75504
2712-8172
Magazine of Civil Engineering
4
64
2016
1-68
RAR
RUS
3-9
6506150284
0000-0003-1139-3164
Sainov
Mikhail
Moscow State University of Civil Engineering (National Research University)
mp_sainov@mail.ru
Moscow, Russia
Analysis of normal operation of a rockfill dam with combination of seepage-control elements: reinforced concrete face and clay-cement-concrete wall
The paper considers results of stress-strain state analysis for a 87 m high rockfill dam that is located in the layer of soil foundation and has a combined seepage-control element. In the lower part of the dam as well as in its foundation there is fixed a grout curtain by using slurry trench cut-off walls, and in the upper part there is fixed a reinforced concrete face. The wall and the face are conjugated via the reinforced concrete gallery. Analyses showed that both seepage-control elements have a favorable stress-strain state: no tensile stresses occur in them. In the considered dam the reinforced concrete face operates in more favorable conditions than in a traditional dam with a reinforced concrete face. This allows recommending this type of the dam for practical application in hydraulic engineering. The alternative is proposed with the design of conjugation of a reinforced concrete face and a seepage-control wall.
10.5862/MCE.64.1
concrete faced rockfill dam
cut-off wall
stress-strain state
numerical modeling
https://engstroy.spbstu.ru/article/2016.64.1/
01.pdf
RAR
RUS
10-25
56352359500
0000-0002-5156-7352
Sergey
Korniyenko
Volgograd State Technical University
svkorn2009@yandex.ru
28, Lenina Ave., Volgograd, Russia, 400005
M-6585-2013
6508103761
0000-0002-1196-8004
Vatin
Nikolai
Peter the Great Saint Petersburg Polytechnic University
vatin@mail.ru
Polytechnicheskay, 29
15730895100
http://orcid.org/0000-0003-3251-3356
Gorshkov
Alexander
Saint Petersburg State University of Industrial Technologies and Design
alsgor@yandex.ru
St. Petersburg, Russia
Thermophysical field testing of residential buildings made of autoclaved aerated concrete blocks
The object of investigation is one-type neighbouring blocks of flats located in Volgograd region (Russia, N 48°). Thermophysical field testing using eco-friendly nondestructive test methods was carried out to estimate whether the level of heat protection in buildings meets requirements of the Russian construction norms SP 50.13330.2012. According to the results of thermophysical field tests of residential buildings made of autoclaved aerated concrete blocks, the following was found out. Design of double-layer exterior walls in the form of AAC blocks with front brick masonry bears thermotechnical risks due to an increase in non-uniform heat protection of buildings’ covers caused by a significant impact on heat protection of buildings’ edge zones. The designed level of heat insulation does not conform to the basic level of heat protection for the majority of regions in the Russian Federation. Two-layer exterior walls without supplementary insulation practically do not have heat protection and energy saving reserves. The reduction of the actual insulation in envelopes, compared to the designed one, can be explained by both unapproved deviations from the design project made by a subcontractor during construction and low-quality construction and assembly work. It is strongly suggested to improve the structural solution of edge zones in envelopes to reduce thermotechnical risks when designing buildings. Supplementary insulation along the surfaces of the walls can be considered as another activity to increase heat protection.
10.5862/MCE.64.2
buildings; construction
energy efficiency
civil engineering
autoclaved aerated concrete
thermophysical field testing
heat monitoring
thermogram
https://engstroy.spbstu.ru/article/2016.64.2/
02.pdf
RAR
RUS
26-39
Saknite
Tatjana
Riga Technical University
tatjana.saknite@rtu.lv
Riga, Latvia
6508223358
Serdjuks
Dmitrijs
Riga Technical University
Dmitrijs.Serdjuks@rtu.lv
1 Kalku Street, Riga LV-1658, Latvia
Goremikins
Vadims
Riga Technical University
goremikins@gmail.com
H-5843-2013
57205122537
0000-0002-8367-7927
Pakrastins
Leonids
Riga Technical University
leonids.pakrastins@rtu.lv
M-6585-2013
6508103761
0000-0002-1196-8004
Vatin
Nikolai
Peter the Great Saint Petersburg Polytechnic University
vatin@mail.ru
Polytechnicheskay, 29
Fire design of arch-type timber roof
Lattice timber structures, which are made of elements connected by punched steel plates, are widely used for residential and industrial buildings. The main types of the structures are trusses, frames, and arches, which enables covering spans up to 30 m and more. The behavior of structures on fire plays an important role in the design process of the structures. The cylindrical roof with a 30 m span and the main load-bearing structures of lattice arches with elements connected by punched metal plates was considered as an object of investigation. The rational geometrical parameters of a lattice timber arch with punched steel plated joints were evaluated. Fire resistance and a possibility to increase it for an arch-type timber roof was also considered. It was obtained that using a protective layer is a preferable method of a fire resistance increase for the lattice timber arch due to arch joints; the material consumption was also increased by 1.65 times. It was shown that the rational values of the height of the arch, depth of the arch cross-section, and distance between the nodes on the top chord are equal to 7.85, 1.10, and 0.95 m respectively.
10.5862/MCE.64.3
punched steel plates
response surface method
fire resistance
https://engstroy.spbstu.ru/article/2016.64.3/
03.pdf
RAR
RUS
40-51
Tusnina
Olga
National Research Moscow State Civil Engineering University
lazoltus@mail.ru
Danilov
Alexander
National Research Moscow State University of Civil Engineering
alenk070911@yandex.ru
Moscow, Russia
The stiffness of rigid joints of beam with hollow section column
At present steel framework based buildings are prevalent in civil engineering. Application of hollow section columns have proven to be efficient in low-rise buildings. In some cases frame joints of beam to column connections are needed in this kind of building structures. This paper considers rigid joints of I-beam to hollow section column connections allowing for an elastic pliability. The results of pliability estimation of these joints are represented for various construction solutions. Dependences are obtained for the relation of the support moment in a beam to its corresponding value in absolutely stiff connection on the rigidity of the joint. The dependence diagrams of rigidity of the joint on the parameters of its elements are obtained.
10.5862/MCE.64.4
rigid joint
steel frameworks
hollow section
frame
https://engstroy.spbstu.ru/article/2016.64.4/
04.pdf
RAR
RUS
52-58
H-9967-2013
16412815600
0000-0002-8588-3871
Kirsanov
Mikhail
National Research University "Moscow Power Engineering Institute"
mpei2004@yandex.ru
14, Krasnokazarmennaya, 111250 Moscow, Russia
Analysis of the buckling of spatial truss with cross lattice
The construction of a beam type spatial truss is proposed. The truss consists of three plane trusses with a cross lattice. The supports of the structure are modeled at the four corner points. The simple analytical dependence of the structure deflection on its size, load and a number of panels has been found for the case of an even number of panels. In the case of an odd number of panels the system is kinematically changeable, which is evident from the zero determinant of the system of equilibrium equations. The system of Maple computer algebra and the method of induction, previously proposed and developed by the author when solving the problems of planar and spatial trusses has been used. A nonmonotonic dependence of the deflection on the number of panels and the expected increase in stiffness at the increased truss height and unexpected decrease in stiffness at an increased base width have been found. The forces in some members of the truss change the sign depending on the parity of the number of panels in half of a span. Asymptotes of the solution are detected. The features of the solution allow optimizing the size of the structure.
10.5862/MCE.64.5
deformation
method of induction
spatial truss
coating
cross lattice
https://engstroy.spbstu.ru/article/2016.64.5/
05.pdf
RAR
RUS
59-68
Kanishchev
Ruslan
Technical University of Kosice
ruslan.kanishchev@gmail.com
Kosice, Slovak Republic
Analysis of local stability of the rectangular tubes filled with concrete
The use of rectangular steel tubes filled with concrete allows combining the advantages of concrete (reinforced concrete) and steel structures with reciprocal compensation of their disadvantages. Building code Eurocode 4 is used for the design of such structures in the European Union, but the main disadvantage of this standard is its limitations for use of the class 4 rectangular steel cross-sections (classification according to standard EN 1993-1-1) filled with concrete. Therefore, the study of local stability of such structures and the impact of friction between the components of the composite section on it is relevant. The analysis of the influence of friction between the steel shell and the concrete core on the local buckling of composite structures was carried out using the ABAQUS computational-graphics software. The models of behavior of axial compressed rectangular cross-section samples with different coefficients of friction between the shell and the core were created for this. The load on the samples was applied in two variants: a) simultaneously through the steel section and the concrete core; b) only through the steel section. The variants with different fixing conditions of loaded edges of the steel section were also considered. Based on this research, the basic laws of development of local buckling deformation of the structures under study were analyzed. The influence of the conditions of fixing the loaded edges of the steel section to local buckling deformation of the composite structure was determined. The dependence of the friction effect between the components of steel-concrete section on the local stability of rectangular tube was shown.
10.5862/MCE.64.6
composite structures
local buckling
friction
finite element method
Eurocode
https://engstroy.spbstu.ru/article/2016.64.6/
06.pdf