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This paper aims to review the nature and practice of earthquake reconnaissance missions since the earliest examples to today’s practice, and to try to show some of the ways in which the practice of earthquake engineering today has benefitted from field observations. To give some historical background, the nature of some of the earliest recorded field missions are reviewed, notably that of Mallet following the 1857 Neapolitan earthquake; the achievements of the UNESCO-supported missions of the period 1963–1980 are considered; and the nature and contributions made by several national earthquake reconnaissance teams (EERI based in the United States, EEFIT based in the UK, and more briefly the Japanese Society for Civil Engineering, the German Earthquake Task Force, and AFPS based in France) are reviewed. The paper then attempts to summarise what have been the most important contributions from the field observations to several aspects of earthquake engineering, particularly to understanding the performance of buildings, both engineered and non-engineered, including historical structures, to geotechnical effects, to gaining understanding of the social and economic consequences of earthquakes, and to loss estimation from future scenario events. The uses and limitations of remote sensing technologies to assess damage caused by an earthquake are considered. Finally, possible changes in earthquake field missions to meet anticipated future challenges and opportunities are discussed.

This article summarizes the work done over last decades regarding the development of new approaches and setting up of new applications for earthquake rapid response systems that function to estimate earthquake losses in quasi real time after an earthquake. After a critical discussion of relevant earthquake loss estimation methodologies, the essential features and the characteristics of the available loss estimation software are summarized. Currently operating near real time loss estimation tools can be classified under two main categories depending on the size of area they cover: Global and Local Systems. For the global or regional near real time loss estimation systems: GDACS, WAPMERR, PAGER, ELER and SELENA methodologies are. Examples are provided for the local rapid earthquake loss estimation systems including: Taiwan Earthquake Rapid Reporting System, Real-time Earthquake Assessment Disaster System in Yokohama, Real Time Earthquake Disaster Mitigation System of the Tokyo Gas Co., IGDAS Earthquake Protection System and Istanbul Earthquake Rapid Response System.

In Europe, the reference document for the seismic assessment of buildings is the Eurocode 8-Part3, whose first draft goes back to 1996 and, for what concerns its safety format, has strong similarities with FEMA 276. Extended use of this document, especially in Italy after the 2009 L’Aquila earthquake has shown its inadequacy to provide consistent and univocal results. This situation has motivated the National Research Council of Italy to produce a document of a level higher than the one in force, characterized by a fully probabilistic structure allowing to account for all types of uncertainties and providing measures of performance in terms of mean rates of exceedance for a selected number of Limit States (LS). The document, which covers both reinforced concrete and masonry buildings, offers three alternative approaches to risk assessment, all of them belonging to the present consolidated state of knowledge in the area. These approaches include, in decreasing order of accuracy: (a) Incremental dynamic analysis on the complete structural model, (b) Incremental dynamic analysis on equivalent SDOF oscillator(s), (c) Non-linear static analysis. In all three approaches relevant uncertainties are distinguished in two classes: those amenable of description as continuous random variables and those requiring the set-up of different structural models. The first ones are taken into account by sampling a number of realizations from their respective distributions and by associating each realization with one of the records used for evaluating the structural response, the latter by having recourse to a logic tree. Exceedance of each of the three considered Limit States: Light or Severe damage and Collapse, is signaled by a scalar indicator Y, expressing the global state of the structure as a function of that of its members, taking a value of one when the Limit State is reached. For the first two LS’s, which relate to functionality and to economic considerations, the formulation of Y is such as to leave to the owner the choice of the acceptable level of damage, while for the Collapse LS the formulation is obviously unique. An application to a real school building completes the paper.

The most common structural system of the precast industrial buildings in Europe consists of an assemblage of cantilever columns tied together with beams. Typical beam-to-column connection in these structures is constructed with steel dowels. Although this system has been used for decades, its seismic response was poorly understood, which reflected in ambiguous code requirements and conservative approach. Therefore, along with innovative precast structural solutions (not discussed in this paper), this system was the main focus of the continuous European research in the past two decades. The key results of this vast research effort (including unprecedented cyclic, PSD and shake table experiments on large-scale structures) led by the associations of the precast producers in Europe and the Politecnico di Milano are presented and discussed in this paper. The details are provided for the work done at the University of Ljubljana. The results of these research projects led to some major modifications and improvements of the relevant chapter in Eurocode 8, when this was evolving from the initial informative annex to the final code provision. Refined FEM models for the complex behaviour of the dowel beam-to-column connections as well as macro models for the post-critical analysis of the complete structures were proposed. Single-storey and multi-storey structures were investigated and the design formulas to estimate high shear and storey-force amplification due to higher-modes effect in multi-storey structures were derived. The design guidelines for connections of precast structures under seismic actions were prepared. Systematic risk studies were done indicating that this structural system can be safe in seismic regions if all Eurocode 8 provisions as well as the recommendations based on the presented research are considered. These include the capacity design of the connections. Behaviour factor for such precast systems was studied and the values initially proposed in preEC8 were modified (increased). However, it was shown that drift limitations typically govern the design and that the nominal value of the behaviour factor is not so decisive. The key factors contributing to the good seismic behaviour of this system (assuming that the connections are properly designed) is the low value of the compressive axial force in the columns confined with adequate hoops and the overstrength caused by drift limitation requirements. Cladding-to-structure interaction has been one of the most poorly understood components of the system, which is now the topic of the on-going research.

This paper summarises the experience gathered on the field following four recent earthquakes: in 2009 at L'Aquila, Italy; in 2010 at Lorca, Spain; in 2011 at Christchurch, New Zealand; in 2012 at Emilia, Italy. These quakes provided useful lessons at the boundary between seismology and engineering, about the difference between what we expected to happen, thanks to more or less simplified models, and what happened in reality. The topics dealt with are: (1) the reliability of “free-field” strong motion recordings, discussing the role of accelerometer housing, spurious transient, city-soil effect, and the possible over-correction of displacements; (2) the mismatch between code provision and observed spectral acceleration due to the role of velocity inversions, the influence of topography, the softening and hardening non-linearity, (3) the importance of vertical component considering the time distribution of phases arrivals and the presence of amplification due to P-velocity contrasts.

Bridges are quite different from buildings regarding their dimensions, structural systems and in general regarding their seismic response. Thus the specialized standards for their seismic design are needed. One of them is Eurocode 8/2 standard (EC8/2), which considerably improved the design practice. It is well organized, practically oriented and designer friendly.

In Slovenia it has been used for years. Some experiences, obtained during its application in practice are presented. Four issues are addressed: (1) the correlation between pre-yielding stiffness and strength of structures as well as the reduction of the seismic forces and equal displacement rule, (2) the application of the nonlinear static (pushover) methods of analysis, (3) the estimation of the shear strength of RC columns, and (4) the protection of the longitudinal reinforcement in RC columns against buckling.

It was concluded that pre-yielding stiffness and strength of structures are strongly correlated. The pre-yielding stiffness is different for different levels of selected strength. This does not negate the equal displacement rule. The EC8/2 is one of the rare standards that explicitly recognized the quite important correlation between chosen strength of structures and corresponding pre-yielding effective stiffness. Accordingly, the equal displacement rule is presented in a modified way. Different interpretations of this rule are discussed in the paper.

The EC8/2 introduced the nonlinear static pushover methods into the design practice. The way of their use is examined in the paper. Specifics in the application of the single mode pushover methods and the scope of their applicability are discussed. Some of the alternative methods are briefly overviewed.

It was found that EC8/2 provisions related to the estimation of the shear strength of some typical bridge columns can be quite conservative. Some of the alternative methods are presented and discussed on the example of the experimentally investigated columns. It is concluded that the estimation of the shear strength, in general, is far from being solved and it demands further investigations.

It was also found that some requirements of EC8/2 related to the prevention of buckling of the longitudinal reinforcement in RC columns are not interpreted in an appropriate way; thus their corrections are needed.

The paper traces the road to the first fully performance- and displacement-based European seismic standard, namely Part 3 of Eurocode 8 on assessment and retrofitting of existing buildings and from there to the part of the Model Code 2010 (MC2010) on performance- and displacement-based seismic design and assessment of all types of concrete structure. Performance-based seismic design is set in the broader context of performance-based engineering and European Limit State design. The major features of Part 3 of Eurocode 8 are presented, focusing on seismic demands and ‒ mainly ‒ on cyclic deformation capacities. Emphasis is placed on the need to use in the analysis an effective elastic stiffness which realistically represents the member secant-to-yield-point stiffness, in order to predict well the seismic deformation demands. The background of the effective stiffness and the deformation and shear capacity sides in Part 3 of Eurocode 8 is presented, with a view on developments of the State-of-Art after these aspects were finalized in Eurocode 8. The focus turns then on the seismic part of MC2010, showing the differences with Part 3 of Eurocode 8 due to recent advances in the State-of-the-Art, the difference between design of new structures and assessment of existing ones (including the need to estimate the secant-to-yield-point stiffness without knowing the reinforcement), the wider scope of MC2010 beyond buildings, etc. It is emphasised that member detailing per MC2010 is not based anymore on opaque prescriptions, but on transparent, explicit verification of inelastic deformation demands against capacities.

This paper provides an overview of the Literature on the behaviour of historic masonry elements and building models. The purpose of this paper is to identify the main parameters affecting the seismic behaviour of historic masonry buildings, as illustrated through the experimental campaigns carried out by numerous researchers. Furthermore, aspects of the seismic behaviour that are not sufficiently studied to-date are identified. Thus, selected publications are evaluated related to the behaviour of historic masonry elements in compression, in diagonal compression, in in-plane shear and simultaneous compression, out-of-plane bending, as well as publications related to the behaviour of subassemblies and building models subjected to monotonic, pseudo-dynamic or dynamic tests on earthquake simulator. The available experimental results illustrate the main weaknesses of historic masonry elements and bearing systems, namely the vulnerability to in-plane shear and to out-of-plane bending, the limited ductility, the negative effect of the flexibility of timber floors and roofs, etc. On the other hand, the beneficial effect of adequate connection between horizontal and vertical elements, as well as the connection among walls is also evident. Moreover, the variety of the construction types of masonry tested by various researchers, the scale of the models, the variety of experimental setups and loading histories do not allow, in most cases, a direct comparison of the experimental results. This is so especially as far as properties related to the deformations of masonry elements are concerned. Thus, the effort to develop sound physical models and to calibrate them is not yet satisfactorily assisted by the available experimental results. Yet, this is a prerequisite for a reliable assessment of the current state of historic structures and, by way of consequence, for the selection of adequate intervention techniques for their preservation.

Earthquakes have a strong effect on the socio-economic well-being of countries; the consequences can lead to a complex cascade of related incidents, expanding across sectors and borders, and in a more serious context, to our basic survivability. An urban area consists on several complex and highly connected systems. A significant loss of housing, education, power outages or other component would have substantial negative impacts. How would constrains in residential areas affect the residential distribution of the region? How would a general change in accessibility due to severe damage affect the population or the economy (employment changes)?

Disasters are still predominantly seen as exogenous events, unexpected and unforeseen shocks that affect normally functioning economic systems and societies rather than as endogenous indicators, an integrated, and mutually influencing process where financial, health, economic and social risks are considered as both facets and at the same time contributing factors in an interdependent process of risk creation, accumulation, mitigation, and transference.

Seismic scenario simulators have been used as tools to estimate damages inflicted by earthquakes in a region. Up to now this powerful simulators calculate and maps the direct damages on urban environment such as the building stock and infrastructures, not including the propagation effects among these components. This paper presents a novel approach to study in a macro scale an urban region, including the systemic interdependencies among urban elements. The methodology allows the observation of urban disruptions caused by the interdependencies and measured through a Disruption index. This index permits to identify the most vulnerable elements, being essential for the risk reduction.

With the ongoing progress of computing power made available not only by large supercomputer facilities but also by relatively common workstations and desktops, physics-based source-to-site 3D numerical simulations of seismic ground motion will likely become the leading and most reliable tool to construct ground shaking scenarios from future earthquakes. This paper aims at providing an overview of recent progress on this subject, by taking advantage of the experience gained during a recent research contract between Politecnico di Milano, Italy, and Munich RE, Germany, with the objective to construct ground shaking scenarios from hypothetical earthquakes in large urban areas worldwide. Within this contract, the SPEED computer code was developed, based on a spectral element formulation enhanced by the Discontinuous Galerkin approach to treat non-conforming meshes. After illustrating the SPEED code, different case studies are overviewed, while the construction of shaking scenarios in the Po river Plain, Italy, is considered in more detail. Referring, in fact, to this case study, the comparison with strong motion records allows one to derive some interesting considerations on the pros and on the present limitations of such approach.