Worldwide, construction is a branch of the economy characterised by a high level of employee safety risks and a high accident rate. In Poland, over the last 20 years, the number of victims and the frequency of accidents in the construction industry have shown a decreasing tendency, but they are subject to large fluctuations. Current accident reporting methods focused on rigidly classified circumstances and root causes do not facilitate drawing general conclusions for the purpose of prediction. The paper presents an analysis of the number and characteristics of construction site accidents of the years 2015-2017 using data from reports of the National Labour Inspectorate. The preliminary analysis of available nationwide sources confirmed that every year nearly 50% of accidents that occur during construction works are falls from height. The analysis is intended as a starting point for further research on factors and causes of accidents at work in construction.
One of the most important documents occurring in the investment process is the administrative decision: building permit. Obtaining it is often a time-consuming process in practice, associated with the need to attach to the application other required decisions and permits necessary for a positive consideration of the case. The procedure itself is not always a long-term process, as long as the investor makes sure to prepare a reliable application free of errors and irregularities together with the construction project and the required attachments. The purpose of the article is to analyze errors appearing in investors’ applications and attached project documentation required in the administrative procedure for obtaining a building permit in the light of the applicable provisions of Polish law.
Volume change in expansive soils due to the intervention of water causes swell. A laboratory investigation using two different gbeosynthetic materials was designed to minimise the swell characteristics. The influence of three parameters, being geosynthetic material [Secutex (ST) and Combigrid (CG)], orientation (horizontal and vertical), and number of layers (1, 2, and 3) on the swell of an expansive soil was studied to better understand the potential for geosynthetics in swell control. The study on the immediate swell characteristics (limited to 24 hours) helps in gaining confidence in the use of geosynthetics in the swell control of expansive soils. From the investigation results, it was found that all three parameters, being type of material, orientation, and number of layers influenced the swell control of the soil. When two layers of ST and CG were placed both vertically and crossed, they reduced the swell of the virgin soil by almost 60% and 44%, respectively. It can, therefore, be concluded that geosynthetics can play an effective role in the swell control of expansive soils.
Lukas Schwan, Jakob Hahn, Michael Barton, Ronja Anders and Christian Schweigler
The building sector offers the largest potential for a significant reduction of greenhouse gas emissions. Based on own preliminary investigations for the State of Bavaria, a complete renovation of the building envelope of the current residential building stock would result in a reduced demand for final thermal energy for space heating and domestic hot water by about 70 %. The present study analyzes different existing reference buildings and reference methods. Based on a general literature review, specific criteria will be developed for reference models to represent the thermal energy consumption of the residential building stock for the regional domain under investigation. The objective is to represent the building stock with a limited amount of reference buildings. The method for the development of a reference building will be shown exemplarily for one category.
This study aimed to develop a knowledge about material parameters identification of the foam core and numerical modelling of the sandwich panels to accurately predict the behaviour of this kind of structures. The polyisocyanurate foam (PIR) with low density used in sandwich panels dedicated to civil engineering is examined in the paper. A series of experiments (tensile, compression and bending tests) were carried out to identify its mechanical parameters. To determine the heterogeneity of analysed foam a Digital Image Correlation (DIC) technique, named Aramis, is applied in the paper. The results obtained from FE analyses are compared with the experimental results on full-size plates carried out by the author and proper conclusions are drawn.
The article presents issues related to modeling of the rainfall-runoff phenomenon. As factors influencing the simulation results, the velocity and direction of precipitation relative to the drainage basin were indicated. The possibility of underestimating the cross-sections of rainwater channels as a result of overlapping rain wave directions and the dominant flow direction in the rainwater channel network was pointed out. The research results to date indicate a reduction in the symptoms of this phenomenon as the complexity of the channel network increases. The final verification was based on the actual catchment. Calculations were made using the Epa SWMM 5.1.013 software. The results are presented in a graphic form to illustrate the variability of stormwater outflow.
Ireneusz Nowogoński, Ewa Ogiołda and Marcin Musielak
The article presents the current state of knowledge in the field of estimating preliminary values of storm water subcatchment calibration parameters in the case of using the Storm Water Management Model (SWMM) for building a model of storm water drainage system. The key issue is estimating the runoff width in the case of reducing the network structure and storm water catchments due to the shortening of calculation time and simplification of the model calibration process. Correction of one of the recommended literature methods has been proposed. The assessment was based on the real catchment model with single and multi-family housing. It was found possible to apply the proposed method in the case of reducing systems connected in series.
Currently, organic halogen compounds (halogen derivatives) are often identified in water. The paper presents the problem of the presence of these newly formed compounds during water treatment processes and their occurrence in sewage. The general indicator determining the content of these compounds in aqueous solutions is the concentration of halogen derivatives of organic compounds adsorbed on activated carbon AOX, which is converted to the concentration of chlorides. The groups of derivatives of halogenated organic compounds containing chlorine and/or bromine in a molecule were characterized, and the precursors and potential for the formation of these compounds in water were described. Moreover, technological methods to prevent and remove them were described.
The article analyses the method of enhancing a steel beam by adding additional steel members like ribs. They are rigidly connected with both flanges in a plane parallel to the web. That plates reduces warping during in-plane bending of steel beam under lateral-torsional bucking. Different thicknesses of steel plates used as ribs and different cross-sections were taken into account. Calculations were conducted using FEM and ABAQUS CAE environment. The outcomes were compared with ones from previous studies which concerned an influence of endplates on load-bearing capacity of an I-beam.
The article describes the gradient-iterative optimization method and outlines the method’s basic assumptions and illustrates its general use. The method’s implementation was illustrated based on a steel I-beam. The described calculation example concerns the optimization of the height of the web of a multi-span beam. The method enables finding an optimal solution with the use of simple and commonly available software.
To illustrate the effectiveness of the optimization method, multiple calculations were performed for beams with various spans and various load conditions.