Subject: the new economy structure is directly related to the active application of digital technologies. Economic processes are more formalized and for making administrative decisions it becomes possible to operate in a greater degree with precise criteria and information than probabilistic assumptions. As a subject of research, new tools for managing construction programs and projects are presented. Research objectives: the purpose of the study is to formulate general principles and directions for the digitization of economic relations in investment and construction activities to ensure the effectiveness of implementation of new generation projects. Materials and methods: to achieve the goal, the article shows the composition of state programs and projects in the construction sector and the system problems of their implementation. Organizational methods of increasing their effectiveness are considered. Results: the most promising areas of implementation of new management tools for investment and construction programs and projects are identified. Conclusions: the article shows the current dynamics of changes in technical and socio-economic systems at the level of construction sector. It is pointed out that the tasks of socio-economic nature require the development of unique approaches since the peculiarities of Russian legislation, of the prevailing norms and rules of economic activity prevent the direct replication of successful foreign experience.

Subject: the recently approved “Housing Stock Renovation Program in the City of Moscow” has generated many public and scientific discussions about its quality and potential efficiency, and also (in more general terms) - about possible methods for assessing the effectiveness of realization of state (municipal) programs. The relevance of these discussions is due, among other things, to a really huge amount of funds allocated by the state (especially, at the federal and sub-federal levels) to various parts of the country’s construction complex. In fact, only in the budget of Moscow for 2018-2020, more than 1.74 trillion rubles is allocated for financing construction programs. Research objectives: study of existing and future methods for making decisions in the process of development, approval, implementation and effectiveness evaluation of the housing stock renovation programs, and also development of practical recommendations in this field is the main objective of the research undertaken by the author. Materials and methods: using the method of comparative analysis of indicators of several previously completed state programs having similar (comparable) objectives and tasks with newly announced Moscow renovation program, the author identifies, generalizes and compares their main parameters which were and were not actually achieved. Results: it is clear that in a modern scientific and economic and practical turnover, there is no scientifically sound methodology for ensuring synchronization of the integrated development of the real estate with the program mechanisms of state participation in the investment and construction process based on, among other things, adjustment of target parameters of state (municipal) programs to comparable economic indicators. Conclusions: recommendations for developers of newly adopted programs are given.

Subject: the results of the study are particularly relevant in the modern system of cyclical crisis generated by the change of Kondratieff’s long waves of economic development and technological structures. From the point of view of synergetics, these processes have the ability to trigger a new order having spontaneous transformation due to endogenous factors. Qualitatively predictable fluctuations in the socio-economic environment and management may lead to self-organization and sustainable development of the economic system. Construction and investment activity of Russia in the majority of cases was investigated by economists without a detailed understanding of system characteristics, inherent properties and laws, which are identified from the results of economic-mathematical modeling. Research objectives: 1. Timely and qualitative prediction of moments of crisis in the investment and construction activities of Russia; 2. Modeling of management activities for the purpose of transitioning to the desired path of development of economic system; 3. Creation of a model that is simple enough for practical use by economists and the use of public data sets in it; studying influence of the bifurcation diagram at a certain time and bypassing the critical points of the system that lead to undesirable outcome. Materials and methods: approximation of the statistical data sets, regression analysis, phase analysis, differential modeling. Results: The authors developed a mathematical model that allows us to use statistical data on investment and construction activities and accurately forecast the chances of recession of the system, and also identify the sensitivity of order parameters to the dynamics of control variables, bifurcation states and behavior of the object under certain management conditions. Conclusions: the paper presents an approach to modeling and forecasting the trends of development of complex cyclic and stochastic subsystem of the national economy - investment and construction activities. We developed economic-mathematical model based on differential equation of the second order, allowing us to use statistical data and predict behavior of the system depending on management actions. We identified the dynamics of the impact of control variables on the order parameter of the economic system under study in various time periods. The obtained results should be used in strategic planning and management of innovative development of investment and construction activities of Russia.

Subject: the article proposes the methods for flexible regulation of administrative and organizational-technical relations between participants of the construction process which are based on integrated management contracts to address the issues related to realization of investment-construction projects in due time and within the funding limit under the influence of random factors. Research objectives: development of a conceptual simulation model of the process of making managerial decisions within the framework of realization of investment-construction project taking into account uncertainty. Materials and methods: We used the principles of the theory of control of technical and manufacturing systems, cybernetics, and also the methods of organizational, logical-semantic and simulation modeling, the works of domestic and foreign scholars on the problem under study. Results: by creating a functional simulation model for realization of investment-construction project, the construction process is considered as an iterative activity that is characterized by a list of indicators describing the state of the project at each control point. Controlled parameters include: planned indicators of the start and end date, and also the cost of execution of works depending on the project realization option (nomenclature of works, material and technical resources, labor intensity, machine capacity). Also, we characterize the basic criteria for efficiency of managerial influence on the realization of construction projects. Conclusions: we substantiated the necessity of taking into account the influence of random factors in the process of realization of investment-construction projects to determine more accurate predictive estimates of cost and duration of construction, especially for objects financed at the expense of state funds and built on the “fixed” contract price.

Subject: In this article we review and analyze structural forms and methods for accounting for deviations in metal roof structures. The article also reviews and analyzes previously performed works and methods for accounting for deviations in the design of metal structures. Research objectives: analysis of deviation values and mounting stress-strain state (MSSS) of the transverse diaphragm of a single-chord hinge-rod metal shell. A comparative calculation of deviations and calculation results analysis was made on the example of a transverse diaphragm of a single-chord hinge-rod metal shell of the roof structure for different technological assembly-mounting schemes: from the supports to the arch center, and vice versa, from the arch center to its supports. Materials and methods: geometrical method for determining deviations is implemented in the the author’s computer program - computing complex of dimensional analysis (CP CCDA); method of finite elements (FEM) is used for determining mounting stress-strain state and is implemented in SCAD 11.5. Results: The calculation and analysis of the mounting stress-strain state (MSSS) of the diaphragm was performed. Out of two assembly schemes considered in the paper we recommend the second technological scheme of assembly-mounting and also possible ways of compensation for the assembly deviations in the end diaphragm of the cylindrical roof structure of the hangar. We suggest possible options for modeling deviations of individual members of rod systems for several types of profiles and we propose possible cross sections of diaphragms of arched roof structures. Conclusions: the methodology for determining the installation deviations and the method for determining the MSSS, proposed in this article, can be used to determine deviations in a variety of large-span hinge-rod metal structures.

Subject: possibility of using random functions and interval prediction method for estimating the residual life of building structures in the currently used buildings. Research objectives: coordination of ranges of values to develop predictions and random functions that characterize the processes being predicted. Materials and methods: when performing this research, the method of random functions and the method of interval prediction were used. Results: in the course of this work, the basic properties of random functions, including the properties of families of random functions, are studied. The coordination of time-varying impacts and loads on building structures is considered from the viewpoint of their influence on structures and representation of the structures’ behavior in the form of random functions. Several models of random functions are proposed for predicting individual parameters of structures. For each of the proposed models, its scope of application is defined. The article notes that the considered approach of forecasting has been used many times at various sites. In addition, the available results allowed the authors to develop a methodology for assessing the technical condition and residual life of building structures for the currently used facilities. Conclusions: we studied the possibility of using random functions and processes for the purposes of forecasting the residual service lives of structures in buildings and engineering constructions. We considered the possibility of using an interval forecasting approach to estimate changes in defining parameters of building structures and their technical condition. A comprehensive technique for forecasting the residual life of building structures using the interval approach is proposed.

Subject: multi-layer building envelope is the subject of the paper. Recently, in the context of energy conservation policies, the heat engineering requirements for enveloping structures of buildings and structures have significantly increased. At the same time, their moisture condition has a significant impact on the operational properties of materials of structures and on microclimate of rooms constrained by these structures. Research objectives: emphasize importance of the task of predicting the temperature and moisture condition of the walling at the stage of design and construction of building envelopes. In this paper, the temperature distributions in layered walls are analyzed. Materials and methods: to achieve the objectives, computational and experimental studies are conducted. By alternating (rearranging) layers and preserving the thermal resistance of the wall on the whole, we find the optimal alternation of layers that minimizes deviation of the maximum wall temperature from the average temperature. Results: for the optimal location of layers in the wall’s structure, the moisture penetration into the wall is minimal or absent altogether. This is possible if the heat-insulating layer is mounted on the outer surface of the structure. Conclusions: the obtained results of computational and experimental studies allow us to verify appropriateness of accounting for alternation of layers in multilayer structures. These calculations proved that the higher the average temperature level, the more energy-efficient the structure will be.

Subject: a groundwater filtration affects the strength and stability of underground and hydro-technical constructions. Research objectives: the study of one-dimensional problem of displacement of suspension by the flow of pure water in a porous medium. Materials and methods: when filtering a suspension some particles pass through the porous medium, and some of them are stuck in the pores. It is assumed that size distributions of the solid particles and the pores overlap. In this case, the main mechanism of particle retention is a size-exclusion: the particles pass freely through the large pores and get stuck at the inlet of the tiny pores that are smaller than the particle diameter. The concentrations of suspended and retained particles satisfy two quasi-linear differential equations of the first order. To solve the filtration problem, methods of nonlinear asymptotic analysis are used. Results: in a mathematical model of filtration of suspensions, which takes into account the dependence of the porosity and permeability of the porous medium on concentration of retained particles, the boundary between two phases is moving with variable velocity. The asymptotic solution to the problem is constructed for a small filtration coefficient. The theorem of existence of the asymptotics is proved. Analytical expressions for the principal asymptotic terms are presented for the case of linear coefficients and initial conditions. The asymptotics of the boundary of two phases is given in explicit form. Conclusions: the filtration problem under study can be solved analytically.

Subject: a rapid increase in the traffic intensity and freight traffic on motor roads leads to premature destruction of road surfaces. At the same time, the actual service life of asphalt-concrete pavements rarely exceeds 4-5 years and in most cases is only 2-3 years. Most intensively defects and fractures appear on asphalt-concrete pavements in the early spring. Nowadays the overhaul intervals for the road surface coverings are significantly lower than those given by the regulatory requirements. One of the main reasons for this phenomenon is the use of obsolete technologies based on traditional materials whose properties are inadequate to resist stresses and deformations arising in the coating. This is especially evident in the climatic conditions of the south of the European part of Russia, where the upper layers of the roadway experience a much wider range of temperatures. Tighter requirements for the initial road-building materials and timely repair of the coatings allow us to increase the service life of motor roads. Research objectives: the aim of the study is to develop a new type of asphalt-concrete, such as porous-mastic one. Materials and methods: the work was carried out based on observations and published sources, a method of theoretical study and analysis. Results: the domestic and foreign experience of using the given asphalt concrete for the top layer of the coating was considered. The technology of preparation and laying of a porous-mastic asphalt-concrete mixture is presented and its advantages and disadvantages are shown. Conclusions: increasing the longevity of highways is an important and urgent task and it can be solved, in particular, due to the wide use of new technologies and non-traditional building materials that allow us to improve the quality of asphalt-concrete pavement and prolong its overhaul intervals.

Subject: we consider the problem of supplying the construction industry, in particular underground construction, with mineral binder for diluted aqueous suspensions that meet the requirements for reinforcement of low-strength sand and clastic soils by injections into the reinforced soil mass. Research objectives: substantiating possibility of using amorphous biosilica in combination with carbide sludge, whose particles size does not exceed 10 mm on average, as a binder for aqueous suspensions being injected. Materials and methods: as raw materials we used: common construction hydrated lime from “Stroimaterialy” JSC, Belgorod, hydrated lime in the form of carbide sludge from the dumps of Protvino plant (carbide sludge, hereafter), active mineral admixture biosilica from the group of companies “DIAMIX” and a plasticizer Sika viscocrete 5 new. Test methods are in accordance with applicable standards. To obtain samples of impregnated soils, a specially developed technique was used in the form of a unidirectional model. Results: properties of the composite binder prepared with different compositions are presented. The optimal component ratios are determined. The following properties of aqueous suspensions are studied: conditional viscosity, sedimentation and penetrating ability. Conditional viscosity is no more than 40 sec on average. Sedimentation does not exceed 1.2 %. Soil-concrete obtained by injection of a dilute aqueous suspension based on this composite binder has a compressive strength in the range from 4.44 to 12.5 MPa. Conclusions: utilization of finely dispersed composite mineral binder, which is based on interaction of amorphous silica with calcium hydroxide, as a binder for high penetration aqueous suspensions has been substantiated. This binder is not inferior to foreign analogues in terms of its strength and technological parameters and can be used for reinforcement of loose and low-strength soils. In case of using carbide sludge, the ecological and environment protection problems are being solved since it is a waste product in production of acetylene.

Subject: factors such as pipe wall roughness, mechanical properties of pipe materials, physical properties of water affect the pressure surge in the water supply pipes. These factors make it difficult to analyze the transient problem of pressure evolution using simple programming language, especially in the studies that consider only the magnitude of the positive pressure surge with the negative pressure phase being neglected. Research objectives: determine the magnitude of the negative pressure in the pipes on the experimental model. The propagation distance of the negative pressure wave will be simulated by the valve closure scenarios with the help of the HAMMER software and it is compared with an experimental model to verify the quality the results. Materials and methods: academic version of the Bentley HAMMER software is used to simulate the pressure surge wave propagation due to closure of the valve in water supply pipe network. The method of characteristics is used to solve the governing equations of transient process of pressure change in the pipeline. This method is implemented in the HAMMER software to calculate the pressure surge value in the pipes. Results: the method has been applied for water pipe networks of experimental model, the results show the affected area of negative pressure wave from valve closure and thereby we assess the largest negative pressure that may appear in water supply pipes. Conclusions: the experiment simulates the water pipe network with a consumption node for various valve closure scenarios to determine possibility of appearance of maximum negative pressure value in the pipes. Determination of these values in real-life network is relatively costly and time-consuming but nevertheless necessary for identification of the risk of pipe failure, and therefore, this paper proposes using the simulation model by the HAMMER software. Initial calibration of the model combined with the software simulation results and with the model of experiment showed the differences in confidence intervals using a model that created valve closure scenarios.