The standard PN-EN_1993-1-5:_2008 (Eurocode 3) compared with the standard (PN-B-03200:_1990) used previously in Poland, introduces extended rules referring to the computations of the bearing capacity of the plated structural elements including the shear lag effect. The stress distribution in the width flanges is variable. Therefore in the case of the beam with the shear lag effect cannot be calculated by the classic beam theory.

In this article a comparison of the results of the calculations of forces distribution, stresses and displacement according to the rule presented in PN-EN_1993 and results of the numerical computations for_3D model (using finite element method) is presented. The elastic shear lag effects, the elastic shear lag effects including effects of the plate buckling and the elastic-plastic shear lag effects including the local instabilities were analysed. The calculations were performed for beams with a small and a large span and an influence of stiffeners was analysed.

The European standards, developed extensively over last 30 years, are driven by the need for continuous evolution and their Authors’ pursuit of better EU-wide quality in civil engineering – combining safety, economy, and sustainable development. The adoption of theory of reliability as the basis for design has played a major role in shaping current geotechnical practice. However, it requires from practitioners a greater understanding of underlying uncertainties. Furthermore, a number of alternative approaches, not generally used in structural design, are also allowed, as some situations in geotechnical engineering require an individual approach. Moreover, the current trends in geoengineering increase the importance of risk assessment and management. The paper presents general philosophy guiding the geotechnical design and pointing to some of the ideas introduced by Eurocode 7 and its requirements, in relation to preexisting practice of geotechnical design in civil engineering.

In Eurocode 5, the stiffness equation for bolted steel-wood-steel is stated as a function ofwood density and fastener diameter only. In this research, an experimental study on various configurations of tested bolted steel-wood-steel (SWS) connections has been undertaken to predict the initial stiffness of each connection. In order to validate the Eurocode 5 stiffness equation, tests on 50 timber specimens (40 glued laminated timbers and 10 laminated veneer lumbers (LVL)) with steel plates were undertaken. The number of bolts was kept similar and the connector diameter, timber thickness, and wood density were varied. The results obtained in the experimental tests are compared with those obtained from the Eurocode 5 stiffness equation. From the analysis, it is signified that the stiffness equation specified in Eurocode 5 for bolted SWS connections does not adequately predict the initial stiffness. The results from Eurocode 5 stiffness equation are very far from the experimental values. The ratio of stiffness equation to experimental results ranges from 3.48 to 4.20, with the average at 3.77, where the equation overpredicted the experimental stiffness value for the connection. There is a need to consider or incorporated other parameters such as geometric configurations in Eurocode 5 stiffness equation to improve the ratio with the experimental data.

Glass is a material commonly used in construction. The development of technology related to it, and the increase in knowledge concerning its mechanical and strength properties offer opportunities for glass to be applied as a structural material. The advancement in glass structures, methods for their design, as well as guidelines and standards in this fields are being developed in parallel. This article describes the main assumptions contained in the German TRxV guidelines, the series of German DIN 18008 standards, and the European EN 16612, and EN 16613 standard. Moreover, the following article presents the concept of structural glass design included in the draft pre-standard prCEN/TS 19100, which provides the basis for the formulation of the European standard Eurocode 10. According to this pre-standard, structural elements of glass will be verified in four limit states, depending on the Limit State Scenario (LSS). Apart from the classic limit states, i.e., the ultimate limit state (ULS), and the serviceability limit state (SLS), it is also assumed to introduce a fracture limit state (FLS), and postfracture limit state (PFLS). The article also addresses the issue of laminated glass working in structural elements. Depending on the coupling between the glass panes and the polymer or ionomer interlayers, laminated glass can be divided into complete coupled or uncoupled, and can work in intermediate situations. The methods for determining the effective thickness contained in European standards and guidelines are discussed in this article.

Admixtures are commonly used nowadays in the mix composition of concrete. These additions affect concrete properties and performance especially creep deformations. This paper shows the effect of admixtures on creep of concrete. In fact, creep deformations have prejudicial consequences on concrete behaviour; an incorrect or inaccurate prediction leads to undesirable consequences in structures. Therefore, an accurate estimation of these deformations is mandatory. Moreover, design codes do not consider admixtures’ effect while predicting creep deformations, thus it is necessary to develop models that predict accurately creep deformations and consider the effect of admixtures. Using a large experimental database coming from international laboratories and research centres, this study aims to update the Eurocode 2 creep model by considering the type and percentage of admixtures using Bayesian Linear Regression method. The effect of two types of admixtures is presented in this paper; the water reducer and silica fume.

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.

Steel-wood-steel connection is widely seen in many applications, such as timber structures. The stiffness of steel-wood-steel connection loaded parallel to grain for softwoods originated from Malaysia was investigated in this study. Numerical models have been developed in ABAQUS to study the stiffness connection. Softwoods of Damar Minyak and Podo have been selected in this analysis. The comprehensive study focused on the effect of bolt configurations on stiffness. Numerical analysis is carried out and the developed model has been validated with the previous study. Further investigations have been made by using the validated model. From this model, numerical analysis of the stiffness values have been made for various bolt configurations, including bolt diameter, end distance, bolt spacing, number of rows and bolts and edge distance. The result shows that the stiffness of bolted timber connections for softwood depends on the bolt diameter, number of rows and bolts, end distance and edge distance. Based on the result, stiffness increased as the diameter of the bolt, end distance, number of rows and bolts and edge distance increased. It is also discovered that the stiffness equation in Eurocode 5 (EC5) is inadequate as the equation only considered parameters which are wood density and bolt diameter. Other connection parameters such as geometry are not considered in the EC5 equation.

The paper presents the methods of determining the characteristic value on the basis of the standards: PN-B-03020:1981, PN-EN 1997-1:2008, prEN 1997-1:2022-09 and Schneider formula. Determination of the characteristic value of the undrained shear strength τfu was carried out using statistical method on the basis of the prEN 1997-1:2022-09 standard and Schneider formula. The statistical calculations were based on the results of field vane tests carried out in organic subsoil of test embankment in Antoniny test site before loading and after the 2nd embankment stage. In order to determine the undrained shear strength τfu of organic soils from field vane tests, the measured values of shear strength τf v were corrected using the average values of correction factors μ = μ(lab) determined on the basis of triaxial compression, simple shear and triaxial extension tests. The analysis of the calculation results shows that with relatively numerous data sets, large values of the coefficient of variation Vx result in significantly lower characteristic values of τfu obtained according to prEN 1997-1:2022-09, compared to the values obtained according to the Schneider formula. In the case of few data sets, for which high values of the coefficient kn are obtained, with high values of the coefficient of variation Vx , the comparison of the values according to prEN 1997-1:2022-09 with the values obtained according to the Schneider formula shows the greatest differences.