. The aim of the paper was to reveal the interaction peculiarities of the constructive and artistic solutions of the formation of the portals of the Armenian churches of 4th-7th centuries. The analysis of the process of formation allowed for carrying out the typological classification of the portals from the point of view of the transformation and development of the lintel construction. The classification showed that the portal created as a decoration of the entrance, as a result of the evolution of compositional-structural components was transformed into a unified constructive-artistic element, which has become the main type used in the later periods of the Armenian medieval architecture. The revealed features of the interaction of decorative and structural elements can be useful in the field of heritage studies and in the development of further works on the formation of decorative elements.

The Importance of Historical Stages of Construction Within the Context of Sustainable Urban Development of Hadrut City

Preservation of Artsakh's architectural heritage and the issues of use have acquired a special significance today. The historical stages of the construction of the city of Hadrut in Artsakh, and, as a result of their analysis, their impact on the further sustainable development of the city have been revealed. There are 5 main stages: formation, late Middle Ages, from the 19th century to the first half of the 20th century, Soviet and independence periods. Suggestions are given on the territorial development of the city.

Study of "Saralsk" Deposit for Practical Applications in Construction

In article the results of research of structural features and technical properties of andesite - basalt stone rock of the “Saralsk” deposit are given. The material is estimated by its mineral - petrographic composition, and the cuts/refinements of stone materials have been made for the microscopic study of mineral-petrographic composition. Researches are conducted according to requirements of acting standards and as a result, it became clear, that the rock consists basically of minerals opacitized hornblende and plagioclase, it doesn't contain any no secondary minerals such as hydroxides of iron, chlorites, epidote, quartz, saricite, etc. Petrographic researches have allowed to determine the species of stone rock. The density, strength, water resistance and frost resistance of stone rock are studied. The suitability of the material for practical application in construction, including for external works, is revealed.

Possibility of Tuff Waste Application in the Production of Thermal Insulation Materials

Possible methods of dust, sand and gravel waste involvement during tuff mining for production of modern thermal-insulating construction materials using energy-efficient technologies are presented. The possibility of using the valuable properties of these wastes for the production of modern competitive materials and products, particularly clinkerless binders, artificial porous fillers, foam concrete, etc is described. The volcanic rocks, which have a glass-like structure, i.e. easily modified, give the system sufficient energy potential, which is accumulated in the rock, allowing work to be performed through chemical reaction. The possibility of increasing rock reactivity both by mechanical (crushing, grinding) and chemical methods (creation of basic, sulfate environments) is presented. It has been theoretically substantiated and practically confirmed that by using the waste materials it is possible to obtain artificial construction conglomerates of various structures using resource-saving technologies and the activities of rocks endowed with nature. The composition of concrete with a cellular structure has been developed and its physical and mechanical characteristics have been brought forth.