Nauki Techniczne

Archives of Civil Engineering

Zawartość

Archives of Civil Engineering | 2023 | vol. 69 | No 1

Abstrakt

Irrigation and hydropower are among the most important sectors in the construction industry that propel the economic needs of a developing country like Vietnam. The construction of these projects often suffers from severe delays, leading to financial losses and other negative impacts on the economy. This paper aims to determine delay factors in the construction of these projects. Among many, 39 most important candidates of delay causes were identified from the literature review. Further surveys on project participants were conducted for the severity of these causes. An exploratory factor analysis was utilized to identify latent factors that cause delays in construction projects. The analysis result categorized a few groups of factors such as abnormal factors on the construction site (e.g., labor accidents, hydrology, water flow, extreme weather) and technical factors related to the construction contractor (e.g., unsuitable schedule, outdated construction technology, unprofessional workers) that have the greatest impact on the delay in construction of irrigation and hydropower projects in Vietnam. These findings contribute to the body of knowledge of project management and risk management, hence an improvement in the efficiency of the project sectors’ performance.
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Autorzy i Afiliacje

Van Son Nguyen
1
ORCID: ORCID
Huu-Hue Nguyen
1
ORCID: ORCID
Duc Anh Nguyen
2
ORCID: ORCID
Dinh Tuan Hai
3
ORCID: ORCID

  1. ThuyLoi University, Faculty of Civil Engineering, No. 175 Tay Son Road, Dong Da District, Hanoi City, Vietnam
  2. Hanoi University of Civil Engineering, Faculty of Department of Building and Industrial Construction, No. 55 Giai Phong Street, Hai Ba Trung District, Hanoi City, Vietnam
  3. Hanoi Architectural University, Faculty of Civil Engineering, Km 10, Nguyen Trai Street, Thanh Xuan District, Hanoi City, Vietnam

Abstrakt

The bridge structure’s development causes a riverbed cross-sections contraction. This influences the flow regime, being visible during catastrophic floods. Then the flow velocity increases and water piles up upstream the bridge, where headwater afflux could be observed. These changes depend on the watercourse geometry and the bridge cross-section properties, especially on the degree of flow contraction under the bridge. Hydraulic conditions under the bridge depend on flow velocity, dimensions, and shape of abutments, the granulometric composition of bedload, which can be quantitatively characterized by hydraulic resistance coefficients. The research subject of headwater afflux is equated with the recognition of morphodynamic processes occurring along the passage route. The headwater afflux could be estimated by empirical formulas and by the energy method using Bernoulli’s law. Empirical methods are optimized by adopting various statistical criteria. This paper compares the headwater afflux values calculated using two existing empirical formulas, Rehbock and Yarnell, and compares them with the results of laboratory tests. Following the assumption that the free water surface is influenced by flow resistance, an attempt was made to include friction velocity in the empirical formulas. Based on the Authors’ database, the coefficients used were optimized using bootstrap resampling in Monte Carlo simulation. The analyses demonstrated that the formula best describing the phenomenon of headwater afflux upstream the bridge is an empirical formula built based on the historical Yarnell formula, which includes friction velocity value. The optimized equation provides an average relative error of 12.9% in relation to laboratory observations.
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Autorzy i Afiliacje

Marta Kiraga
1
ORCID: ORCID
Sławomir Bajkowski
1
ORCID: ORCID
Janusz Urbański
1
ORCID: ORCID

  1. Warsaw University of Life Sciences, Institute of Civil Engineering, Faculty of Civil and Environmental Engineering, ul. Nowoursynowska 159, 02-776 Warsaw, Poland

Abstrakt

RC flat slabs are one of the most popular and effective methods of shaping plates in buildings. Although failures of entire structures are relatively rare, they cannot be excluded from the occupancy cycle of the facility. The research analysis presented in this paper is an attempt to understand more precisely the phenomena that occur in the RC flat slab system and to assess the influence of the additional protection of the flat slabs against progressive collapse in the case of failure of one of the supports. The results were obtained from destructive experimental investigations of a flat reinforced concrete slab made in scale 1:3. The collapse in the analysed model was simulated by removing three edge columns and additional loading by means of hydraulic actuator. In place of the columns removed, differential tie reinforcement was applied. The results obtained confirm that the structure achieved a much higher ultimate load than the one resulting from the design calculations.
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Autorzy i Afiliacje

Lidia Buda-Ożóg
1
ORCID: ORCID
Joanna Zięba
1
ORCID: ORCID
Katarzyna Sieńkowska
1
ORCID: ORCID
Damian Nykiel
1
ORCID: ORCID

  1. Department of Building Structures, Faculty of Civil Engineering and Environmental Engineering, Rzeszow University of Technology, Poznańska 2, Rzeszow 35-084, Poland

Abstrakt

The paper discusses the principles of the Critical Shear Crack Theory (CSCT) in terms of the punching shear analysis of flat slabs made from lightweight aggregate concretes. The basic assumptions of the CSCT were discussed, explaining the differences with regard to the calculation of ordinary concrete flat slabs, relating mainly to the adopted failure criterion associated with ultimate slab rotation. Taking into account the observations and conclusions from the previous experimental investigations, it was confirmed, that contribution of lightweight aggregate particles in the aggregate interlock effect should be ignored, due to possibility of aggregate breaking. However, the analysis of the profile of failure surface confirmed, that particles of the natural fine aggregate increase the roughness of the surface and should be included by formulating failure criterion for LWAC slabs.
The theoretical load-rotation relationships were compared with the results of measurements, confirming good agreement in most cases. The theoretical ultimate rotations were lower on average by about 11% than the experimental ones. The analysis of 57 results of the experimental investigations on punching shear of LWAC slabs made from various types of artificial aggregates showed a very good agreement with predictions of the CSCT. The obtained ratio of the experimental to theoretical load was 1.06 with a coefficient of variation of 9.1%. The performed parametric study demonstrated a low sensitivity of the correctness of the CSCT predictions to a change in a fairly wide range of parameters such as: the longitudinal reinforcement ratio, concrete compressive strength and concrete density.
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Autorzy i Afiliacje

Michał Gołdyn
1
ORCID: ORCID

  1. Lodz University of Technology, Department of Concrete Structures, al. Politechniki 6, 93-590 Łódz, Poland

Abstrakt

The problem of optimal design of a steel plated girder according to the Eurocode 3 is considered. Code regulations admit the Finite Element Analysis (FEA) in designing plated structures with variable cross-sections. A technique of determining an approximate solution to the optimization problem is presented. It is determined a solution of a control theory optimization task, in which Eurocode requirements regarding the Ultimate Limit State (bearing capacity, local and global stability) as well as Serviceability Limit State (flexural rigidity) are used as appropriate inequality constraints. Static analysis is performed within the framework of linear elasticity and Bernoulli-Euler beam theory making an account for second-order effects due to prescribed imperfections. Obtained solutions, after regularization, may be used for direct verification with the use of FEA or as the first guess for iterative topology optimization algorithms. Code requirements governing the determination of optimal shape are visualized in the constraint activity diagram, which is a proposed tool for analysis of optimization process.
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Autorzy i Afiliacje

Paweł Szeptyński
1
ORCID: ORCID
Leszek Mikulski
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, ul. Warszawska 24, 31-155 Kraków, Poland

Abstrakt

This research aims to determine the influence of the cyclic process of freezing and defrosting on the mechanical properties of the chosen glass fibres and PTFE-coated woven fabrics. The specimens were subjected to freezing at about -20˚C for 4 h and thawing by full immersion into the water at about +20˚C for 4 h. The fabric samples after 25 and 50 frozen cycles were air-dried at room temperature for one week and then subjected to uniaxial tensile tests. The same tests have been performed on a reference group of specimens, which were not exposed to temperature change. The authors determined the tensile strength, and longitudinal stiffnesses resulting from performed tests. Although the investigated coated woven fabrics expressed a reduction in the tensile strength in water soaking conditions, the performed frozen cycles don’t show a significant decrease in strength under uniaxial tensile tests.
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Autorzy i Afiliacje

Andrzej Ambroziak
1
ORCID: ORCID
Paweł Kłosowski
1
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, St. Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland

Abstrakt

This study was carried out to evaluate the effect of steel slag (SS) as a by-product as an additive on the geotechnical properties of expansive soil. A series of laboratory tests were conducted on natural and stabilized soils. Steel slag (SS) was added at a rate of 0, 5, 10, 15, 20, and 25% to the soil. The conducted tests are consistency limits, specific gravity, grain size analysis, modified Proctor compaction, free swell, unconfined compression strength, and California Bearing Ratio. The Atterberg limit test result shows that the liquid limit decreases from 90.8 to 65.2%, the plastic limit decreases from 60.3 to 42.5%, and the plasticity index decreases from 30.5 to 22.7% as the steel slag of 25% was added to expansive soil. With 25% steel slag content, specific gravity increases from 2.67 to 3.05. The free swell value decreased from 104.6 to 58.2%. From the Standard Proctor compaction test, maximum dry density increases from 1.504 to 1.69 g/cm3 and optimum moisture content decreases from 19.77 to 12.01 %. Unconfined compressive strength tests reveal that the addition of steel slag of 25% to expansive soil increases the unconfined compressive strength of the soil from 94.3 to 260.6 kPa. The California Bearing Ratio test also shows that the addition of steel slag by 25% increases the California Bearing ratio value from 3.64 to 6.82%. Hence, steel slag was found to be successfully improving the geotechnical properties of expansive soil.
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Autorzy i Afiliacje

Worku Firomsa Kabeta
1 2
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Gabriela Narutowicza 11/12, 80-233, Gdansk, Poland
  2. Jimma University, Faculty of Civil and Environmental Engineering, Jimma saris, 378, Jimma, Ethiopia

Abstrakt

The article discusses the physical and chemical mechanisms of the carbonation phenomenon itself, as well as points out the synergistic effect of frost destruction and concrete carbonation on reinforced concrete elements. Examples of structural damage from engineering practice in the diagnosis of reinforced concrete structures are presented. Two cases of frost and carbonation damage of precast reinforced concrete elements are analyzed. It was noted that the most common cause of damage to concrete structures is the lack of frost resistance. Carbonation of concrete leads to deprivation of the protective properties of the concrete lagging against the reinforcing steel. The examples cited include precast elements that, for technical reasons, had a relatively small lagging thickness. The first one relates to the thin walled elevation elements, which are exploited during 60 years and the second relates to the energetic poles with very advanced concrete corrosion damage. The examples given of corrosion of concrete and reinforcement of elements indicate that synergistic environmental interactions can intensify the destruction of elements.
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Autorzy i Afiliacje

Kaja Kłos
1
ORCID: ORCID
Grzegorz Adamczewski
2
ORCID: ORCID
Piotr Woyciechowski
2
ORCID: ORCID
Paweł Łukowski
2
ORCID: ORCID

  1. TPA Sp. z o.o., ul. Parzniewska 8 05-800 Pruszków, Poland
  2. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland

Abstrakt

The paper focuses on the static behavior of double-layered tensegrity grids. Due to the specific characteristics, like the self-stress states and infinitesimal mechanisms, tensegrities can be used as deployable structures. For such structures, the possibility of the control of the behavior is very important. The main purpose of the work is to prove that the control of tensegrity structures with mechanisms is possible. The stiffness of such structures is found to depend not only on the geometry and material properties, but also on the initial prestress level and external load. In the case, when mechanisms do not exist, structures are insensitive to the initial prestress. It is possible to control the occurrence of mechanisms by changing the support conditions of the structure. Grids built with modified Simplex modules are considered. Two-stage analysis is performed. Firstly, the presence of the characteristic tensegrity features is examined and then, on that basis, the structures are classified into one of two classes. Next, the influence of the level of initial prestress on the behavior of structures under static load is analyzed. To evaluate this behavior, a geometrically non-linear model is used.
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Autorzy i Afiliacje

Justyna Tomasik
1
ORCID: ORCID
Paulina Obara
1
ORCID: ORCID

  1. Kielce University of Technology, al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland

Abstrakt

Footbridges, like all building structures, must be designed in a way that ensures their safe and comfortable use. Steel footbridges characterised by low vibration damping often turn out to be a structure susceptible to the dynamic influence of users during various forms of their activity. For these structures, the impact of running users may be a key type of dynamic load for the verification of the serviceability limit state due to vibrations. In the literature, there are several proposals for models of dynamic load generated by runners (models of ground reaction forces – GRF). The paper presents the characteristics, analyses and comparisons of selected GRF load models. The analyses were performed using the GRF recorded during the laboratory tests of runners (tests planned and carried out by the author) and the GRF determined using various load models. In order to illustrate the accuracy of the estimation of the dynamic response of the structure, depending on the GRF model used, dynamic field tests and dynamic numerical analyses of the selected steel footbridge were carried out. The obtained results were analysed and compared.
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Autorzy i Afiliacje

Marek Pańtak
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, Warszawska 24, 31-155 Krakow, Poland

Abstrakt

Environmental protection is one of the objectives of the implemented concept of sustainable development and circular economy. The construction industry and its products (building objects) have a large contribution in negative influences, therefore all actions limiting them are necessary. One way of doing this is to apply substitution to existing unfavourable solutions, both in terms of construction and materials as well as technology and organization. The aim of the article was to determine the key factors conditioning the use of substitution at each stage of the investment and construction cycle, leading to environmental protection. The research paid attention to the use of substitute recycled products. The defined factors were subjected to a SWOT analysis and then, using the DEMATEL method, cause-andeffect relationships were identified that determine development in the application of substitution in the environmental context of sustainable and closed-cycle construction. The analysis was carried out by using a summative, linear aggregation of the values of the position and relationship indicators.
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Autorzy i Afiliacje

Anna Sobotka
1
ORCID: ORCID
Kazimierz Linczowski
1
ORCID: ORCID
Aleksandra Radziejowska
1
ORCID: ORCID

  1. AGH University of Science and Technology in Cracow, Faculty of Civil Engineering and Resource Management, Department of Geomechanics, Civil Engineering and Geotechnics, Av. Mickiewicza 30, 30-059 Cracow, Poland

Abstrakt

The construction and operation of buildings is characterized by resource intensity in the form of massive consumption of raw materials and products, large financial and human labor expenditures, energy consumption, water consumption, long term, and significant environmental impacts, especially during their use. The currently implemented concept of sustainable development and circular economy influences the directions of development of construction industry and increases interest in self-sufficient buildings, especially in terms of energy, use of closed water circuits, use of waste materials. The aim of the article is to analyse the key determinants for the development of autonomous buildings. The general idea is that an autonomous building is designed to function without the support and services provided by public facilities, such as power, water, gas and sewage networks, waste management, and even the provision of food. On the basis of literature analysis and expert interviews, the factors characterizing this type of construction were determined. Their analysis by means of the DEMATEL method allowed to assess and indicate the most significant cause-and effect relationships conditioning the development of autonomous buildings.
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Autorzy i Afiliacje

Aleksandra Mach
1
ORCID: ORCID
Joanna Sagan
1
ORCID: ORCID
Anna Sobotka
1
ORCID: ORCID

  1. AGH University of Science and Technology, Faculty of Civil Engineering and Resource Management, Al. Mickiewicza 30, 30-059 Kraków, Poland

Abstrakt

Adetailed tie model of cracking is proposed. The model is dedicated to both semi-massive RC (reinforcement concrete) members subjected to early-age imposed strains and non-massive members in which imposed strains occur after concrete hardening. As distinct from the currently applied European guidelines, the proposed model enables an analysis of crack width changes. These are a function of progressive imposed strain, material and geometry data, but also depend on the scale of cracking which determines the strain conditions of a member. Consequently, the new model takes account of not only the factors determining the cracking development but also the member relaxation effect that results from cracking. For this reason a new definition of restraint factor is proposed, which takes into account the range of cracking of a structural member, i.e. the number and width of cracks. Parametric analyses were performed of both the changes of the degree of restraint after cracking as well as the changes of crack width depending on the adopted type of aggregate, class of concrete and the coefficient of thermal expansion of concrete. These analyses indicate the potential benefits of the application of the presented model for both a more accurate interpretation of research and economical design of engineering structures.
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Autorzy i Afiliacje

Mariusz Zych
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, St. Warszawska 24, 31-155 Cracow, Poland

Abstrakt

Dynamic biaxial compression tests and Particle Flow Code numerical simulations of the cement mortar specimens with a single joint were carried out to study the mechanical properties and crack evolution of artificial rock samples with a single joint. The effects of lateral stress 𝜎2, loading rate V , the dip angle β (between the vertical loading direction and the joint) on the biaxial compressive strength 𝜎 b, and the evolution lawof crackwere investigated. Test results showed that; (1) when both the dip angle β and the loading rate V remained unchanged, the biaxial compressive strength 𝜎 b increased with the increase in the lateral stress 𝜎2, while 𝜎2 had no obvious effect on the crack evolution law; (2) when both the dip angle β and the lateral stress 𝜎2 were kept unchanged, the loading rate V had an insignificant effect on the biaxial compressive strength 𝜎 b and the crack evolution law; (3) when both the lateral stress 𝜎2 and the loading rate V were constant, the biaxial compressive strength 𝜎 b decreased first and then increased with the increase in the dip angle β ; however, the dip angle β did not significantly affect the crack evolution law. The conclusions obtained in this paper are presented for the first time.
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Autorzy i Afiliacje

Xiong Liangxiao
1
ORCID: ORCID
Haijun Chen
2
ORCID: ORCID
Xinghong Gao
3
ORCID: ORCID
Zhongyuan Xu
4
ORCID: ORCID
Deye Hu
1
ORCID: ORCID

  1. School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang 330013, China
  2. Geotechnical Engineering Department, Nanjing Hydraulic Research Institute, Nanjing,210029, China
  3. China Construction Third Bureau First Engineering Co., Ltd., Wuhan 430040, China
  4. Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China

Abstrakt

The article presents modelling using artificial neural networks (ANN) of the phenomenon of creep of comply polymer SIKA PS which can be used in various applications in civil engineering. Data for modelling was gathered in compressive experiments conveyed under a set of fixed conditions of compressive stress and temperature. Part of the datawas pre-processed by smoothing and rediscretisation and served as inputs and targets for network training and part of the data was left raw as control set for verification of prognosing capability. Assumed neural network architectures were one- and two-layer feedforward networks with Bayesian regularisation as a learning method. Altogether 55 networks with 8 to 12 neurons in varying structural configurations were trained. Fitting and prognosing verification was performed using mean absolute relative error as a measure; also, results were plotted and assessed visually. In result, the research allowed for formulation of a new rheological model for comply polymer SIKA PS in time, stress and temperature field domain with fitting quality of mean absolute relative error 1.3% and prognosis quality of mean absolute relative error 8.73%. The model was formulated with the use of a two-layer network with 5+5 neurons.
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Autorzy i Afiliacje

Anna M. Stręk
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, ul. Warszawska 24, 31-155 Kraków, Poland

Abstrakt

The paper presents the results of laboratory tests of SCB (semi-circular beam) samples of asphalt concrete, subjected to the destructive effect of water and frost as well as the aging processes. The determined values of material parameters show significant dispersions, which makes the design of mixtures difficult. Statistical analysis of the test results supplemented by computer simulations made with the use of the proprietary FEM model was carried out. The main distinguishing feature of the model is the assignment of material parameters of coarse aggregate and bituminous mortar to randomly selected finite elements. The parameters of the mortar are selected by trial and error to match the numerical results to the experimental ones. The stiffness modulus of the bituminous mortar is, therefore, a substitute parameter, taking into account the influence of many factors, including material degradation resulting from the aging and changing environmental conditions, the influence of voids, and contact between the aggregate and the bituminous mortar. The use of the Monte Carlo method allows to reflect the scattering of the results obtained based on laboratory tests. The computational algorithm created in the ABAQUS was limited only to the analysis of the global mechanical bending response of the SCB sample, without mapping the failure process in detail. The combination of the results of laboratory tests usually carried out on a limited number of samples and numerical simulations provide a sufficiently large population of data to carry out a reliable statistical analysis, and to estimate the reliability of the material designed.
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Autorzy i Afiliacje

Cezary Szydłowski
1
ORCID: ORCID
Łukasz Smakosz
2
ORCID: ORCID
Marcin Stienss
1
ORCID: ORCID
Jarosław Górski
2
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Department of Highway and Transportation Engineering, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland
  2. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Department of Structural Mechanics, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland

Abstrakt

The presented analysis concerns deflections of the reinforced concrete slab in the fire-fighting water storage tank with volume of 950 m3. It was built on human-altered soil which led to deflection of the tank. When water was pumped out from the tank, rectification was performed. The tank and its slab foundation were non-uniformly elevated by means of hydraulic jacks. These jacks were installed under the slab, on foundation made of concrete block stacks, which were pressed into the ground. The computational analysis was conducted for displacements and deflections of the slab supported on the jacks. The number of jacks under the slab and stiffness of jack supports on the stacks were the variable parameters of the model. Stiffness of the jack supports was found to have non-significant impact on deflections of the foundation slab of the rectified tank. On the other hand, the number of jacks under the tank affected both deflections of the slab and displacements of the whole tank. The greatest deflection of the tank slab supported on three jacks was 15.233 mm, and the smallest one was 10.435 mm at 32 jacks.
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Autorzy i Afiliacje

Krzysztof Gromysz
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Civil Engineering, ul. Akademicka 5, 44-100 Gliwice, Poland

Abstrakt

Standard PN-EN 1992-1-1 for designing reinforced concrete structures gives a major priority to the issues relating to second-order effects, but presents in detail only two approximate calculation methods: the nominal stiffness method and the nominal curvature method. As regards the general method, only certain requirements and suggestions are provided. In typical situations, when the appropriate assumptions are satisfied, the approximate methods yield satisfactory results. However, in engineering practice one can come across several cases (e.g. very tall columns, columns with a cantilever for a gantry girder, and floor joists) in which the approximate methods will prove unreliable. This paper presents and discusses a procedural algorithm for analysing second-order effects using the general method. The algorithm is employed to perform exemplary calculations and their results are compared with the results yielded by the approximate methods commonly used by engineers. Moreover, areas in which the approximate methods can be unreliable are indicated. The analyses have confirmed the significant advantage of the general method over the approximate methods. Therefore it is worth popularizing this method, the more so that its calculation procedures can be to a large extent automated and dedicated computer programs can be developed.
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Autorzy i Afiliacje

Janusz Pędziwiatr
1
ORCID: ORCID
Michał Musiał
1
ORCID: ORCID

  1. Wroclaw University of Science and Technology, Faculty of Civil Engineering, Wybrzeże Stanisława Wyspiańskiego 27, 50-370 Wrocław, Poland

Abstrakt

The bridge horizontal swivel system generally adopts a symmetrical structure and uses a spherical hinge structure that can adjust the rotation to complete rotation construction. Because of the complexity of railway lines under bridges, some asymmetrical horizontal swivel systems have been increasingly applied in practical engineering in recent years. This system is more suitable for areas with complex railway lines, reduces the bridge span, and provides better economic benefits. However, it is also extremely unstable. In addition, instability can easily occur under dynamic loads, such as earthquake action and pulsating wind effects. Therefore, it is necessary to study their mechanical behavior. Based on the horizontal swivel system of an 11,000-ton asymmetric continuous girder bridge, the dynamic response of the horizontal swivel system to seismic action was studied using the finite element simulation analysis method. Furthermore, using the Peer database, seismic waves that meet the calculation requirements are screened for time-history analysis and compared to the response spectrum method. The mechanical properties of the structural system during and after rotation were obtained through calculations. During rotation, the seismic response of the structure is greater. To reduce the calculation time cost, an optimization algorithm based on the mode shape superposition method is proposed. The calculation result is 87% that of the time-history analysis, indicating a relatively high calculation accuracy.
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Autorzy i Afiliacje

Jiawei Wang
1
ORCID: ORCID
Hongshuai Gao
2
ORCID: ORCID
Kexin Zhang
3
ORCID: ORCID
Zongyun Mo
1
ORCID: ORCID
Hongchun Wang
1
ORCID: ORCID

  1. Anhui Polytechnic University, School of Architecture and Civil Engineering, Wuhu City, Beijing Middle Road, China
  2. Heilongjiang University, College of Civil Engineering, Harbin City, Xuefu Road, China
  3. Shenyang Jianzhu University, School of Architecture and Civil Engineering, Shenyang City, Hun Nan Road, China

Abstrakt

This paper investigates the fact that construction projects, due to their specificity, are complex, temporary and dynamic. Over their course, participants change, successive construction works are done and new information becomes available. This carries over to difficulties in communication. In the literature, numerous studies note the fact that a network-based approach to the analysis and monitoring of communication as a part of complex construction projects is commendable. Relations between agents, knowledge and tasks in the context of communication within a construction project can be visualized in the form of a meta-network, and suitably developed structural measures can be used to analyze them.
In this paper, the authors used meta-network theory to analyze relations between project participants, knowledge and tasks in the context of communication within a construction project, on the basis of the construction of a housing estate located in Katowice, Poland. Meta-network structural analysis allowed for a deeper understanding of these relations and the detection of essential information about the level of communication in the project under investigation, which was a basis for further discussion. The authors also stress the benefits from the approach presented and argue that it should be a starting point for effective management in the sphere of communication in construction companies.
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Autorzy i Afiliacje

Ewelina Kania
1
ORCID: ORCID
Grzegorz Śladowski
1
ORCID: ORCID
Elżbieta Radziszewska-Zielina
1
ORCID: ORCID
Bartłomiej Sroka
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, ul.Warszawska 24, 31-155 Cracow, Poland

Abstrakt

The demands placed on industry today are increasingly challenging and demanding. To meet these challenges, designers, contractors, and technology managers are constantly looking for effective solutions. Industry has always thrived on new technologies and innovations to achieve better results, so it is critical to undertake new developmental research to simulate and test new technological proposals. In this paper, the author describes a new direction in civil engineering technology that interdisciplinary couples solutions known to the bridge industry with geotechnical aspects in the technology space and the possibility of implementation in the construction industry. The author proposes the application of prestressing together with technological aspects of this solution to diaphragm walls, which are not only a temporary housing but also the foundations of a new investment. Thanks to this solution it is possible, among other things, to resign from one level of diaphragm expansion of diaphragm walls, which translates into cost optimization. It is an innovative approach to designing and most of all constructing the load-bearing structure, which directly influences the technological optimization of selected issues of completing the underground parts of the investment. Additionally, the presented solution contributes to the balanced execution of the investment by reducing the use of materials and construction equipment. The author discusses technological, execution and implementation problems related to the application of innovative solutions in construction companies together with examples of cost optimization. The author presents the results of conducted research with application of the proposed solution in the implementation of the underground commercial investment.
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Autorzy i Afiliacje

Mateusz Frydrych
1
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland

Abstrakt

The implementation of public-private partnerships has become one of the effective models of cooperation between the public and private sectors in the development of infrastructure in Vietnam. This model has been adopted in Vietnam for many years and is intended to help governments build infrastructure and provide an opportunity to reduce government debt profiles. This study aims to identify the most critical factors that could determine the success of these projects. A questionnaire was conducted based on the participants’ experience in the implementation of public-private partnerships projects and a total of 216 respondents were received. A regression analysis shows that six critical success factors, including factors relevant to public sector, factors relevant to private sector, factors relevant to selected process partnerships, factors relevant to risk management systems, factors relevant to project information, and factors relevant to natural environment. The findings indicated that the most effective development projects could be carried out via PPPs if the government could focus on these important factors in the implementation process. The results will influence political development towards PPP and guide partners in developing public-private partnerships projects.
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Autorzy i Afiliacje

Nguyen Quoc Toan
1
ORCID: ORCID
Dinh Tuan Hai
2
ORCID: ORCID

  1. Hanoi University of Civil Engineering, Faculty of Construction Economics and Management, No. 55 Giai Phong Street, Hai Ba Trung District, Hanoi, Vietnam
  2. Hanoi Architectural University, Faculty of Civil Engineering, Km 10, Nguyen Trai Street, Thanh Xuan District, Hanoi City, Vietnam

Abstrakt

A quantitative study is performed to determine the performance degradation of Y-shaped reinforced concrete bridge piers owing to long-term freeze-thaw damage. The piers are discretized into spatial solid elements using the ANSYS Workbench finite element analysis software, and a spatial model is established. The analysis addresses the mechanical performance of the piers under monotonic loading, and their seismic performance under low-cycle repeated loading. The influence of the number of freeze-thaw cycles, axial compression ratio, and loading direction on the pier bearing capacity index and seismic performance index is investigated. The results show that freeze-thaw damage has an adverse effect on the ultimate bearing capacity and seismic performance of Y-shaped bridge piers in the transverse and longitudinal directions. The pier peak load and displacement ductility coefficient decrease with increasing number of freeze-thaw cycles. The axial compression ratio is an important factor that affects the pier ultimate bearing capacity and seismic performance. Upon increasing the axial compression ratio, the pier peak load increases and the displacement ductility coefficient decreases, the effects of which are more significant in the longitudinal direction.
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Autorzy i Afiliacje

Yanfeng Li
1
ORCID: ORCID
Jialong Li
1
Tianyu Guo
1
ORCID: ORCID
Tongfeng Zhao
2
Longsheng Bao
3
ORCID: ORCID
Xinglong Sun
1

  1. School of Transportation and Geomatics Engineering, Shenyang Jianzhu University, Shenyang 110168, China
  2. Liaoning Provincial College of Communications, Liaoning Bridge Safety Engineering Research Center, Shenyang 110168, China
  3. School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China

Abstrakt

The paper provides an overview of selected scientific articles presenting research carried out in recent years on methods for producing autoclaved aerated concrete. Traditional technologies are briefly presented, together with innovative solutions for the production of low-density and ultra-lowdensity materials. In addition to the presentation of the manufacturing methods themselves, the results of research into the properties of the autoclaved aerated concrete obtained and their dependence on the technology used are also presented. A subjective selection and review of articles covering research into the thermal conductivity of concrete, the technological factors influencing them and the ways in which they can be shaped was also carried out. A significant number of the cited articles do not function in the world scientific circulation due to the language barrier (they are mainly in Ukrainian). In the meantime, they contain interesting research results which can inspire further research into the issues discussed concerning the production technology and the thermal and strength properties of autoclaved aerated concrete, with particular emphasis on lightweight and ultra-lightweight concrete.
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Autorzy i Afiliacje

Yaroslav Yakymechko
1
ORCID: ORCID
Roman Jaskulski
2
ORCID: ORCID
Maciej Banach
2
ORCID: ORCID
Piotr Perłowski
2
ORCID: ORCID

  1. Lviv Polytechnic National University, Institute of Chemistry and Chemical Technologies, Bandera str. 13, Lviv, Ukraine
  2. Warsaw University of Technology, Faculty of Civil Engineering Mechanics and Petrochemistry, ul. Łukasiewicza 17, 09-400 Płock, Poland

Abstrakt

The running speed of high-speed trains in the tunnel is as high as 350 km, which is very sensitive to the construction disturbance of the new shield tunnel. Therefore, it is of positive significance to study the influence of shield tunneling on existing high-speed railway lines and tunnel structures and control standards. Combined with centrifuge test and three-dimensional numerical simulation, the dynamic response of shield tunnel undercrossing existing high-speed railway tunnel is studied, and the influence of settlement joint and steel pipe pile reinforcement on existing tunnel is analyzed. Studies have shown that the existence of existing tunnels will reduce the surface settlement caused by tunnel excavation, but this shielding effect will be reduced if the influence of construction joints is considered. Therefore, if the construction joint is not considered in the numerical calculation, the ground deformation will be underestimated and the mechanical performance of the existing tunnel structure will be overestimated. In addition, steel pipe piles can effectively control the settlement of existing tunnels.
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Autorzy i Afiliacje

Ruizhen Fei
1 2
ORCID: ORCID
Limin Peng
1
ORCID: ORCID
Chunlei Zhang
2
ORCID: ORCID
Jiqing Zhang
2
ORCID: ORCID
Peng Zhang
2
ORCID: ORCID

  1. Central South University, School of Civil Engineering, Changsha, 410075, China
  2. China Railway Design Corporation, Tianjin, 300142, China

Abstrakt

This paper proposes a method to optimize reinforcement layout of three-dimensional members under a state of complex stress and multiple load cases (MLCs). To simulate three-dimensional members, the spatial truss-like material model is adopted. Three families of truss-like members along orthotropic directions are embedded continuously in concrete. The optimal reinforcement layout design is obtained by optimizing the member densities and orientations. The optimal design of three-dimensional member is carried out by solving the problem of minimum volume of reinforcing bars with stress constraints. Firstly, the optimized reinforcement layout under each single load case (SLC) is obtained as per the fully stressed criterion. Second, on the basis of the previous results, an equivalent multi-case optimization is proposed by introducing the idea of stiffness envelope. Finally, according to the characteristics of the truss-like material, a closed and symmetrical surface is adopted to fit the maximum directional stiffness under all SLCs. It can be proved that the densities and orientations of truss-like members are the eigenvalues and eigenvectors of the surface coefficient matrix, respectively. Several three-dimensional members are used as examples to demonstrate the capability of the proposed method in finding the best reinforcement layout design of each reinforced concrete (RC) member and to verify its efficiency in application to real design problems.
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Autorzy i Afiliacje

Hao Cui
1
ORCID: ORCID
Junjie Xia
1
ORCID: ORCID
Lang Wu
1
ORCID: ORCID
Min Xiao
1
ORCID: ORCID

  1. College of Civil Engineering and Architecture, Jiangxi Science and Technology Norma lUniversity, No.605 Fenglin Avenue, 330013, Nanchang, China

Abstrakt

In this paper, based on the feasible method and sensors for the full-scale prestressed monitor, the novel optical fiber sensors and the traditional monitoring sensors will be set up into two prestressed concrete beams with the same geometrical dimensions, material properties, and construction conditions, etc. to investigate the working state of the novel sensors and obtain the evolution law of prestress loss of the prestressed feature component under the static load. The results show that the evolution law of prestress loss of the loaded beam under the condition of no damage state and initial crack is the same as the non-loaded one; however, the prestress loss increases with the increase of time under the situation with the limit crack. The total loss of the prestressed beam with the limit crack is 36.4% without damage. The prestress loss of the prestressed beam under the static load increase with the development of the crack (injury).
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Autorzy i Afiliacje

Jinbo Wang
1
ORCID: ORCID
Guodong Li
1
ORCID: ORCID
Chunguang Lan
2
ORCID: ORCID
Nan Guo
1
ORCID: ORCID

  1. Northeast Forestry University, School of Civil Engineering, Al. Harbin City, Heilongjiang Province, China
  2. Beijing Building Construction Research Institute Co., Ltd, A1. Beijing, China

Abstrakt

The historical past of a building has a key influence on the variability of geotechnical conditions. These conditions change with a modification of the structural system, a change in function or only architectural elements (fashionable in a given period). In the article, various geotechnical and geophysical surveys are described, which led to a discovery of potential causes of a structural failure at historical Castle of Dukes of Pomerania in Szczecin. The investigation resulted in a discovery of an underground tunnel system constructed under the Castle, which existence was only suspected. The tunnels were constructed primarily during II World War, but also before that period. The article summarizes facts discovered due to investigation as well as historical and geological background related to the execution of the reinforced concrete and masonry tunnels. The lesson learned resulting from this discovery is that great care should be taken when historical areas are considered, even if the structure seems to be massive and robust.
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Autorzy i Afiliacje

Tomasz Godlewski
1
ORCID: ORCID
Radosław Mieszkowski
2
ORCID: ORCID
Maciej Maślakowski
3
ORCID: ORCID

  1. Building Research Institute, 21 Ksawerów St., 02-656 Warsaw, Poland
  2. Warsaw University, Geology Department, 93 Zwirki i Wigury St., 02-089 Warsaw, Poland
  3. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland

Abstrakt

This article discusses in a simplified manner how to use the multiple functions of the Geographic Information System (GIS) to support the engineering decision for vital and important sites that require the decision-maker to have a high degree of certainty, such as the decision related to choosing the best location for the airport among several sites. This paper aims to provide a practical model that allows for a decision support system on how to adopt a GIS software by both its part Arc-Map and Arc-Catalog combined with analytic hierarchy process (AHP) method to make strategic decisions by spatial and non-spatial analysis to choose the appropriate site for the project as those related to choosing an airport location. Nineteenth criteria were considered to analyze the study area which is represented by three governorates of the middle Euphrates region in Iraq, Babil, Kerbala, and AL-Najaf. Finally, the research presented a practical and efficient approach for the decision maker to select the appropriate location for the airport based on the value of the highest suitability index.
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Autorzy i Afiliacje

Ali Kadhim Manea
1
ORCID: ORCID

  1. Civil Engineering Department, University of Babylon, Babylon, Iraq

Abstrakt

In the research of long-time operating road bridge superstructures, it should note that when the internal forces in the beam elements reach specific values, the stiffness of the cross-section of these elements should decrease. Besides that, if there are damaged places in the beam-element of the road bridge superstructures, the element could not work normally, and the redistribution of internal forces between elements in the whole system would happen. This phenomenon was not taken into account in the initial design calculation. In practice, it shows that many road bridges are subjected to greater loads than the calculated loads in the design process, but they still normally operate. This article proposes the other limit state criteria in evaluating the load capacity reserve of road-bridge superstructures using nonlinear analysis based on nonlinear deformational models of modern construction codes. The proposed calculation procedure is established to explain the load capacity reserve of long-time operating road bridge superstructures in the case of the lack of experimental evaluation. From the obtained results, the suitable limit state criteria for road bridge superstructures are suggested, and the conclusions about the accuracy of the proposed approach of nonlinear structural analysis are recommended.
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Autorzy i Afiliacje

Thuy Van Tran Thi
1
ORCID: ORCID
Quyen Vu Thi Bich
1
ORCID: ORCID

  1. Hanoi Architectural University, Faculty of Civil Engineering, Km.10 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam

Abstrakt

Closed form solutions for the flexural-torsional buckling of elastic beam-columns may only be obtained for simple end boundary conditions, and the case of uniform bending and compression. Moment gradient cases need approximate analytical or numerical methods to be used. Investigations presented in this paper deal with the analytical energy method applied for any asymmetric transverse loading case that produces a moment gradient. Part I of this paper is devoted entirely to the theoretical investigations into the energy based out-of-plane stability formulation and its general solution. For the convenience of calculations, the load and the resulting moment diagram are presented as a superposition of two components, namely the symmetric and antisymmetric ones. The basic form of a non-classical energy equation is developed. It appears to be a function dependent upon the products of the prebuckling displacements (knowfrom the prebuckling analysis) and the postbuckling deformation state components (unknowns enabling the formulation of the stability eigenproblem according to the linear buckling analysis). Firstly, the buckling state solution is sought by presenting the basic form of the non-classical energy equation in several variants being dependent upon the approximation of the major axis stress resultant M�� and the buckling minor axis stress resultant Mz. The following are considered: the classical energy equation leading to the linear eigenproblem analysis (LEA), its variant leading to the quadratic eigenproblem analysis (QEA) and the other non-classical energy equation forms leading to nonlinear eigenproblem analyses (NEA). The novel forms are those for which the stability equation becomes dependent only upon the twist rotation and its derivatives. Such a refinement is allowed for by using the second order out-of-plane bending differential equation through which the minor axis curvature shape is directly related to the twist rotation shape. Secondly, the effect of coupling of the in-plane and out-of-plane buckling forms is taken into consideration by introducing approximate second order bending relationships. The accuracy of the classical energy method of solving FTB problems is expected to be improved for both H- and I-section beam-columns. The outcomes of research presented in this part are utilized in Part II.
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Autorzy i Afiliacje

Marian Giżejowski
1
ORCID: ORCID
Anna Barszcz
1
ORCID: ORCID
Paweł Wiedro
1
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland

Abstrakt

The subject of this article is the analysis of the relationship between G 0/ M DMT and K D, where G 0 is the small strain shear modulus, while M DMT and K D are respectively the constrained modulus and the horizontal stress index determined from DMT tests. This relationship allows to determine a profile with depth of G 0 from standard DMT test results, useful when data from nonseismic DMT investigations are available. The analysis was based on a large amount of data for a wide range of soils of different origins in Poland. The dataset included OC and NC loams, silts, medium sands, silty sands and fine sands. The overconsolidation ratio (OCR) was estimated using data from CPTU and DMT tests. The obtained empirical G 0/ M DMT vs. K D relationships were compared with the correlations established by Marchetti et al. [1] for different soil types. To account for the significant influence of overconsolidation, an original empirical relationship between G 0/�� p and K D, where �� p is the preconsolidation stress, was defined based on data from all investigated fine-grained soils.
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Autorzy i Afiliacje

Zbigniew Młynarek
1
ORCID: ORCID
Jędrzej Wierzbicki
2
ORCID: ORCID
Paola Monaco
3
ORCID: ORCID
Katarzyna Stefaniak
2
ORCID: ORCID

  1. University of Life Sciences, Poznan, Poland
  2. Institute of Geology, Adam Mickiewicz University, Poznan, Poland
  3. University of L’Aquila, L’Aquila, Italy

Abstrakt

Prestressed anchor cables are active reinforcement to improve slope stability. However, the anchoring is not a permanent guarantee of stability, and the slope retains a potential risk of instability. From the perspective of the internal force of anchor cables, a new early warning method for the safety of the slope is provided, and a slope analysis model is established. With the increase in the strength reduction factor, the internal force increment curves of anchor cables under different prestresses are obtained. The point corresponding to strength reduction factors λ1 and λ2 represents a warning point. Key conclusions are drawn as follows: (1) The internal force of an anchor cable can be used to judge the stability of the slope strengthened by a prestressed anchor cable. (2) A warning index based on the internal force increment ratio of anchor cables is established. (3) The internal force increment ratio of anchor cables eliminates the influence of the initial prestress and is convenient for engineering applications.
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Autorzy i Afiliacje

Jincai Feng
Jiaxin Chen
Jian Li
Yu Zhang
ORCID: ORCID
Jianhua Guo
Hongyong Qiu

Abstrakt

To explore the application of cold-formed thin-walled steel-paper straw board(CTSPSB) composite wall in practical engineering and further meet people’s living requirements, it was proposed to open holes in the composite wall to simulate the doors and windows in practical applications. Two composite wall specimens were tested to study the shear performance of the CTSPSB composite wall. Through the analysis of specimens’ damage forms and experimental data, the characteristic values of bearing capacity and lateral stiffness were obtained. And then, the model of the composite wall was built by ANSYS, and finite element analysis (FEA) results were consistent with the experimental results, which could verify the feasibility of the finite element model. Moreover, the model needed to open holes and extensive parameter analysis was carried out. The FEA results indicate the most reasonable distance between screws around the opening is 150 mm; the most suitable spacing between the small studs is 400 mm; the position of the opening has the least influence on the shear performance, and the difference between the results of the five groups of models is within 5%; while the width of the opening has the greatest impact on the shear performance. Compared with the wall without opening, the bearing capacity of the wall with an opening width of 600 mm, 1200 mm and 1800 mm decreases by 38%, 46% and 52% respectively. Besides, the calculation formula of shear capacity of CTSPSB composite wall with openings was improved, which could be used as experience for practical engineering.
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Autorzy i Afiliacje

Xiuhua Zhang
1
ORCID: ORCID
Shuijing Xu
1
ORCID: ORCID
Siyu Li
1
ORCID: ORCID

  1. Dept. of Civil Engineering, Northeast Forestry University, Harbin 150040, China

Abstrakt

The effects of hydroxypropyl methylcellulose (HPMC) on the rheology and viscoelasticity of cement-limestone paste were evaluated, as was the mechanism of HPMC from the viewpoint of zeta potential and adsorption amount. The results revealed that the greater the content of HPMC or the viscosity of its aqueous solution, the lower the fluidity of the composite paste and therefore the higher the rheological parameters. The relation between torque and rotational velocity of cement-limestone paste is linear; nevertheless, the shear thickening degree of paste increased following the addition of HPMC, demonstrating typical viscoelastic properties. The addition of HPMC prolonged the induction duration and delayed the emergence of the exothermic peak of hydration, decreased zeta potential and conductivity, and increased the propensity of suspension particles to agglomerate. The adsorption amount of polycarboxylate superplasticizer (PCE) decreased with increasing aqueous solution viscosity and HPMC concentration due to the winding effect of HPMC’s high molecular chain structure and the competing adsorption of HPMC and PCE.
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Autorzy i Afiliacje

Ling Guan
1
ORCID: ORCID
Xiaolin Liu
1
ORCID: ORCID
Xinyuan Liu
2
ORCID: ORCID

  1. Chongqing Institute of Foreign Studies, School of International Business and Management, Chongqing, 401120, China
  2. Central South University, School of Civil Engineering, Changsha, 410075, China

Abstrakt

Complex construction projects require appropriate planning that allows for time and cost optimization, maximization of the use of available resources and appropriate investment control. Scheduling is a complicated process, due to the uncertainties and risks associated with construction works, the paper describes the development of the scheduling method traditionally used in Poland, based on data from KNR catalogs, by using the RiskyProject Professional program. In the RiskyProject Professional program, the risk and uncertainty with reference to a specific construction project were modeled, and the calculation results were compared with the real time of the project implementation. The conclusions from the work carried out confirm that the SRA (Schedule Risk Analysis) analysis of the base schedule allows for a more faithful representation of the actual conditions of a construction project. The probability of investment realization generated on the basis of the SRA analysis may be assumed at the level of 75÷90%.
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Autorzy i Afiliacje

Paulina Kostrzewa-Demczuk
1
ORCID: ORCID
Magdalena Rogalska
2
ORCID: ORCID

  1. Kielce University of Technology, Faculty of Civil Engineering and Architecture, Al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland
  2. Lublin University of Technology, Faculty of Civil Engineering and Architecture, Nadbystrzycka St. 40, 20-618 Lublin, Poland

Abstrakt

While constructing and documenting civil structures, large machines, and industrial facilities, one can encounter a situation where relevant control points are hardly accessible. The instruments with appropriate surveying equipment available on the market provide relatively standard measurements. The limitations mentioned above may transfer into an increased working time (or financial effort) that must be considered while performing the prescribed measuring works. One of the possible solutions (assuming financial capabilities) is utilizing a video-total station (a scan station) with additional supporting equipment. Another possibility would be employing a terrestrial laser scanner (TLS) or close-range photogrammetry. However, such technologies demonstrate significant limitations, especially in the industrial environment.
Regarding that, the authors propose an original measuring set collaborating with a free electronic total station. The main working principle is a known surveying 3D-polar method that can determine XYZ coordinates. The solution presented in the paper facilitates the performance of inventory works, consisting of dimensioning civil structures and rooms with difficult access. Such situations can often be encountered in industrial plants or while documenting architectural or other engineering structures. The device can also be used for dimensioning ventilation ducts, elevator shafts, and other similar facilities. Depending on the configuration of the measuring equipment and the target shapes, the final accuracy may reach a sub-millimeter or millimeter level. Hence, the solution can successfully be applied in civil engineering, industrial surveying, and industrial metrology.
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Autorzy i Afiliacje

Kazimierz Ćmielewski
1
ORCID: ORCID
Krzysztof Karsznia
2
ORCID: ORCID
Piotr Gołuch
1
ORCID: ORCID
Janusz Kuchmister
1
ORCID: ORCID

  1. Wrocław University of Environmental and Life Sciences, Faculty of Environmental Engineering and Geodesy, ul. Grunwaldzka 55, 50-357 Wrocław, Poland
  2. Warsaw University of Technology, Faculty of Geodesy and Cartography, Pl. Politechniki 1, 00-661 Warsaw, Poland

Abstrakt

In June 2021, a tornado struck a large area in southern Moravia, causing extensive damage to property owned by individuals and legal entities. A need thus arose to speed up the process of estimating the amount of insurance indemnity. This process involved local inspections and subsequent assessment of quotations from construction companies for repairs, as the adjusters did not have the time and resources to estimate the amount of damage using the usual method, i.e. an itemised budget containing a list of works, supplies and services necessary to restore a structure to its original condition based on an on-site inspection. This article contains a retrospective analysis of the accepted quotations and evaluates differences in terms of scope and price compared to the standard procedure. Four apartment buildings were selected for assessment of the insulation and roof repairs. The results show that there are clear discrepancies between the price as determined by the itemised budget using the usual prices and the construction companies’ quotations. The analysis of the selected buildings has indicated that the quotations can by no means be accepted without first establishing the total damage and its actual scope. Major damage caused by a natural disaster will still have to be estimated on the basis of a personal inspection of the damaged property and preparation of an itemised budget created in line with the applicable pricing system.
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Autorzy i Afiliacje

Michal Mikulík
1
ORCID: ORCID
Tomáš Hanák
1
ORCID: ORCID
Patrik Sokol
1
ORCID: ORCID
Miloslav Výskala
1
ORCID: ORCID

  1. Faculty of Civil Engineering, Brno University of Technology, 602 00 Brno, Czech Republic

Abstrakt

The non-uniformity of temperature field distribution of long-span steel structure is proportional to the intensity of solar radiation. Based on the background of Guangzhou Baiyun Station large-span complex steel roof structure, this paper studies the non-uniformtemperature field distribution of large-span steel structure under the Summer Solstice daily radiation-thermal-fluid coupling action based on Star-ccm¸ finite element software, and uses Spa2000 software to analyze the stress and deformation of steel roof under temperature action. Combined with the on-site temperature monitoring, the maximum difference with the measured value is 2.5˚C compared with the numerical simulation results, which verifies the validity of the finite element simulation. The results show that: from 8:00, with the increase of solar altitude angle, the intensity of solar radiation increases, the temperature rises, and the temperature distribution of large-span steel structure becomes more and more non-uniform. From14:00 to18:00, the solar radiation weakens, and the temperature distribution tends to be uniform. Finally, reasonable construction suggestions and measures are proposed to reduce the adverse effects of temperature effects, which can provide theoretical references for the safe construction and normal operation of large-span steel structures located in the subtropics.
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Autorzy i Afiliacje

Pengcheng Jiang
1
ORCID: ORCID

  1. Station Construction Command, China Railway Guangzhou Group Co., Ltd., Guangzhou, Guangdong, China

Abstrakt

Labor productivity in building construction has long been a focused research topic due to the high contribution of labor cost in the building total costs. This study, among a few studies that used scaled data that were collected directly from measuring equipment and onsite activities, utilized neural networks to model the productivity of two main construction tasks and influencing factors. The neural networks show their ability to predict the behaviors of labor productivity of the formwork and rebar tasks in a test case of a high-rise building. A multilayer perceptron that had two layers and used sigmoid as its activation function provided the best effectiveness in predicting the relations among data. Among eleven independent factors, weather (e.g., temperature, precipitation, sun) generally played the most important role while crew factors were distributed in the mid of the ranking and the site factor (working floor height) played a mild role. This study confirms the robustness of neural networks in productivity research problems and the importance of working environments to labor productivity in building construction. Managerial implications, including careful environmental factors and crew structure deliberation, evolved from the study when labor productivity improvement is considered.
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Autorzy i Afiliacje

Duc Anh Nguyen
1
ORCID: ORCID
Dung Quang Tran
1
ORCID: ORCID
Thoan Ngoc Nguyen
1
ORCID: ORCID
Hai Hong Tran
1
ORCID: ORCID

  1. Hanoi University of Civil Engineering, Department of Building and Industrial Construction, 55 Giai Phong Street, Hanoi, Vietnam

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Procedura recenzowania

Manuscript Peer-Review Procedure

”Archives of Civil Engineering” makes sure to provide transparent policies for peer-review, and reviewers have an obligation to conduct reviews in an ethical and accountable manner. There is clear communication between the journal and the reviewers which facilitates consistent, fair, and timely review.

-The model of peer-review is double-blind: the reviewers do not know the names of the authors, and the authors do not know who reviewed their manuscript (but if the research is published reviewers can eventually know the names of the authors). A complete list of reviewers is published in a traditional version of the journal: in-print.
-It is the editor who appoints two reviewers; however, if there are discrepancies in the assessment the third reviewer can be appointed.
-After having accepted to review the manuscript (one-week deadline), the reviewers have approximately 6 weeks to finish the process.
-The paper is published in ACE provided that the reviews are positive. All manuscripts receive grades from 1-5, 5 being positive, 1 negative, the authors receive reviews to read and consider the comments.
-Manuscript evaluations are assigned one of five outcomes: accept without changes, accept after changes suggested by the reviewer, rate manuscript once again after major changes and another review, reject, withdraw.
-Manuscripts requiring minor revision (accept after changes suggested by the reviewer) does not require a second review. All manuscripts receiving a "Rate manuscript once again after major changes and another review " evaluation must be subjected to a second review. Rejected manuscripts are given no further consideration. There are cases when the article can be withdrawn, often upon the request of an author, technical reason (e.g. names of authors are placed in the text, lack of references, or inappropriate structure of the text), or plagiarism.
-The revised version of the manuscript should be uploaded to the Editorial System within six weeks. If the author(s) failed to make satisfactory changes, the manuscript is rejected.
-On acceptance, manuscripts are subject to editorial amendment to suit house style.
-Paper publication requires the author's final approval.
- As soon as the publication appears in print and in electronic forms on the Internet there is no possibility to change the content of the article.

Editor’s responsibilities
-The editor decides whether the paper fulfills all requirements i.e. formal and scientific and which articles submitted to the journal should be published.
-In making these decisions, the editor may be guided by the policies of the journal’s editorial board as well as by legal requirements regarding libel, copyright infringement, and plagiarism.
-The editor maintains the integrity of the academic record, precludes business needs from compromising intellectual and ethical standards, and is always willing to publish corrections, clarifications, retractions, and apologies when needed.
-The editor evaluates manuscripts for intellectual content without regard to race, gender, sexual orientation, religious belief, ethnic origin, citizenship, or political philosophy of the author(s).
-The editor does not disclose any information about a manuscript under consideration to anyone other than the author(s), reviewers and potential reviewers, and in some instances the editorial board members, as appropriate.

Reviewers' responsibilities
Any manuscripts received for review are treated as confidential documents. They must not be shown to or discussed with others except if authorized by the editor. Privileged information or ideas obtained through peer review is kept confidential and not used for personal advantage Any invited reviewer who feels unqualified to review the manuscript or knows that its timely review will be impossible should immediately notify the editor so that alternative reviewers can be contacted. Reviewers should identify relevant published work that has not been cited by the authors. Any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. A reviewer should also call to the editor's attention any substantial similarity or overlap between the manuscript under consideration and any other published data of which they have personal knowledge. Reviewers should not consider evaluating manuscripts in which they have conflicts of interest resulting from competitive, collaborative, or other relationships or connections with any of the authors, companies, or institutions connected to the submission. Reviews should be conducted objectively. Personal criticism of the author is unacceptable. Referees should express their views clearly with appropriate supporting arguments. All reviews must be carried out on a special form available in the Editorial System.

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