Evacuation simulations in the BIM model
Andrzej Szymon Borkowski
Abstract:
BIM technology (Building Information Modeling) is increasingly used in the design and implementation of cubature and infrastructure investments. Polish designed offices are made possible by high-quality executive designs produced using modern BIM tools, thus generating increased benefits for the client or investor. The basic advantage of a project made using BIM technology is the three-dimensional model. Having a good and accurate three-dimensional model makes carrying out analysis on the project more effective, including the running of important simulations for the evacuation of people from the designed building. The aim of the paper was to analyse available solutions in BIM applications in regards to safety during the operation of the designed office building. This paper presents how BIM technology can be used to create such simulations, and to review various variants and related documentation.
Keywords:
BIM technology; building information modeling; evacuation simulations, operational safety
Sylwia Anna Borowska
Abstract:
The paper presents an assessment of the degradation of cyclic freeze/thaw on high-strength concretes, based on changes in the stress intensity factor KIC. The degree of HSC destruction due to cyclic freeze/thaw was determined by the longitudinal modulus of elasticity E, weight loss, and wall strength reduction, determined after 150, 250, 300, and 350 cycles and the total mass of surface scaling after 28 and 70 cycles. The degree of degradation was compared with the modification of stress intensity factor values. Three types of high-strength concretes (compressive strength about 90 MPa) were tested: concrete without fibres, concrete with steel fibres in the amount of 0.5% by volume (39 kg/m3) and concrete with a mixture of steel fibres (19.5 kg/m3) and basalt (6.8 kg/m3). The testing methodology is based on RILEM recommendations and ASTM C666 and PKN-CEN/TS 12390 Slab Test.
Keywords:
high-strength concrete; fibres; concrete degradation; stress intensity factor; surface scaling
Irina S. Cheredina, Ekaterina Yu. Rybakova
Abstract:
The article is devoted to the construction experience of German settlements in the 1920s and post-warhousing estates. Its impact on the development and construction of mass housing in the USSR was reviewed. Сommon features and differences were identified.
Keywords:
villages for workers in Germany and the USSR; Moscow; the industrial housing estates; prefabricated panel construction; reforms of the 1960s
Influence of wind direction and velocity on the work parameters of the S-160 gravity chimney cap
Adam Deska, Adam Rubnikowicz
Abstract:
The presented study contains the test results on the operating parameters of the S-160 chimney cap, another construction from among those already tested. The measurements were carried out for the airflow in the horizontal plane. The following physical parameters were changed: airflow speed within the tested chimney cap and degree of leakage in the room model. The chimney cap drawing schemas, the range of the tests and schema of the test stand are presented. The research methodology is described.
Keywords:
gravity ventilation; natural ventilation; chimney caps
Modification of the Magnel method in the design of cross-sections of post-tensioned concrete beams
Roman Gąćkowski
Abstract:
Designing cross-sections of prestressed beams based on Magnel's graphic method was first introduced in the mid-20th century. The graphic method is very useful for determining the initial prestressing force and its eccentricity action. This method is also used nowadays despite various computer programs accelerating the process of dimensioning prestressed structures. In the article, the author briefly outlined the idea of the Magnel method, and attempted to combine the classical method of adopting optimal dimensions for a cross-section of a post-tensioned concrete I-beam with the graphic method of Magnel to determine the prestressing force and its eccentricity. The purpose of this test is to simplify Magnel's graphic method and use analytical geometry in calculations to precisely determine the optimal prestressing force and its eccentricity. The prestressing forces and their eccentricity were calculated for beams with spans of 12.0 to 36.0 meters and the results are presented in diagrams.
Keywords:
Magnel diagram; post-tensioned concrete beam; prestressed force
The authenticity of architectural heritage: on the issue of interpretation of the concept (Part II)
Татьяна Георгиевна Горанская
Abstract:
Currently, the “authenticity of architectural heritage” is one of the basic concepts of restoration theory and practice. The article presents modern interpretations of “authenticity” in the humanities, each of which reveals a certain aspect of the concept. It is shown that the idea of “authenticity” changes over time, differs in various cultural traditions and is determined by the world view of a particular historical era. Two approaches to the interpretation of the “authenticity of architectural heritage” are distinguished as follows: the historical approach, the basis of which is the understanding of the architectural monument as documentary evidence of the past and the connection of the times, and the structural approach, which rejects continuity and allows the possibility of “replacing” parts of the whole.
Keywords:
authenticity; architectural heritage
The finite element model for electron beam soldering of carbide cutting elements to a mandrel
Г.Г. Горанский, А.И. Поболь
Abstract:
Generalized finite-element models for the electron-beam treatment of the surface of materials with significantly different thermophysical properties have been created, allowing the calculation and optimization of process conditions. For products of different geometries, taking into account the thermodynamics of the process and the temperature dependences of the properties of materials, controlling the electron beam geometry and the process cycloramas, the ranges of energy parameters of electron beam processing have been optimized. Finite-element modeling of surface heating during electron-beam processing was carried out for a flat-shaped part by a stationary source with scanning, as well as when exposed to linear beam movement without scanning. To optimize electron beam reflow during soldering, a thermodynamic finite-element model is proposed that takes into account the geometric features of the cutter inserts and the thermophysical properties of their constituent materials. It is shown that taking into account the temperature dependence of the thermophysical properties of the materials makes it possible to realize electron beam processing schemes with a shorter duration of exposure to a beam of greater power.
Keywords:
finite element model; electron beam processing; carbide tool
The influence of intensive plastic deformation on iron-based materials by free precipitation
Оlena Gumen, Vitalii Mykhailichenko, Irina Selina, Adam Ujma
Abstract:
The development of many branches of modern production is inextricably linked with the development of new materials with a certain complex of mechanical, physio-chemical and technological properties. One of the effective ways to obtain materials with clearly defined properties is powder metallurgy. Materials obtained by pressing the powder usually have a high residual porosity. In order to improve their mechanical properties, we suggest using free sludge. We experimentally investigated various methods of intense plastic deformation and measured the hardness and strength of the obtained samples. We believe that our results show that free sludge can be used for reducing porosity levels in powder materials on an industrial scale.
Keywords:
powder metallurgy; reduction of porosity of materials; free sediment; increase of physical and mechanical properties of materials
A calculation of the load bearing capacity of glulam beams with BFRP reinforcement
Damian Jończyk
Abstract:
Strengthening timber elements using fiber composites increasingly being used in construction. Despite the increasing popularity of this solution, there are still no normative provisions. The article discusses the effectiveness of the most common method used to determine the load capacity of glued laminated timber beams reinforced with BFRP materials. Load capacity values, calculated analytically, were compared with the values determined in experimental tests. The method presented in the article may be helpful from an engineering perspective.
Keywords:
timber; fiber composites; BFRP; analytical calculations
Jarosław Kalinowski
Abstract:
The final stage of grinding concrete surfaces is performed by floaters with solid grinding discs. The working element in the shape of a solid wheel uses the full surface of the disc, ensuring maximum geometrical effectiveness. The disc moves in a steady progressive manner, while at the same time, rotating around its center axis. The contact line length of the full disc with the machined surface is set by geometrical effectiveness Sg. After one cycle of machining the surface with the full disc, the geometrical effectiveness measured at points on a line in a perpendicular direction from the disc moving direction has a local minimum within the machining area and zero values on the edges and outside of the machined area. Decreasing the unfavorable impact of local minimum effectiveness inside the central machining area for the uniformity of machining can be achieved by using discs with concentric working elements – rings and wheel with correctly selected sizes and rotation speeds. For increasing the machining uniformity at the edges of the machined area, partial overlap of machining zones is used in the following cycles. The article describes a disc in a three-element system consisting of a wheel, and two rings used for optimizing uniformity of machining concrete surfaces.
Keywords:
geometric effectiveness; floating; concrete; optimalization
Przemysław Kasza, Jacek Nawrot
Abstract:
The paper analyses the load-carrying capacity of a bolted overlapping connection between a floor beam and a column. Three variants of the connection were considered: without the support seat and with support in the form of an angle bracket and a plate. The value of force acting on the connection was determined based on calculations made for the adopted conditions. The load-carrying capacity of bolts and plates for the assumed load was evaluated and the values of stress in the contact zone were compared for the analysed cases. It was demonstrated that the load-carrying capacity of bolted overlapping connections of the beam/column type depends on the adopted solution in terms of contact shape (presence or absence of a support seat), the type of support seat (if any) and the number, class and spacing of bolts. The results of the calculations showed that the most effective method of connection for the adopted assumptions is the connection with the support seat capital in the form of an angle bracket. The use of this type of beam support significantly reduces bolt tension and reduces the stresses occurring in the contact zone of the connected elements.
Keywords:
steel constructions; bolt connections; designing
The use of an optical system for bending and torsional analyses of open cold-formed profiles
Mariusz Kosiń
Abstract:
The paper presents the application of the Aramis optical system for determining the bending and torsional rigidity of cold-formed C profiles. Cold-formed thin-walled beams have many advantages that are technically important. The subject of the experimental research were thin-walled cold-formed beams loaded with a concentrated force in 1/3 of the beam span. The paper presents an example of using this system as an auxiliary tool for testing the free torsion of unstiffened and stiffened C-elements. The presented results are part of the research on the impact and effectiveness of the use of longitudinal bracing made in 3D printing technology.
Keywords:
Aramis; light steel skeleton; thin-walled elements
Comparison of calculation methods for sheet piling
Wiesława Kosmala-Kot, Jacek Selejdak
Abstract:
Basic methods for calculating sheet piling were presented in the paper. The Blum’s graphical and analytical-graphical methods were characterized for a sheet pile that is single anchored at the top and freely supported at the bottom. Methods for determining the sheet pile length, sinkage into the soil and the selection of the sheet pile profile were shown. The method for determining the reaction value on the sheet pile support was also presented. The calculated design parameters for both methods were compared in a table. On the basis of the above calculations, it was determined that the two calculation methods lead to similar cross-sections of sheet piling.
Keywords:
sheet pile; calculation method; sheet piling profile
Underground buildings – caprice or pragmatism
Krzysztof Kubicki
Abstract:
The purpose of the work is to try to find the answer to the issue in the title. In the paper the examples of structures built underground, which are usually erected on the surface, are presented. These include residential houses and factories. An unusual location is a great challenge for designers and contractors, but it can bring huge benefits. One of them is an increase in the energy efficiency of the building. The basis for the decision to choose an underground construction must be an analysis of the benefits, disadvantages and risks associated with this type of facilities carried out for individual cases.
Keywords:
underground construction; underground house; underground factory; energy efficiency
Jolanta Kwiatkowska-Malina, Hubert Horynek
Streszczenie:
W artykule w szczególny sposób zwrócono uwagę na rolę oświetlenia wnętrza urbanistycznego, które z jednej strony stanowi zasadniczy element kreujący przestrzeń miejską, a z drugiej strony jest istotnym źródłem zanieczyszczenia światłem. Jednym z czynników generujących zanieczyszczenie światłem jest zastosowanie oświetlania o zbyt wysokim natężeniu, czyli zbyt silnego. Na potrzeby niniejszego opracowania za emitery zanieczyszczenia światłem uznano jedynie instalacje oświetlenia ulicznego. Występowaniu zjawiska zanieczyszczenia światłem sprzyjają unormowania prawne dotyczące między innymi oświetlenia dróg. W pracy wskazano, że spójna strategia oświetleniowa przestrzeni miejskiej obejmująca między innymi dobór takich parametrów, jak: typ źródeł światła, w tym temperatura barwowa i natężenie emitowanego światła, oprawa, lokalizacja instalacji oświetleniowej, może ograniczać zanieczyszczenie światłem.
Słowa kluczowe:
zanieczyszczenie światłem; iluminacja; strategia oświetleniowa
Piotr Lis
Abstract:
In the last few years there has been a tendency towards the air-tight sealing of buildings. This phenomenon can be seen both in older buildings being refurbished, as well as in those that are new or thermallyupgraded. The use of excessively air-tight windows in educational buildings with gravity (natural) ventilation system limits the inflow of external air to classrooms. The analysis covered 50 educational buildings in Częstochowa, which are used by primary and middle schools. Windows in those buildings were in a bad or very bad technical condition and their air-permeability was very high. Their defects cause excessive heat losses from heated rooms. It turns out, however, that the high air-permeability of windows (rate of outdoor air leakage (a) at the level of 6-7 m3/(hmdaPa2/3) allows for a relatively beneficial level of natural ventilation and sufficient inflow of fresh air in the absence of other inflow of outside air solutions. Unfortunately, as a result of the replacement of old windows with new ones and no changes in the existing system of natural ventilation, a considerable deterioration of microclimate in classrooms can be expected, especially due to non-compliance with the requirements related to the sufficient supply of fresh air. To prevent this, it is necessary to take action to improve existing ventilation systems.
Keywords:
educational building; outdoor air leakage; air infiltration; natural ventilation
The effect of the resistance spot welding current on weld quality and joint strength
Judyta Niemiro-Maźniak
Abstract:
Thin-walled area elements are becoming increasingly popular and necessary in construction and various other industries. This trend is also accompanied by the need for development and research into joining methods that will ensure that the structures have an appropriate ratio of their load capacity to their weight. A commonly used method for joining thin metal elements is resistance welding, using the natural electrical resistance property of metals. The study examined the impact of the resistance welding current value on the quality and load capacity of the RSW weld. Lap joints with a single weld, using alternative current flow values during welding, were made. The joints were subjected to a static tensile test. Load capacities of the analyzed joints and force-displacement graphs were obtained. A numerical analysis of joints with different weld diameters was also carried out. Plastic deformation graphs were obtained in the cross-section through the center of the weld and the distribution of plastic deformations throughout the sample. As the weld diameter increases, the load capacity of the joint increases and the plastic deformation decreases. However, the use of excessive current flow may cause molten metal splash and reduce the strength of the joint.
Keywords:
resistance welding; thin-walled constructions; RSW joint
Reviewing modern solutions for the foundations of engineered structures
Przemysław Palacz, Maciej Major
Abstract:
The foundations of various types of engineered structures are a key element of any facility as it is the only point of contact with the subsoil and ensures stability and safety during operation. During the design of a structure, a suitable foundation solution should be selected that will ensure adequate stability in encountered ground conditions. This article presents contemporary solutions for the foundations of engineered structures that have been subjected to analysis and research over the last few years.
Keywords:
modern constructions; bearing capacity; substructures; foundation solutions
Witold Paleczek
Abstract:
Formulas approximating land surface depression resulting from the combination of two geometrical-integral theories: Chudek-Stefański theory and Knothe-Budryk theory are presented. The proposed mathematical formulas have been developed in 2D and 3D spaces. The differences of results obtained from integral formulas and approximating formulas were compared. The presented solutions are used in modeling terrain surface deformation as a result of underground mining operations for the needs of analyzes in construction in mining areas without the need to use integral calculus.
Keywords:
numerical modeling; integral
Witold Paleczek
Abstract:
The proposed mathematical formulas for calculating the radius of the range of main influences as a function of a number of rock mass geomechanicaal parameters are presented. These formulas are applicable in Knothe-Budryk theory and Chudek-Stefański theory. The proposed formulas use dependencies obtained as a result of statistical analysis of a set of known values of geomechanical parameters of the rock mass obtained from 16 boreholes in the same region, taking into account 34 types of rocks. The obtained correlation dependencies enabled the creation of mathematical formulas for modeling rock mass settlements as a function of: rock compressive strength, their cohesion, tensile strength, compressive strength when saturated with water, softening foctor, Youngs modulus, volumetric weigth, depth of deposit, thickness of the exploited layer, service factor. The current formulas found in the literature include a smaller number of variables. The formulas also make it possible to calculate the angle of range of main influences, its value is used to determine the protective pillars. The proposed solutions are used in modeling terrain surface deformations as a result of underground exploitation for the needs of conducting analyzes in construction in mining areas – without the need to use integral calculus.
Keywords:
numerical modeling; integral and approximation formulas; Knothe-Budryk theory; Chudek-Stefański theory; construction in mining areas
Uplift capacity of tower foundations with plates of transmission lines
Jarosław Paluszyński, Sławomir Labocha, Agnieszka Biernacka
Abstract:
The ultimate uplift capacity of foundations with special reference to transmission tower footings is evaluated. Special foundations with overlay plates were analysed. Full scale tests according to standard PN-EN 61773 were presented. The results were studied and compared with FEM models and requirements according to standards PN-EN 50341-1 and PN-B-03322.
Keywords:
uplift foundations; lattice tower foundations; transmission tower foundations; in-situ testing
Zeolite as an additive for mortars and concretes
Maria Pietras, Janusz Konkol
Abstract:
Nowadays, zeolites are being used more and more in various fields of industry. Conclusions from numerous studies indicate their favourable properties for use in construction and architecture. The aim of the article is to provide a description of zeolites` influence on the properties of cement composites and to present the author’s own test results. The tests were conducted on mortar with the addition of zeolite in the amount of 10% cement weight, and determined the flexural and compressive strength, after 3,7 and 28 days of curing. Some fractographic research was also conducted on the obtained results from the flexural strength test, and surface breakthroughs.
Keywords:
zeolite; mortar; flexural strength; compressive strength; fractography
Cracking state analysis of reinforced concrete grain silos structures
Jolanta Anna Prusiel
Abstract:
Silo structures are classified as objects with a higher degree of risk and disaster hazard compared to other engineering structures. In reinforced concrete silos, the following may occur: excessive cracks or strains, exceeding capacity of the wall or the floor to withstand bending moments and normal forces, corrosion of structural members, or explosions of a part or the whole silo bin. Silo failures may be caused by yet not fully recognized stress and strain states in sections of the silo chambers, which result from random and variable interactions of stored granular media in combination with temperature fields. Circadian fluctuations of ambient temperature that occur particularly during early winter and spring coupled with the static pressure of the granular medium produce overload states in the silo wall structures. As a result, additional tensile stresses combined with bending are produced. All these factors cause increased cracking in reinforced concrete silo walls, which may reduce the load capacity and durability of the silo structure. The paper presents assumptions and design procedures regarding verification of the cracking state in reinforced concrete silo chambers based on the latest recommendations given in EN 1992-3, EN 1992-1-1 and fib Model Code 2010.
Keywords:
cracking state; silos; RC structures
3D printing technology for the prototyping of prosthesis construction and exoskeletons
Paweł Rajczyk, Karolina Bednarczyk
Abstract:
The article discusses the manufacturing a limb prosthesis and exoskeleton using 3D printing technology. Hand prostheses available on the market and the direction of development in the construction of exoskeletons have been characterized. An example of a prosthesis made using incremental technology by the FFF/FDM method using a Zortrax M200 printer is presented. The mechanism of prosthesis work and elements of exoskeleton construction as well as the general characteristics of materials used are described. Attention was paid to the low cost of printing the components of the prototype structures.
Keywords:
hand prosthesis; exoskeleton; 3D printing; mechanical prosthesis; biomedical engineering
A new legalisation procedure concerning unlawful building work in Poland
Sybilla Stotko
Abstract:
This article presents the characteristics of the simplified legalisation procedure concerning unlawful building work which has been in force since 19 September 2020 in Poland. The newly-introduced solution will enable to make the buildings or their parts made unlawfully more than 20 years ago legal in a significantly simplified scope, beneficial for the building owners and administrators. The so-called old unlawful building work can be legalised in this procedure, provided complete legalisation documents are submitted, with no need to pay the legalisation fee and even when the buildings or structures do not comply with the area development plans. However, legalisation is possible solely if it is verified that the technical condition of the building or structure does not pose any hazard to human health or life and ensures its safe use. The article discusses the assumptions of the amendment and summarises the introduced regulation.
Keywords:
simplified legalisation procedure; unlawful building work legalisation; unlawful building work; construction law, administrative procedure
Traditions of Siheyuan manor in China’s modern architecture
Ping Zhou, Nina Kazhar
Abstract:
The article continues the study of the role of traditions in the development of modern Chinese architecture. The analysis of the most common form of the Chinese people's apartment building (manor) Siheyuan was made. It is shown that today’s Chinese architects are turning to this type of national architecture, critically reviewing the historical heritage and formulating a new aesthetics of space; shaping an environment that meets the climatic conditions of the country.
Keywords:
residential manor Siheyuan; Dougong; architectural traditions of China
Modal tests of a modelled metal element with a truss structure
Mariusz Żółtowski, Katarzyna Jeleniewicz
Abstract:
Contemporary truss structures must maintain appropriate strength requirements for safe use. This may result in the fact that the influence of vibrations on a truss structure exposed to horizontal forces as well as transverse forces caused by wind may be dangerous for safe use (e.g. bridge structures). Recognizing the need to improve methods of testing truss elements for the purpose of assessing their condition as well as assessing the safety factors in this work, an attempt was made to examine the destruction of the modelled bridge span element using the theoretical modal analysis method.
Keywords:
modal analysis; natural frequencies; stabilization diagram; structure vibrations
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