Magazine of Civil Engineering

RAR RUS 3-10 0000-0003-2533-9732 National Research Moscow State Civil Engineering University Samarin Oleg samarin-oleg@mail.ru Temperature in linear elements of enclosing structures Window slopes are one of the most important linear elements of external wall structures with two-dimensional and even three-dimensional temperature field. Thereby, they cause additional risk of non-compliance of sanitary and hygienic requirements. In the proposed work one of the typical designs of window slopes is considered as the object of study, namely the fastening of the window unit with steel fixings to one of the two major layers of the wall – insulation or constructive. Peculiarities of designing two-dimensional stationary temperature field in the structure of the site abutting window units to the aperture of residential and public buildings are considered. Results of calculation of temperature in hazardous adjunction points for the design winter conditions with the help of software that implements the finite element method are presented. The analysis of the obtained data is given and the comparison of the behavior of minimum temperatures in the zone of adjacency of the fill of the lighting aperture with the results of analytical calculation based on the conform transformation for the concave corner is proposed if you move the window block in the cross section of the outer wall. It was discovered that the closer the fill to the outer plane of the facade a minimum of the temperature decreases according to the law which coincides enough closely with the analytical solution. Recommendations on the optimal placement of fill within the structural layer of the wall for the best sanitary-hygienic requirements for outdoor enclosures are confirmed. The presentation is illustrated with examples of temperature fields for the node of adjunction in a residential building on one of the modern projects. 10.18720/MCE.70.1 window unit slope thermal nonuniformity temperature field concave corner energy efficiency buildings https://engstroy.spbstu.ru/article/2017.70.1/

RAR RUS 11-17 Peter the Great Saint Petersburg Polytechnic University Statsenko Elena staclena@mail.ru

Polytechnicheskay, 29

57189345350 0000-0002-8380-0067 Peter the Great St. Petersburg Polytechnic University Koriakovtseva (Musorina) Tatiana

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great Saint Petersburg Polytechnic University Ostrovaia Anastasiia stasya2609@yandex.ru

Polytechnicheskay, 29

Peter the Great St. Petersburg Polytechnic University Olshevskiy Vyacheslav 79119199526@yandex.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great Saint Petersburg Polytechnic University Antuskov Anton antuskov.anton@gmail.com

Polytechnicheskay, 29

Moisture transport in the ventilated channel with heating by coil This article considers the moisture transport phenomenon in the vertical ventilated channel. HVF construction parameters are determined influencing the rate of moisture transport. It is necessary to have h ≤ L/25 ≈ 8 cm. The greatest air movement is created in the construction with the open rustications. The optimal location of the heat sources on the channel height, as well as their favorable combination from the point of view for the process of drying the outer surface of the thermal insulation material, was identified. The air velocity dependences on height of an air gap are determined and it was found that the greatest values taken at the maximum height velocity. Ratio between the moisture transport and the distance to the heat source is installed. Drying processes are compared with the various combinations of heat sources. The direct dependence of the vaporation weight rate of the time is installed. 10.18720/MCE.70.2 buildings ventilated facades moisture transport facing layer thermal insulation air gap heating coil https://engstroy.spbstu.ru/article/2017.70.2/

RAR RUS 18-32 57194112309 0000-0001-6184-2365 Vyatka State University Tyukalov Yury yutvgu@mail.ru The functional of additional energy for stability analysis of spatial rod systems The problem solutions of stability of spatial rod systems by finite elements method in stresses were considered. The proposed method is based on a combination of functional additional energy and the principle of virtual displacements, used for the construction of the equilibrium equations. After discrediting of the subject field, solution of the problem is reduced to the search of the minimum of additional strain energy functional with constraints in the form of the system of linear algebraic equilibrium equations of the nodes. The equilibrium equations are included in the functional with the help of Lagrange multipliers, which are displacements of the nodes. Equations are derived for the static analysis based on approximations of internal forces (stresses) for the spatial rod systems. To solve the stability problems, in the functional of additional energy there are added additional energy the longitudinal deformations, arising due to the bending of rods. Form of the rod buckling is approximated by a linear function on finite element field. Two variants of the internal forces approximations on the finite element field: linear and piecewise constant were considered. Calculations of critical forces (loads) have been performed by the proposed method for the straight rods with different variants of the ends support and the spatial frameworks. The calculation results were compared with the analytical solutions and the solutions obtained by the method of finite elements in displacements. Analysis of the results shows that the use of piecewise constant approximations of internal forces leads to convergence to the exact values of the critical forces (loads) is strictly from below and provides solution with the reserve of stability. 10.18720/MCE.70.3 stability finite element method in stresses piecewise constant stress an additional energy functional the lower limit of solutions critical force reserve of stability https://engstroy.spbstu.ru/article/2017.70.3/

RAR RUS 33-41 Peter the Great St. Petersburg Polytechnic University Sokolov Vladimir sva0808@rambler.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great St. Petersburg Polytechnic University Strakhov Dmitry sdaleks2008@rambler.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great St. Petersburg Polytechnic University Sinyakov Leonid

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great Saint Petersburg Polytechnic University Vasiutina Sofia sofi-le@yandex.ru

Polytechnicheskay, 29

Stress state of protective shells in the area of holes due to prestressed reinforcement curvature The stress state around the holes in cylindrical part of prestressed concrete protective shells is examined in this paper. This stress state is caused by general shell prestressing having the aim to compensate internal emergency pressure and the curvature of the reinforcement elements near technological holes in cylindrical part of shell. Presence of technological holes predetermines occurrence of so called “disturbed” stress state of a local nature (stress concentration). The exact solution of the stress concentration problem at any load does not exist even for a plate. So the approximate solution using complex functions and Fourier series for a plate with a hole is proposed. It can be concluded on the basis of the calculation results that the stress concentration due to curvature of reinforcement elements near hole has to be taken into account, since in this case the maximum compressive stress is considerable. 10.18720/MCE.70.4 prestressed concrete shell reinforcement holes in shell curvature of reinforcement elements stress concentration complex functions Fourier series approximate solution https://engstroy.spbstu.ru/article/2017.70.4/

RAR RUS 42-56 56503963100 Lomonosov Moscow State University Zavyalov Mikhail zavyalov.m.a@gmail.com 7102546144 0000-0001-7651-1534 Moscow Automobile and Road Construction State Technical University Kirillov Andrey kirill806@gmail.com

Sochi, Russia

Evaluation methods of asphalt pavement service life A functional relationship of the dynamics of asphalt concrete pavement condition and its thermodynamic and thermophysical functions and parameters (Helmholtz's energy, internal energy, entropy, specific heat, etc.) is described. Based on this functional relationship, novel approaches to the estimation of asphalt pavement lifetime are proposed. The dependence of pavement lifetime from the basic thermodynamic parameter – specific heat (for the determination of which expensive and complicated equipment is not required) is derived. The statistical approach to determination of pavement lifetime, based on the analysis of the temporal changes in the spatial distribution of the basic parameter (specific heat) is proposed. Overall, three alternative but complementary approaches are described to determine pavement service interval using either a molar weight, a change of free energy, or the uniformity of the basic parameter – specific heat based the index of thermophysical uniformity (a dimensionless coefficient). Numerical pavement lifetime values suitable for exploitation under the Russian service conditions (transportation and construction terms) are calculated analytically. Regardless of the approach used of the calculated pavement lifetimes are of the same order of magnitude. These initial results are quite promising and offer a new thermodynamic approach to the estimation of pavement condition and its useful lifetime. This practical new approach can be utilized to replace or complement the traditional "mechanical" and geo-radar methods. 10.18720/MCE.70.5 civil engineering road construction asphalt pavement pavement evaluation energy characteristics thermodynamic framework https://engstroy.spbstu.ru/article/2017.70.5/

RAR RUS 57-71 Peter the Great Saint Petersburg Polytechnic University Korovkin Vladimir korovkin40@yandex.ru

Polytechnicheskay, 29

Engineering kinematic theory in application to the calculation of pile foundations The author has proposed a variant of calculation of pile foundation with the use of the engineerin kinematic theory of ground contact pressure. This calculation uses two separate graph connection, the pressure – vertical or horizontal offset. The diagrams are dimensionless, so is not related to the scale of the building. The absolute values of the end points of the graphs are determined considering the plastic deformation modulus of the soil. Diagram enables the calculation of pile foundation for the entire load cycle. Practical implementation of calculations uses variable from of the depth and the load of the coefficient stiffness soil. The author considered the combined model the stiffness of the soil based on the structural surrounding the pile. The article presents fragments of the calculation of stresses and displacements of pile foundations. 10.18720/MCE.70.6 pile foundation lateral pressure vertical jet pressure high and low pile grillage the stiffness coefficient of the soil dimensionless curve relation from the horizontal and vertical pressure https://engstroy.spbstu.ru/article/2017.70.6/

RAR RUS 72-83 Military Space Academy named after A.F. Mozhaysky Soldatenko Vladimir soldatenko_vs@mail.ru Military Space Academy named after A.F. Mozhaysky Smagin Vladimir va_smagin@mail.ru Military Space Academy named after A.F. Mozhaysky Gusenitsa Yaroslav Yaromir226@mail.ru Military Space Academy named after A.F. Mozhaysky Gera Vasiliy geratv33@mail.ru Peter the Great St. Petersburg Polytechnic University Soldatenko Tamara soldatenko_tn@bk.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

The method of calculation for the period of checking utility systems The model and the procedure of optimization of the periods of control and scheduled maintenance in relation to the equipment of technical systems are considered. This approach is implemented on the basis of performance of a condition of a minimum of average losses of target use of the equipment. The specified losses are possible because of non-optimal frequency of control and prophylaxis of objects of technical networks. In article the approach used in the theory of information for minimization of decrease in informative value because of breaks by its transfer is considered. Feature of the offered approach is use of integer quantization of intercontrol intervals and the accounting of casual duration of operation of the equipment. Theoretical conclusions are illustrated by settlement examples. 10.18720/MCE.70.7 equipment engineering and technical systems optimal control period technical condition failure https://engstroy.spbstu.ru/article/2017.70.7/

RAR RUS 84-92 Peter the Great Saint Petersburg Polytechnic University Terleev Vitaly vitaly_terleev@mail.ru

Polytechnicheskay, 29

56825555100 0000-0001-6865-245X Peter the Great Saint Petersburg Polytechnic University Nikonorov Aleksandr coolhabit@yandex.ru

St. Petersburg, Russia

Peter the Great Saint Petersburg Polytechnic University Volkova Yulia yv1975@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Togo Issa issatogo@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Ginevsk Roman rginevski@gmail.com

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Lazarev Viktor lviktor.97@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Khamzin Emil Ham_mer97@mail.ru

Polytechnicheskay, 29

St.Petersburg State Agrarian University Garmanov Vitaly garmanovv@mail.ru Leibniz-Centre for Agricultural Landscape Research Mirschel Wilfried wmirschel@zalf.de Peter the Great Saint Petersburg Polytechnic University Akimov Luka lukas-ak@mail.ru

Polytechnicheskay, 29

Hysteretic water-retention capacity of sandy soil Before the construction project, it is necessary to investigate the hydrological conditions of territory. For this purpose some hydrophysical indicators of the soil should be measured. Among the most important indicators is the water-retention capacity. It is convenient to use a physically justified model to research sorption-desorption properties of soil with respect to moisture. The authors have investigated the mathematical model, which was developed to describe the hysteresis of water-retention capacity. The computer program “HYSTERESIS” was been used to implement this research. Three computational experiments were carried out with the use of this program. The results allow improving the accuracy of calculating the dynamics of soil moisture. The results of the research could be applied to the agricultural research, hydrological conditions investigations and other area of knowledge. 10.18720/MCE.70.8 soil; water-retention capacity; hysteresis; reversal points; scanning curves; approximation accuracy; “pump effect” parameters identifying; model verification https://engstroy.spbstu.ru/article/2017.70.8/