"Last-Mile" preparation for a potential disaster

Extreme natural events, like e.g. tsunamis or earthquakes, regularly lead to catastrophes with dramatic consequences. In recent years natural disasters caused hundreds of thousands of deaths, destruction of infrastructure, disruption of economic activity and loss of billions of dollars worth of property and thus revealed considerable deficits hindering their effective management: Needs for stakeholders, decision-makers as well as for persons concerned include systematic risk identification and evaluation, a way to assess countermeasures, awareness raising and decision support systems to be employed before, during and after crisis situations. The overall goal of this study focuses on interdisciplinary integration of various scientific disciplines to contribute to a tsunami early warning information system. In comparison to most studies our focus is on high-end geometric and thematic analysis to meet the requirements of small-scale, heterogeneous and complex coastal urban systems. Data, methods and results from engineering, remote sensing and social sciences are interlinked and provide comprehensive information for disaster risk assessment, management and reduction. In detail, we combine inundation modeling, urban morphology analysis, population assessment, socio-economic analysis of the population and evacuation modeling. The interdisciplinary results eventually lead to recommendations for mitigation strategies in the fields of spatial planning or coping capacity

Improved dynamical particle swarm optimization method for structural dynamics

A methodology to the multiobjective structural design of buildings based on an improved particle swarm optimization algorithm is presented, which has proved to be very efficient and robust in nonlinear problems and when the optimization objectives are in conflict. In particular, the behaviour of the particle swarm optimization (PSO) classical algorithm is improved by dynamically adding autoadaptive mechanisms that enhance the exploration/exploitation trade-off and diversity of the proposed algorithm, avoiding getting trapped in local minima. A novel integrated optimization system was developed, called DI-PSO, to solve this problem which is able to control and even improve the structural behaviour under seismic excitations. In order to demonstrate the effectiveness of the proposed approach, the methodology is tested against some benchmark problems. Then a 3-story-building model is optimized under different objective cases, concluding that the improved multiobjective optimization methodology using DI-PSO is more efficient as compared with those designs obtained using single optimization.Peer ReviewedPostprint (published version

Development of a Multi Modular platform for seismic engineering courses and research

Small-scale shaking tables are usually employed in seismic engineering for studying structural models' dynamic behavior and for investigating innovative solutions, as active and passive structural control systems. In an increasingly complex and dynamic world, the ability of responding community natural disasters, such as those induced by earthquakes, is also becoming a pressing issue. With the aim of supporting the research in the field of resilience and emergency management, with particular reference to earthquakes, this paper has the main goal of illustrate the development of a multi modular platform to be used by students during dynamic and seismic courses. Indeed, another peculiarity of this platform, with respect to literature, is that the system has been entirely developed by undergraduate students at the Politecnico di Torino, for both the unidirectional and bidirectional applications. Virtual reality is also an additional tool that can enrich the possible applications of the proposed shaking table in the seismic engineering research field. Indoor and outdoor virtual environments have been developed for reproducing the emergency conditions, where the human response to earthquake shaking can be explored by employing both ground shaking and floor response records as well. The project under consideration is rooted in the perspective of realizing a vibrating table capable of simulating the earthquake and, through instrumentation, measuring the stress characteristics and deformation. Specifically, it is an instrument designed to replicate a seismic event seismic on structural model of a reduced scale, such as a building, a bridge, or, at a larger scale, a portion, e.g. a district, of an urban area. With the prototype of a shaking table herein proposed it is possible to reproduce a seismic event on a model of structure and to execute hybrid simulations. The university experience of students in understanding the intricacies of real structural systems results consequently improved by visualizing their complex behavior when subjected to earthquake loading

Quantification of potential macroseismic effects of the induced seismicity that might result from hydraulic fracturing for shale gas exploitation in the UK

The furore that has arisen in the UK over induced microseismicity from ‘fracking’ for shale gas development, which has resulted in ground vibrations strong enough to be felt, requires the urgent development of an appropriate regulatory framework. We suggest that the existing regulatory limits applicable to quarry blasting (i.e. peak ground velocities (PGV) in the seismic wavefield incident on any residential property of 10 mm s<sup>−1</sup> during the working day, 2 mm s<sup>−1</sup> at night, and 4.5 mm s<sup>−1</sup>1 at other times) can be readily applied to cover such induced seismicity. Levels of vibration of this order do not constitute a hazard: they are similar in magnitude to the ‘nuisance’ vibrations that may be caused by activities such as walking on wooden floors, or by large vehicles passing on a road outside a building. Using a simple technique based on analysis of the spectra of seismic S-waves, we show that this proposed daytime regulatory limit for PGV is likely to be satisfied directly above the source of a magnitude 3 induced earthquake at a depth of 2.5 km, and illustrate how the proposed limits scale in terms of magnitudes of induced earthquakes at other distances. Previous experience indicates that the length of the fracture networks that are produced by ‘fracking’ cannot exceed 600 m; the development of a fracture network of this size in one single rupture would correspond to an induced earthquake c. magnitude 3.6. Events of that magnitude would result in PGV above our proposed regulatory limit and might be sufficient to cause minor damage to property, such as cracked plaster; we propose that any such rare occurrences could readily be covered by a system of compensation similar to that used over many decades for damage caused by coal mining. However, it is highly unlikely that future ‘fracking’ in the UK would cause even this minor damage, because the amount of ‘force’ applied in ‘fracking’ tends to be strictly limited by operators: this is because there is an inherent disincentive to fracture sterile overburden, especially where this may contain groundwater that could flood-out the underlying gas-producing zones just developed. For the same reason, seismic monitoring of ‘fracking’ is routine; the data that it generates could be used directly to police compliance with any regulatory framework. Although inspired by UK conditions and debates, our proposals might also be useful for other regulatory jurisdictions

Optimal configuration of active and backup servers for augmented reality cooperative games

Interactive applications as online games and mobile devices have become more and more popular in recent years. From their combination, new and interesting cooperative services could be generated. For instance, gamers endowed with Augmented Reality (AR) visors connected as wireless nodes in an ad-hoc network, can interact with each other while immersed in the game. To enable this vision, we discuss here a hybrid architecture enabling game play in ad-hoc mode instead of the traditional client-server setting. In our architecture, one of the player nodes also acts as the server of the game, whereas other backup server nodes are ready to become active servers in case of disconnection of the network i.e. due to low energy level of the currently active server. This allows to have a longer gaming session before incurring in disconnections or energy exhaustion. In this context, the server election strategy with the aim of maximizing network lifetime is not so straightforward. To this end, we have hence analyzed this issue through a Mixed Integer Linear Programming (MILP) model and both numerical and simulation-based analysis shows that the backup servers solution fulfills its design objective

Present and future resilience research driven by science and technology

Community resilience against major disasters is a multidisciplinary research field that garners an ever-increasing interest worldwide. This paper provides summaries of the discussions held on the subject matter and the research outcomes presented during the Second Resilience Workshop in Nanjing and Shanghai. It, thus, offers a community view of present work and future research directions identified by the workshop participants who hail from Asia – including China, Japan and Korea; Europe and the Americas

Analytical Content Vulnerability Assessment Methodology for Earthquake Catastrophe Models

The scarcity of detailed claims data for building contents (Coverage C) from historical earthquake events poses a significant challenge for property insurance catastrophe models to reliably estimate the losses associated to building contents. To develop content vulnerability functions empirically, one would need to have access to data from a multitude of historical events; however, loss disaggregation by coverage is rarely reported even when claims data become available from recent significant events such as Maule (2010) and Tohoku (2011). While damage to the building structure (Coverage A) can be estimated analytically using simulation-based fragility functions to amend sparse historical observations, the adoption of analytical approaches for other coverages is limited in the current generation of catastrophe models. In the absence of analytical methods, content loss estimation often relies on a combination of expert opinion and abstract reasoning on top of precious-little available data which is often limited to residential properties. In this paper, the authors employ FEMA P-58’s component-based methodology to develop a framework for simulation-based derivation of content vulnerability functions. Following a review of published literature and the types of content components in FEMA P-58’s PACT library, the authors present the simulation-driven vulnerability function for a four-story office building in Los Angeles, and compare the results against respective functions for office buildings from commercial models. Moreover, this paper discusses the need for new content component types in offices and professional service occupancy. Through this study, the authors demonstrate the possibility of improving content loss estimates in catastrophe models by adopting approaches similar to those involved in the development of structural vulnerability functions