Magazine of Civil Engineering

RAR RUS 3-12 “B.E. Vedeneev VNIIG”, JSC Ivanova Tatyana IvanovaTV@vniig.ru

21, Gzhatskaya St., Saint Petersburg, Russia, 195220

JSC “VNIIG im.B.E.Vedeneeva” Albert Yuliy AlbertYU@vniig.ru JSC "B.E. Vedeneev VNIIG" Kaufman Boris KaufmanBD@vniig.ru

St. Petersburg, Russia

JSC “VNIIG im.B.E.Vedeneeva” Shulman Sergey The load-bearing capacity of hanging piles by the strength criterion of a pile or soil material The article describes various methods of assessment of load-bearing capacity (reliability) of a pile as a main element of pile foundation. It is shown that deterministic, probabilistic and possibilistic methods have a number of advantages and limitations. An actual task is to develop new approaches to assessment of foundations load-bearing capacity. The combined method providing the optimal assessment according to the given examples is developed in the article. Some features of the proposed methods are in the probability and possibility theories application to account uncertainty or incompleteness of initial data in quantifying the reliability of a pile. Presented in the article methods for a quantitative assessment of single piles reliability can be used for more complex computational models, including multielement pile foundations and more complex models of soil foundations. These methods have not been applied to piles reliability research so far and the article pre-sented is a pioneering one and has no analogues known to the authors. 10.5862/MCE.67.1 pile foundation load-bearing capacity probability theory possibility theory the combined methods of reliability assessment buildings construction civil engineering https://engstroy.spbstu.ru/article/2016.67.1/

RAR RUS 13-21 Kuban State Technological University Litvinova Tatiana soleado_STA@mail.ru

Krasnodar, Russia

Organo-mineral additives based on oil and gas complex waste to building materials The use of waste and products of their utilization as secondary raw materials is promising and rational way for their disposal. The addition of waste to mixtures provides either highquality products or improvement some of the physical and mechanical characteristics. Organo-mineral additives are produced by oil-contaminated waste and spent sorbents utilization meet environmental safety requirements and are suitable for use as an additive in building materials, for example, expanded clay and asphalt mixtures. The aim of the paper is to develop technology for producing organo-mineral additives that is aimed at the elimination of environmental pollution with wastes, their involvement into resource circulation and ensures rational nature management with reducing the consumption of reagents and receiving high quality ecologically safety products. It is established the minimum necessary quantity of quicklime (calcium oxide reagent) required to transfer viscous sludge in bulk and obtain organo-mineral additives. In order to achieve the most important technical parameters of building materials in particular expanded clay – a bulk density and strength, it is used various additives. Application of the complex additives can increase the swelling clay factor up to 3 times and get the required strength of concrete block with less energy consumption, which significantly reduces the cost of the products. It is carried out the research to develop formulations of puddle clay with organo-mineral additives and choose burning conditions for preparing expanded clay. It's established the optimal temperatures and a thermal presintering for producing products that meet the requirements of the standards, with minimal energy consumption. The impact of the percentage of organo-mineral additive on the coefficient of clay swelling is determined. In the process of burning poor swelling clay with using organo-mineral additive at temperature 1050 °C constructive quality factor is increased by 70–97 % in comparison with the expanded clay obtained from raw materials without additives. Proposed technology for production of expanded clay with organo-mineral additives allows getting high-quality environmentally friendly products and disposing in its composition oil and gasing complex waste, involving them into resource management, and satisfies best available techniques due to encouraging re-use of waste. 10.5862/MCE.67.2 buildings organo-mineral additives oilcontaminated waste spent sorbents waste utilization ecological safety secondary resources expanded clay https://engstroy.spbstu.ru/article/2016.67.2/

RAR RUS 22-30 Military Space Academy named after A.F. Mozhaysky Avsyukevich Dmitriy avsdim@mail.ru

Saint Petersburg, Russia

Exergoeconomic model of a central air conditioning system The article considers the issues of energy saving in central air conditioning systems by means of their operation parameters optimization, based on the exergoeconomic (thermoeconomic) approach. The necessity of joint consideration thermodynamic and economic factors of system operation is identified. Literature review in the field of study is submitted. There is the schematic diagram of the central air conditioning system provided for which the exergyeconomic model is created. Necessary assumptions are stated. Exergy economic model of central air conditioning system is shown in graphical form. The model is presented as separate zones, connected in-series. Basic expressions of the exergyeconomic model are stated. The expressions allow solving the problem of energy consumption minimization using the Lagrange's method of undetermined multipliers. Expression of a lagranпian for a problem of optimization of parameters of the functioning of the central air conditioning system is received. The performance control laws of separate zones of the air conditioning system providing minimal energy consumption during its operation are offered in a general view. As a conclusion possibility of considerable energy consumption decreases during operation of the air conditioning system. 10.5862/MCE.67.3 energy efficiency air conditioning thermodynamic analysis buildings construction exergoeconomic model civil engineering https://engstroy.spbstu.ru/article/2016.67.3/

RAR RUS 31-38 V.I. Vernadsky Crimean Federal University Alekseenko Vasiliy avn108@mail.ru 57194105536 https://orcid.org/0000-0003-4486-5869 V.I. Vernadsky Crimean Federal University Zhilenko Oksana o.b.zhilenko@mail.ru Seismic stability of the restored architectural monument The conservation of monument of architecture of XIX century – the Church of St. Archangel Michael in Sevastopol is discussed in the article. The analysis of the results of the survey of the building is developed and recommendations to strengthen the supporting structures of the church are worked out. The use of traditional methods for enhancing structural and seismic reinforcement of buildings with walls of masonry leads to the inevitable loss of the original facade or interior of the temple. To enhance the analysis and design of earthquake resistant walls pasted anchors performed experimental research collaboration adhesive bonding steel anchors in the stone elements from limestone Krymbalsk deposits. The proposed measures to strengthen allow performing repair and restoration work, without breaking the historical reliability of the facades. Comprehensive solutions for strengthening and ensuring of an acceptable level of safe operation in seismic areas are developed. 10.5862/MCE.67.4 architectural monument seismic authenticity strengthening pasted anchor https://engstroy.spbstu.ru/article/2016.67.4/

RAR RUS 39-54 57194112309 0000-0001-6184-2365 Vyatka State University Tyukalov Yury yutvgu@mail.ru Stress finite element models for determining the frequencies of free oscillations Development of calculation methods, allowing determining the lower limits frequencies of free oscillations is actual. Such methods, in combination with the decisions by the method of finite element in displacements, will let to assess the accuracy of the frequencies of free oscillations calculated values. The frequencies of free oscillations constant cross section rods with different supports of the ends are calculating by the stress finite element analysis. The proposed method is based on combination of the additional potential energy functional and the virtual displacements principle. The last is used to construct the equilibrium equations. The solution reduces to finding the minimum of the additional energy functional with constraints in form of the linear algebraic system equilibrium equations. The equilibrium equations, taking into account inertia forces, are writing for the finite element mesh nodes in the directions of coordinate axes. Using the Lagrange multipliers the equilibrium equations are included in the functional. The Lagrange multipliers are the nodes displacements values. Considered two variants of bending moment’s approximation on the finite element field: linear and piecewise constant. The free oscillations forms are represented as polygonal lines. According to the proposed method the first three frequencies of free oscillations were defined for constant cross-section rods with different supports of the ends. The calculated values of the frequencies were compared with the exact values. In comparison with the method of finite elements in displacements, it is shown that the proposed method allows to get the opposite bound values for the frequencies of free oscillations. 10.5862/MCE.67.5 finite element method in stresses free vibration frequency lower limit values principle of virtual displacements https://engstroy.spbstu.ru/article/2016.67.5/

RAR RUS 55-69 Peter the Great St. Petersburg Polytechnic University Pavlenko Anna anna.pavlenko.1996@yandex.ru

St. Petersburg, Russia

56296687300 0000-0002-2299-3096 Peter the Great Saint Petersburg Polytechnic University Rybakov Vladimir fishermanoff@mail.ru

Polytechnicheskay, 29

Peter the Great St. Petersburg Polytechnic University Pikht Artem tamas96@rambler.ru

St. Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Mikhailov Egor egormi95@mail.ru

St. Petersburg, Russia

Non-uniform torsion of thin-walled open-section multi-span beams In the article a calculation of the bending moment and bimoment for different occasions single- and multi-span continuous thin-walled channel section beams using B.P.E. Clapeyron and N.L. Kuzmin methods have been made. Article considers the cases of uniformly distributed loading with the eccentricity relative to the center line of the bend sections of one-, two-, three- and five-span beams with with spans 2.5 meters long and 5 meters. Ratio between the bending moment and bimoment in feature points and proportionality coefficients between the bending moment and bimoment has been calculated experimentally. Article suggests a formula that allows to determine bimoment, if only the bending moment and the eccentricity of applied load are given. 10.5862/MCE.67.6 structural mechanics light steel thinwalled structures bending moment bimoment multi-span continuous thin-walled beams frame system beam deformation normal stress coefficient of proportionality method by B.P.E. Clapeyron https://engstroy.spbstu.ru/article/2016.67.6/

RAR RUS 70-80 Military Institute of rail transport troops and military communications Kalugin Yuri yuri_kalugin@inbox.ru Universal method for calculation of reliable completion times Usually the actual duration of construction projects significantly exceeds the scheduled durations.The reason is the lack of realistic scheduling. This paper presents a universal method for computing the reliable completion time for a construction project with network plans that have imprecise durations. The study is based on the consecutive comparison and calculation of the time distributions for the fulfilment of construction events. The general applicability of the algorithm is demonstrated. The method was used for the calculation of a more realistic time span for the construction of a road. The network schedule is formed on the basis of the flow sheet. A comparison was drawn between the proposed method and traditional techniques. The mean duration of the technological process calculated by a universal method is 30% more than for a known critical path method. It is confirmed that the traditional method of calculating the time to complete a project is almost always shorter. The method and algorithm presented in this study used Microsoft Excel. The calculations lasted some seconds. Implementation of the universal method will allow for the determination of a more precise duration for the performance of complex works at the planning stage.The suggested methodology can be recommended for use by construction project managers. 10.5862/MCE.67.7 civil engineering construction management project scheduling critical path method https://engstroy.spbstu.ru/article/2016.67.7/