Magazine of Civil Engineering

RAR RUS 3-11 Peter the Great Saint Petersburg Polytechnic University Smolenkova Aleksandra sashasmolenkova@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Korovkin Vladimir korovkin40@yandex.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Nina Orlova orlova.ns@edu.spbstu.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Ragulin Kirill kir3221@gmail.com

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Kuzina Aleksandra 19sacha94@mail.ru

Polytechnicheskay, 29

Shielded retaining wall in the form of substandard rack-mount frame The article gives a practical implementation of the engineering method for calculation of different retaining walls types. The main provision of the method is to provide the construction calculation model as a combination of construction elements with the respective conditions of their fixing. The calculation model of shielded retaining wall (covered type of sheet pile wharf) is proposed in the form of substandard rack-mount frame where resilient ground attachment is accepted instead of rack lower anchorage. This model uses stiffness characteristics of the ground in the form of variable foundation modulus. The article considers the definition of lateral earth pressure on the wall while staying in sliding wedge of pile bent. The article gives an engineering solution for definition of diagrams of lateral pressure on the front wall with allowance for nonlinear influence of pile bent location, piles pitch and cross section. 10.18720/MCE.72.1 berth shielded retaining wall variable foundation modulus silage pressure incomplete sliding wedge https://engstroy.spbstu.ru/article/2017.72.1/

RAR RUS 12-19 57192664941 Peter the Great Saint Petersburg Polytechnic University Mishakova Anastasiia nastya.misha14@gmail.com

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Vakhrushkina Anna anna.vahrushkina@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Anishchenko Daria impurus@rambler.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Tatarkina Yuliya yuliya21121995@yandex.ru

Polytechnicheskay, 29

Program Evaluation and Review Technique as the tool for time control The free market economy comes to the life of the people and creates the new structure of the work relationships between the investors and builders. One of the most important thing of the investment and construction project is the meeting of the target date. The delays in the implementation of this project entail the material and image losses. But the building is a complex process, many factors such as delivery delays, adverse weather conditions, the correcting of low quality works, machinery and mechanisms breakdowns influence on it. During the planning stage it is unknown which of these situations may arise in the implementation process and disrupt the work schedule. That is why building projects require the strongest time control. This article presents one of the best ways to control the building process, which is named Program Evaluation and Review Technique (PERT). Although there were mentioned other variations of the time control methods, such as Graphical Evaluation and Review Technique (GERT) and method of the statistic modeling (Monte Carlo), the advantages of PERT and disadvantages of them are presented. It allows to control the expectancy of the erection and the probability of the project completion in time. This means that it allows manager to control the activity time of the project. The example of the PERT usage is represented with the comparison between the controlled project and the non-controlled project. 10.18720/MCE.72.2 project control time control investment and construction project probabilistic modeling Program Evaluation and Review Technique activity chart https://engstroy.spbstu.ru/article/2017.72.2/

RAR RUS 20-27 6602801860 0000-0001-7532-0074 Penza State University of Architecture and Construction Loganina Valentina loganin@mail.ru Penza State University of Architecture and Construction Pyshkina Irina glazycheese@gmail.com Penza State University of Architecture and Construction Martyashin Georgiy nowargore@gmail.com Effect of the supplement based on calcium hydrosilicates on the resistance of lime coatings It was proposed to use synthesized calcium hydrosilicates in lime finishing dry mixes as a modifying supplement. The effect of substances containing amorphous silica, which are used in the synthesis, on the activity of the modifying supplement was established. The effect of the synthesis mode of supplement on the structure formation of lime compositions was illustrated. It was found that the injection of supplements of hydrosilicates accelerates the increase of mechanical strength. The efficiency of the using of modifying supplements of amorphous silica, such as diatomite, in the synthesis was shown. The evaluation of hydrophysical properties of coatings based on lime dry mix with the using of supplements synthesized in the presence of calcium hydrosilicates was provided. It was shown that the injection of supplements of hydrosilicates accelerates the increase of water resistance and frost resistance of coatings. It was found that the adhesion of the lime compositions with the supplement based on calcium hydrosilicates, synthesized in the presence of diatomite, is higher than that of the compositions with the addition of calcium hydrosilicates synthesized without diatomite. 10.18720/MCE.72.3 supplement calcium hydrosilicates dry mixes diatomite https://engstroy.spbstu.ru/article/2017.72.3/

RAR RUS 28-35 Peter the Great Saint Petersburg Polytechnic University Andreeva Darya tarasovads@gmail.com

Polytechnicheskay, 29

56426211200 0000-0002-3541-0072 Peter the Great Saint Petersburg Polytechnic University Petrichenko Mikhail fonpetrich@mail.ru

Polytechnicheskay, 29

Buildings quasi-stationary thermal behavior The typical building constructions absorb the temperature wave caused temperature fluctuations of external air. It means this building construction has a thermal stability. Therefore, there is a reserve for warmth accumulation which can be used for decreasing of thermal losses. The developed mathematical model of temperature distribution in an enclosure structure allows estimating the cooling velocity of assorted designs of enclosure structures. And it shows the time which it is possible to turn off heating during the non-working period with maintenance required temperature condition in working period. This method allows reducing losses of heat energy considerably. It gives the chance to perform the optimum choice of periodic schedules of heating. Cost efficiency of implementation of the periodic mode of heating of the building is proved. 10.18720/MCE.72.4 enclosure structure thermal stability energy-efficiency average temperature construction materials https://engstroy.spbstu.ru/article/2017.72.4/

RAR RUS 36-45 Industrial University of Tyumen Rachkov Dmitry rachkov1991@yandex.ru Industrial University of Tyumen Pronozin Yakov geofond.tgasu@gmail.com OOO "GEOFOND" Chikishev Victor chikishev@tgasu.ru Qualified method of layer-by-layer summation to define the settlement of foundation The calculation of setting is the main criterion while designing shallow foundations as the complete setting. Methods of defining deformation in soil body show the calculation value of the final settlement which is several times different from the real. It is stated that the deformability of the ground coat is defined to a great extent by the degree of the horizontal intensity caused by natural pressure and by exterior additional loading. Here is offered a specified method of calculation of shallow foundations settlement based on the method of layer-by-layer summing. This method takes into account the separation of the exterior additional loading diagram into component parts which cause elastic and elastic-plastic deformations as well as changing the module of the general deformation of the layers of the earth foundation depending on the state of stress. To test the method there was conducted a comparative analysis with field testing of the ground coat of natural consistency by rigid stamps with its static loading. The calculation of setting by the method offered by the authors has a high convergence with the results of the experiments and reflects the general picture of deformations of the soil body while loading as well as unloading. 10.18720/MCE.72.5 elastic half-space settlement deformation modulus triaxial compression https://engstroy.spbstu.ru/article/2017.72.5/

RAR RUS 46-53 Demidov Nikolai Design of steel beams cross three directions with sprengel The article presents one of the possible formulations and solutions of the optimization problem of designing the cross-beams of the combined system, reinforced bongs. The basis for efforts as functions of variable parameters was a displacement method. Approximate analytical depending forces and displacements in beams, and the puffs. Analytical expressions possible to formulate the problem of how to design optimization. The article points out that the problem was posed and solved for a fixed geometry puffs and beams. This narrows the area of optimal solutions, but greatly simplifies the solution itself. The objective function – linear. Restrictions – nonlinear functions, therefore considered the problem relates to the problems of nonlinear programming. Optimum obtained in one of the points of intersection of two active constraints – for tightening strength and maximum permissible deflection of the structure. Because of this discrete mathematical optimum mix does not coincide with the physical, so the solution obtained approximately. 10.18720/MCE.72.6 dimensional steel construction cross beams with spatial tightening terms beams strength terms strength puffs deflection of the structure https://engstroy.spbstu.ru/article/2017.72.6/

RAR RUS 54-61 Peter the Great Saint Petersburg Polytechnic University Cherkashin Artemiy jizm@mail.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Pykhtin Kirill kirillandreevich@yahoo.co.uk

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Yasmin Begich yasmin1010@yandex.ru

Polytechnicheskay, 29

Peter the Great Saint Petersburg Polytechnic University Sherstobitova Polina polya-sherstobitova@yandex.ru

Polytechnicheskay, 29

Peter the Great St. Petersburg Polytechnic University Koltsova Tatyana annelet@yandex.ru

St. Petersburg, Russia

Mechanical properties of nanocarbon modified cement This article covers use of nanocarbon modified cement (nCMC) that was made with use of chemical vapor deposition method. The tests were performed with traditional destructive method as well as with the use of special ultrasonic equipment. The specimens with nCMC was tested for compressive and tensile strength. However, the results showed that use of nCMC made only minor effect on these characteristics, when results from other research groups indicate that nCMC improves cement’s properties greatly. Therefore, authors hypothesize that characteristics of nCMC modified paste matrix highly dependent on the geometrical characteristics of nanofiber such as length, type of structure (singlewalled, multi-walled) and chirality. This hypothesis is based on the ultrasonic tests' results. Furthermore, the positioning, distribution and the proportion in the material of carbon nanotubes (CNTs) needs to be researched more. 10.18720/MCE.72.7 buildings concrete CNT cement civil engineering construction materials carbon nanotubes nanofibers https://engstroy.spbstu.ru/article/2017.72.7/

RAR RUS 62-72 JSC "INSOLAR-INVEST" Vasilyev Gregory gpvassiliev@mail.ru JSC "INSOLAR-INVEST" Gornov Victor insolar-invest@yandex.ru Lomonosov Moscow State University Konstantinov Pavel kostadini@mail.ru JSC "INSOLAR-INVEST" Kolesova Marina eco-insolar@mail.ru Federal State Budgetary Institution "Institute of Global Climate and Ecology of Federal Service for Hydrometeorology and Environmental Monitoring and Russian Academy of Sciences" Korneva Irina comissa@mail.ru Analysis of ground temperature variations on the basis of years-long measurements The article deals with results of the analysis of years-long measurements of the ground temperatures, for example: Russia, Moscow. Data are given on variations of the ground temperatures in the course of a year, at a 10-days interval, in two plots of land – one under exposed surface, the other under natural cover. Trends of ground temperature variations have been shown, for a period of over 50 years. As a part of research, an important application task is being handled, that is acquisition of information on a typical curve of ground temperatures to enable carrying-out more correct calculations of ground heat exchangers for any region of any country, and making forecasts of operating efficiency of geothermal heat pump systems, including long-term forecasts. 10.18720/MCE.72.8 ground temperature ground heat exchangers ground warming thermal regime geothermal heat pump system https://engstroy.spbstu.ru/article/2017.72.8/

RAR RUS 73-83 57190161363 0000-0002-2328-6238 Ogarev Mordovia State University Nizina Tatyana nizinata@yandex.ru Ogarev Mordovia State University Balykov Artemy artbalrun@yandex.ru Ogarev Mordovia State University Volodin Vladimir volodinvv1994@gmail.com Ogarev Mordovia State University Korovkin Dmitrii asfkorovkin@yandex.ru Fiber fine-grained concretes with polyfunctional modifying additives The purpose of the experimental study was to research the efficiency of dispersive reinforcement and modifying of compositions of cement fiber fine-grained concretes with active mineral and chemical additives, and to optimize the developed compositions according to the strength efficiency criteria. Multicriteria optimization of compositions and properties of modified fiber fine-grained concretes is an urgent task in connection with the complexity of their formulations. The experimental study was planned on the basis of a D-optimal plan containing 15 experiments. Upon the experimental results, experimental and statistical models were built to reflect the dependencies of the limit of compressive strength and tensile strength in bending of fiber fine-grained concretes on the type and concentration of modifiers (mix I) and dispersive fibers (mix II). Analysis of study results of saturated D-optimal plan was carried out on triangular diagrams Gibbs-Roseboom, they was built with use polynomial models of "mixture I, mixture II, technology – properties" and allowed to trace influence of 6 to variable factors in two-dimensional space. Optimum fields of variation of fine-grained modified fiber concrete components are identified with use method of experimental-statistical modeling. The efficiency of modifying finegrained concretes with polyacrylonitrile fiber, astralene-modified basalt microfiber as well as with highly active metakaolin has been established. Use of these modifiers in the compositions allowed to obtain cement composites with a wide range of strength characteristics: from 30 to 53 MPa at compression, from 3.7 to 6.6 MPa for bending tensile. 10.18720/MCE.72.9 fine-grained concretes modifiers dispersive fiber mineral additive optimization limit of tensile strength in bending limit of compressive strength https://engstroy.spbstu.ru/article/2017.72.9/