A considerable part of the world population is living in a geographical belt of hot and dry climate. The rainfalls there are rare and there is lack of fresh water basins and water sources. That’s why a powerful water supply system was developed here, which has been operating for centuries, and a technology of its construction has been improved to the level of art. The specific nature of hydro-technical water supply system of Iranian settlements is considered in this article. Such specificity is typical for the regions with mountain relief in the conditions of hot-dry climate. Also, the construction characteristics of the system, its structure and building components are given as well as short information about the features of buildings constructions and their technical operation. Functional, urban-architectural and environmental aspects are considered; the influence of the hydraulic system on the population resettlement is specified. The role of these structures is noted in respect of environment greening. Informational and cognitive nature of the given material allows using it in educational process of architects and civil engineers, expanding their professional horizons, as well as in scientific researches aimed at finding the ways of ecologization of modern architectural environment in the condition of urbanization development.

The wide use of reinforced foundation pads is complicated because of the absence of technical rules and regulations on design of such structures. It is necessary to investigate the main parameters and regularities of such structures operation under loading. For this aim numerical study of the foundation was carried out, the parameters of which were improved by reinforced foundation pad. The numerical modeling of reinforced foundation pads was carried out in the Plaxis 2D for study of the basic laws and operating parameters and for determination of the application area of these structures. The main goal of this study was to establish the optimal structures of reinforced foundation pads. This goal was achieved by solving the following tasks: determination of the optimal parameters of reinforced foundation pads; study of the stress-strain state of reinforced foundation pads and a soft base; estimation of the load, at which the ultimate settlement is achieved for all types of reinforced foundation pads. It was concluded that the lower reinforcement separating layer allows increasing the loading of the foundation. The typical and optimal reinforcement spacing were specified and analyzed.

It has been known that the use of karst stability categories classified by sinking diameter and the rate of its occurrence creates contradictions between researchers and designers. These contradictions are most discernable when implementing special projects such as construction of linear objects. The article provides an example of risk management when placing linear objects on karsted territories as exemplified by trunk line submerged crossings in a valley of a large transit river. The conditions of the regional karst development were identified, as well as the features determining sink risk. The authors provide the factual material analysis using the concepts that describe the reasons for the formation sink mechanism. The risk assessment is carried out during the analysis of necessary and sufficient conditions for the occurrence of sink mechanisms forming the karst hazard. The research results showed that the seasonal variations influence the possibility of karst risk. It is proposed to use an algorithm of karst management based on the variability approach, taking into account the changes in environmental conditions that affect the essence of the danger existence.

Sprayed-on concrete is a special type of concrete using which structures are created by spraying a concrete mix on the surface under compressed air. This technology may be used in the construction of spatial structures. There is a method to increase the quality parameters of a concrete mix by modification of the used binder. The authors considered the aspects of sprayed-on modified concrete mixes application for underground structures. It is also possible to apply them for repair and reinforcement of concrete structures, protective coatings. The authors investigated the influence of nanomodified particles with individual hydraulicity with conventional diameter up to 100 nm on the properties of sprayed-on-concrete mix. The structure-formation kinetics of sprayed-on-concrete is observed depending on the additive activity and average diameter of particles. The effectiveness of the applied additive is proved, as well as the increase of technological, physical and mathematical and operational features of the obtained sprayed-on concrete.

Increase of the amount of fungi spores and micotixines causes the increase in the number of different diseases. Because of this, ensuring the biological safety in buildings is becoming more and more important today. The preferred way to guarantee the biological safety of a building is to employ modern building materials that prevent the settlement of the fungi colonies on the inner surfaces of walls. Such building materials can be produced using novel biocidal modifiers that allow controlling the number of microorganisms on the surface and in the bulk of a composite construction. The precipitation product of zinc hydrosilicates and sodium sulfate is one of the mentioned modifiers. Till now, the exact chemical composition of such precipitation product is controversial; it is obvious, though, that the efficacy of the biocidal modifier is mostly determined by the type of the copper compounds. In the present work an integrated approach is used for the investigation of the chemical composition of the biocidal modifier. Such an approach consists in the examination of the modifier’s composition by means of different, yet complementary, research methods: X-ray diffraction, infrared spectroscopy and DTA. It is shown that the chemical composition of the modifier mainly depends on the amount of precipitant. X-ray diffraction reveals that the major part of the modifier is represented by amorphous phase. Along with the increase of the precipitant’s amount the crystalline phase Zn4SO4(OH)6•xH2O formation takes place. Such a crystalline phase is not appropriate as a component of the biocidal modifier. Another two methods - DTA and IR spectroscopy - reveal that the amorphous phase consists essentially of zinc hydrosilicates.

Construction compositions having nonlinear response to dynamic loading are compound compositions possessing disperse and liquid phases. They functionally comprise agents which give the composition the required properties depending on its aim and field of application. Under dynamic loadings such compositions are nonlinearly changed. Though such compositions are quite simple it is necessary to solve a number of tasks when developing their formula. The article considers scientific approaches to design of compound compositions aimed for operation under dynamic loadings. A composition model is proposed and analyzed. Basing on the analysis the formula parameters of the considered compositions are specified. The requirements to disperse and liquid phases are determined. The authors showed that the cancellation of the dependencies of quantity and strength on contacts from the diameter of disperse phase particles influences the strength of the considered compositions. It is noted that spot contact is formed when the layers of liquid phase which surround the contacting particles of the disperse phase merge. The features of the components are specified. The considered features should be preferred when choosing the disperse and liquid phases of compound compositions.

The information about the evolution of the bottom topography in the construction area is necessary in the design and construction of hydraulic structures in sea, as well as information about possible deformations of the bottom caused by both natural reasons and the appearance of new hydraulic objects in the waters. In the given research the authors propose an analysis of lithodynamic processes in the area of the construction of the bridge across the Kerch Strait. Several physico-mathematical models were used for calculation and description of lithodynamic processes in the construction site of the Kerch Bridge. They may be divided into two groups: atmospheric and water. Many important properties of hydrometeorological conditions may be obtained only by modeling. The model WRF is used in the research, which is applied in many foreign and domestic centers for simulation and forecast of regional atmospheric circulation due to its high quality and ease. The main steps of the calculations are provided: beginning with the collection of basic information up to combining the results of numerical experiments on several mathematical models. Special attention is paid to sedimentation and erosion associated with construction of temporary piers and waterways to them.

The authors calculated the settlement probability of suspended particles inflowing to the clarifier. The limit distributions of dangerous sedimentation particles are considered: in a parabola and uniform for all the groups of particles, as well as distribution in trapezia having upper and lower bases with gradual increase of the length of the upper base from zero to the length of the lower base. It was stated that the sedimentation pattern of the particles in depth of the flow at the inlet of the settling basin greatly influences the required length of the basins. It was established that at the 80 % probability of dangerous particles’ sedimentation and at the flow velocity of 0.5 m/s the fluctuations range of the relative basin length S/H is 5 ea, for 94 % probability - 8.5 ea, and the fluctuations range is increasing with the increase of the probability. It is recommended to organize the experimental study of the distribution of suspended particles’ concentration at the inlet of operating clarifier basins and to take a uniform or close to the uniform distribution before obtaining this experimental data.

The article considers the current problematic issues in the management of investment-construction projects, examines the questions of efficiency increase of construction operations on the basis of the formation of a reflex-adaptive organizational structure. The authors analyzed the necessity of forming a matrix of key events in the investment-construction project (ICP), which will create the optimal structure of the project, basing on the work program for its implementation. For convenience of representing programs of the project implementation in time the authors make recommendations to consolidate the works into separate, economically independent functional blocks. It is proposed to use an algorithm of forming the matrix of an investment-construction project, considering the economic independence of the functional blocks and stages of the ICP implementation. The use of extended network model is justified, which is supplemented by organizational and structural constraints at different stages of the project, highlighting key events fundamentally influencing the further course of the ICP implementation.

The management of construction companies’ development is rarely aimed at harmonization of business and at the development of the ways of its sustainable development. Case studies and the application scope for harmonization as an approach allowing systematic and balanced development of business showed its practical relevance. The use of this approach allows not only correlating the objectives, clarifying the mission, structuring the problems, or determining the optimal salary of employees, but also correlating the costs to each other, which is particularly important in light of the need for rapid transformation of the building production methods. They are based on competent use of system properties of the systems. The properties of emergence, resonance, measurability, and others are of particular importance. Their accounting allows achieving the optimal cost outlay required in the process of investment and construction activities. It complies with the requirements and conditions of the market economy. The mentioned advantages of the use of harmonization technologies to ensure the stability and sustainability of investment and construction activities enable to confirm the hypothesis of the impossibility to achieve the optimum cost, for example, for the implementation of an investment and construction project without implementation of the system properties of a harmonious approach.

Projective graphics is a polyhedra simulation method, which is based on the use of trace diagrams of initial polyhedron. Previously developed computer software allows using Cartesian coordinates. In some cases it is advisable to use polar coordinate system for description of projective graphics drawings. Using the example of icosahedron the authors analyzed the advantages of using projective graphics drawings in the polar coordinate system. The transition to the polar coordinate system is a tool that allows using certain patterns of projective graphics drawings in the process of calculation. When using polar coordinate system the search of Polar correspondence for the directs is simplified. In order to analyze the two lines in the polar coordinate system it is enough to compare the corresponding coefficients of the equations of these lines. The authors consider a diagram of the icosahedron in polar coordinates, and a corresponding fragment of calculation program in the Mathematica system. Some examples of forming based on icosahedrons are offered. Optimization of computer programs using polar coordinate system will simplifies the calculations of projective graphics drawings, accelerates the process of constructing three-dimensional models, which expand the possibilities of selecting original solutions. Finally, the authors conclude that it is appropriate to use the polar coordinate system only in the construction of projective graphics diagrams of the planes system having rich symmetry. All Platonic and Archimedean solids, Catalan solid possess this property.

Due to wide implementation of enveloping structures with increased heat-insulation properties in modern construction here appeared a necessity to assess their moisture conditions. Assessment of moisture conditions of enveloping structures is carried out according to maximum allowable moisture state basing on determining the surface of maximum damping. In relation to it the necessity of additional vapour barrier is checked using moisture balance equation. Though the change of indoor climate parameters in premises is not taken into account in moisture balance equations defined for different seasons. The author improves the method of calculating moisture protective parameters of enclosing structures according to the maximum allowable damping state for a year and a period of moisture accumulation. It is shown in this article that accounting of temperature and relative humidity change of inside air allows specifying calculated parameters of indoor climate in residential and office rooms in assessment of moisture protective properties of enclosing structures for the case of an effective enclosing structure with a façade heat-insulation composite system. Coordinates of the maximum moistened surface of the envelope depends on indoor climate design parameters. It is concluded that the increase of requirements for moisture protection of enclosing structures when using design values of temperature and relative humidity of internal air according to the Russian regulation (SP 50.13330.2012) is not always reasonable. Accounting of changes of indoor climate parameters allows more precise assessment of moisture protective properties of enclosing structures during their design.