75504
2712-8172
Magazine of Civil Engineering
4
72
2017
1-83
RAR
RUS
3-11
Nina
Orlova
Peter the Great Saint Petersburg Polytechnic University
orlova.ns@edu.spbstu.ru
Polytechnicheskay, 29
Ragulin
Kirill
Peter the Great Saint Petersburg Polytechnic University
kir3221@gmail.com
Polytechnicheskay, 29
Kuzina
Aleksandra
Peter the Great Saint Petersburg Polytechnic University
19sacha94@mail.ru
Polytechnicheskay, 29
Smolenkova
Aleksandra
Peter the Great Saint Petersburg Polytechnic University
sashasmolenkova@mail.ru
Polytechnicheskay, 29
Korovkin
Vladimir
Peter the Great Saint Petersburg Polytechnic University
korovkin40@yandex.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
Anishchenko
Daria
Peter the Great Saint Petersburg Polytechnic University
impurus@rambler.ru
Polytechnicheskay, 29
Tatarkina
Yuliya
Peter the Great Saint Petersburg Polytechnic University
yuliya21121995@yandex.ru
Polytechnicheskay, 29
57192664941
Mishakova
Anastasiia
Peter the Great Saint Petersburg Polytechnic University
nastya.misha14@gmail.com
Polytechnicheskay, 29
Vakhrushkina
Anna
Peter the Great Saint Petersburg Polytechnic University
anna.vahrushkina@mail.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
Martyashin
Georgiy
Penza State University of Architecture and Construction
nowargore@gmail.com
6602801860
0000-0001-7532-0074
Loganina
Valentina
Penza State University of Architecture and Construction
loganin@mail.ru
Pyshkina
Irina
Penza State University of Architecture and Construction
glazycheese@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
Andreeva
Darya
Peter the Great Saint Petersburg Polytechnic University
tarasovads@gmail.com
Polytechnicheskay, 29
56426211200
0000-0002-3541-0072
Petrichenko
Mikhail
Peter the Great Saint Petersburg Polytechnic University
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
Chikishev
Victor
OOO "GEOFOND"
chikishev@tgasu.ru
Rachkov
Dmitry
Industrial University of Tyumen
rachkov1991@yandex.ru
Pronozin
Yakov
Industrial University of Tyumen
geofond.tgasu@gmail.com
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
Yasmin
Begich
Peter the Great Saint Petersburg Polytechnic University
yasmin1010@yandex.ru
Polytechnicheskay, 29
Sherstobitova
Polina
Peter the Great Saint Petersburg Polytechnic University
polya-sherstobitova@yandex.ru
Polytechnicheskay, 29
Koltsova
Tatyana
Peter the Great St. Petersburg Polytechnic University
annelet@yandex.ru
St. Petersburg, Russia
Cherkashin
Artemiy
Peter the Great Saint Petersburg Polytechnic University
jizm@mail.ru
Polytechnicheskay, 29
Pykhtin
Kirill
Peter the Great Saint Petersburg Polytechnic University
kirillandreevich@yahoo.co.uk
Polytechnicheskay, 29
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
Konstantinov
Pavel
Lomonosov Moscow State University
kostadini@mail.ru
Kolesova
Marina
JSC "INSOLAR-INVEST"
eco-insolar@mail.ru
Korneva
Irina
Federal State Budgetary Institution "Institute of Global Climate and Ecology of Federal Service for Hydrometeorology and Environmental Monitoring and Russian Academy of Sciences"
comissa@mail.ru
Vasilyev
Gregory
JSC "INSOLAR-INVEST"
gpvassiliev@mail.ru
Gornov
Victor
JSC "INSOLAR-INVEST"
insolar-invest@yandex.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
Volodin
Vladimir
Ogarev Mordovia State University
volodinvv1994@gmail.com
Korovkin
Dmitrii
Ogarev Mordovia State University
asfkorovkin@yandex.ru
57190161363
0000-0002-2328-6238
Nizina
Tatyana
Ogarev Mordovia State University
nizinata@yandex.ru
Balykov
Artemy
Ogarev Mordovia State University
artbalrun@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/