1.029
2712-8172
Magazine of Civil Engineering
1
61
2016
1-88
RAR
RUS
4-13
Utkin
Vladimir
Vologda State University
UtkinVoGTU@mail.ru
Vologda, Russia
Calculation of the reliability of the earth foundations of buildings and structures according to the deformation criteria with limited information on the soils and loads
GOST R 54257–2010 recommends calculating the reliability of the earth foundations of structures by probabilistic methods with full statistical information about random quantities. Currently, there are no guidelines for calculating the reliabilityof earth foundations by the settlement with limited information about the parameters. The earth foundation (foundation bed) is a part of a mechanical system also including the foundation itself and the above-foundation construction. One of the indicators of the safety of this system is the probability of non-failure, where the probability of non-failure of an earth foundation is included. In this article, we discussed a new method for calculating the reliability of earth foundations of buildings and structures during the operation stage according to the deformation criterion with limited information on the soil and loads by using Zadeh’s extension principle from fuzzy sets theory. The article presents formulas and an example of an algorithm for calculating earth foundation reliability by the settlement criterion.
10.5862/MCE.61.1
foundation bed; foundation workability; safety; foundation settlement; reliability calculation; possibilistic method; Zadeh’s extension principle; fuzzy sets; reliability interval; theory of evidence
https://engstroy.spbstu.ru/article/2016.61.1/
01.pdf
RAR
RUS
14-24
Serpik
Igor
Bryansk State University of Engineering and Technology
iserpik@online.debryansk.ru
57191530761
0000-0002-4765-5819
Alekseytsev
Anatoly
National Research Moscow State Civil Engineering University
aalexw@mail.ru
Optimization of flat steel frame and foundation posts system
The development of effective design solutions for many construction projects requires taking into account the bearing capacity and the cost of manufacturing the superstructure and the foundation as a single system. We suggested an algorithm of complex optimal design of a steel flat frame for the building frame, and foundation posts under its columns on the natural foundation. It is proposed to minimize the cost of materials of basic variable parts of the structure. The search is carried out using a genetic algorithm on the discrete sets of standard sizes of cross-sections of frame rods, sizes in terms of foundation bases and base steel plates, foundations heights and overhangs of their jumps, concrete and reinforcement grades, diameters and installation steps of longitudinal reinforcement bars. The rod design scheme is used for the frame. The influence of normal forces in bars on their bending strains is taken into account. Vertical and angular compliances of ground base are taken into consideration. The example of optimizing a three-span steel frame and foundation posts of a building during the construction process in the town of Bryansk is given.
10.5862/MCE.61.2
steel frames; foundation posts; natural foundation bed; optimization; genetic algorithms; design parameters; strength
stability
https://engstroy.spbstu.ru/article/2016.61.2/
02.pdf
RAR
RUS
25-32
Tinkov
Dmitriy
"Raduga" State Engineering Design Bureau JSC named after A.Y. Bereznyak
dvtinkov@yandex.ru
Dubna, Russia
The optimum geometry of the flat diagonal truss taking into account the linear creep
We have found the exact analytical expressions for the optimal geometry and minimum mass of a diagonal truss beam made of a material with properties of linear creep. We have derived simple analytical expressions for the deflection of the optimal weight of the truss. The deflection of the truss was calculated by the Maxwell - Mohr formula. We found solution generalizations for any number of panels by induction. The research was carried out with the support of the Maple computer mathematics system in symbolic form. The multifunctional Lira software package intended for the design and numerical calculation of buildings and engineering structures was used for comparing and testing the solutions.
10.5862/MCE.61.3
diagonal truss; weight; deflection; analytical solution; induction; linear creep
https://engstroy.spbstu.ru/article/2016.61.3/
03.pdf
RAR
RUS
33-41
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
The exact formulas for calculating deflection and forces in the rods of the ’Molodechno’ truss with an arbitrary number of panels
We have obtained an analytical expression for the deflection and forces in the rods of a flat truss of beam type in the elastic stage. We found that the induction method, which has been tested for a wide class of two-dimensional elastic and regular trusses, does not yield a direct and compact result for trusses with an inclined upper chord. Decomposing the deflection into a series of a small parameter characterizing the slope is only suitable for very small tilts that are not typical for real practical application. The formulas for the forces in the rods of the truss include the geometrical and physical parameters, the number of a rod in the belt or grid, and the number of panels. The asymptotics of the solution for the deflection taking into account the different rod stiffnesses (the slope of the upper belt is random) were found. All the analytical transformations were executed in the Maple computer algebra system.
10.5862/MCE.61.4
truss
deflection; induction method; exact solution; Maple
https://engstroy.spbstu.ru/article/2016.61.4/
04.pdf
RAR
RUS
42-59
Kikot
Andrey
Polzunov Altai State Technical University
deltaing@mail.ru
Barnaul, Russia
Design of cold-formed tension members using the CFSteel software
A review of literature in research and calculate of cold-formed steel tension members with bolt attachments is presented. Limit States of such members may be: excessive elongation, a rupture in the weakened cross-section along the member, a rupture in the net cross-section with the holes at connection, bearing, block shear. A CFSteel software for calculation of the strength of tension members was developed. The Russian building code SP 16.13330.2011, Eurocode and North American Specification AISI S100 were implemented. It was shown that at short attachments with the number of transverse rows of bolts not exceeding two (in some cases, three) design strength according to the general case of Russian code is not reliable. It was suggested the members with cross-sections similar to channel, to treat as a members consisting of two angles, attached by one leg, and calculate the strength using appropriate formula of SP 16.13330.2011. In the case of member attachment by bolts in the flanges the value of reduction coefficient U and tensile strength for rupture in net section according to standards AISC 360–10 and AISI S100 gives similar results.
10.5862/MCE.61.5
cold-formed steel member; tension; attachment by bolts; SP16; Eurocode; North American Specification; CFSteel
https://engstroy.spbstu.ru/article/2016.61.5/
05.pdf
RAR
RUS
60-73
Bondarev
Alexey
Donbas National Academy of Civil Engineering and Architecture
bondarev_a_b_rus@mail.ru
Makiyivka, Ukraine
Yugov
Anatoliy
Donbas National Academy of Civil Engineering and Architecture
amyrus@mail.ru
Makiyivka, Ukraine
Тhe method of calculating the accuracy of large-span metal rod systems
The article presents a method for calculating the accuracy of large-span metal rod systems and its mathematical model. The method takes into account the connectivity of hinged-rod metal shells, the technology of their construction and the gaps in the bolted joints. The latter are caused by the the center of the hole deviating from its designed position and by the actual shape of the holes for the bolts designing from the nominal form. An example of calculating the hinged-rod shell with polybolted seams on the lining is described in the article. It is also shown how to use the proposed methodology for calculating the accuracy of hinged-rod metal shells in general combined with the previously proposed method for generating hinged-rod systems. Consequently, the proposed method for calculating the accuracy of large-span metal rod systemscan be used for determining the deviations of both the whole hinge-rod system and its individual elements. in the method presented in this papercan be used when calculating the accuracy of a variety of joint-core multiple systems, made from metal, e.g., support tower chimneys, radio telescopes, cooling towers, antennas and similar structures.
10.5862/MCE.61.6
large-span metal shells
calculation of accuracy
deflection assembly
geometric modeling
theory of dimensional chains
control theory
mounting loads
https://engstroy.spbstu.ru/article/2016.61.6/
06.pdf
RAR
RUS
74-81
Sergeyev
Oleg
Nizhny Novgorod State Technical University n.a. R.Е. Alekseev
nnsoa@rambler.ru
Nizhny Novgorod, Russia
Kiselev
Vladimir
kis_vg@mail.ru
Sergeyeva
Svetlana
Nizhny Novgorod State Technical University n.a. R.Е. Alekseev
nnsveta@rambler.ru
Nizhny Novgorod, Russia
Optimal design of 3d frame structures taking into account the stress and multiple natural frequency constraints
The problem of determining the optimal cross-sectional parameters and joint positions of linearly elastic space frames with imposed stress and multiple frequency constraints was considered. The frame was assumed to be acted on by different independent load systems, including temperature and self-weight loads. The stress-state analysis includes tension, bending, shear and torsion of beam elements. The warping of beam elements was not taken into account in this problem. The sensitivity analysis of multiple frequencies was performed through analytic differentiation with respect to the joint positions and the sizes of the cross-sections of beam elements. The optimal design is attained through solving a sequence of quadratic programming problems.
10.5862/MCE.61.7
optimization of frame structures; sensitivity analysis; linearly elastic space frames; multiple natural frequencies
https://engstroy.spbstu.ru/article/2016.61.7/
07.pdf
RAR
RUS
82-88
6602693779
Petinov
Sergey
Peter the Great St. Petersburg Polytechnic University
sergei.petinov@gmail.com
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
Guchinsky
Ruslan
Sidorenko
Valentina
Peter the Great St. Petersburg Polytechnic University
Valentina.sidorenko@list.ru
Saint Petersburg, Russia
Damage identity in fatigue assessment of structures
The modified strain criterion-based method for fatigue assessment of structures is discussed. The damage is estimated based on the specified parameters of the criterion and the damage summation procedure by employing the finite-element method. With a reasonably fine mesh of the finiteelement model of the ‘critical location’ structure, the condition of the identity of damage in the material of the test specimen and the structure is provided and, respectively, the effect of uncertainty on the fatigue life assessment of the structure is reduced. The implementation of this version of the method is using the example of the fatigue life evaluation of a ship hull and superstructure detail at expansion joint. For comparison, the fatigue life of the detail is estimated using the standard S-N approach. The results are in approximate agreement; however, reducing the computational uncertainties with the help of the deformation criterion shows more physically reasonable fatigue properties of the detail.
10.5862/MCE.61.8
fatigue life of structures; strain-life approach; damage summation technique; identity of damage
https://engstroy.spbstu.ru/article/2016.61.8/
08.pdf