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This work presents several results of the stability in steel columns subject to pure compression. A square hollow cross-section with different sizes was considered. This study presents all the analytical equations that need to be used to verify the stability of each column with different lengths and boundary conditions. A finite element program was also chosen to achieve the most critical loads (Euler and buckling resistance loads) in the calculation for each element under study, using linear and nonlinear geometric and material modeling. Steel material was used for the columns, where damage due to plasticity was included, through plastic behavior with isotropic hardening. Comparing the results allows us to conclude that the use of the finite element method is an alternative methodology to be used in other types or configurations of columns, where parameterized tests can be easily implemented and to contribute to the development of a wide-ranging database. The finite element method led to an accurate solution when compared with the analytical results with a maximum deviation of 14.7%. By increasing the column length and reducing the cross-section size, the design buckling resistance of the studied columns also decreases. These studies demonstrate that the length and size of the column cross-section can meaningfully increase the structural behavior of the columns. [ABSTRACT FROM AUTHOR]

This article presents an analytical approach for calculating web stiffeners in thin-walled columns. A novel method is introduced, which treats each bending point in the cross-section web as a separate stiffener. The advantages of this calculation method are discussed, highlighting its increased versatility in designing cross-section geometry. The load-bearing strength of axially compressed thin-walled closed cross-section columns, calculated using this method, is compared to analytical calculations based on the Eurocode 3-1-3 methodology and to the finite element method analysis. Calculation results of columns with cross-sections including shallow web stiffeners were up to 9.22% less conservative when compared to the Eurocode 3-1-3 methodology. The results demonstrate great compliance of the proposed method for column crosssections with deep stiffeners. Finite element method (FEM) analysis was performed to verify the calculated load bearing strengths of the columns according to both calculation methodologies. FEM analysis confirmed the reliance of the calculated results and showed, that the load bearing strengths calculated using the newly presented methodology were ranging from 88.77% to 97.86% of load bearing strength calculated using finite element method. These results proved, that the proposed method provides an accurate load bearing strength of thin-walled columns with web stiffeners. [ABSTRACT FROM AUTHOR]

Effective width, as presented in Eurocode 3 is analysed. Efforts have been made to distinguish between the behaviour of the various structural parts acting as wide flanges. Different mechanical models are adopted: for the bridge deck plate between girders, for the cantilever deck part, and for the bottom plate of box girders with the presumption to reflect more adequately their actual participation in the complex girder work at bending. Also, the interaction between girders in a superstructure at loading is simulated as far as possible in order to replace to some extent a sophisticated spatial analysis. The Eurocode 3 way of presenting the matter is preserved. The results obtained are compared with the corresponding Eurocode parts and an assessment on the reported differences is given. The goal is to supply the designers with extended understanding the effects arising from the shear lag phenomenon. [ABSTRACT FROM AUTHOR]

Biaxially prestressed large concrete structures of the confinement building in nuclear power plants (NPPs) should meet the safety requirement for the extension of the service time. Long‐term delayed strains of concrete are one of the key factors determining the safety factor in these structures. This article presents 30‐year long in situ measurement results of strain evolution of confinement buildings in four different NPPs. The delayed strains are predicted at a material level using the next‐generation Eurocode‐2, and the influence of temperature as proposed by the fib model code 2010, making use of delayed strain characteristics of the corresponding concrete from a previous study. We found that the default law given in Eurocode underestimates the delayed strain. However, with the possibility of adjusting the shrinkage and creep laws, the prediction results fit with a good accuracy for the in situ measurement. [ABSTRACT FROM AUTHOR]

Introduction. The Republic of Belarus is one of the first countries on the territory of the CIS, which introduced European design standards (Eurocodes) on its territory, while preserving the effect of building standards developed on the basis of Soviet SNIP. The republic accumulated considerable experience in the practical application and comparative analysis of these two systems of standards. The relevance of this study is contained in the discovery of the most distinctive features of normative documents, on the basis of which it is possible to determine further directions of scientific research and improvement of domestic norms.Materials and methods. Analysis and generalization of experience.Results. The paper presents the results of generalization of the experience of practical application and comparative analysis of Eurocode and CP in relation to the design of steel structures. The analysis of partial factors, classification of cross sections, welded and bolted joints is given.Conclusions. Methodological approaches to checking limit states and ensuring the reliability of steel structures in CP and Eurocodes are very similar, but there are differences in the values and sets of partial factors. When designing steel structures according to Eurocode, the methods of classification of cross-sections of rolled profiles produced according to GOST or TS need to be adjusted. Eurocode 3 provides more possibilities in the design of welded and bolted joints.

The evaluation of seismic forces is very important for the design of all types of structures. In the present, Republic of Moldova is in a period of transition in the construction industry from the national design norms to the European design norms. The comparison provides an interesting and imperative approach in design of structures. During the design process it is very important to be aware of all the forces acting on a structure, especially the accidental forces. This paper presents a comprehensive analysis of a concrete frame structure, subjected to seismic action. A calculation is performed according to the current national design code SNiP II-7-81 and according to Eurocode 8. The purpose of the paper is the quantitative comparison of the values of the seismic forces and the qualitative evaluation of the factors that influence these forces.

Abstract This study proposes a modification for the current design approach for square and rectangular silos that accounts for silos’ wall flexibility. First, the authors investigated the effect of wall stiffness symbolized by the wall width-to-thickness ratio (a/t) and silo’s dimensions, on the wall-filling pressure using a recently validated 3D finite element model (FEM). The model was then employed to predict the pressures acting on silos’ walls accounting for the stress state in stored granular materials. Most design formulas and guidelines assume silos’ walls to be rigid. This assumption is acceptable for the case of rigid wall concrete silos; however, it is questionable for semi-rigid, flexible wall metal silos. Consequentially, it is crucial to determine the minimum wall stiffness necessary to secure the applicability of the current design rigid wall assumptions and to propose a way to deal with semi-rigid and flexible walls. To this end, several wall pressure distributions that correspond to filling steel silos with varied wall thicknesses were studied. A new adjustment to the Janssen technique was proposed for a better estimate of the wall-filling pressures for square and rectangular silos. In the case of prismatic silos, the Eurocode uses the Janssen equation together with an equivalent radius of a corresponding circular silo (with the same hydraulic radius) to determine the wall pressure. This method predicts pressure values that are practically accurate for rigid-wall silos, but its accuracy decreases for semi-rigid and flexible-wall silos. As an enhancement, the Janssen equation was modified in this research to generate more accurate pressure estimates based on the equivalent volume concept. The finite element results of several developed models with the same granular material were compared to the estimations of the newly established approach to verify the broad range of its applicability.

Copyright of Engineer Military Bulletin / Muszaki Katonai Közlöny is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study proposes a modification for the current design approach for square and rectangular silos that accounts for silos’ wall flexibility. First, the authors investigated the effect of wall stiffness symbolized by the wall width-to-thickness ratio (a/t) and silo’s dimensions, on the wall-filling pressure using a recently validated 3D finite element model (FEM). The model was then employed to predict the pressures acting on silos’ walls accounting for the stress state in stored granular materials. Most design formulas and guidelines assume silos’ walls to be rigid. This assumption is acceptable for the case of rigid wall concrete silos; however, it is questionable for semi-rigid, flexible wall metal silos. Consequentially, it is crucial to determine the minimum wall stiffness necessary to secure the applicability of the current design rigid wall assumptions and to propose a way to deal with semi-rigid and flexible walls. To this end, several wall pressure distributions that correspond to filling steel silos with varied wall thicknesses were studied. A new adjustment to the Janssen technique was proposed for a better estimate of the wall-filling pressures for square and rectangular silos. In the case of prismatic silos, the Eurocode uses the Janssen equation together with an equivalent radius of a corresponding circular silo (with the same hydraulic radius) to determine the wall pressure. This method predicts pressure values that are practically accurate for rigid-wall silos, but its accuracy decreases for semi-rigid and flexible-wall silos. As an enhancement, the Janssen equation was modified in this research to generate more accurate pressure estimates based on the equivalent volume concept. The finite element results of several developed models with the same granular material were compared to the estimations of the newly established approach to verify the broad range of its applicability. [ABSTRACT FROM AUTHOR]

The purpose of the study is an experimental determination of the stress-related characteristics of the structural steel produced in the Republic of Kazakhstan for use in conventional and earthquake-resistive construction. Since 2015, the construction industry has been using European regulatory documents--Eurocodes--as a statutory framework. In particular, the Eurocode 1993 for steel structures and the Eurocode 1998 for the design of earthquake-resistant structures However, the study of stress-related properties of structural steel using experimental methods of ISO standards has not been performed. Therefore, in the construction industry of the Republic of Kazakhstan, steel-work structures have been used in fairly limited volume since 2015. The experimental studies were conducted on 7 types of structural steel with thicknesses of 8, 10, and 20 mm manufactured by Arcelor Mittal. The yield strength, ultimate tensile strength (breaking stress), and tensile strength at break were studied. The experimental studies were carried out on the basis of ISO standards. In each test run, 5 samples were used. In two series, 20 samples each were tested, which made it possible to estimate the yield strength and strength distribution functions. The correlation relationships between Brinell hardness and yield and strength limits have been studied. As a result of experimental studies, it was found that the strength and deformability parameters fully comply with the requirements of Eurocode 1993. Based on the application of the Student's test, it is revealed that the distribution functions of yield strength and resistance correspond to the normal law (Gaussian function). The calculation of a three-story, two-span residential building with box section columns for construction in an area with a seismicity of 8 points is performed by the finite element method. The work results will significantly increase the scope of Kazakhstani structural steel use in seismic and conventional areas of the Republic of Kazakhstan. [ABSTRACT FROM AUTHOR]

This article presents an analytical approach for calculating web stiffeners in thin-walled columns. A novel method is introduced, which treats each bending point in the cross-section web as a separate stiffener. The advantages of this calculation method are discussed, highlighting its increased versatility in designing cross-section geometry. The load-bearing strength of axially compressed thin-walled closed cross-section columns, calculated using this method, is compared to analytical calculations based on the Eurocode 3-1-3 methodology and to the finite element method analysis. Calculation results of columns with cross-sections including shallow web stiffeners were up to 9.22% less conservative when compared to the Eurocode 3-1-3 methodology. The results demonstrate great compliance of the proposed method for column crosssections with deep stiffeners. Finite element method (FEM) analysis was performed to verify the calculated load bearing strengths of the columns according to both calculation methodologies. FEM analysis confirmed the reliance of the calculated results and showed, that the load bearing strengths calculated using the newly presented methodology were ranging from 88.77% to 97.86% of load bearing strength calculated using finite element method. These results proved, that the proposed method provides an accurate load bearing strength of thin-walled columns with web stiffeners.

This paper presents the theoretical basis of dimensioning and an example of the calculation of a retaining wall. The first part provides an insight into the loads acting on retaining structures and the basic design principles according to Eurocode, common to all types of retaining walls. In the practical part of the paper, on the example of a reinforced concrete cantilever retaining wall with a height of 4 m, the calculation procedure for static and seismic actions is presented, using the European standards for geotechnical design, EN 1997-1 and the design of structures for earthquake resistance, EN 1998-5. For the other heights of the retaining walls defined by the task, due to the extensiveness and limited space of the paper, only the calculation results within the analysis of the results are presented. The conclusion of the analysis of the conducted calculation is given at the end of the paper.

This work presents several results of the stability in steel columns subject to pure compression. A square hollow cross-section with different sizes was considered. This study presents all the analytical equations that need to be used to verify the stability of each column with different lengths and boundary conditions. A finite element program was also chosen to achieve the most critical loads (Euler and buckling resistance loads) in the calculation for each element under study, using linear and nonlinear geometric and material modeling. Steel material was used for the columns, where damage due to plasticity was included, through plastic behavior with isotropic hardening. Comparing the results allows us to conclude that the use of the finite element method is an alternative methodology to be used in other types or configurations of columns, where parameterized tests can be easily implemented and to contribute to the development of a wide-ranging database. The finite element method led to an accurate solution when compared with the analytical results with a maximum deviation of 14.7%. By increasing the column length and reducing the cross-section size, the design buckling resistance of the studied columns also decreases. These studies demonstrate that the length and size of the column cross-section can meaningfully increase the structural behavior of the columns.

The Eurocode 8—Part 4 approaches, per their December 2022 update, are presented for the design of acceleration-sensitive industrial ancillary components. The seismic performance of such nested and/or supported ancillary elements, namely mechanical and electrical equipment, machinery, vessels, etc. is critical for the safety and operability of an industrial facility in the aftermath of an earthquake. Of primary importance are the structural characteristics of the supporting structure and the supported component, pertaining to resonance, strength, and ductility, and whether these are known (and to what degree) during initial design and/or subsequent modifications and upgrades. Depending on the availability and reliability of information on the overall system, the Eurocode methods comprise (a) a detailed component/structure-specific design accounting for all pertinent component and building characteristics, equivalent to typical building design per Eurocode 8—Part 1–2, (b) a conservative approach where a blanket safety factor is applied when little or no such data is available, and (c) a ductile design founded on the novel concept of inserting a fuse of verified ductility and strength in the load path between the supporting structure and the ancillary element. All three methods are evaluated and compared on the basis of a case-study industrial structure, showing how an engineer can achieve economy without compromising safety under different levels of uncertainty. [ABSTRACT FROM AUTHOR]

The article presents the current status of the revision of EN 1993‐1‐11 with regard to the design of saddles and clamps for ropes or for parallel wire tension components for suspended structures. The focus here is on presenting a general approach for clamps. For saddles, emphasis is on types where the slip resistance is – in addition to the component from deviation forces – increased by clamping forces, although general aspects are also covered. This part 2 deals with the geometrical requirements for clamps and in particular saddles and with the associated verification of the transverse pressure. Finally, testing is briefly discussed, with the emphasis on linking the design and the confirmation of the assumptions made thereby with the tests. [ABSTRACT FROM AUTHOR]

The current first generation of Eurocodes is a suite of ten European standards for the design of buildings and civil engineering works, whose implementation started in 2010. EN 1990 sets the basis of structural design, with the other Eurocodes dealing with different materials and specific aspects of design. Geotechnical aspects of design are covered by EN 1997 "Geotechnical design", usually called Eurocode 7. The evolution of the Eurocodes started in 2012 and the main objectives of their revision were to incorporate improvements that reflect the state‐of‐the‐art in engineering design and the needs of the civil engineering market, to improve the ease‐of‐use and to harmonize practice between countries. While the original version was developed largely based on soil mechanics, the aim was that the revised version treats soil and rock on an equal basis. The second generation of the Eurocodes is now nearly finished, and the revised EN 1997 is expected to be formally approved in 2024. This paper is the first of a set of six informative papers on the revised Eurocodes and rock engineering, prepared by members of the Rock Engineering Platform of CEN/TC250/SC7, a group of rock engineering experts that has been assisting in drafting EN 1997 from a rock‐engineering perspective. The paper presents the main changes to EN 1990 and EN 1997 as far as they affect geotechnical and rock engineering design. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the contents of 2nd Generation Eurocode 7 Part 2, highlighting two of the major changes introduced, being the Ground Model and the Rock Engineering implementation. The document is organized from a ground property perspective so that the role of Part 2 and the links with the geotechnical design are much clearer than in the previous edition. Its new title is a clear indication of this idea: "Ground properties" including both soil and rock properties. The need to have representative values for the ground properties is the objective of this new Part 2, which is intended to guide designers on the path to obtain those values by means of the Desk Study, Site Inspection, Field Investigation and Laboratory Testing. Given this framework, the paper explains the concepts behind the Ground Model, the main output of the Ground Investigation, which includes the ground profile, the geometric properties of the ground and its layers, groundwater, and the derived values of the ground properties, paying attention of the role of discontinuities in such ground profile. The tasks that form the Ground Investigation and the minimum number of activities to be performed are described. This new version of EN 1997 will include a Rock Engineering perspective for all above items. And finally, the ground properties of the rock material and the rock mass are listed and discussed. [ABSTRACT FROM AUTHOR]

The current Eurocode revision process is sought to improve Eurocode 7 for application to rock engineering, while including only techniques and procedures that are in widespread customary use. The revision process has exposed much about the application of the Eurocodes to rock engineering, thereby offering hints as to what material should be included in the next revision – tentatively suggested for publication in 2035. Crucially, ideas have developed about how rock engineering practice may need to develop to embrace the principles on which the Eurocodes are based. In particular, aspects of determining the properties of rock masses, and design verification by observational methods, partial factors, numerical modelling, and prescriptive rules are all thought to require significant improvement or dramatic modification. This paper highlights challenges identified regarding the application of the Eurocodes to rock engineering, and which will need to be addressed in the future. Ideas are presented about how these challenges may be overcome, but these are given in the spirit of stimulating ongoing conversation within the rock mechanics and rock engineering community rather than presenting definite proposals. [ABSTRACT FROM AUTHOR]

In 2025 the new generation of the Eurocode 7 will be introduced and set a framework for geotechnical design for the next 20 years. As Eurocode 7 is an essential design code, the changes will affect numerous practising geotechnical Engineers. The paper provides an overview of significant changes in rock engineering design introduced in the new EN 1997 part 3, considering limit state design, durability, reliability, testing and other crucial design aspects. It focuses on the anchor clause revision and first introduced design rules for rock bolts and soil‐nailed structures. The improvements described include distinguishing between different tension supporting elements that have often been confused. Furthermore, the provisions for groundwater control measures influencing the working condition and limit states for all other geotechnical systems that have not yet been comprehensively addressed in the current Eurocode 7 are also clarified. Finally, the design of the described geotechnical structure will also be strongly affected by changes in the overall philosophy of the Eurocodes, which is also explained. [ABSTRACT FROM AUTHOR]

The second generation of Eurocode 7 includes both soil and rock. In addition to the current practice of ground engineering, this document aims at incorporating rock engineering, improving the ease of use, the harmonization of regulations and covering new developments. This paper provides an overview of some of the significant changes to Eurocode 7 in rock engineering design, taking into consideration limit state design, robustness, durability, and reliability. It focuses on the design of slopes, spread foundations, and retaining structures. The clauses focus on soil mechanics, but also include special rock mechanical issues such as the influence of discontinuities and strength anisotropy on the limit states. Many matters associated to verification of rock mechanical design are linked to the use of prescriptive rules and shall be given in National Annexes. For geotechnical structures in rock, it is mentioned that geotechnical mapping and documentation is important to verify the limit states. However, the basic issues with partial factor methods for verification of the ground‐structure interaction of reinforced slopes and retaining structures are not fully resolved. This has caused some difficulties in setting up partial factors and obtaining a sufficient overview of the application of partial factor method, especially in rock engineering. The design of slopes, spread foundations and retaining structures must likewise consider other clauses in the Eurocode. Rock support for slopes and retaining structures is described in Clause 13 "Rock Bolts and Surface Support". Groundwater‐related issues are described in clause 12 "Ground water control" which influence the design and limit states for the actual geotechnical structure. Dams and levees are featured in Clause 4 "Slopes, Cuttings and Embankments". [ABSTRACT FROM AUTHOR]

The second generation of Eurocode 7 aims at covering ground, including both soil and rock. Current practice of ground engineering forms the basis, and the aim is to include rock engineering, improving ease of use, harmonization of regulations, and covering new developments. This paper deals with EN 1997 part 1 addressing the general rules of geotechnical design, connected to EN 1990, the basis of structural and geotechnical design, and parts 2 and 3 of EN 1997. The design process from ground investigation to the verification of limit states is illustrated with a focus on rock engineering. The following topics are dealt with in more detail: Geotechnical Categories: They are now based on Consequence Classes and newly introduced Geotechnical Complexity Classes. A limit state design to be sufficient has to be combined with other checks depending on these classes.Replacement of the Design Approaches of the current Eurocode 7: Ultimate limit states will be verified by a combination of Verification Cases with partial factors on actions and action effects, and sets of partial factors on ground properties and resistances, respectively.Application of numerical methods, where a ULS‐verification with two sets of partial factors is defined.Use of probabilistic methods in design by calculation, especially appropriate in cases where properties of discontinuities govern the design.Practice of the Observational Method, including design variants and regulations about their choice. [ABSTRACT FROM AUTHOR]

Aluminum alloys provide corrosion resistance, lightweight construction, and functionality through extruded profiles. The creation of heat-affected zones (HAZs), which can reduce load-bearing capacity by up to 50% and complicate K-joint design, makes it difficult to apply aluminum in truss systems. Since EN 1999-1-1 (EC 9) does not even provide guidelines for welded aluminum K-joints, practitioners turn to EN 1993-1-8 (EC 3), resulting in a conservative design that ignores the advantages of aluminum. This study investigated the behavior of welded K-joints in lattice girders made of alloy EN AW6082 T6. The comparison of the experimental and numerical results showed different load-bearing behaviors depending on dimensions and cross-section types. Further tests were carried out. The aim was to derive an aluminum-specific design procedure. [ABSTRACT FROM AUTHOR]

Türkiye is prone to earthquakes due to its location on various tectonic plates, which can lead to a loss of lives and property. Recently, on 6 February 2023, two major earthquakes hit Pazarcık and Elbistan in Türkiye, causing widespread destruction on the East Anatolian Fault (EAF) zone. Even Diyarbakır, a distant province from the epicentre, was severely affected, highlighting the need to evaluate Turkish earthquake codes. As part of this evaluation, a structural analysis was conducted on earthquake-damaged and collapsed buildings in Diyarbakır. The study analysed three buildings with different levels of damage and six collapsed buildings as case studies. The seismic parameters of the earthquakes were compared to the values in the two recent earthquake hazard maps used in Türkiye's codes, as well as the Eurocode 8 damage limit values obtained from pushover analysis. The results revealed significant differences between the current seismic values of earthquakes and the current peak ground acceleration (PGA) values specified in the Turkish Earthquake Design Regulations. Additionally, the selected buildings showed inadequate structural behaviours, with significant differences between the expected and actual seismic performances with respect to the PGA values as one of the most important earthquake characteristics. [ABSTRACT FROM AUTHOR]

This paper aims to propose an optimized thin‐walled built‐up cross‐section for axially compressed columns, which can be feasibly produced and utilized in building assemblies. The European standard Eurocode 3 [1] was employed, along with an optimization solving algorithm, to calculate the performance of axially compressed thin‐walled columns. The analysis considered the buckling capacity of the column, encompassing local, distortional, and global buckling modes. 3 types of box cross‐sections were examined: without web stiffeners, with web stiffeners bent inwards, and with web stiffeners bent outwards. The cross‐sections were constructed by connecting 2 "C" type or "Sigma" type profiles through their flanges. In the calculations, the thickness of the overlapping parts of the flanges was assumed to be equal to the thickness of the profiles. Experimental investigations have shown that this assumption, where the overlapping parts of the flanges are considered equal to the profile thickness, is conservative and reliable [2]. Consequently, the built‐up cross‐section can be treated as one rigidly connected entity [3]. The results of the calculations reveal that the optimized built‐up axially compressed column cross‐section with web stiffeners exhibits a higher level of effectiveness, with a cross‐sectional area up to 23% smaller compared to the optimized cross‐sectional area of columns without web stiffeners. [ABSTRACT FROM AUTHOR]

This paper presents a method of estimating the hot‐spot stress in orthotropic bridge decks (OBD) using a shell Finite Element (FE) model, in which local thickening is applied around the welded. The dimensions of the area of local thickening are a function of the weld throat thickness and the plate thickness. A comparison of this method with 3D solid element FE models is presented for various fatigue sensitive details. The comparison is carried out for OBD with trapezoidal stiffeners, both with continuous stiffeners through crossbeams and with stiffeners welded in between crossbeams. It is concluded that the accuracy of estimating the hot‐spot stress with a shell element model using local thickening is significantly higher as compared to a conventional shell element model without thickening. The method of local thickening is adopted in the new prTS 1993‐1‐901. This paper functions as the background to this technical specification. [ABSTRACT FROM AUTHOR]

The seismic design of Cold‐Formed Steel (CFS) building structures is not covered by the current edition of Eurocode 8. In order to update Eurocode 8 to reflect the findings of extensive research undertaken over the last ten years, the University of Naples "Federico II" is taking part in the evaluation of current seismic design criteria and the creation of new guidelines for the design of CFS systems. This paper especially examines various Lateral Force Resisting System (LFRS) types that may be found in the second version of Eurocode 8. It also provides background information on the research initiatives and reference design standards in use in various parts of the world that served as the basis for the development of design criteria included in the new version of Eurocode 8. [ABSTRACT FROM AUTHOR]

The design of orthotropic bridge decks (OBD) is driven by fatigue. The Eurocode on fatigue of steel structures – prEN 1993‐1‐9:2023 – provides fatigue resistance (S‐N) curves for relevant details in OBD. These curves are to be used with the far field (nominal) stress. However, due to the complex geometry and loading of OBD, the nominal stress is not well defined for many details. In addition, cracks have been found in practice in OBD at locations for which S‐N curves are not provided. In order to overcome these issues, experimental and numerical studies are carried out on the use of local stresses (hot‐spot stresses where possible) for the fatigue design of OBD. The different stress extraction method also implies the use of different S‐N curves. A large number of fatigue tests carried out in the past have been re‐evaluated to determine the hot‐spot stress S‐N curves. Additional fatigue tests have been carried out for details lacking data. The study has resulted in a guideline to design OBD for fatigue with the hot‐spot stress method. This guideline, TS 1993‐1‐901:2023, will be published as a Technical Specification (TS) to the standard prEN 1993‐1‐9:2023. This paper provides a short background to the newly created TS. It demonstrates the derivation of S‐N curves based on available tests for a number of details. It highlights fatigue relevant details that are missing in prEN 1993‐1‐9:2023 and that are added to TS 1993‐1‐901. It explains how to evaluate cracks starting from the root of the weld, for which the hot‐spot stress method is traditionally not applicable. Finally, the paper demonstrates how the method can be applied in the fatigue design, including the application of the load in finite element models. [ABSTRACT FROM AUTHOR]

Stiffened plates may be loaded by axial forces in two directions, i.e., along and transverse to the stiffeners, by in‐plane shear force, and by out‐of‐plane loads as from traffic or water pressure. Special care must be taken for buckling effects caused by the compressive in‐plane forces. The buckling behaviour of plates stiffened with four trapezoidal stiffeners was investigated for the case of compressive axial force directed transverse to the stiffener direction. The width and length of the stiffened plate and the ratio between the plate‐ and stiffener stiffnesses were varied. The investigation aimed to determine criteria to ensure that the dominating buckling mode was either buckling of the plate between the stiffeners, or a predictable buckling pattern of the stiffeners. For this, two formulas are presented, giving the necessary plate‐to‐stiffener stiffness ratio or the maximum length of the panel. Furthermore, capacity approaches for the axial resistance for transverse axial loading are studied, applying the Effective Width Method (EWM) and the Reduced Stress Method (RSM). Comparisons with nonlinear FE‐simulations show that the predictions range from 45% to 99% of the FE‐results. [ABSTRACT FROM AUTHOR]

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.

UHPFRC in bridge strengthening – examples and challenges UHPFRC stands for ultra‐high‐performance fibre‐reinforced cementitious composite material, which, because of its material properties, is well suited for the rehabilitation and strengthening of reinforced concrete bridges. A layer of UHPFRC increases the resistance of reinforced concrete elements and functions also as waterproofing layer. While the material is already widely used in Switzerland, especially for bridges, it is relatively unknown in the rest of the world and is hardly applied. There are several reasons, the lack of standards is only one of the challenges to address. To improve the conditions for implementing UHPFRC in Germany and other countries, it is necessary to work together internationally. The experience from Switzerland, with more than 350 realized UHPFRC projects, could be used by other countries to launch a new European standard. [ABSTRACT FROM AUTHOR]

The article presents the current status of the revision of EN 1993‐1‐11 with regard to the design of saddles and clamps for ropes or for parallel wire tension components for suspended structures. The focus here is on presenting a general approach for clamps. For saddles, emphasis is on types where the slip resistance is – in addition to the component from deviation forces – increased by clamping forces, although general aspects are also covered. The starting point is a (retrospective) look at the provisions in national standards and guidelines as well as in the current version of EN 1993‐1‐11 (2006). Subsequently, the new provisions are presented, and the different new coefficients are explained in detail. [ABSTRACT FROM AUTHOR]

Double‐headed studs as shear and punching reinforcement – Current status and outlook Double‐headed studs have been established for decades as a very effective punching shear reinforcement because these reinforcement elements, which are optimized for shear and punching loads, combine a particularly high anchorage performance with a practicable installation on site. In this paper, an overview of current usability and applicability verifications for double‐headed studs in Germany is given. Afterwards, the currently valid design and construction rules for the use of double‐headed studs as shear reinforcement as well as punching reinforcement are summarized. Finally, the next Eurocode 2 generation 2023+is looked at, with excerpts presenting some significant innovations in the future integration of double‐headed studs into the shear and punching rules. [ABSTRACT FROM AUTHOR]

This study is a comparison of wind and seismic loads on medium and high-rise buildings in Muscat, Oman. It uses the proposed Omani Seismic Code and Eurocode EN1991 for seismic and wind calculations, respectively. Muscat falls under Zone-1 in the Omani seismic code and experience basic wind speed of 30 m/sec. The research investigates buildings with varying aspect ratios (1:1 and 1:2), heights (11, 15, and 19 stories), and structural layouts (frame only, core shear wall, and corner shear wall), using ETABS for structural analysis. The findings reveal that seismic actions are generally more significant than wind actions for buildings in Muscat. In frame-only structures, wind-induced base shear ranges from 16%-33% for 1:1 aspect ratio and 21%-43% in the x-direction and 10%-20% in the y-direction for 1:2 aspect ratio, when compared to seismic actions. This difference decreases with increasing building height. Incorporating shear walls notably reduces the maximum lateral displacement across all scenarios, with core-located walls being most effective, leading to a 49% reduction in lateral displacement. Shear walls also substantially mitigate first-story column shear forces and bending moments. The study concludes that seismic actions are more critical than wind actions in Muscat for simple moment-resisting frame systems. Additionally, using shear walls in these buildings is highly beneficial for controlling lateral displacements and reducing member forces. [ABSTRACT FROM AUTHOR]

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Purpose. The purpose of the present study is to determine the geomechanical parameters for calculating the stability of side slopes by partial and general angle in the working front to ensure the completeness of coal mining in accordance with geotechnical rules and standards based on the regulations (EC-7) of the Kosovo Energy Corporation, which is the state corporation, producing not only electricity in the Republic of Kosovo. Methods. In the course of the present study, 60 additional drillings were carried out to a depth of 150 m up to green clay contact to determine the coal thickness. It was realized using a Type EK-650 drilling machine and a drilling diameter of 145/101 mm. To determine the angle φ and cohesion C, two methods were used, such as the Direct test and the Triaxial test. To obtain the most accurate results, a mathematical model was used to derive geomechanical parameters for calculating the slope geometry for the design geometry, where coal is mined to achieve a safety factor according to geotechnical standards. Findings. The results of this study have demonstrated that there are inappropriate physical-mechanical parameters due to tectonics, especially the presence of groundwater and clay masses. There are locations with coal thickness from 0.5 to 1 m. This entirely affects the decrease in the calorific value of coal, but it also makes difficult to mine coal in the field in terms of geotechnical safety. Therefore it is important to design the slope geometry that can ensure the stability of the mine as well as coal mining in full compliance with market demands. Originality. A large number of physical-mechanical parameters were analyzed, including a mathematical model, with which the slope geometry was calculated using the design profiles and 9 methods. This has given satisfactory results based on Eurocode EC-7 which can be implemented in the field. Practical implications. To analyze the numerical and analytical methods for the design slope geometry, geotechnical Eurocodes were used according to two standards: Eurocode EC7-1 for geotechnical designs and Eurocode EC7-2 for field verification. They were tested on two factors: Category of terrain and Category of objects (excavator), to remove the coal cover using technology in compliance with the conditions in the field, such as the presence of surface water, underground waters and tectonics. This whole analysis is time consuming, so a safety factor has been determined based on the numerical analysis data. [ABSTRACT FROM AUTHOR]

Influence of the arrangement of the punching shear and composite reinforcement made of L steel plates on the load‐bearing capacity The CLIXS punching shear and composite reinforcement system consists of L steel plates with one or two connected stirrups made of reinforcing steel. It is possible to increase the load‐bearing capacity by more than twice the load‐bearing capacity without punching shear reinforcement. The experimental investigations described in the paper were carried out on square slab cut‐outs with a length of 2.8 m and a thickness of 18 and 25 cm. The load‐bearing capacity as a function of the number of uniform arranged L steel plates was determined based on 17 experiments. For this purpose, test specimen with 6 L steel plates up to 36 L steel plates in the first three perimeters were investigated. In addition, 10 test specimen with different sized areas without L steel plates were tested. The areas without L steel plates were between 25 % and 75 % of the area within the first three perimeters. The use of stirrups with a diameter of 8 mm instead of 6 mm was investigated using two test specimens. [ABSTRACT FROM AUTHOR]

The present research deals with the cyclic and standard pull-out resistance of deformed steel bars embedded in lightweight and normal concrete. This paper is a continuation of a previous paper, where the experimental results are detailed. In the present paper, the experimental results are set against the formulas and the diagrams provided by the Eurocode standard and the Model Code 1990, and then a comparative discussion is performed. In the case of cyclic loading, the damage defined by the Palmgren–Miner hypothesis, as well based on the recommendations of various national annexes of Eurocode and the Model Code, is calculated. A multiplier corresponding to the maximum load is calculated, which indicates by how much the applied load should be multiplied to obtain a damage value equal to 1.

Abstract Negative skin friction (NSF) effect on pile foundation design attracts the attention of geotechnical engineers and requires comprehensive research. However, the ways of consideration of NSF for the pile foundation design vary with different design codes. This study aims to compare design code requirements adhering to Construction Codes and Regulations (i.e., SNiP), Eurocode 7 (EC7), Canadian Highway Bridge Design Code (CHBDC), and AASHTO for the pile foundation design subjected to NSF and provide insights for the understanding effect of NSF on the behavior of pile foundation. The overall objective is achieved by designing three cases of a driven pile for given design conditions in Astana city. Then, a sensitivity analysis was performed to estimate the effects of the dimensions of the pile foundation and the shear strength of soils on the bearing resistance. The comparative analysis shows that pile foundation design adhering to CHBDC and AASHTO results in a more conservative strategy than SNiP and EC7 when considering Kazakhstani soil engineering conditions.