Search

Investigations on the shear‐compression‐load‐bearing‐capacity of masonry consisting of small‐format bricks The load‐bearing‐capacity of masonry consisting of small‐format artificial bricks with regard to a combined shear‐compression load is a complex and not conclusively researched topic. Due to the practical relevance of this topic and for reasons of sustainability, research must therefore be carried out continuously in order to be able to close the existing gaps in knowledge. Intensive and extensive theoretical and practical tests have therefore been and are being carried out at the Chair of Concrete and Masonry Structures at the Technical University of Munich, with the aim of systematically analyzing and evaluating the load‐bearing and damage mechanisms of small format masonry for a wide variety of load scenarios and parameter combinations. In order to minimize the experimental effort, a methodology was created that enables the realistic representation of the load‐bearing behavior of small‐format masonry in an efficient manner on the basis of predominantly small‐scale tests. With the help of the so‐called unit‐cell method it was possible to derive statements on the biaxial load‐bearing capacity of historical masonry with regard to the influence of the normal stress level and the angle of inclination of the resulting diagonal force. [ABSTRACT FROM AUTHOR]

Investigation of an engineering model for the assessment of the seismic behaviour of large mobile equipment For large mobile equipment in seismically active regions, seismic stability is an essential and often decisive design criterion. The seismic behaviour of such large equipment is usually characterised by complex nonlinear types of behaviour (uplift, tilting and rocking), which are difficult to compute and analyse in practice. In this paper, a highly simplified engineering model is presented or developed step by step, which should be able to represent basic features of the typical behaviour of large mobile equipment transverse to the rail under seismic excitation. The typical rocking motion of the equipment, as determined in previous analyses, is to be reflected in the simplified model. The engineering model will be designed in such a way that it is able to reproduce qualitative statements about uplift and rocking or tilting as a function of incisive model parameters and seismic excitation. The dissipation mechanisms of the model are presented and seismic tilting spectra are generated using different approaches. The suitability and applicability of these approaches for assessing uplift and rocking tendencies for large mobile equipment is reviewed using representative series of bucket wheel machines and stackers as examples. In addition, parameters are determined for quantitative application to further large mobile equipment and the delimitation criteria of qualitative and quantitative applicability are compiled. [ABSTRACT FROM AUTHOR]

Copyright of Österreichische Wasser- und Abfallwirtschaft is the property of Springer Nature 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.)

Simplified consideration of framing effects in masonry buildings Due to the increased requirements resulting from higher wind and earthquake loads, it is necessary to improve and optimise the calculation and design approaches for masonry structures. An important contribution to a better utilisation of the structural load‐bearing reserves is the consideration of the framing effects through the activation of the floor slabs in the calculation models, which has not been utilised in practice so far due to the complexity of the wall‐slab interaction. The paper presents a simplified approach based on the contributory slab width, which captures the essential influencing factors in parameterised tables. This provides structural engineers with a simple tool to exploit the frame load‐bearing effect in masonry design. [ABSTRACT FROM AUTHOR]

The Magnitude 6.4 – earthquakes in Albania and Croatia – engineering analysis of earthquake damage and lessons for standardization in Europe In 2019 and 2020, the Balkan region was hit by two earthquakes of magnitude MW = 6.4. On November 26, 2019, an earthquake struck Northwestern Albania. It was the strongest to hit Albania in more than 40 years. Cities such as Thumanë, Tirana, and Durrës suffered damage, but Durrës was the hardest hit with several building collapsed. On December 29, 2020, an earthquake occurred in the Sisak‐Moslavina county of Croatia, located approximately 50 km south of Zagreb. Comparable to Albania, it was the strongest to hit in the Pokupsko‐Petrinja seismic zone since the October 8, 1909 Pokupsko earthquake and the largest earthquake in the region in 140 years. It caused extensive damage in the cities of Petrinja, Glina, and Sisak as well as in numerous neighboring small towns and small settlements in the region. The shaking effects and building damage of both earthquakes could be investigated and documented during field operations. In Durrës (Albania), the most affected buildings by the earthquake damage were reinforced concrete (RC) frame buildings with infill walls. Whereas, the Croatia earthquake caused major damage on the older and modern unreinforced masonry buildings. The paper provides an overview of the earthquake‐induced damage in different types of buildings and their variations. The causes of the damage as well as the consequences for rapid response to earthquake are discussed in close relation to the standardization in low to moderate seismic regions in Europe. [ABSTRACT FROM AUTHOR]

Investigation of the out‐of‐plane behavior of non‐load‐bearing masonry walls in German earthquake zones Due to earthquakes, non‐load‐bearing masonry partition walls have to withstand horizontal loads, herein out‐of‐plane loads are of great importance. The out‐of‐plane behavior of masonry walls is very complex due to the strong non‐linearity. Current design methods do not consider important parameters, and detailed investigations of typical non‐load‐bearing masonry types in Germany do not exist. As part of a research project, extensive analytical, numerical and experimental investigations for load‐bearing masonry walls were carried out and a model was developed to determine the out‐of‐plane capacity, considering significant parameters. The results of these investigations were transferred to non‐load‐bearing walls in a simplified manner. With this, the previous methods in the earthquake standards DIN EN 1998‐1/NA (2020) and DIN 4149 (2005) could be reviewed and adjusted to the current state of the art. Based on the updated seismic hazard map, simplified design methodologies were derived and summarized. The model and the derivation of the simplified design methods are presented and discussed in this paper based on a case study. [ABSTRACT FROM AUTHOR]

Experimental investigation of the out‐of‐plane behavior of masonry walls Masonry has very good properties for vertical load‐bearing, but out‐of‐plane loads that occur in earthquake scenarios can only be absorbed to a limited amount. The out‐of‐plane behavior of unreinforced masonry walls depends on a variety of parameters and is very complex due to the strong non‐linearity. Despite the practical relevance in construction, no uniform model for the calculation of load‐bearing capacity has been established in literature and standardization. In the present work, shaking‐table tests with bricks to investigate the out‐of‐plane behavior of vertical spanning unreinforced masonry walls are presented. Furthermore, the experimental verification of an analytical design model to determine the out‐of‐plane loadbearing capacity considering all significant parameters is presented. [ABSTRACT FROM AUTHOR]

Innovative application of ring springs for seismic design Ring springs are hardly used in earthquake engineering and have been little investigated. Though they offer several benefits: they are extremely robust, heat‐resistant, durable and low‐maintenance. Their behavior is superelastic, whereby the spring always returns to its initial state despite large plastic deformations and high energy dissipation. A system equipped with ring springs can withstand an earthquake without major plastic deformation and damage, thus makes a significant contribution to investment protection (economic efficiency) and the sustainable use of scarce materials and resources. The dampers themselves also remain damage‐free and do not need to be replaced. In this paper, a novel use of ring springs to increase earthquake resistance and reduce vibration of structures is investigated. Here, the classical bracing elements are replaced by ring springs. To enable practical application in earthquake engineering and to evaluate the efficiency in comparison to other systems, nonlinear dynamic simulations are performed, quantifying the classical vibrational properties of the spring analytically and numerically. Finally, the practical application of ring springs for reducing vibrations and optimizing the seismic design of a high‐rise building is demonstrated by means of a practical example. [ABSTRACT FROM AUTHOR]

"Smart Structures" – active and passive vibration control for buildings and structures – considerations and practical applications To reduce unwanted structural vibrations, the conventional strategy is to increase the mass or stiff‐ness of a structure. However, this strategy is often inefficient and uneconomical. Therefore, the use of intelligent measures for vibration reduction is increasing. In addition to long‐established passive systems, there are also active or adaptive solutions that can adapt to the vibration state of a structure and specifically reduce the vibrations that occur in the structure. The innovation potential here lies either in the optimization of the dynamic parameters of a passive solution and the achievement of these characteristic values for all relevant load conditions, or in the implementation of a semi‐active, active or hybrid vibration control. In the following, these measures will be described in more detail and illustrated by means of implementation examples (own expe‐rience and those described in the literature). The focus is on practical optimization approaches for passive systems and a description of active or adaptive systems, as well as their suitability for practical implementation. In addition to the general description and mode of operation, the selection of suitable actuators and control concepts will be considered in more detail. [ABSTRACT FROM AUTHOR]

Seismic verification of masonry buildings according to DIN EN 1998/NA‐2021 With the forthcoming introduction of the National Annex DIN EN 1998‐1/NA, masonry buildings in Germany must be verified on the basis of a new probabilistic earthquake map. For successful seismic verifications of masonry buildings with typical ground plan configurations, the new document provides novel computational verification approaches which allow a better utilization of the load‐bearing reserves of masonry buildings in the building practice with a manageable effort. The standard calculation method is still the force‐based verification, which can now be carried out with higher behaviour factors compared to DIN 4149. The higher behaviour factors are based on the utilization of building‐specific deformation capacity, energy dissipation and load redistribution of the shear forces in the ground plan with consideration of frame effects through wall‐slab interactions. Alternatively, a non‐linear verification based on pushover analyses can be applied. The regulations for masonry buildings are completed by new rules for partition walls and claddings. This article presents the basics and background of the new computational verifications in DIN EN 1998‐1/NA and demonstrates their application with a practical example. [ABSTRACT FROM AUTHOR]

Investigation of the out‐of‐plane behavior of non‐load‐bearing masonry walls in German earthquake zones Due to earthquakes, non‐load‐bearing masonry partition walls have to withstand horizontal loads, herein out‐of‐plane loads are of great importance. The out‐of‐plane behavior of masonry walls is very complex due to the strong non‐linearity. Current design methods do not consider important parameters, and detailed investigations of typical non‐load‐bearing masonry types in Germany do not exist. As part of a research project, extensive analytical, numerical and experimental investigations for load‐bearing masonry walls were carried out and a model was developed to determine the out‐of‐plane capacity, considering significant parameters. The results of these investigations were transferred to non‐load‐bearing walls in a simplified manner. With this, the previous methods in the earthquake standards DIN EN 1998‐1/NA (2020) and DIN 4149 (2005) could be reviewed and adjusted to the current state of the art. Based on the updated seismic hazard map, simplified design methodologies were derived and summarized. The model and the derivation of the simplified design methods are presented and discussed in this paper based on a case study. [ABSTRACT FROM AUTHOR]

Site‐specific and action‐dependent spectra in DIN EN 1998‐1/NA‐2021 The paper presents the basic investigations that have led to the provision of the seismic action parameter for the new national annex to DIN EN 1998‐1/NA‐2021. It is shown how the results of modern probabilistic seismic hazard analyzes (PSHA) can be made available in a code‐compatible manner. Initially, procedures for determining and checking the spectra for different subsoil classes are presented. With the site‐specific soil movement models, an outlook is given of how practical building applications can be carried out on the basis of strong motion records in the future. Since the particularities of the German earthquake areas are not covered by the classification scheme provided in EC 8, preference should still be given to the concept of geology and building site‐dependent spectra and the introduction of corresponding combinations in the form of subsoil classes. The control parameters of the elastic spectra for the subsoil combinations according to DIN EN 1998‐1/NA‐2021 are determined on the basis of simulative site response analyses on representative model profiles for the relevant range of impact intensities and thus also for different return periods. In this way, the reference to the behavior or limit states and the associated verification tasks can be established. Finally, an outlook on the next phase of European earthquake standardization is given. [ABSTRACT FROM AUTHOR]

Introduction of Eurocode 8 in Switzerland In Switzerland, Eurocode 8 was introduced in three phases. The first phase includes since 2003 a new version of the SIA structural standards compatible with the Eurocodes. For this purpose, the earthquake‐resistant design provisions were integrated into the other structural standards. In the second phase, starting in 2005, all six parts of Eurocode 8 were published as Swiss standards together with a National Foreword, but without a National Annex with the Nationally Determined Parameters. They have to be defined on a project‐specific basis, compatible with the SIA structural standards. In the third phase, in 2019, National Annexes were published for Part 1 (general rules and buildings) and Part 2 (bridges) of Eurocode 8. National Annexes have definitely not been prepared for the remaining four parts of Eurocode 8, which concern special as well as existing structures. The paper explains the background of the three‐phase approach and its acceptance in practice. A special focus is placed on the seismic zoning map and its harmonization along the borders with neighboring countries. It concludes with an outlook on the introduction of the second generation of Eurocodes (EC2G) beginning in 2025. [ABSTRACT FROM AUTHOR]

DIN EN 1998‐1/NA‐2021 within the context of German and European Code development The paper gives an overview of the basic investigations, partly controversially discussed issues and milestones, which have been established in the long‐term activity of the Standardization Committee (NABau) and its Technical Committee for Earthquakes and Special Questions (NA 005‐51‐06 AA as the Mirror group to CEN/TC 250/SC 8), and which finally have contributed to the National Annex DIN EN 1998‐1/NA‐2021. Corresponding research work is recognized in a synopsis and as an introduction to this special issue. The NA refers to the 1st generation of Eurocode 8; work of the 2nd generation shows the direction in which standardization will develop with regard to the design goals and verification methods. In the outlook it can be stated that the NA is already taking up or implementing essential lines of the ongoing development. From the review of the chair persons it becomes clear which decision‐making constraints exist in the stress field of necessary safety requirements and supposed economic restrictions, and that the earthquake‐resistant regulations do not provide simple answers or solutions, especially for national risk decisions. It shows the changes that have been introduced in the international and European standards development compared to the previous DIN 4149:2005. In addition to the hazard and load action parameters, they particularly focus on the investigations initiated for the nationally dominant masonry buildings, in order to enable the practicing engineer to apply a wide range of simplified rules and to provide the necessary decision criteria and design tools. [ABSTRACT FROM AUTHOR]

Recent earthquake activity in Germany: registered ground motions and shaking effects The article presents the recent earthquake activity on the territory of Germany of the last years, starting with 2002 up to and including 2019. Ground motion measurements are processed and for selected time histories correlated with the subsurface situation of the current and previous earthquake standard DIN EN 1998‐1/NA for selected earthquakes (Alsdorf 2002, Waldkirch 2004, Goch 2011, Nassau 2011). For the selected earthquakes, samples of measured ground motions and the observed macroseismic intensity are correlated. The investigation of the maximum observed ground motion magnitudes as well as the macroseismic effects is of high interest for applications in the field of engineering seismology, especially for the realistic estimation of ground motion in low to moderate seismic regions like Germany. Shake maps are determined for the selected events, which show the potential shaking effects. [ABSTRACT FROM AUTHOR]

Approximate method for verification against ground liquefaction in regions of medium seismicity according to DIN EN 1998‐5/NA:2021 The re‐assessment of the earthquake hazard for Germany as part of the preparation of the new National Annex to DIN EN 1998‐1 gave the reason to evaluate and update the verification against soil liquefaction specified in the applicable DIN EN 1998‐5. In this context, an easy‐to‐use calculation method was developed for regions of medium seismicity, which takes into account the current state of the art. It is based on the results of cone penetration tests at the site and allows a direct determination of the potential liquefaction hazard. The procedure is part of the new National Annex to DIN EN 1998‐5. [ABSTRACT FROM AUTHOR]

Die große Herausforderung bei der Planung von Gebäudehüllen besteht häufig darin, anspruchsvolle Fassadensysteme mit hohen architektonischen Anforderungen sowie einer maximalen Transparenz auszulegen. Bei der Entwicklung der Fassadenkonstruktion sind dabei in Abhängigkeit von der geographischen Lage zum Teil hohe seismische Beanspruchungen und die daraus resultierenden großen horizontalen Verformungen bzw. Kräfte zu berücksichtigen. Dieser Artikel erläutert anhand von drei sehr unterschiedlichen Projekttypen detailliert, wie der Schutz von Tragwerk und Gebäudehülle gegen seismische Beanspruchungen bei einer seilversteiften Gitternetzschale, im strukturellen Glasbau sowie bei einer Elementfassade mit komplexer Tragstruktur im Einzelnen geschehen kann. Transparent building envelopes in seismic areas. One major challenge when planning building envelopes is often to design sophisticated facade systems with high architectural requirements and maximum transparency. Depending on the geographical location of the site, high seismic loads and the resulting large horizontal deformations and forces must be taken into account during design development of the facade construction. Considering three different projects the article explains in detail how protection of the building structure and the envelope against seismic action for a gridshell, in structural glazing and for a unitized facade with a complex supporting structure could be achieved. [ABSTRACT FROM AUTHOR]

Le mot hébreu  אֶלְגָּבִישׁ généralement été compris comme désignant la grêle, ce qui présente un problème lexical étant donné que tous les mots apparentés semblent se référer à la roche. Basée sur un nouvel examen des données lexicales existantes avec l'inclusion de nouveaux cognats et une nouvelle analyse de l'imagerie contenue en Ez 13 et 38, cette étude propose que l'hébreu  אֶלְגָּבִישׁ , l'akkadien  algamešu , l'ougaritique  a͗lgbṯ , l'égyptien  i͗rḳbs , et d'autres mots apparentés dérivent tous de l'égyptien  i͗nr-km. [ABSTRACT FROM AUTHOR]

The multidisciplinary research described here shows how archaeologists can help reconstruct past seismic episodes and understand the subsequent relief operation, rehabilitation, and reconstruction processes. In October 1522, a major earthquake and landslide struck the then capital of the Azores, Vila Franca do Campo, 1500 km from the European mainland. Damage was extensive, destroying key monuments, affecting most of the inhabited area, and leaving few survivors among the early colonists. The results from twenty-six archaeological trenches, geological and geoarchaeological investigations, and documentary analysis are reviewed here. Distinctive archaeological deposits are identified and explained, using the high density of artefacts and the erosional contact between the landslide and the pre-1522 palaeosol to reconstruct the episode in detail. [ABSTRACT FROM AUTHOR]

Comparison of collapse frequency and failure probability of retaining structures In this contribution observed collapse frequencies and calculated failure probabilities of retaining structures are compared. Such comparisons are so far only available for bridges, dams and tunnels. The comparison is mainly based on values from the literature. These were recorded in the context of a literature search. Furthermore, collapse frequencies for earthquake impacts were determined by own calculations. The comparison of collapse frequencies and failure probabilities of retaining structures shows a good agreement. However, the comparison of the values with other types of structures shows an above‐average frequency of collapses. This seemingly accepted high frequency of collapse is justified by the lower number of victims and damage costs when retaining structures fail. [ABSTRACT FROM AUTHOR]

Einkaufen wird zunehmend zum Erlebnis. Dazu werden weltweit einzigartige „Flag ship Stores" mit aufwendigen Fassaden errichtet, die durch einen Wow‐Effekt begeistern sollen. Ihr Erfolg gibt ihnen Recht, erfordert jedoch zuvor eine detaillierte Planung und Umsetzung. Anhand eines Projektes in Santa Clara, CA, USA, wird gezeigt, welche Liebe zum Detail und technische Raffinesse nötig sind, um auch mit vergleichsweise kleinformatigen Fassaden ein transparentes Ausrufezeichen zu schaffen. Im Zentrum der 300 m2 großen Ganzglasfassade stehen zwei überdimensionale, 9 m hohe Flügel einer gläsernen Schiebetür. Der fünflagige Glasaufbau wird über Bohrungen und Edelstahlbolzen mit einem Tragrahmen verbunden. Darüber hinaus müssen auch Glaskonstruktionen Erdbeben sicher ertragen und Beschleunigungen schadlos abtragen können. Der Beitrag zeigt sowohl die Entwicklung der Antriebstechnik sowie der konstruktiven Details und den Nachweis der Anlage. Versuche sichern die Berechnungen zusätzlich ab und zeigen, dass bis zu 180 kN Einzellasten in die Platten eingeleitet werden können, ohne die Gebrauchstauglichkeit einzuschränken. Als Gipfel des Projektes folgt der Einbau der fünf Tonnen schweren Türflügel. Ganz im Sinne des Auftraggebers beginnt bereits der erste Lebenstag der Türen mit einem unvergesslichen Höhepunkt und unterstreicht eine innovative Herangehensweise. Large‐scale glass doors – Movement in seismic regions. Shopping evolves more and more into an experience. This is why one‐of‐a‐kind "Flagship Stores" with complex facades are designed to thrill by a "wow‐effect". Their success proves them right but raises the need for detailed planning and implementation. With the aid of an exemplary project in Santa Clara, CA, USA, it is shown what attention to detail and technical sophistication is necessary, even in a small‐scale facade project, to create particularly transparent head‐turner. Two over‐dimensional, 9 m high door leaves are in the center of the 300 m2 full‐glass facade. Its five‐layered laminate is form‐fixed to a stainless steel frame through holes in the glass. As an additional provision, even glass structures shall carry seismic movements and acceleration without fracture. The paper shows the development of the drive engine, the structural details as well as the proof of the structure. An experimental campaign ensures that single loads up to 180 kN can be transferred through the glass without compromising serviceability. Finally, the voyage of the facade to the San Francisco Bay is traced. The installation of the door leaves – weighting astonishing five metric tons each –marks a first highlight. In accordance with the wishes of the client, the first day in the life‐cycle of the structure starts with a memorable climax and underlines an innovative approach. [ABSTRACT FROM AUTHOR]

In Los Angeles soll der neue Gebäudekomplex „Academy Museum of Motion Pictures" im Dezember 2019 eröffnet werden. Für Ausstellungsflächen wird hierzu das historische „May Company Building" renoviert und über mehrere verglaste Fußgängerbrücken mit einem sphärischen Kinoneubau verbunden. Für die Gesamtplanung sind die renommierten Architekturbüros „Renzo Piano Building Workshop" und M. Arthur Gensler Jr. & Associates verantwortlich. Im Artikel wird die Planung, Fertigung und Montage der erdbebensicheren Stahl‐/Glaskonstruktionen der Brücken und der Kuppel über dem Kino beschrieben. Eine Besonderheit stellt auch das sphärische Glasdach mit einem Durchmesser von 46 m dar. Die Stahlstruktur folgt verschiedenen geometrischen Vorgaben. Glass sphere for the Academy Museum of Motion Pictures. In Los Angeles, the new building complex "Academy Museum of Motion Pictures" is to be opened in December 2019. The historic "May Company Building" is redesigned as an exhibition space and connected to a new spherical theater building via several glazed pedestrian bridges. The renowned architects Renzo Piano Building Workshop and M. Arthur Gensler Jr. & Associates are responsible for the overall planning. The article describes the design, fabrication and installation of the earthquake‐proof steel/glass structures of the bridges and the dome above the theater. Another special feature is the free‐span spherical glass roof with a diameter of 46 m. The steel structure is following different geometrical rules. [ABSTRACT FROM AUTHOR]

Seismic safety of existing reinforced concrete structures in the context of Eurocode 8 application In Germany, earthquakes represent a rare but generally possible hazard for buildings and parts thereof. The publication of the latest findings on the earthquake hazard in Germany was accompanied by a re‐evaluation of the action level in the National Annex to Eurocode 8, resulting in higher design loads in many earthquake‐prone regions. Since the introduction of normative requirements for earthquake design, the action level has increased continuously in most cases. For existing reinforced concrete structures, the question of proportionality between the protection of existing structures and the obligation to safeguard them arises for reasons of traffic safety in general, and for structural interventions due to resource‐saving revitalization in particular. Despite basically earthquake‐compliant design with ductile frames and ductile shear walls – especially with low horizontal load levels compared to the vertical load – the existing bracing systems are mostly not verifiable for the higher loads. For the range between a minimum seismic load capacity and complete seismic resistance to current actions, a risk‐based assessment using performance factors based on the Swiss SIA 269/8 is proposed. [ABSTRACT FROM AUTHOR]

Differences, relationships and similarities between the earthquake maps according to the previous and the new National Annex to Eurocode 8 – Earthquake zone map according to DIN EN 1998‐1/NA:2011‐01 and map of spectral response ground accelerations according to E DIN EN 1998‐1/NA:2018‐10 The map of the spectral elastic response ground accelerations for the draft of the new National Annex to EC 8 (E DIN EN 1998‐1/NA:2018‐10) has triggered some discussion. These were related to the comparison with the earthquake zone map of the previous National Annex (DIN EN 1998 1/NA:2011‐01). Basically, it has to be emphasized that a direct connection between the two maps cannot be established, since they are based on very different parameterizations. In order to provide a factual basis for further discussions, this article compares the basic characteristics of both calculation models, i.e. the earthquake maps of the previous and the new NA. In addition, four variants are presented to show how the two different map types can be related, at least indirectly. For this purpose, basic limitations associated with such relationships are described. As a result, the variants show that they follow a common trend, apart from a few systematic deviations, both to smaller and to larger values. [ABSTRACT FROM AUTHOR]

Comparison of the new seismic hazard maps of Switzerland, Germany, Austria and France for the National Annexes to Eurocode 8 The comparison of the new seismic hazard maps for Switzerland, Germany, Austria and France, which were developed for the National Annexes to Eurocode 8, is the subject of this study. The presented common map covers the southern part of Germany together with adjacent areas of the mentioned neighbouring countries. The map is parameterised for peak soil acceleration (PGA), for a mean return period of 475 years, for median values and for a subsoil with a mean shear wave velocity of the uppermost 30 m of 800 m/s. Along the boundary between Germany and its southern neighbours, the contour lines of the independently calculated seismic hazard maps show an astonishingly good overall agreement. Slightly more significant deviations are only observed for areas with lower seismic hazard. This good to very good agreement can be seen as an indication of the resilience and thus realistic assessments. [ABSTRACT FROM AUTHOR]

Masonry infill walls in reinforced concrete frames under earthquake loading Reinforced concrete frame structures with masonry infill often show severe damage after earthquakes. The reasons for this are the stresses brought to the infill walls due to the frame deformations in the wall plane and the simultaneously occurring inertial forces perpendicular to the wall plane in combination with the construction details of the masonry infills. The infill is usually rigidly connected with the mortar to the frame columns, with the upper joint being closed with mortar or polyurethane foam. In the event of an earthquake, this leads to local interactions between the infill and the frame, which can lead to the failure of individual infill walls or to the successive failure of the entire building. The observed damages were the motivation for the European research project INSYSME for reinforced concrete frame structures with infills made of high thermal insulating bricks, to develop innovative solutions for improving the seismic behaviour. This paper presents the solutions developed by the German project partners (University of Kassel, SDA‐engineering GmbH) and compares their seismic behaviour with the traditional design of infill walls. Basis for the comparison are static‐cyclic tests and simulations on the infilled frame level. The results are used to derive recommendations for the earthquake‐proof design of reinforced concrete frames with infills made of masonry bricks. [ABSTRACT FROM AUTHOR]

Retrofitting method for stiffening masonry walls in earthquake regions To improve the load carrying behavior of stiffening masonry walls under earthquake action a new retrofitting method was developed at TU Dortmund University. Thin textile reinforced concrete elements fastened at the masonry wall with anchors lead to a wall system which not only fulfills the requirements for integrity and resistance but is also capable to develop a ductile limit state mechanism. Following the presentation of the concept and construction principles, the capacity and operation of the retrofitting system are presented with reference to experimental and analytical investigations. In this connection, earthquake simulation tests on full scale walls are especially instructive with the direct comparison of unretrofitted and retrofitted masonry walls. Next to the detailed description of its behavior and prerequisites, the effectiveness of the retrofitting system for a building with stiffening masonry walls is identified by means of comparative seismic analysis. [ABSTRACT FROM AUTHOR]

Seismic verification of masonry buildings based on realistic calculation models and increased behavior factors With the application of the traditional linear verification concept to masonry structures it is already no longer possible to carry out structural safety verifications even for buildings with standard ground plan configurations in areas with moderate seismicity. This problem will be exacerbated in Germany with the introduction of continuous probabilistic earthquake maps. Due to the increased seismic actions, it is necessary to make the existing load‐bearing capacity reserves that have not yet been taken into account available in comprehensible verification concepts in construction practice. This article presents a concept for the building‐specific determination of increased behavior factors. The behavior factors are composed of three components, which take into account the load redistribution in ground plans, the deformation capability and energy dissipation and all kinds of overstrength effects. For the calculation of these three components, a non‐linear verification concept based on pushover analyses is applied, in which the interactions of walls and floor slabs are described by a level of restraint. A non‐linear modeling approach of the overall building is introduced for the determination of the restraint levels, with which the interaction of walls and floor slabs can be simulated. The results of the linear verifications with increased behavior factors for this building are significantly closer to the results of non‐linear verifications and thus the standard ground plan configurations in areas with moderate seismicity can still be verified with the traditional linear calculation approaches. [ABSTRACT FROM AUTHOR]

Cyclic shear tests on walls made of clay block masonry Cyclic shear tests are a common method to assess the load‐bearing capacity and the deformation behaviour of walls under dynamic loads in the horizontal direction, such as those that occur during earthquakes. In the presented work, cyclic shear tests on 36 walls made of different types of masonry are described, the test results are shown and compared with calculated resistances according to Eurocode 6. After a list of the building materials used, the materials used and their dimensions are given for all examined walls. This is followed by a description of the experimental setups used at the institutes UTCB in Bucharest and ZAG in Ljubljana. The main part is the presentation of the measured values regarding achievable loads and drift values, as well as the determination of a bilinear approximation for each test. The envelope curves of the hysteresis loops of all experiments are then shown and compared. Finally, a comparison of the test results to calculated resistances according to Eurocode 6 is shown. With these investigations it could be shown that walls made of masonry have large drift capacities and that the assessment with the models of the Eurocode 6 delivers very realistic results. Furthermore, it could be shown, that conservative results are achieved when the resistance of masonry from concrete‐filled blocks is calculated with a composite stone strength, especially for walls with a higher degree of reinforcement. [ABSTRACT FROM AUTHOR]

Historic masonry buildings under earthquakes – Load‐bearing behaviour in contradiction to the currently applied methods of analysis The stability of historic masonry buildings must be guaranteed not only under normal conditions, but also during natural disasters. The seismic assessment of the masonry buildings of the Gründerzeit (1840–1918) in Vienna is a central topic in the qualitative and constructive assessment. Although masonry construction has been used for many centuries, the realistic evaluation of the load‐bearing behaviour is still a complex challenge. The methods of analysis according to current regulations are only insufficiently able to reflect the real load‐bearing behaviour and the possible activation of global failure mechanisms. As a result, the simplified verification is often difficult to calculate for many historic buildings, and questionable reinforcement measures are taken to compensate, even though the buildings have already experienced several earthquakes and survived most of them without damage. The present work deals with the approaches of current methods of analysis and aims to identify problem points and to compare them with time history analysis, which is supported by a powerful material model based on test series. It is shown that the conventional analysis for the historic masonry buildings without consideration of the interaction and load transfer effects as well as the characteristic construction methods only partially reflect the real load‐bearing behaviour. The work is intended to be a contribution to the technical expert discussions on the seismic safety of historic buildings and to stimulate the discussion on the formulation of realistic methods of analysis. [ABSTRACT FROM AUTHOR]

Experimental and analytical investigation of the seismic out‐of‐plane behavior of unreinforced masonry walls In addition to the vertical and horizontal load‐bearing in‐plane, masonry must also withstand out‐of‐plane loads that occur in earthquake scenarios. The out‐of‐plane behavior of unreinforced masonry walls depends on a variety of parameters and is very complex due to the strong non‐linearity. Current design methods in German codes and various international codes have not been explicitly developed for out‐of‐plane behavior and contain considerable conservatism. In the present work, shaking‐table experiments with heat‐insulating masonry walls have been conducted to investigate the out‐of‐plane behavior of vertical spanning unreinforced masonry walls. As shown in previous numerical investigations, important parameters are neglected in existing design and analysis models and the out‐of‐plane capacity is underestimated significantly. In the conducted experiments the results of these numerical investigations are verified. Furthermore, the development of an analytical design model to determine the force‐displacement relationship and the out‐of‐plane load‐bearing capacity considering all significant parameters is presented. [ABSTRACT FROM AUTHOR]

Seismic verification of masonry buildings in German earthquake regions With financial support of the "Deutsche Gesellschaft für Mauerwerks‐ und Wohnungsbau e.V." (DGfM) and the "Deutsches Institut für Bautechnik" (DIBt) in Berlin, two consecutive research projects were carried out to improve the seismic verification of masonry buildings in German earthquake regions. First, the seismic behavior of three modern unreinforced masonry buildings in the region of Emilia Romagna in Italy during the earthquake series in 2012 was investigated in detail in cooperation with the University of Pavia. Based on the results of these investigations an improved seismic design concept for unreinforced masonry buildings was developed. The paper presents the main results of the conducted research work and their transfer into standardization and engineering practice. [ABSTRACT FROM AUTHOR]

Lateral Bracing of Buildings with a Basement – Influence on the Stress Resultants and Deformations of Reinforced Concrete Bracing Walls when including the Basement in the Mechanical Model This paper presents an investigation of the influence on the shear force distribution and on the displacements of reinforced concrete bracing walls continuous through a basement, when modelling these walls. The shear forces and displacements are compared with those obtained when simplifying the wall by a cantilever with full fixity at the top of the basement, ignoring the transfer of shear force and bending moment into the basement. First, the influence of the basement is modelled by hinged connections between the wall and the base slab and the floor diaphragm above the basement, respectively. This will result in an unrealistically large wall shear force in the basement. Then, the flexural restraint of the wall by the base plate, and the lateral compliance of the floor diaphragm are modelled by a rotational spring and a lateral spring at those levels. Recommendations are given for reasonable values of the spring constants for practical design purposes. Special attention is given to the way in which including the basement in the mechanical model of such walls will influence aspects of their seismic design. Such aspects are the rigidity of the bracing system which influences the lateral earthquake loads, and the displacement ductility factor which influences the maximum admissible behaviour factor q. [ABSTRACT FROM AUTHOR]

Hybrid design of 18‐story "Tall Wood Building" in Vancouver and alternative in wood The first part of this paper discusses the design of one of the world's tallest hybrid wood buildings: the "Tall Wood Building", a 18‐story, 53 m tall student residence on the campus of the University of British Columbia in Vancouver, Canada. The building consists of 17 floors in solid wood construction on one floor in reinforced concrete. Two vertical concrete cores provide the required lateral load resisting system. The timber construction system consists of cross laminated timber, point supported on glulam beams. While the construction of the concrete cores lasted 14 weeks, the entire solid wood structure took only ten weeks to complete. Substantial shortening of the project duration and reduction of the ecological footprint of the building could have been achieved, if wood had been used for the cores. In the second part of this work, we examine the possibility of designing the building with solid wood cores. The results of a validated numerical model show that the criteria for earthquake and wind design of the current Canadian building standards can be met. [ABSTRACT FROM AUTHOR]

The global burden of structural collapse In this article, the global health burden of structural collapse is determined. For this purpose, mean ratios of buildings to inhabitants are determined and applied to the total population, subdivided into industrialized and developing countries. Based on known collapse frequencies of structures, mean annual worldwide collapse frequencies of structures are determined. The average number of victims is then used to estimate worldwide victim numbers, considering not only fatalities but also injuries. These casualties are converted into lost life years, which are often used as a measure of the health burden. In addition, the gain in life years is also estimated. [ABSTRACT FROM AUTHOR]

Synopsis of natural hazards for Cologne The synopsis of natural hazards for the city of Cologne has proven to be a prime example for the consideration of multiple natural hazards. Various research projects use the results presented within the framework of the German Research Network for Natural Disasters (DFNK). In these studies, partly identical approaches for the building stock, impact or correlation are used to determine the losses. From a current perspective, this paper reflects the progress that has been made in the area of multi hazard and risk assessment, how these changes are reflected in the prognosis and scenarios and, not least, which research needs are still to be derived. In the foreground is the question of which consequences arise from the detailed survey of the affected areas and the existing building stock. In this context, the vulnerability and damage functions developed by the authors are used, which allow for the expected natural hazards (earthquake, storm, flood) a prognosis of the expected distribution of the damage grades and the re‐assessment of the losses. Depending on the return period and taking into account the current value development, qualitative and quantitative changes can be justified as a result of the microscale building analysis. [ABSTRACT FROM AUTHOR]

Strengthening of seismically damaged reinforced concrete beam‐column joints by means of FRP rope connections through the joint area In areas of medium and high seismic hazard, reinforced concrete frame structures in seismic events often are damaged at the joints (beam‐column connections) and then need to be repaired for further use of the structure. In the following, a new strengthening procedure and experimental investigations will be presented. Test specimens with previously generated moderate pre‐damage are repaired with high‐strength repair mortar and Carbon Fiber filament bundles (C‐FRP) at the beam‐column connection. The test results of a test specimen on a scale of 1:1 in the undamaged state (JA1V) as well as in the pre‐damaged rehabilitated state (JA1FXb) are evaluated and compared. To simulate the earthquake effects, the undamaged test specimen is first cyclically loaded on the test bench. Subsequently, the same test specimen pre‐damaged by the first test is strengthened with C‐FRP in the node and beam area and again exposed to identical cyclic loads on the test bench. The essential measurement results of both tests are recorded and compared with each other with regard to load‐bearing capacity, stiffness, absorbed energy (ability to dissipate energy). Furthermore, the applied rehabilitation technique is presented in detail. On the basis of the investigations carried out, it is shown that rapid and efficient rehabilitation of joints by high‐strength cement without high‐pressure injection is possible. [ABSTRACT FROM AUTHOR]

Simulative earthquake damage modeling based on EMS‐98 – reliability and predictability Internationally, various damage models exist to quantify the structural damage to the structure and the resulting losses due to seismic action. The application of the different types of damage functions for a realistic assessment of damage requires a detailed knowledge of the structure and its vulnerability and site‐specific conditions. The intensity‐based damage model for general building stock, developed at the Earthquake Damage Analysis Center of the Bauhaus‐Universität Weimar within the framework of the German Research Network Natural Disasters (DFNK), was validated on the mean damage grades Dm and the reported losses of the 1978 Albstadt earthquake. A consideration of the spreads and uncertainties in the distribution of damage grades Di as well as the mirroring of comparable damage models was still pending. The validation and evaluation of the investigated model approaches is carried out in the paper on the basis of the distribution of the actually occurred structural damages of the seismic events characterized by different site intensities (e.g. Albstadt 1978, L'Aquila 2009). Looking back at the study of DFNK, the results for the metropolitan area of Cologne will be examined again with new building data and the extended damage model. The building vulnerability, aggregated in the DFNK, is transferred to the individual building stock and the influence on the earthquake scenarios is examined. The scatter of structural damage and losses are taken into account by Monte Carlo simulations. The changes in the results compared to the DFNK study are identified and discussed. [ABSTRACT FROM AUTHOR]

Die vorliegende Arbeit befasst sich mit der Behandlung von Naturkatastrophen (Erbeben, Kraterbildungen, Seebeben, usw.) in der historischen Literatur der römischen Kaiserzeit. Anhand von ausgewählten Beispielen wird zunächst die Haltung der Betro­ffenen einschliesslich der ergriffenen Massnahmen zur Beseitung der Schäden untersucht. Danach stellt sich die Frage, wie die antiken Autoren die Ursachen und die Wirkung der Naturkatastrophen bewerteten. Ihre Meinungen reichen von der Aufbietung von ratio­nalen Erklärungsmustern bis zum Rekurs auf religiöse Deutungen. Letzteres gewinnt in der christlich inspirierten Literatur der Spätantike zunehmend an Bedeutung.

Displacement behavior of undercut anchors under tension loading and crack cycling – Comparison of single anchor tests and large‐scale seismic tests Undercut anchors are used in nuclear facilities for post‐installed anchorages of mechanical components in reinforced concrete structures. For ensuring component integrity in case of accidental actions such as earthquakes, anchors have to show sufficient load‐bearing capacity. For assuming a stiff anchorage, permanent displacements of anchors have to be kept within narrow limits because anchor displacements directly influence load distribution and transfer of component supports. For verification of load‐bearing capacity and displacement behavior of safety‐relevant anchorages, approval tests according to European and German guidelines are carried out. In these tests, different loading and crack conditions as well as crack cycle collectives are investigated. In order to verify the transferability of the displacement behavior in approval tests to realistic loading, results of approval tests are compared to results of large‐scale seismic tests. [ABSTRACT FROM AUTHOR]

Determining the overstrengthfactor based on statistical values of European steel grades In dissipative seismic design concepts, capacity design rules have to be applied to control the plastic mechanism. For this purpose, non‐dissipative structural elements require an overstrength in respect to dissipative regions. Scattering of the yield strength of structural steel is considered in DIN EN 1998‐1 by the material overstrength factor γov with a recommended value of 1.25. However, current measurement data show often significant higher yield strength especially for steel grades with low nominal strengths. In this article, new yield strength data of European steel grades are evaluated and compared with statistical values from literature. Based on a new probabilistic model for the yield strength a steel grade‐dependent overstrength factor is proposed, which is also implemented in the new German National Annex DIN EN 1998‐1/NA:2018. [ABSTRACT FROM AUTHOR]