Until recently, the design of steel and composite structures for the relatively low seismicity of Germany was predominantly performed in accordance with EN 1993-1-1 [9] and EN 1994-1 [10]. This was also allowed due to the low demands on joints generated by seismic loads. Alternatively, the application of capacity design in accordance with the European seismic code often led to less economical outcomes. In this context, it became common practice to design steel and composite structures considering a low ability of seismic energy dissipation (q ≤ 1.5). However, the seismic risk in moderate-to-low seismic regions is not negligible. Risk factors include increased density of the population and high industrialisation of many regions in Germany. Moreover, civil engineering design offices are generally not very familiar with seismic design. Another risk is the underestimation of the seismic hazard in Germany demonstrated by a state-of-the-art probabilistic seismic hazard assessment [11]. Consequently, new seismic hazard maps were introduced in the updated version of German National Annex DIN-EN-1998-1/NA [12]. According to these maps, the relevance of the seismic hazard in Germany had increased due to expanded seismic areas and to higher spectral accelerations. Because of this, seismic action should not be disregarded in the design of steel and composite structures. This is also of particular importance to the design of beam-to-column connections, which are regularly configured in accordance with the German catalogue of typical connections "Standardised Joints in Steel Structures to DIN EN 1993-1-8" [13] and not with EN 1998-1 [14]. The main aim of

Owing to the new rules of the German National Annex to EN 1998-1, the relevance of the seismic action has increased, materialising in extended seismic areas and higher spectral accelerations. This may lead to seismic loading being decisive on the design of steel and composite frames. However, the demand is lower in Germany than in other seismic areas. Consequently, these challenges are addressed in an ongoing German national research project, by developing joints with dissipative connections, classified as semi-rigid and partial-strength, for steel and composite frames that could allow for the use of behaviour factors in the range of 1.5 to 3. The development started with typical connections from the German catalogue, designed to withstand static loads in the elastic range, followed by performance and detailing improvements. Developments (e.g., increase in sagging/hogging bending: 125 %/18 % of steel joints and 70 %/40 % of partially composite joints) resulted from pretest finite element analyses (FEA) on joints and frame models. Improvements to joint detailing were made according to the provisions of the newest draft of Eurocode 8. The optimised joints were integrated in frame specimens, which are currently being tested under monotonic and cyclic loads at RWTH-Aachen University. This article introduces the developed joint solutions, describes the experimental and numerical programs and presents the monotonic response of frame specimens based on the results of FEA, as well as the main conclusions.

Recently, timber has gained increasing importance as a structural material, as it offers competitive structural performance and efficient production combined with a significant reduction of the environmental impact. Light-weight timber frames provide an efficient structural solution for wooden multi-storey buildings, in which the wall elements -acting as diaphragms -provide lateral stiffness and resistance to wind and earthquake loads. Light-weight timber frame elements are built up of several components (sheeting, fasteners, frame, support and anchorages), each of them contributing to the total performance of the structure. The current paper presents the outcome of experimental and numerical investigations on a ductile and replaceable supporting and anchoring system for wood shear walls. The aim of the examined novel system is two-fold: (i) to limit the damage of the superstructure under seismic loads by concentrating plastic deformations on the anchoring elements, placed at the base of the building and (ii) to be replaced after getting damaged because of a significant earthquake. The supporting and anchoring detail is made of steel and designed appropriately to behave nonlinear in a ductile manner under severe seismic loads and thus to provide additional energy dissipation. The damage is concentrated on the steel part, which acts as a dissipative mechanism limiting the forces transferred into the timber building. Consequently, the timber members remain undamaged for moderate earthquakes and slightly damaged in case of strong seismic events. A parametric study, using FE models validated based on experimental results, was conducted with the objective to investigate the influence of the geometrical characteristics of the anchorage. Moreover, a built-up anchoring configuration optimized for replaceability was developed and analyzed. Finally, recommendations for applications are provided, as well as the main conclusions of the study.

This paper describes the concept of an innovative, interdisciplinary, user-oriented earthquake warning and rapid response system coupled with a structural health monitoring system (SHM), capable to detect structural damages in real time. The novel system is based on interconnected decentralized seismic and structural health monitoring sensors. It is developed and will be exemplarily applied on critical infrastructures in Lower Rhine Region, in particular on a road bridge and within a chemical industrial facility. A communication network is responsible to exchange information between sensors and forward warnings and status reports about infrastructures' health condition to the concerned recipients (e.g., facility operators, local authorities). Safety measures such as emergency shutdowns are activated to mitigate structural damages and damage propagation. Local monitoring systems of the infrastructures are integrated in BIM models. The visualization of sensor data and the graphic representation of the detected damages provide spatial content to sensors data and serve as a useful and effective tool for the decision-making processes after an earthquake in the region under consideration.