Construction and Geotechnics

Last studies have shown that radon and it progeny in indoor air forms the most part of human annual radiation dose. As a result, investigation of the radon situation regularities in a building is an actual scientific and practical problem. Radon situation in a building is the result of the radon transport processes in the “ground - atmosphere - building»” media system. The multifactor character of radon situation formation process makes the difficult interpretation of the “in situ” measurements results. Therefore mathematical modeling is the only effective means of radon entry describing into the lower floor apartments of the buildings. The radiation safety of the designed buildings and structures is the object of this study, and it purpose is to substantiate the type and characteristics of the mathematical model that allows to describe adequately the radon entry into the projected buildings on the basis of diffusion radon transport model. Experimental (experiment and modeling) and theoretical (idealization and correlation analysis) research methods are used in the work. The “equivalent” radon diffusion coefficient in the material introducing justified the laboratory experiment results. This coefficient allows for the contribution of thermodiffusion and bardiffusion effects to the radon transport process. In addition, the mathematical model of radon transport in the “soil - atmosphere - building” media system is a proposed; the calculations results showing the relationship between the main radon situation parameters in a building.

Express methods are actively used in the control of compaction and determining the deformation characteristics of the soil in foreign construction practice. Earlier, the authors have made an overview of methods and selected method of dynamic stamp for further research. The method of dynamic stamping has the following advantages: low labor intensity and speed of experiments, moreover, there are theoretical prerequisites for the use of the method of dynamic stamping, which can help to find a functional relation between the deformation characteristics of the soil. In the present work the analysis of existing theoretical methods for the calculation of the soil from the action of the shock of ramming. Since the impact on the soil from the impact of the tamper and the method of dynamic stamp is similar, it is possible to use this technique to analyze the dynamic modulus obtained during the dynamic stamp tests. To determine the applicability of this method, the authors conducted experimental studies. The method of dynamic die is implemented using dynamic density meter DPG 1.2. Dynamic density meter is a device consisting of a guide rod, a falling load and a die, as well as sensors for measuring force and acceleration. The description of the program of experiments is given. The results of the experiments after removal of gross errors using the approximation was built by the following dependencies: dependency of the compression deformation modulus and dynamic modulus of elasticity of the compression ratio; the dependence of the compression modulus of deformation and modulus of elasticity is determined using the theoretical method of compaction ratio. The resulting dependences are analyzed and recommendations are given for assessing the deformation characteristics of the soil.

The article presents the results of the study of the stress-strain state of the pile Foundation reinforcement system by means of their transformation into a combined Foundation with the pressing and cementation of the soil base. The regularities of the interaction of the object under study with the soil base are revealed. As a result of the technical inspection it was revealed that the building is in a limited working condition. To stabilize the deformations and to stop their further development, the authors of this article proposed comprehensive solutions to strengthen the bases and foundations. These solutions included strengthening existing tape of pile foundations by their conversion to combined foundation and crimping and subsequent grouting of the foundation soil. The complexity of the approach is to increase the reliability due to the redistribution of the load from the building to the previously unloaded areas of the base without additional sediment, performed by pressing the cement mortar of the span zones between the grillage. The implementation of soil cementation is due to the need to increase the rigidity of the base, which is redistributed part of the load, and deter the manifestation of «floating» properties of soils. According to the results of the survey of the technical condition of the object, it was decided to strengthen the foundations with shells, with the pressing of the ground base pressure of about 110 kPa and cementation of the ground base to a depth of 7 m from the bottom of the grillage on the cuff technology. The technology of work performance and the results of geotechnical monitoring, confirming the effectiveness of the proposed method of strengthening at the time of work was described as well.

In this article, the issue of modeling a reinforced earth retaining structure, facing of which is made of individual face elements, is used in the cramped conditions of urban development. One of the main issues of the current dissertation research is the determination of the optimal parameters of the facial elements of the retaining wall, which justifies the conduct of experimental work. The author performed simulation of a reinforced earth structure. The parameters of the main elements of the tested structure are given: the front wall (lining), reinforcing tapes, ground-backfilling. The method of erecting a model of a reinforced earth retaining structure is described step by step, and variants of its loading are indicated. To record the horizontal deformations of each face element during the loading, indicators of the watch type IC-10 are used. The degree of compaction of sand during the construction of the model is measured using a density meter Y.N. Murzenko. As a material for the execution of the model, PVC cloth Unisol was adopted. Experiments are carried out at the Department of ICEGaF SRSPU (NPI) name of M.I. Platov in a flat deformation tray made of organic glass with working space dimensions of 0.8×0.1×0.6 m. The test results are entered in the tabular form, where: the time of the experiment is recorded; density of base and backfilling ρ; all geometric parameters of the model; indicators of displacement of facial elements and other observations on the course of the experiment. The aim of the conducted studies is to obtain the most reliable behavior of the reinforced earth retaining structure taking into account the different lengths of the vertical and horizontal sections of the face elements under different loading options in accordance with the patent No. 2604933 «Design of the urban security system and the method of its erection.».

The problem of energy saving is particularly acute at the present time. The high degree of wear and tear of the housing stock in Russia is also manifested in the serious aging of heat networks and their operation modes. A large proportion of the heat supplied to the facilities is lost without reaching the end user. This creates a situation where residents of residential buildings are forced to pay for the heat that goes nowhere. As a result, utility bills, whose constant growth is a major social problem, become even bigger, and the resulting economic effect is less.One of the modern measures to improve the energy efficiency of residential buildings is the transition from a centralized heating system to an Autonomous one. This decision in the Russian conditions, in addition to the benefits, carries a potential danger. Thus, the thermal power station, in addition to generating thermal energy, produces electricity. In this case, there is a situation when the CHP to maintain the profitability of its work will be forced to raise electricity tariffs. For this reason, measures to optimize its costs within the centralized heating system are preferable to save the coolant. Improving the efficiency of the use of the coolant can bring tangible economic benefits to management companies and residents. In this article the solution of the problem of increase of efficiency of use of thermal energy in apartment houses will be considered: a number of actions for optimization of work of heating system are offered, results of economic efficiency of these actions within the given conditions of the investment project are calculated, energy efficiency of object and its class of energy saving is defined.

Reliability and technical safety of the bearing structures is one of the most important areas of operation of industrial buildings. Petroleum products (PP), which are widely used in industrial processes, fall on concrete and reinforced concrete structural elements and gradually impregnate them. This leads to a significant modification of the original physical and mechanical characteristics of concrete and reinforced concrete and can serve as the technical cause of accidents and emergencies. Different Effects of PP is due to the unequal changes of their hydraulic pressure in the pores of the skeleton of cement stone. Methods and recommendations for the assessment of the reliability of concrete and reinforced concrete structures, which are currently not take into account changes in their initial physical and mechanical characteristics, arising under the influence of petroleum products. In the researches we used samples of concrete and cement-sand mortar, divided into two series: impregnated in PP of different viscosities and controlled samples - without impregnation by PP. The study was performed on the basis of analyzing and generalizing the data of experimental study of the influence of PP of different viscosity on the physical and mechanical properties of concrete, using the methods of probability theory and mathematical statistics. The developed empirical models of effect of viscosity of PP on strain properties and endurance of concrete allow to calculate the safety index as a measure of the reliability of load-bearing CRC structures soaked by PP. The obtained results allow to make the scientifically substantiated forecast the variations in physical and mechanical characteristics of load-bearing CRC structures soaked by PP and give a quantitative characterization of their technical condition. The research in this direction is continued.

This article is a full-scale study based overview of a military town construction and its architecture, which was constructed in Krasnoyarsk of the early XX century for the 31st East Siberian shooting regiment. In here organization and deployment principles of military infrastructure in Russia in the early 20th century years century are discovered. Stylistic features characteristics of the military department buildings are provided as well. After Russian army was turned into the all classes military service (in January 1874), an increased number of troops made a problem of units deployment quite actual. In 1876, in order to resolve this problem, the Government adopted an order on the rapid construction of the most necessary military infrastructure - military towns. A right to resolve these problems was provided to the specially created Economic and Construction Commissions. Simplified norms and rules were developed and published, containing requirements and general conditions on the construction of barracks. Barracks commissions which included engineers and architects were involved in construction of military infrastructure. One of the military infrastructure objects, the construction of which was especially intensive in Siberia in 1900s, was a military town in Krasnoyarsk. It was designed to house the 31st East Siberian shooting regiment, which took an active part in the Far East military activities, and after the Russian-Japanese War (1904-1905) was transferred to the Siberian military district. The reason for such deployment, as well as any other Siberian military units, was the real threat of a new armed conflict on the eastern borders of Russia. The planning structure of the Krasnoyarsk military town, located at the eastern edge of the Yenisei province capital, on the land area allocated by the city council, was planned to become a large town-planning ensemble, formed on the principles of regularity. Around the central planning core of the ensemble, occupied by an large square-parade ground, some buildings of various functional purposes were constructed. Among the two- and three floor buildings, built of bricks in good quality (with the exception of wooden services in the officer wings), the largest beauty was the regimental church, which was named after and in honor of Metropolitan Alexy from Moscow. Its architecture, which had eclectic features with elements of Russian style, corresponded to the exemplary design of the military church, created in 1901 by the order of the Russian authorities by military engineer F.M. Verzhbitsky. All the buildings of the Krasnoyarsk military town ensemble were constructed in a «brick style».