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Precast structures are widely used in Southern Europe particularly for industrial buildings. Most of such buildings have been built before the enforcement of modern anti-seismic regulations showing a poor performance during past major earthquakes. Focusing on existing one-storey precast industrial buildings, the paper investigates the influence of modelling choices on the risk assessment, direct losses, and required structure retrofit time. RC forks, cladding panels, and elements connections were specifically considered. A precast industrial building with structural details compatible with 1980s Italian regulations was selected and analysed. In general, the failure was associated with the collapse of roof elements. [ABSTRACT FROM AUTHOR]

Sinkholes are a severe problem in urban areas located in karstic regions, especially where evaporitic rocks such as gypsum exist. Identification and proposal of mitigation measures are needed to reduce this geo-hazard effect on buildings and social urban living. This paper presents a case study of the town of Alcalá de Ebro (Spain), which is located in the highest sinkhole risk region of Europe. The identification and mitigation of a series of sinkholes that appeared are analyzed. The former involves a geological investigation, including boreholes, field tests and geophysics. The latter is addressed by the use of geogrids, mortar injections and polyurethane injections. A complementary finite element analysis is carried out to set the ground behavior associated with the sinking process and assess its future evolution. The Ebro River appears to be the main cause of sinkholes, and results show that ground treatments applied were successful in their purpose, as there are no apparent deformations indicating that the subsidence or sinking process is still active in the area. The use of different techniques depending on the size of the sinkhole, the objectives pursued and the element affected is discussed. [ABSTRACT FROM AUTHOR]

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• A novel approach for regional ionosphere grid model with high spatial-temporal resolution is suggested. • The results of the new model is analyzed at different disturb geomagnetic and solar conditions. • A comparative analysis between the results of new model, GIM, NeQuick and GPS-TEC is made. In this paper, a novel approach based on C1 finite element (FE) interpolation is used to construct a regional ionospheric grid model (RIGM) with high spatio-temporal resolution over Europe. The spatial resolution of the new model is 0.50 for a longitude and latitude and a temporal resolution is 15 min. Observations of 38 GPS stations at different days and seasons with different geomagnetic and solar activity conditions are used to evaluate the new method. All stations are used to discretize the whole domain of the problem into separate triangular patches using a Delaunay triangulation algorithm. In this case, GPS stations would be the vertices of the triangular patches. Also, the position of stations in sun-fixed coordinate system with coordinates of latitude and longitude are chosen in order to consider the temporal variations of vertical total electron content (VTEC). To model the behavior of VTEC in each triangular patch, a particular shape function is defined which is fitted to VTEC values at three vertices of each triangle while it satisfies C1 continuity of VTEC at the common edges of the adjacent triangles. The results of the new model are compared with the VTEC of GPS at 4 control stations as well as global ionosphere map (GIM) and NeQuick models. Statistical parameters, including correlation coefficient, root mean square error (RMSE), standard deviation and dVTEC = |VTEC GPS - VTEC model | have been used to evaluate the error of the models. In low geomagnetic activity (KP < 4), the average RMSE at 4 control stations for FE, GIM and NeQuick models are 0.89, 1.05 and 6.42 TECU, respectively, while in the high geomagnetic activity (KP > 4), they are 1.24, 1.68 and 7.62 TECU, respectively. For further analysis, the accuracy of three models in precise point positioning (PPP) has been also evaluated. In PPP method, there is an improvement of about 1–16 mm compared to GIM and NeQuick models at coordinate components of control stations in high geomagnetic activity. The results of the analysis performed in this paper show that the FE model has a very high capability and accuracy in regional VTEC modeling in high and low geomagnetic conditions. The regional accuracy of this model is higher than GIM and NeQuick models and therefore can be considered as a new model for the ionosphere. [ABSTRACT FROM AUTHOR]

• Paper describes a methodology that was successfully applied for the development of a temporary road traffic steel barrier in compliance with T1/W1 level according to EN 1317; • A simplified theoretical analysis of 178 barrier, laboratory test of three types of barrier connectors (for two types of barrier), explicit FEM modeling of four chosen barrier, and a full-scale crash test for final barrier are presented; • The stiffness of barrier connector was established based by laboratory barrier test (the FEM model was validated based on laboratory tests); • The chosen final barrier alternative passed the crash test for T1/W1 (TB21) containment level, performed by certified laboratory [35] , which proves that the presented procedure could be used successfully for traffic barrier development. Over a million people die in road crashes and tens of millions result injured or disabled each year, globally. Hence, there is a constant concern for improving the safety of the roads to protect road users, and those at the most risk, the road workers. Construction, maintenance, and utility work are constantly needed to ensure safety and functionality of roads and highways. Temporary road traffic barriers are used to separate passing traffic from the workspace and protect the workspace from an errant vehicle intrusion. Steel barriers are light, and their major advantage is rapid installation. These barriers are not anchored to the ground, and their behavior relies on the base-pavement friction, mass inertia, and stiffness of the system. The paper describes a methodology that was successfully applied for the development of a temporary road traffic steel barrier in compliance with the European specification EN 1317. The study included a simplified theoretical analysis of 178 barriers, static laboratory tests of three types of barrier connectors, development of explicit finite element models (EFEMs) of four selected barrier designs, and a full-scale crash test of the final barrier design. It is shown that static laboratory tests of complex connector systems can help to improve the design process and reduce the cost. The analysis and use of EFEMs was enough so that just a single full-scale crash test was sufficient for certification of the barrier design for use in Europe. The final barrier is compliant with the EN 1317–2 requirements for T1/W1 (TB21) containment level, which was confirmed by a full-scale crash test. [ABSTRACT FROM AUTHOR]

The fatigue life of orthotropic steel bridge decks in road bridges depends on the load effects exerted by heavy lorries. The contact surface of tyres is one of the important variables. Measurements described in the literature demonstrate that the actual tyre contact surfaces of today's traffic representative for Europe are shorter and slightly wider than the contact surface defined for the load model in the European standard for fatigue loads in bridges — EN 1991-2. This paper derives a new, realistic tyre contact surface to be used with the tyre loads in EN 1991-2, in such a way that the load effects for fatigue are realistically captured and that the required safety level is met. • Fatigue of orthotropic bridge decks depends on the lorry tyre contact surface. • The contact surface in Eurocode's Fatigue Load Model 4 is too long and narrow. • The width of the traction axle (tyre-to-tyre distance) in the load model is too large. • The finite element method is used to calibrate the contact surface in the load model. • Realistic tyre contacts are therein compared to a square contact with uniform stress. [ABSTRACT FROM AUTHOR]

In Europe, 1132 Mt of sand and gravel were mined in 2019, which causes major changes to the hydrogeological cycle. Such changes may lead to significantly raised or lowered groundwater levels. Therefore, the aggregate sector has to ensure that impacts on existing environmental and water infrastructures are kept to a minimum in the post-mining phase. Such risk assessments are often made by empirical methods, which are based on assumptions that do not meet real aquifer conditions. To investigate this effect, predictions by empirical and numerical methods about hydraulic head changes caused by a pit lake were compared. Wrobel's equation, which is based on Sichardt's equation, was used as the empirical method, while a numerical groundwater flow model has been solved by means of the finite-element method in FEFLOW. The empirical method provides significantly smaller ranges of increased/decreased groundwater levels caused by the gravel pit lake as the numerical method. The underestimation of the empirical results was related to the finding that field measurements during pumping tests show a larger extent of groundwater drawdown than calculations with the Sichardt's equation. Simplifications of the 2D model approach have been evaluated against hydraulic head changes derived from a 3D groundwater model. Our results clearly show that the faster and cheaper empirical method—Wrobel's equation, which is often preferred over the more expensive and time-consuming numerical method, underestimates the drawdown area. This is especially critical when the assignment of mining permits is based on such computations. Therefore, we recommend using numerical models in the pre-mining phase to accurately compute the extent of a gravel/sand excavation's impacts on hydraulic head and hence more effective protection of groundwater and other related environmental systems. [ABSTRACT FROM AUTHOR]

This paper presents the development of efficient design equations for high strength steel (HSS) welded I-section beam–columns under the framework of the Continuous Strength Method (CSM). The present work includes a collection of available experimental data on HSS S690 and S960 welded I-section beam–columns and a comprehensive numerical modelling programme considering a wider spectrum of parameters that influence the structural behaviour of the HSS welded I-section beam–columns. The developed FE models were first validated against test results collected from the literature, after which parametric studies were performed to generate further results to assess the accuracy of the codified design methods as used in Europe and the US, as well as to underpin new design proposals for HSS non-slender welded I-section beam–columns. It has been shown that the proposed CSM-based design approach is able to provide reliable design predictions with improved accuracy and reduced scatter over the existing design methods, and its reliability has been confirmed by means of statistical analyses. • Numerical models validated against test results for HSS beam–columns. • Validated numerical models used to perform parametric studies considering key parameters. • Current European and American design provisions assessed using the experimental and numerical data. • The Continuous Strength Method extended to cover the design of HSS beam–columns with welded I-sections. • Reliability of the CSM evaluated by means of statistical analyses according to EN 1990. [ABSTRACT FROM AUTHOR]

The development of artillery in Europe at the end of the Middle Ages brought a necessary change in military architecture. This change was a radical rethinking of the entire geometry and architectural design of city walls which required an increase in thickness to resist repeated artillery strikes. The damage due to the impact loads on Middle Age fortification walls is analyzed herein with explicit dynamic analyses. This study was developed both with finite element models and an innovative rigid body-spring model with diagonal springs (RBSM), showing the different peculiarities of these two different approaches and how their results can be integrated. The numerical models clearly showed that the presence of an inner core of softer material tends to modify the impact effects by reducing the degree of damage at the expense of an extension of the damaged area. [ABSTRACT FROM AUTHOR]