Rail transport generates lower external costs related to environmental pollution in comparison to other means of transport. Sustainable development and environmentally friendly attitudes are increasingly used in prese...
Rail transport generates lower external costs related to environmental pollution in comparison to other means of transport. Sustainable development and environmentally friendly attitudes are increasingly used in present construction projects. Railway investments usually involve large projects in the field of transport infrastructure (megaprojects in transport infrastructure). construction and modernization encompasses railway lines and overhead lines, engineering structures, buildings and railway traffic control devices. In the case of railway projects, numerous different risk factors that are not reflected in other construction projects may exist. Such investments typically generate high costs and require appropriate methods to manage risk factors. Effective project management relies primarily on the precise recognition of its characteristics, existing conditions as well as political and economic situation in its environment. The paper describes mechanisms related to implementation of railway construction investments in Poland in the context of the financial perspective planned for 2014 - 2020 period. In addition, formal and legal environment existing on the railway market has been analysed.
Most failures of transmission towers are attributed to the actions of severe thunderstorm downbursts and tornadoes with nonstationary characteristics. This paper presents an analytical framework for predicting quasi-s...
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The application of environmental criteria in public procurement should be considered in terms of implementing the principle of sustainable development. Hence, dissemination of environmental criteria in public procurem...
The application of environmental criteria in public procurement should be considered in terms of implementing the principle of sustainable development. Hence, dissemination of environmental criteria in public procurement is one of the strategic objectives of the European Union, enabling the improvement of environment. There are specific solutions that allow the contracting authority to take environmental aspects into account while evaluating offers and contractors educationse.g. Eco-Management and Audit Scheme (EMAS). The contracting authority has the option of requiring the contractor to demonstrate the implementation of environmental management measures or systems. During the procurement procedure, the contracting authority may require from the contractor to demonstrate the implementation of environmental management measures or systems and verify that the contractor's existing quality system guarantees the proper performance of the contract or minimizes negative environmental impacts or whether the proposed products meet the requirements of certain standards or technical specifications. To confirm that the offered supplies, services or works meet the specific requirements, the contracting authority may demand specific documents. The legal system, indicating the executive regulations of the Public Procurement Law, provide such opportunity. The purpose of the paper is to indicate how the contracting authority can apply environmental requirements at the stage of preparing tender documentation for the construction and extension of waste water treatment plants and wastewater infrastructure. The article presents the original research carried out in dozens of municipalities, which in 2009−2015 carried out public sewage infrastructure contracts. The results of the studies indicated that the contracting authorities generally did not require the contractor to implement environmental management systems and did not indicate such criteria when selecting contractors.
Generation and quality of as built models influence the subsequent applications such as progress monitoring, quality control, and deviation detection. The quality of any 3D reconstructed model heavily depends on the r...
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Generation and quality of as built models influence the subsequent applications such as progress monitoring, quality control, and deviation detection. The quality of any 3D reconstructed model heavily depends on the raw inputs and the post processing involved. While laser and LiDAR-based scanning are widely prevalent, lower cost equipment and sensors are increasingly becoming adaptable for 3D reconstruction. This study tests the feasibility of using IR-based scanning tablets and passive stereo vision cameras to acquire data from a construction environment based on the type of applications (such as progress monitoring, deviation detection) on a construction site. Two different off the shelf technologies: Tango tablet and ZED camera are tested during this research for developing as-built models using 3D reconstruction. The devices are compared on the basis of metrics such as preparation time for each scan, calibration of the scanner and total scanning time for determining the ease of scanning process, accuracy of generated point clouds. Also, the influence of external factors such as scanning parameters, ambient lighting, and characteristics of the object being scanned, and angle/orientation of scanner with respect to the object are studied.
In general, the process of building construction makes the inevitable wastes such as nails, formwork, steel and concrete. In order to reduce these wastes, parts of building have therefore been produced by using the ma...
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To establish a working system in field to evaluate the degree of fire-damage readily for both brittle and ductile tunnel supporting materials, this research focused on the failure characteristics and evolution on both...
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ISBN:
(纸本)9791156103158
To establish a working system in field to evaluate the degree of fire-damage readily for both brittle and ductile tunnel supporting materials, this research focused on the failure characteristics and evolution on both macro-scale (stiffness, strength and toughness) as well as micro-scale (localization, crack initiation and propagation). After applying various heat-driven-damage treatments, both brittle material such as concrete (rock-like material) and ductile steel were conducted uniaxial compressive and tensile tests respectively. Furthermore, this study propose a velocity ratio, defined as VS/VP, to be an index to identify the degree of thermos-induced damage in field. By applying maximum temperature varied from 25 to 1200 with constant rate of heating (5 /min), exposure time (300 mins), and cooling condition (cooling in furnace), the uniaxial compressive and tensile tests with post-peak behavior were obtained by controlling the lateral COD (crack opening displacement) as a feedback signal to conduct the closed-loop experiences. Associated with ultrasonic pulse (UP) and synchronized acousto-optic nonintrusive technique (AE & ESPI), macro- and micro-scale failure of materials were examined corresponding to entire loading histories of uniaxial compressive tests. The results show that VS/VP has a positive correlation with degree of thermos-induced damage on concrete, the correlation coefficient of VS/VP between stiffness, strength and toughness are -0.90, -0.87 and -0.77 respectively. It proves that the VS/VP can be used to identify the degree of thermos-induced damage such as fire disaster. In macro-scale, concrete suffer heat-driven damage cause the post-peak stability from snap back (Class II) convert to snap through (Class I), and the transition temperature is between 200 to 400. In micro-scale, as the maximum temperature increase, the more severe the degree of thermos-induced damage, in addition, it leads to more insignificant "localization" phenomenon graduall
Insulated concrete sandwich panels are composed of two concrete wythes separated by an insulation layer and connected by shear connectors. This paper develops a multifunctional photovoltaic (PV) integrated insulated c...
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In present work thermal and moisture concentration effects on laminated composite hypars is explored. Third degree thickness coordinate is considered in plane displacement variables. The twist curvatures of hypars is ...
In present work thermal and moisture concentration effects on laminated composite hypars is explored. Third degree thickness coordinate is considered in plane displacement variables. The twist curvatures of hypars is considered in present analysis. The shear correction factor is eliminated due to actual representation of transverse shear in present work. Imposition of nil transverse shear stress conditions at top and bottom of the surface of hypars is done mathematically. Finite element (FE) formulation of present mathematical model is done using a nine noded curved isoparametric element with seven unknowns at each node. FE formulation is coded in FORTRAN. The comparison study of present work is found to be consistent with previous published works by different methods. The parametric study is done by varying different parameters like moisture concentration, temperature variations, and boundary conditions.
Tibetan stone masonry is different from common masonry structure. However, currently, few studies on its structural characteristics and mechanical properties are conducted. This paper summarizes the materials, composi...
Tibetan stone masonry is different from common masonry structure. However, currently, few studies on its structural characteristics and mechanical properties are conducted. This paper summarizes the materials, composition and masonry methods of Tibetan stone masonry, and analyzes its structural characteristics. A uniaxial compression test on the small specimens built in the laboratory and the full-scale wall specimens on the site is conducted to explore the damage mechanism of the Tibetan stone masonry. Based on the compression performance of Tibetan stone masonry, this paper proposes the factor set, weight coefficient, and rating criteria of the safety assessment of the Tibetan stone masonry components by using the fuzzy comprehensive evaluation and analytic hierarchy method. The evaluation method of the safety status of components is also put forward, which is validated by the test results.
Erythromycin（ERY）,a widely used antibiotic,has recently been detected in municipal secondary effluents and poses serious threats to human health during wastewater *** this study,the removal,fate,and degradation path...
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Erythromycin（ERY）,a widely used antibiotic,has recently been detected in municipal secondary effluents and poses serious threats to human health during wastewater *** this study,the removal,fate,and degradation pathway of ERY in secondary effluent during soil aquifer treatment was evaluated via laboratory-scale SAT *** to a 92.9%reduction of ERY in synthetic secondary effluent was observed in 1.0 m depth column system,which decreased to 64.7%when recharged with wastewater treatment plant secondary ***-fractionation results demonstrated that the transphilic acid and hydrophobic acid fractions in secondary effluent compete for the adsorption sites of the packed soil and lead to a declined ERY ***,aerobic biodegradation was the predominant role for ERY removal,contributing more than 60%reduction of ERY when recharged with synthetic secondary *** of 14-member macrocyclic lactone ring and breakdown of two cyclic sugars（L-cladinose and D-desosamine） were main removal pathways for ERY degradation,and produced six new intermediates.
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