Construction Technologies and Architecture Vol. 2

Abstract: About 90% of the apartment buildings that constitute Armenia's housing stock were built before 1990. After the devastating 1988 Spitak earthquake, the seismic conditions in the country were revised and these buildings no longer meet current seismic standards. About half of Armenia's population lives in these buildings, so the reliability, cost-effectiveness and durability of these structures are extremely important for the country. In addition, a number of other causes contribute to the deterioration of the technical condition of the housing fund over time: exogenous geological phenomena, physical and mechanical properties of the soil, the service life of the housing fund, non-compliance with operating conditions, bombardment, etc. The houses built in the Republic of Artsakh are relatively new, but during the September 27, 2020 war unleashed by Azerbaijan, more than a thousand houses were bombarded. They are no longer suitable for use. Following from the above, it is worth to note that in Armenia, as well as in Artsakh, there is a great demand for the reconstruction of the housing stock. In recent years, mainly monolithic, sometimes stone buildings have been constructed in Armenia and Artsakh. Large-panel buildings are almost completely excluded from construction projects. The reason for this is the low energy efficiency of these buildings. However, there are now new high-performance thermal insulation materials that can easily solve this problem. The purpose of the article is to show the feasibility and advantages of constructing large-panel buildings as an effective way to replenish the housing stock in Artsakh and Armenia.

Abstract: Earthen construction, as an architectural heritage, need to be studied and preserved. The analysis of the construction system’s clusters of Syunik region of the Republic of Armenia allows developing a model of restoration in the unified system and adaptation to the new requirements of the time. Documentation of the current condition of the preserved earthen structures in the Syunik region, analysis of the mechanisms of construction features. The study of the international experience of the earth structures makes it possible to propose ways for the implementation of the earthen structures typical of the region with new technology.

Abstract: This paper considers the problem of the mathematical theory of elasticity on the stressed state of a piecewise homogeneous half-space at an antiplane deformation in the presence of stress concentrators such as cracks and stringers. The piecewise homogeneous half-space consists of an elastic layer and an elastic half-space with different shear modules. The arbitrary finite number of collinear system of tunnel cracks is located at the joint line between the layer and the half-plane, and the upper edge of the layer is reinforced by an arbitrary finite number of collinear system of stringers. It is assumed that under the action of tangential forces applied to the crack faces and stringers, the piecewise homogeneous half-space is in the conditions of antiplane deformation (longitudinal shear). Such problems arise in research in structural mechanics, geomechanics, geophysics, measuring technology and other areas of applied mechanics and engineering practice. Using the Fourier integral transformations, solving the described problem is reduced solving a system of SIE systems. Based on the solution of these systems, important characteristics of the problem such as the dislocation densities on the crack edges, crack opening, breaking tangential stresses outside the system of cracks on their line, stress intensity coefficients (SIF), tangential contact stresses under the stringers are determined. These values are represented by explicit analytical formulas that are convenient for practical calculations. Particular cases are considered.

Abstract: Structural health monitoring and control (SHMC) for Post-earthquake realignment and repairs (PERR) is one of the most challenging issues facing earthquake engineers worldwide. Currently, neither SHMC nor PERR are parts of contemporary curricula and codes of practice. The ultimate aim of SHMC is to help achieve a viable degree of structural sustainability (SS) under predictable environmental conditions. In the present context SHMC refers to the effort that aims at achieving structural operability before and after severe earthquakes. SHMC is generally associated with the use of piezoelectric sensors to measure changes in stresses and strains of critical elements of important engineering structures. Regardless of the effectiveness of the SHMC systems no structure can lend itself well to PERR or remain seismically sustainable unless it has been designed specifically for the purpose, otherwise it would be disposable with no gains from the SHMC effort. A SS structure is one that can be designed to prevent actual collapse, overcome residual effects and lend itself well to PERR. All indications are that the use of multifunction design in conjunction with SHMC can lead to the evolution of viable SS archetypes. The purpose of the current article is to introduce a practical basis for efficient use of SHMC concepts in multi-objective earthquake resisting structures (ERSs). Replaceable energy dissipating moment connections (REDMC), rigid rocking cores (RRCs), high strength tendons, built-in stressing devices and support level grade beams have been introduced as natural instruments of structural control. The use of monitoring devices has been directed towards evaluation of the effects of formations or elimination of plastic hinges and the variations of the global drift of the system. The proposed methodologies impose and control the desired modes of lateral response and facilitate the PERR operations. Key words: Health monitoring; structural control; earthquakes; recentering; repairs.

Abstract: As a result of the design and construction of buildings and structures, the level of reliability of the construction structure or construction object as a whole is formed. The reliability specified in the project does not remain constant, but changes over time as a result of the imperfection of the design model of the building, inaccuracies of installation, as well as during the accumulation of defects and damage to the building during its use. Currently, the scope of work related to the assessment of the technical condition of buildings is constantly increasing. This is due not only to the increasing number of operated structures, but also an increase in safety requirements and an increase in the qualitative characteristics of buildings. The article proposes to maintain a unified approach to the inspection of the engineering and technical condition that uses the reliability criterion for the basic structural elements of buildings and structures. In modern conditions, it is important to determine the necessary level of reliability acceptable to economic considerations and meets modern safety requirements. It is important to calculate the numerical threshold values of the categories of the technical condition of building structures to eliminate the subjective approach to the assessment of their technical condition.