The scope of this Workshop is the presentation of pre-normative design recommendations for seismically qualified steel joints and the presentation of design guidelines on order to design steel structures accounting for the type of joints and their relevant non-linear response.

Significant developments have been made, in the last few decades, to provide more accurate and reliable design methods for structures, infrastructures and foundations, particularly, when subjected to dynamic (mainly seismic) actions. Numerical methods have played a major role in these advances. Nevertheless, their remarkable potential should be broadened and improved, since geotechnical earthquake engineering hazards are still difficult to mitigate.

The Mini-Symposium “Recent advances and challenges in geotechnical earthquake engineering” will offer an opportunity for the presentation and discussion on several geotechnical earthquake engineering issues. All those involved with computational mechanics, related to geotechnical earthquake engineering, are welcome to present their recent experience and research findings. Contributions related to hybrid, analytical, as well as, experimental methods in the field of soil dynamics and earthquake engineering are also welcome.

This Mini-Symposium aims to attract academic staff, researchers, post-graduate students and professional engineers dealing with advanced topics, which include but are not limited to: Performance-based design; Liquefaction and other types of major soil failures; Dynamic soil-structure interaction; Codes, standards and safety evaluation; Foundations and Ground Improvement; Retaining structures; Slopes, dams and embankments; Tunnels and lifelines; Wind turbines; Man-made vibrations.

A paper submitted in this Mini-Symposium should have a content that combines numerical simulations of various problems that belong in the field of Earthquake Engineering and Structural Dynamics with relevant experimental studies through laboratory or in-situ measurements. Particular applications may belong to dynamic and earthquake response of structures and components, influences arising from seismic retrofitting towards upgrading the dynamic and earthquake performance of structures and components as well as earthquake protection measures from various forms of base isolation, damping or energy dissipation devices for controlling the dynamic and earthquake response of structures and components. Moreover, in-situ or laboratory measurements dealing with influences arising from soil-structure interaction during the dynamic / earthquake response of structural systems accompanied by relevant numerical simulations are also included. Fields of application may include a variety of modern structures or cultural heritage structures constructed with a variety of materials including steel, reinforced concrete, masonry etc.

Today’s transport networks play a key role in supporting economic growth. A smart transportation system that is capable of monitoring the condition of its critical infrastructure can plan preventive maintenance activities. Deterioration and damage will inevitably occur in transport infrastructure such as roads and railway systems. The aim of this symposium is to bring together academic scientists and industry researchers to present their recent advancements in the field of structural health monitoring of transport infrastructure. It covers a broad research area from simple models to applications, numerical modelling, laboratory-scale experimental case studies and field tests.

The session will focus on, but is not limited to, the following topics:

• Bridge damage detection and health monitoring (highway and railway bridges)
• Identification of bridge modal properties
• Road pavement health monitoring methods
• Railway track health monitoring methods
• Dynamic interaction of trucks with bridges and roads
• Bridge traffic loading

Since the late 1970s numerical simulation methods have been developed in order to consider soil-structure-interaction (SSI) problems. In the beginning, such approaches performed linear analyses that are generally appropriate to describe low amplitude ground motions, but they are not able to address non-linear effects of the system. In this regard, it is important to use SSI based approaches to understand baseline elastic and low amplitude response, and then move towards soil-foundation-structure-interaction (SFSI), where the non-linear effects of the soil, foundation and structure are taken into account.

This mini-symposium focusses on research where case studies have been used to validate SSI and SFSI numerical simulation approaches. Results from large scale field tests and case histories from past earthquakes are used as the basis to assess numerical simulation approaches. Both small strain SSI based modelling and large strain SFSI modelling outcomes will be presented, highlighting the effectiveness of current simulation techniques.

Experience and research developments have led to significant advances in the subject of seismic engineering over the past years. In the particular field of seismic design, the development and revisions of a new generation of design codes such as the Eurocode 8 is an important milestone. Although this code still promotes the use of classical seismic design approaches deeply imbedded in current practice, e.g. force-based approaches considering the use of behaviour factors (q-factors) and enforcing capacity design principles, Eurocode 8 also encourages the use of more advanced methods of analysis. Although the core of such analysis methods, i.e. nonlinear static and nonlinear dynamic analysis methods, can be seen to be reasonably well established, several developments and studies are still needed from the practical use and design process point of views. Namely, an adequate safety format, similar in scope to the one involving linear analysis methods, is yet to be explicitly addressed in a framework which foresees the use of nonlinear analysis methods. Papers that address this thematic are welcome, namely on the following specific fields: nonlinear dynamic analysis; seismic input; structural safety assessment methodologies; experimental characterization of structural elements under cyclic loadings; case studies.

The solution of simulation-based problems comprising complex mathematical models such as large finite element models involving uncertainty requires a large number of re-analyses. This type of problems includes Bayesian uncertainty quantification, uncertainty propagation, structural dynamic simulation, model updating, reliability analysis, reliability sensitivity analysis, uncertainty management in structural dynamics, reliability-based design optimization, etc. The corresponding computational demand for solving these problems is computationally very demanding or even prohibitive due to the large number
of analysis of the high fidelity model required by the corresponding simulation processes. Even with the latest developments on efficient simulation strategies and the advent of parallel computing, the application of methods for solving complex simulation-based problems is still challenging. In such scenario, one possible approach for rendering the solution feasible is developing approximate and inexpensive mathematical representations of high fidelity models.

This mini-symposium aims to address the latest progress on approximate mathematical representation techniques in the context of complex simulation-based problems. The scope of possible contributions is wide, including intrusive or non-intrusive formulations, online or offline training strategies, developing special techniques for coping with highdimensional input-output models, applying meta-models with different fidelity levels, substructuring techniques, parametric reduced-order models, adaptive schemes, hyperreduction, and application to complex problems of engineering interest. Problems of uncertainty quantification such as reliability estimation, robust or reliability-based design, Bayesian finite element model updating, system identification, sensitivity analysis, etc. of complex dynamical systems are particularly welcomed.

In the last few decades, significant developments were made to provide more accurate and reliable modeling approaches to assess the seismic performance of historical masonry structures. Among others, rigid block modeling approaches have demonstrated to be suitable in both static and dynamic fields to simulate in-plane and out-of-plane failure modes of masonry structures, especially for those buildings that do not conform to box behavior because of lack of stiff floor slabs or because of weaker partial collapses affecting the façade or inner walls. On the other hand, the assessment of the rocking and overturning response of free or restrained rigid blocks to earthquakes still represents a challenging task in the research field of structural analysis. Moreover, it is recognized that the nonlinear dynamic behavior of historical masonry structures is influenced by the effects of the kinematic soil-structure interaction (SSI) and the foundation-soil damping. This can be translated into a special boundary condition for the rigid block model, which accounts for the SSI effects.

The Minisymposium “Rigid block modeling approaches for static and dynamic analysis of masonry structures” will offer an opportunity for the presentation and discussion on the recent advances in this field. All those involved with the seismic response of masonry structures modeled as rigid blocks at micro and macro-scale and adopting force and displacement-based techniques, limit analysis, as well as discrete element methods and rigid block dynamics, are welcome to present their recent experience and research findings. Contributions related to the dynamics of different types of rocking structures, as well as experimental investigations in static and dynamic fields of rigid blocks and current SSI-approaches for rigid block models are also well accepted.

This Minisymposium aims at attracting academic staff, researchers, post-graduate students and professional engineers dealing with advanced topics, which include but are not limited to:

Analytical and computational strategies for masonry block structures; In-plane and out-of-plane behaviour of masonry structures; Standard and non-standard limit analysis of masonry block structures; Analytical and experimental contact mechanics; Experimental seismic performance of rigid blocks; Rocking response of rigid blocks to earthquakes; Non-linear dynamic analysis of out-of-plane mechanisms of masonry structures; Critical rocking response and the worst-case scenario; Consideration of the soil-structure interaction in rigid block models of masonry structures; Case studies.

The mini-symposium is focused on the new developments in dynamics of aerospace, civil, mechanical, structural, biomechanical, wind, earthquake and transport engineering. The proposed mini-symposium welcomes papers dealing with traditional dynamics, wave propagation and contact-impact problems as well as emerging multi-physics of analytical, numerical and experimental nature, addressing dynamic stability of deterministic/stochastic, Hamiltonian/non-Hamiltonian and holonomic/non-holonomic, self-excitation, auto-parametric systems under deterministic/random excitations, waves in stochastic and random continuum, waves in dispersive, heterogeneous, functionally graded and multi-layered medium and solitons. The work oriented on dynamics and wave propagation in smart and advanced materials and structures are welcome. This mini-symposium is devoted also on new developments in numerical methods for structural dynamics, wave propagation phenomena and contact-impact problems of solids. Especially welcome are papers on recent and ongoing research and papers of multi-disciplinary and multi-scale nature.

Rail tracks represent an important backbone of a modern and sustainable society with an awareness of ecological responsibility. It is predicted that in the near future rail-bound transportation will be one of the driving means of economic growth with enhanced performance and interconnectivity, as well as higher traffic volume. The space requirement for new rail lines is expected to compete with the construction development, and thus, the distance between rail tracks and urban areas will decrease. These aspects impose new challenges to the engineers, requiring outstanding solutions such as high-speed and silent trains, reliable and cost-friendly bridge structures, rail tracks with low maintenance efforts and so forth. Many of these issues are regulated in guidelines and codes of various disciplines as, for instance, rail track engineering, design of bridge structures, and acoustics. In specific cases, simplified codified procedures result in over-conservative (i.e., uneconomical) design of the track or underestimate the induced dynamic response. For all these reasons the need of more realistic approximations in track engineering is emerging.

The scope of this minisymposium is to provide a forum for discussing recent advances in simplified yet accurate modelling of problems in rail track dynamics as well holistic computational approaches related to vehicle-track-soil interaction, vehicle-track-bridge interaction, structure-borne and air-borne noise, as well as ground-borne noise and vibration. Presentations of experimental, analytical and numerical findings, are highly welcome along with opinion papers on recent advances and future challenges.

After the striking of damaging earthquakes, the civil protection, administrators and the engineering community have to respond to a series of successive emergencies. In the aftermath of the event there is the need to rapidly proceed with building tagging, usually relying on the judgment of experts that give their opinion on building safety level and related usability after visual inspection. Also it is crucial to verify the functionality of main infrastructures (e.g. hospitals, road network). On the other hand, when the reconstruction process starts, smooth resolutions on fate of damaged buildings are crucial to avoid further delaying of an already complex process towards effective recovery.

Recent proposals based on the development of aftershock fragility curves for Multi-Degree-Of-Freedom systems modeling real or archetype buildings or for Single-Degree-Of-Freedom infrastructure elements represent a significative advancement of the research, ideally finalized to support and/or complement with a quantitative approach the judgment-based tagging process. These methods, relying on suitably refined modeling and analysis of the response of the building structural system and/or single components, allow to investigate on possible damage patterns and accumulation, evaluating consistently the safety variation in MDOF or SDOF systems. On the other hand, also simplified methods based on static nonlinear analyses or on equivalent systems, can give useful indications on the residual capacity and the safety variation for damaged buildings and infrastructures. Methods for evaluation of system’s post-earthquake behavior can also provide insights on reparability. Indeed, decisions on whether to repair, repair and upgrade or demolish a building or infrastructure depend on a number factors encompassing the initial usability tagging, the damage state, capacity loss and safety level variation as well as the feasibility and costs for repairing and upgrading, if necessary; also, they may be influenced by other exogeneous aspects such as the socio-economic context of the area, pre-existing insurance coverage, the active policies, economic incentives or owner’s investment plan among other.

The objective of this mini-symposium is to share and discuss research results and ideas on currently available procedures and their applicability in the field of post-earthquake assessment. Relevant topics include, but are not limited to, evaluation of aftershock fragilities for buildings or infrastructures, simplified methods for assessment of post-earthquake behavior and safety, damage, costs and reparability. Papers that address conceptual, theoretical, computational, and/or methodological developments facilitating both the post-earthquake assessment and the wide issues of repairability, as well as novel and/or large-scale applications, are welcome.

Existing structures designed without modern seismic design provisions represent one of the largest seismic safety concerns worldwide. Such structures are vulnerable to significant structural and non-structural damage and even collapse when subjected to medium-to-strong ground shaking. This resulted in number of fatalities and significant economic losses, which promoted the development of seismic assessment and retrofit procedures for existing structures.

Recent massive reconstruction processes pointed out the need for new, practical, and cost-effective seismic strengthening solutions. Over the past three decades, several techniques emerged. Fiber-reinforced polymer (FRP), High Performance Fiber Reinforced Cementitious Composites (HPFRCC) composites, base isolation, dissipative devices, low-damage systems gained popularity as attractive solutions for repair and retrofit of civil infrastructures. They are successfully used for strengthening/rehabilitation of existing buildings and bridges. However further research effort is needed to improve their effectiveness, develop new applications, numerical modelling, design procedures, and techniques for installation. The use of advanced materials and repair/retrofit techniques will continue to grow to meet the demands of the construction industry and seismic designers.

In this context, the mini symposium intends to attract academic staff, researchers, post-graduate students and professional engineers dealing with seismic repair and retrofit of structures, such as buildings and bridges, with innovative materials or with innovative seismic devices. The refinements in the analysis, design procedures and numerical modeling of repair/retrofit interventions are also of particular interest.

Conservation and preservation of historical buildings in seismic zone are still today scientific research challenges. Within this context, the understanding and prediction of the structural response of heritage constructions subjected to seismic loads play a fundamental role. At the same time, this aspect represents a crucial task due to the complexity of the constituent materials, mostly characterized by masonry. Masonry is a heterogeneous material which behaviour depends on several features: mechanical characteristics of matrix and inclusions, interface properties, in-plane texture, out-of-plane composition, etc. In this perspective, during the last decades the scientific community has developed different approaches, to achieve a consistent description of historical masonry constructions.

The aim of this mini-symposium is to discuss the new advances in modelling of masonry material with specific applications to historical masonry monuments. Topics to be covered, but not limited to, are:

• New strategies for the preservation of heritage structures (SHM, damage detection, …)
• Seismic assessment of historical constructions
• Vulnerability analysis
• Non-linear static and dynamic analysis
• Incremental Dynamic Analysis applied to historical structures
• Constitutive models for masonry materials
• Homogenization techniques
• Multi-scale analysis

The interaction of earthquakes with the complex and vulnerable socio-economic system of exposed communities often results in damage and loss, sometimes with catastrophic consequences. As also strongly stated by the Sendai Framework for Disaster Risk Reduction, understanding disaster risk is the first priority in the pursuit of a global strategy for risk reduction. Furthermore, the implementation of risk monitoring and early warning systems is one of the viable solutions to actively prevent or reduce damage to specific structures, or even to whole regions.

The determination of seismic risk is the foundation for risk mitigation decision-making, a key step in risk management. Large corporations and other enterprises (e.g., local governments) analyze their 'portfolio' of properties, to determine how to best allocate limited funds for structural strengthening of buildings, or other risk reduction measures such as emergency planning. When assessing the seismic vulnerability of buildings it is essential to first establish the project objectives, before subsequently choosing the most appropriate strategy and tools necessary for building assessment and fulfillment of these objectives. It is also extremely important to understand the difference between the detailed approaches used for individual building assessment and those methods most efficient for larger scale analysis, pursued for city center assessment. While the latter results can be used as a general measure of seismic risk for different types of buildings, the actual seismic risk for any individual building may vary considerably and will depend upon its exact configuration and condition. This Minisymposium will deal with: 

• Modeling the potential impact of earthquakes in terms of damage to physical assets, loss of life and livelihoods, economical consequences and functional disruption of infrastructure;
• Understanding the underlying uncertainties in the modeling process, and the role of these uncertainties in the subsequent seismic risk management phase;
• Devising innovative methodologies to efficiently collect and integrate the information needed in order to reliably carry out seismic risk assessment and impact forecasting at different spatial scales.
• Exploration of the modeling of cumulative damaging mechanism and the effect of vulnerability interaction.

The objective of this symposium is to discuss new advances in numerical methods for linear and non-linear dynamics and wave propagation. Topics of interest include, but are not limited to: new space and time discretization methods for dynamical systems; high-order accurate methods including finite, spectral, isogeometric elements and others; methods with reduced numerical dispersion; filtering spurious oscillations; fictitious domain methods with the special treatment of the boundary conditions; new implicit and explicit time-integration methods for structural dynamics, wave propagation and impact problems; adaptive methods and space and time error estimators; application of new numerical methods to engineering dynamics and wave propagation problems; and others.

In the last decades, a new concept for reducing structural response has emerged. By allowing foundation uplift, structural performance can improve. This research paper concerns an experimental analysis of the structural response of buildings allowed to uplift when subjected to near-source earthquakes considering nonlinear soil –foundation-structure-interaction (NSFSI). Ten records of actual near-source earthquakes were considered, to study the benefits of the uplift and NSFSI on the structural response, and a simplified procedure is used to find lateral displacement at the start of uplift to compute and compare time response of the structure and maximum uplift values.  Newmark (1971) proposed an empirical equation for calculating the time period of a rocking chimney, but the structural dimensions were not incorporated in the equation. From the analysis done on the experimental results, it has been shown in the research paper that the uplift v/s time period graph do not overlap for the experimental results and equation generated results. A constant factor is thus multiplied in the empirical equation which modified the equation incorporating the structural dimensions and estimating the time response of a structure with a rocking base to a useful degree of accuracy for practical structural design.

Methods for seismic risk assessment of building portfolios are assuming a growing importance within earthquake engineering, due to the developing strong interest in cat modeling both from insurance and reinsurance companies and from public stakeholders interested in employing resources in risk mitigation planning (e.g., see the Sendai Framework for Disaster Risk Reduction). These methods generally cover large (urban- or regional-) scale assessments, and include models for the assessment of seismic hazard, vulnerability – empirical (observational-based) or mechanical (usually simplified) – and losses (human, functional and monetary). In all of these steps, managing uncertainties plays a key role and deserves a special attention. The expected contributions to this MS include studies proposing procedures for seismic risk assessment and example case-study applications, including validation/comparison with post-earthquake damage scenarios and loss observations. Contributions covering multi-hazard scenarios with cascading events (i.e. tsunamis or landslides) would be welcome, as well as studies focusing on community resilience analysis. The proposed MS is aimed at collecting advanced contributions from researchers in all these fields, promoting stimulating discussion and comparison.

In the past decades, vibrations monitoring has gained widespread use in civil and structural engineering as a useful tool not only in Structural Health Monitoring but also to calibrate numerical models for the assessment of the seismic response of buildings.

In particular, for the latter aim, experimental measures from real earthquakes represent a precious source for a better understanding of the seismic behaviour of structures (even in the nonlinear phase) and supporting detailed numerical calibrations. Both requisites are essential for improving the reliability of quantitative safety assessments.

Within this context, from ’90 valuable data are provided in Italy by the OSS (acronym of the Italian name ‘‘Osservatorio Sismico delle Strutture’’) that is a network of permanent seismic monitoring systems mainly installed in public buildings by the Department of Civil Protection (http://www.protezionecivile.gov.it/jcms/it/osservatorio.wp). Recordings acquired by OSS on selected structures hit by the Central Italy earthquake in 2016/2017 have been analysed last years by various researchers involved in ReLUIS project founded by the DPC. Such structures exhibited various damage levels, from slight to near collapse, highlighting various issues on the system identification techniques, potential of modelling strategies and evidences on amplification phenomena at different storeys.

In addition to the presentation of such an experience, researchers are invited to contribute to this Mini-Symposium, according to their perspective and presenting their results, both through theoretical papers and applications on existing buildings.

Recent advances on the investigation of the response of structures interacting with soil under earthquake or other dynamic excitations have provided novel and effective design solutions for geotechnical systems, including retaining walls and foundations of structures and critical infrastructures such as bridge piers and offshore wind turbines. Strong support on this topic has been given by relevant theoretical studies and experimental data at real or laboratory scale. In this regard, this Minisymposium encourages contributions on the dynamic analysis and design of retaining walls, surface and deep foundations or other engineering solutions including soil improvement, geotechnical isolation etc. Emphasis will be primarily (but not exclusively) given to: (i) Theoretical and/or numerical analysis of the dynamic response of coupled SSI systems (ii) Real instrumented cases of foundations and their supporting structure (iii) Field or laboratory tests on novel foundation systems and interpretation of recorded data. Studies on kinematic soil-foundation interaction and the behavior of foundations in complex soil conditions are particularly welcome.

It is envisioned that this Minisymposium will create an interacting forum among scientists and practitioners to exchange knowledge and new research ideas on the analysis and design of geostructures under dynamic loads.

Damages of structures due to earthquake and tsunami show a wide variety of characteristics, depending on the combinations of structures and natures of earthquake and tsunami.  Structural materials include woods, concretes, reinforced concretes, steels and so on.  There are another classification in structures such as civil constructions, buildings and architectures, chemical, petro-chemical and power plants, in which multi-physics phenomena such as fluid-structure interaction may occur.  There are possibilities such that those structures may be attacked by a variety of earthquakes and tsunami in magnitudes and frequency spectra.  In order to quantitatively predict such complex damage phenomena and to prevent them, high-performance computing technologies with sophisticated material modeling and analysis algorithms play key roles. In this mini-symposium, focusing on high-performance computing modeling issues in structural mechanics and earthquake / tsunami engineering, we exchange ideas and information to advance computational mechanics for earthquake / tsunami engineering.

The topics of the Minisymposium are strongly multidisciplinary. The methods and strategies to retrofitting, valorization, and management of the historical center of the cities (in particular existing buildings), are the core of the Mynisimposium. The decision to reuse of the historical buildings is a difficult problem and should be performed by decision makers with consideration of the natural hazards. Appropriate mitigation strategies, that considers a suitable re-use, can result in a sustainable preservation of historical assets and safety.

In seismic prone countries, historical centers have an important role in natural events. They have shown that the vulnerability of historical sites is generally higher that of the more recent neighbourhoods. The mitigation strategies could be an important role to avoid many casualties and losses. In the retrofitting strategies, the requirements of historical centres are often related to social and economic changes (effects of the delocalization of the population, effects of the tourism). Moreover, often historic centres or their significant part became a ghost town after natural events. Really, these historical centres are unique and fascinating: thanks to effective mitigation strategies they could become an important source of territorial development and could produce significant economic growth.

Their management reuse and development must be based on their vulnerability reduction. The role of the vulnerability of buildings on the resiliency of the cities is the fundamental critical aspect. Consequently, the research will be carried out considering the fundamental role of the resilience of the cities in risk mitigation and government.

In accordance with the objective of seismic risk analysis and territorial scale (until the analysis on single buildings), different kinds of direct and indirect losses can be considered.

The proposed Minisymposia would like to show and compare different approaches, existing operative proposals, and cases study about the following (but not limited) topics:

-        Innovative and economically sustainable mitigation strategies and optimized rules for planning.

-        Definition of rational criteria for risk-mitigation policies resilience based.

-        Allocation of the resources based on novel approches and methods.

-        Seismic vulnerability assessment and retrofit.

-        Innovative and economically sustainable retrofitting strategies.

-        Structural control, monitoring and assessment of structural damage.

-        Case Studies.

Minisymposium sponsored by:

SHMII Committee on Resilient Structures and Infrastructure (CORSI) of the International Society for structural Health Monitoring of Intelligent Infrastructures

Despite that it has long been assumed that the consideration of the effect of the horizontal component of earthquakes suffices for seismic reliability of structures, the vertical component should be consistently considered along with the horizontal one. This issue becomes a great concern for conventional seismic isolation system that can reduce the structural effects of the horizontal component of an earthquake, while the vertical component is transmitted directly into the structure. As such, there is considerable and increasing research interest worldwide in vertical and three-dimensional isolation systems to protect a wide range of structures and valuable facilities such as heritage assets and specialized equipment.

The scope of this session is to collect experiences and proposals to expand traditional base isolation schemes toward innovative solutions with special mention to three-dimensional base isolation. Contributions to these issues are critical to improve the current isolation technologies toward resilience. This session aims to attract academics, researchers, students, post-graduate students and professional engineers dealing with the following advanced topics:

• Innovative base isolation devices;
• Three-dimensional isolation solutions;
• Negative stiffness mechanisms;
• Machine learning for smart isolation solutions;
• Embedded monitoring systems in isolation devices.

Modern design codes recalls the importance of the consideration of the infill masonry (IM) walls in the design and assessment of buildings, but it is recognized that the available guidelines and knowledge is still limited. Recent earthquakes in southern European regions showed that the damage on these non-structural elements can cause important human and economic losses. IM walls can influence the global behavior and performance of building structures, in terms of global lateral stiffness, strength, energy dissipation and ductility, but can also chance the distribution of seismic demands among the structural elements. Recent evidences showed the importance of the in-plane and out-of-plane walls' responses and their interaction.

This Mini-symposium is focused on the recent research outputs on the studies of infill masonry walls behavior, their contribution to the buildings safety and response, to the new techniques and solutions adopted in construction of IM walls and in the retrofitting of existing buildings, as well as on the design methodologies and detailing of IM walls concerning their seismic behavior.

The proposed minisymposium deals with recent advances in structural design. Thanks to the developments in engineering research, as well as the advancement of personal computers, structural design has progressed significantly. Design of structures with special requirements has become increasingly more frequent in practice, while the time from the initial research work to its application in practice has minimized. New structural assessment methods, simulation of blast loadings, design or retrofit against progressive collapse, design and analysis of structures subjected to extreme natural disasters such as hurricanes or tsunamis, damage-free design, design of buildings incorporating innovative devices are only few of the topics engineering researchers are currently working on. This minisymposium aims to bring together researchers working on topics of structural design beyond its conventional principles.

A central principle in performance-based seismic design (PBSD) is to guarantee that structural systems have adequate ductility and energy dissipation capacity so that the expected damage can be controlled to lie within the limits of chosen performance states. Even though the seismic performance of a structure is directly related to the global and local deformations of the structure, the energy balance formulation appears much more effective in concept, as it permits a rational assessment of the energy absorption and dissipation mechanisms that can be effectively accomplished to balance the energy imparted to the structure. Various recent studies have demonstrated the advantages of an energy-based seismic design methodology and the important role it would play in future seismic design codes. Although, compared to forces and displacements, energy is a more difficult concept for a designer to rationalize, significant advantages of the energy-based approach are that it explicitly addresses cumulative damage and it takes in to account localized structural damage. A significant amount of research is required to incorporate energy-based methodologies throughout current seismic design codes. For example, to assess the performance of a structure in terms of energy, engineers must have the necessary analysis tools, including models for hazard, response, damage and costs.

This Mini-symposium is focused on the recent research outputs on the studies regarding. energy-based hazard analysis, energy-based engineering demand parameters, energy-based damage measures, and energy-based measures of economic loss. All these studies are necessary for an explicit energy-based formulation of performance criteria for both conventional and innovative structural systems.

Model reduction techniques have been extensively used to improve the computational efficiency in various structural dynamics problems since the 1960s. Recently, they have been employed not only for conventional applications such as free vibration, transient analysis and finite element model updating, but also uncertainty quantifications, multiphysics problems, and design optimization. They can offer theoretical backgrounds of digital twin and virtual sensing in Industry 4.0 revolution. The aim of this mini-symposium is to provide a forum for researchers to discuss recent advances of model reduction techniques for the computational and structural dynamics community. The proposed MS invites researchers to present their research progresses on the following and related topics:

• New reduction and/or component mode synthesis;
• Experimental Dynamic substructuring, virtual sensing; 
• Finite element model updating, system identification; 
• Nonlinear reduced-order modeling, hyper reduction, POD–DEIM model order reduction; 
• ROM for multiphysics and multidisciplinary problems; 
• Model reduction for stochastic model and/or optimization issues;
• Industrial applications of model reduction techniques;
• Other related topics.

Masonry infills are traditionally inserted in reinforced concrete or steel frame structures. During seismic events infills strongly interact with primary structures, significantly modifying strength, stiffness, collapse modes and structural ductility. Research in the field of infilled frames has been carried out for more than 60 years but several issues are still open regarding computational modeling, in-plane / out-of-plane response interaction, seismic performance of new and existing buildings, influence of infills on structural robustness.  

This mini-symposium encourages the submission of papers presenting new findings in the field of computational modeling and experimental testing of in-plane and/or out-of-plane response of infilled frames, and new advances in the assessment of their seismic response or their contribution to structural robustness.

Topics to be covered, but not limited to, are:

• In-plane / out-of-plane interaction;
• Infill/frame local interaction;
• Experimental test results;
• Innovative technologies for masonry infills;
• New proposals for macromodelling of infilled frames;
• Seismic design of infilled frames;
• Results of FEM analyses and analytical studies;
• Analysis and simulation of case studies via nonlinear static or dynamic analysis;
• Analysis of seismic vulnerability;
• Strategies for repairing damaged infills and related computational issues;
• Robustness of infilled frame structures.

Explicit consideration of the main seismic event constitutes the cornerstone of current seismic code provisions. Describing long-term seismicity by a homogenous Poisson process implies that the damaged structure is restored back to its intact state immediately each time an earthquake takes place. Well-established concepts such as fragility and risk (e.g., mean annual rate of exceeding a given performance level) are derived based on the assumption of Poisson occurrence –which is reasonable within the time scale of the service life of a civil infrastructure (e.g., 50 years). In other words, there is usually enough time to repair the damaged structure before it is affected by another strong earthquake. The effects of the triggered aftershock sequence are apparently missing from this context –they are often disguised in the definition of the desired performance levels. Since the reference time frame for a triggered aftershock sequence is small with respect to the time required for carrying out major repair operations on a structure/infrastructure, aftershock seismic risk assessment cannot be arguably tackled based on the same simplifying assumption (i.e., homogenous Poisson) used for long-term seismic risk assessment. The problem is rendered challenging both by the short-term surge in seismicity in the aftermath of a strong earthquake and by the cumulative damages caused by the triggered seismic sequence.

Recent earthquakes have provided evidence for the significant amount of damage caused by the triggered aftershocks. In fact, in the past decade, a lot of research efforts have been carried out with the aim of shedding some light on the specific challenges of aftershock risk assessment. This mini-symposium aims to discuss the state of art and future challenges of aftershock risk assessment.

This mini-symposium session invites contributions dealing with any of the following topics:

• Post-mainshock vulnerability assessment;
• Challenges in the application of nonlinear dynamic analysis procedures for calculating the response to a seismic sequence;
• Quantifying the cumulative damages caused due to the triggered aftershock sequence;
• Quantifying the effect of aftershocks on short- and long-term risk assessment;
• Suggestions for explicit consideration of the aftershocks in the design building codes;
• Tagging criteria and post-event evaluation procedures for buildings and infrastructure (e.g., re-occupancy of buildings and allowing traffic on bridges);
• Loss assessment considering the aftershock sequence;
• Database development for seismic sequences;
• Alternative models for spatio-temporal aftershock clustering;
• Operational aftershock hazard and risk forecasting;

Reinforced concrete buildings are one of the most common structural solutions adopted, over the years, for seismic areas. Strong difference can be otherwise evidenced comparing the structural performance of new constructions, usually designed in agreement with the capacity design rules (EN1998-1:2005) and following specific executive details allowing to achieve the desired ductile mechanism, and traditional existing buildings, built following the typical strong beam/weak column behaviour used in the past. In particular, several problems were highlighted in the case of RC constructions provided by smooth steel reinforcing bars (typical of the period before the 1970s), since the structural performance of such construction appears strongly influenced by bond-slip phenomena; the modelling of the bond-slip behaviour have been deeply studied during the last decades providing several technical and mechanical models that may result often difficult to be applied especially in the case of complex and big constructions. From the 1970s ribbed reinforcements and, in particular, TempCore® steel rebars were introduced in the European scenario becoming progressively the most common typology of reinforcing steel used for buildings. Recent scientific works otherwise evidenced durability problems of TempCore® steel in presence of aggressive environmental conditions (for example in proximity of the coast), with relevant decrease of the mechanical performance (mainly in terms of ductility) and modification of the bond-slip performance. Stating these considerations, it becomes evident that the modelling of structural aspects such as bond-slip phenomena, deterioration due to durability problems and others – opportunely calibrated basing on the results of experimental tests - is fundamental for the understanding of the structural performance of RC constructions, both in the case of modern and existing ones. In the symposium, new approaches for the numerical modelling of RC constructions are presented.

In recent years the seismic assessment of museums’ content, such as collections and/or artifacts, has been collecting the increasing interest of researchers. Important research contributions have been developed regarding the reliability evaluation of single pieces of art, with reference to numerical models to simulate their seismic response, to special devices aimed at their protection and to synthetic classification criteria to help an easy evaluation of their vulnerability. This session is aimed at collecting the recent developments in such research field. Special attention will be paid to the innovative proposals for the seismic safety assessment of the artifacts and to the application of existing protection criteria to real cases. This session aims to attract academics, researchers, students, post-graduate students and professional engineers dealing with the following advanced topics:

- Classification criteria aimed at protecting art collections;
- Simplified modeling of artifacts;
- FEM analysis of artifacts;
- Experimental analysis of artifacts;
- Design of proper devices for the seismic reliability of artifacts;
- Application to real case-studies.

True behaviours of structural systems are dynamic and nonlinear. The conventional approach to analyze these behaviours is discretization in space and analysis in time, while also controlling and localizing the nonlinearities. In view of the everyday growing size of the structures and the more knowledge of the behaviours, the sizes and complexities of the mathematical models increase day by day. From the other side of view, the importance of the financial aspects and optimization of the qualified designs are in everyday increase, and hence the systems need to be analyzed rapidly and with adequate precisions. The details of nonlinear time history analysis in the recent seismic code of New Zealand is an evidence in this regard, which did not exist about a decade ago. Based on these considerations, the fact that time history analysis is the most versatile tool in analysis of nonlinear dynamic behaviours, and more, that some basic questions are yet unanswered, the main objective in this mini-symposium is to promote the efforts on nonlinear dynamic analysis, especially the earthquake-related issues, towards better seismic codes.

The topics of interest include, but are not limited to: Time integration methods, Numerical stability; Elimination of higher erroneous modes; Details of nonlinear time integration; Efficient approaches for time integration; Adaptive time stepping; Rapid methods for time history analysis against several earthquakes records; Wave propagation; Pseudo-dynamic testing, Accuracy of time history analysis; Theoretical and practical errors estimations; Analysis of different nonlinear behaviours; Time history analysis in seismic codes of Japan, China, NewZealand, EUROCODE 8, etc..

I hope that, the attendees will leave the mini-symposium and the conference, with new ideas about nonlinear dynamic analysis and the regulations in the seismic codes, as well as new collaborations and wonderful memories from the surely very friendly environment of Crete.

REFERENCES

1. J.T. Oden and T. Belytschko and I. Babuska and T.J.R. Hughes, “Research directions in computational mechanics”, Comput Method Appl M, 192(7-8), 913-922 (2003).
2. T. Belytschko and W.K. Liu and B. Moran, Non-linear Finite Elements for Continua and Structures, Wiley (2000).
3. Structural design actions part 5: Earthquake actions–New Zealand commentary (Supplement to NZS 1170.5:2004) NZS 1170.5 Supp 1: 2004 (2004).
4. H. Krawkinkler, "Importance of good nonlinear analysis", Struct Des Tall Special Build, 15(5), 481-492 (2007).
5. A. Soroushian and S. Amiri, "A comment on nonlinear time history analysis regulations of seismic code of NewZealand applicable in EUROCODE 8 and many other seismic codes", 16th European Conference on Earthquake Engineering (16ECEE), Thessaloniki, Greece, June 18-21 (2018).

A special session on the Seismic Resilience of Museum contents will be organized under the framework of the 7^th Conference on Computational Methods in Earthquake Engineering to be held in Crete, Greece on 24-26 June 2019.

We invite papers that focus on the recent advances on the seismic protection of artefacts and museum exhibits. The mini-symposium is open to a variety of topics, including (but not restricted): shake table tests, seismic isolation of low mass objects, numerical methods and modelling, loss assessment, among others. The main goal is to present state-of-the-art recent developments on the seismic protection of valuable contents and to offer a multidisciplinary approach on the topic. Of special interest is the study of novel seismic hazard mitigation measures and techniques. The symposium wishes to attract researchers active in this area and also to become a forum for information exchange and debate for both researchers, practicing engineers and stakeholders.

As you are an active researcher in this field it is our great pleasure to invite you or one of your co-workers to contribute within this subject area to the 7^th COMPDYN conference. Should you be able to accept this invitation, we would be grateful if you could submit an abstract of no more than one A4 page through the conference web page.

We are looking forward to meeting you in Crete.

Contributions to this minisymposium are invited to discuss recent developments in two fundamental aspects of seismic input definition for the design or assessment of engineering structures: seismic hazard assessment and the selection or generation of input motions for dynamic analysis.

While probabilistic seismic hazard assessment in its classical form is consolidated enough, there is continuous drive for advances, mainly regarding the possibility to account for clusters of seismic events (foreshocks, mainshock and aftershocks), triggered and induced seismicity, near source effects, spatial correlation, etc. All of these topics can benefit from improvements and innovation in methodologies, empirical and semi-empirical models, and computational tools.

On the other hand, the assessment of nonlinear structural seismic behavior requires dynamic analyses that typically involve ground motion time-histories consistent with the seismic hazard of the site. Methods and numerical models for the selection of natural ground motion records, the simulation of artificial signals and hybrid procedures that artificially modify recorded motions, introducing peculiar characteristics, are still under development and represent topical issues in earthquake engineering.

This MS aims at bringing together a multidisciplinary team of academic and industrial researchers working on novel efficient damage modelling, detection and identification methodologies. Global industrial and academic stakeholders have long recognized the need for the development of robust platforms able to i) detect damage, preferably during operation of a structural product, ii) identify the type and size of the detected damage and quantify its criticality through estimating the remaining operational time of the structure. Focal point of these objectives is the accurate representation of damaged segments via data and/ or physics driven approaches.

This mini-symposium will form a platform for ideas exchange and knowledge dissemination concerning the latest developments in the field of multiscale damage representation, composite damage - wave interaction, as well as data driven identification and maintenance technologies for composite materials. Topics relevant to the Minisymposium include, but are not limited to, implementations and algorithmic solutions for:

- Wave interaction with damage modelling

- Damage detection methods for industrial composites

- Damage identification methods

- Bayesian and AI identification methods

- Multiscale finite element methods

- eXtended finite element and phase field methods

Contributions pertaining to the implementation of such methods on real-life applications are especially welcomed.

Through recent advances in earthquake engineering, it is now possible to design buildings and structures to withstand almost any earthquake motion. Unfortunately, much of the existing infrastructure is vulnerable to strong earthquakes as it is typically designed to old obsolete code provisions or built without any code provisions at all.  Therefore, there is an urgent need in high seismic risk areas to strengthen the built infrastructure. To this end, an assessment of the vulnerability of existing buildings is a crucial part, while the effectiveness of any strengthening carried out should be confirmed through an assessment taking due account of the fact that strengthening has been applied.

The aim of this symposium is to discuss recent advancements in seismic assessment of buildings, with emphasis on seismic strengthening techniques. Contributions to this minisymposium are expected to cover displacement and deformation based analysis methods, comparisons and critical discussion of different national and international code requirements, and models to determine the structural capacity before and after strengthening.

It is aimed that the Symposium will constitute a forum for the exchange of research results and ideas on currently available procedures and their applicability to the seismic assessment of buildings, and provide guidance to engineers faced with the task of building a safer future for the public.

Numerical and analytical models constitute fundamental tools for engineers and researchers to design new structures, to retrofit existing ones or to increase knowledge of specific problems. In the field of soil-structure interaction, advances in the research are nowadays often achieved through new analytical models or by exploiting available numerical approaches. Therefore, the importance of confidence in models adopted for the aforementioned purposes is undisputed. Confidence and reliability of numerical and analytical models can be achieved by means of benchmarks available in the literature or, better, through comparisons with full scale or small scale tests as well as monitored case studies.

The Mini-Symposium “Full and Small scale dynamic tests to increase confidence in numerical and analytical models for SSI analysis” offers the opportunity to present and discuss several aspects relevant to the confidence of numerical and analytical models for the seismic soil-structure interaction analysis of (i) geotechnical systems (e.g. foundations, retaining walls for both port and transport infrastructures, tunnels) and (ii) critical structures (e.g. bridges, tall buildings, wind turbines).

This Mini-Symposium welcomes academic staff, researchers and professional engineers dealing with topics including: the development and/or the validation of analytical models to address the soil-structure interaction problem, through available benchmarks or experimental data; numerical modelling strategies (e.g. finite element, boundary element, macroelement) with relevant convergence and/or validation analyses; experimental results of dynamic full scale and small scale tests, which can be adopted to increase confidence of available numerical or analytical models; proposal of new experimental approaches or new post-processing techniques of experimental data.

Damping and isolation bearings are often employed to control and enhance the seismic performance of structural systems. These devices are conventionally designed to achieve target performances under prescribed earthquake intensities. However, their reliability under extreme events has not been adequately investigated in the literature, due to lack of accurate models for describing the behavior under large deformations and the need of advanced probabilistic techniques to assess the risk up to low probabilities of collapse. 
Moreover, the reliability of isolation and dissipation systems may be significantly affected by manufacturing tolerances, and structures equipped with devices whose properties deviate from the nominal ones may exhibit a performance very different than expected. These issues are object of increasing research interest worldwide, and this session aims to gather the experiences and perspectives of researchers and professional engineers working in this field. Thus, contributions addressing experimental, computational, and methodological developments are expected in the following areas: 

• Experimental testing and numerical modelling of the behavior of isolation/dissipation devices; 
• Performance-based assessment and reliability-based design of structures equipped with isolation/dissipation devices; 
• Techniques for uncertainty modelling and propagation (both aleatoric and epistemic ones); 
• Applications and case studies of isolation/dissipation devices; 
• Innovative techniques for seismic isolation or energy dissipation. 

Dynamics of periodic structures is a research subject being actively explored in modern literature. The goal of this mini-symposium is to provide a forum for researchers in this field to discuss recent advances and challenges in modelling and analysis of performance of periodic structures. Topics to be covered by this mini-symposium include, but are not limited to:

• Wave finite element method and its spin-offs
• Stationary dynamics of multi-modal periodic waveguides
• Transients in periodic structures
• Free and forced vibrations of finite periodic structures
• Effects of spatial versus temporal periodicity
• Nonlinear effects in periodic systems
• Experimental dynamics of periodic systems
• Applications of periodic structures

The scope of the mini-Symposium includes the various strength, vibration and stability problems in thin beams, plates and shells. Analytical, numerical and experimental results for both isotropic and anisotropic thin-walled structures may be presented and both classical and non-classical beam, plate and shell models may be discussed. 

Bridges are the most vulnerable components of transport systems. European Highway Networks are subjected to ageing, often worsened by poor maintenance, thus there is the need to employ construction methods and new techniques to improve their durability. Moreover, a large number of these bridges were designed without considering seismic actions, so they need to be assessed and retrofitted using up-to-date techniques. Recently, progress has been made in the investigation of bridges, focusing on specific problems and bringing to a number of innovative methods in the design, assessment and retrofit. One of the novelties that is becoming popular across Europe is the Integral Abutment Bridge (IAB) typology, a bridge without bearings and expansion joints, which has many advantages with respect to the conventional ones, especially in terms of durability. From a dynamic point-of-view their behavior is different and in some cases it is advantageous if some drawbacks are appropriately tackled. A number of numerical and experimental studies are ongoing and investigate the behavior of IABs.

This Minisymposium aims at discussing new methods and techniques to improve the durability of infrastructure and, in particular, bridges, welcoming studies on durability and reinforcements corrosion , strengthening of bridge elements with innovative techniques, advances in linear and nonlinear analysis methods, performance-based design, novel experimental campaigns on bridges (field and laboratory), hybrid and pseudo-dynamic testing, retrofitting strategies, investigations and innovative approaches for the study of integral abutment bridges including soil-structure interaction both for static and dynamic loads, seismic isolation techniques for bridges. In addition to Bridge Engineering contributions, we are also welcoming work on geotechnical earthquake engineering and engineering seismology applied to bridges specifically focused on seismic input selection. Presentations will include, among others, recent work carried out on this topic by members of the EAEE Working Group 11 ‘Seismic design, assessment, and retrofit of Bridges.

Many people in seismic prone Mediterranean areas, such as Italy, South Portugal, Greece, etc., live in old historic centres made of low rise buildings that are made of three–leaf masonry walls. Enhancing the seismic safety of these centres is a theme of paramount importance for public safety and for increasing tourist attraction, given the high seismic vulnerability of three-leaf masonry structures combined with a relatively high seismic hazard. 

Three-leaf masonry walls are made of two external relatively slender stone leaves, typically un-connected through the wall thickness, and an inner core made of loose aggregates kept together by poor quality lime mortar. This type of masonry is affected by significant fragilities under earthquake actions, due to its intrinsic attitude to experience delamination phenomena under out–of–plane forces that produce overturning of the outer slender leaves. Moreover, the intrinsic vulnerability of the inner core of this type of masonry leads to a weak in–plane behaviour. For low, mainly elastic, states of stress, compression forces act on the internal core that tends to expand pushing the outer leaves in the out-of-plane direction. For higher stress levels, if the above delamination does not take place and/or is prevented, the internal core fails and the limited amount of load that was carried by the inner core is transferred to the stiffer external leaves that can undergo in–plane failure mechanisms. In order to investigate the seismic behavior of three-leaf masonry walls, an experimental activity has been undertaken within the SERA-H2020 European Project. This activity will culminate in February 2019 with shake table tests on half scale specimens that will be carried out at the EQUALS laboratory of the University of Bristol. As a preliminary activity, a blind-test numerical contest has been organized, in order to predict the experimental response through the application of different modelling/analysis techniques. Participants to the contest will be given data on the test setup, the geometrical features of the specimens, the mechanical features of the masonry obtained through preliminary tests carried out at the University of Chieti-Pescara, the records that will be used during the shake table tests. 

The Minisymposium will provide an opportunity to present and compare the results of different modeling techniques and assumptions and to discuss about how they affect the prediction of the structural behavior of three-leaf masonry walls. 

Currently there is a general interest towards the design of more flexible structures, with the aim of finding a trade-off between innovative engineering solutions and cost savings. The nature of such flexible structures makes them more vulnerable towards dynamic operational and environmental loads. Virtual models of complex engineering structures are widely used from the preliminary design stages to the operating structural life-time assessment.  However, one of the key challenges in developing reliable models of such systems consists in characterizing the dynamic behaviour of mechanical joints.

With the aim of discussing new advances in this field, this MS invites contributions on fundamental work, advanced techniques and industrial applications showcasing recent progress in modelling and experiments of joints and jointed structures under dynamic conditions. The session will focus on, but is not limited to, the following topics:

- Experimental techniques to characterize the dynamic behaviour of structural joints;
- Advanced modelling and model reduction schemes of jointed structures;
- Validation of joint models;
- Damping and friction mechanisms in mechanical joints;
- Vibration-based damage identification of jointed structures;
- New technologies in mechanical joints.

Masonry structures, as repeatedly noted after significant seismic events, present significant vulnerability to seismic loads. A variety of computational methods and many alternate simulation methods are currently available to evaluate their seismic behaviour. Despite the fact that new retrofit methods have been developed, the difficulty of complying with high seismic risk requirements is still a challenge. The mini-symposium intends to cover several aspects regarding the assessment of seismic response of masonry structures with experimental and numerical methods, including advances in: Condition assessment; Surveying; Detection of damage; Measurement of mechanical properties; Computational, analytical and experimental methods; Failure criteria; Monitoring; Assessment of the impact of geotechnical parameters; Regional seismicity issues; Intervention techniques; Compatibility of intervention materials; Rehabilitation of monuments and historic structures.