68 research outputs found

    Disaster Resilience Assessment of Building and Transportation System

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    The paper presents a new methodology to assist decision-makers in the management of critical events such as earthquakes evaluating the recovery time, and the resilience index of a building system that is a component of the physical infrastructure dimension of the PEOPLES Resilience framework. The interdependencies between building system and transportation network in term of accessibility are modeled. Finally, the methodology has been implemented in a software and has been applied in two case studies: (a) the old medieval center of L’Aquila town and (b) the Treasure Island in the San Francisco Bay area

    The Dynamic Behavior of the Basilica of San Francesco in Assisi Using Simplified Analytical Models

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    The Basilica of San Francesco in Assisi endured stronger earthquakes for centuries before 1997 earthquake, which generated the collapse of the two vaults. Experts blame as possible reasons of collapse the damage cumulated from previous earthquakes and/or the retrofitting made to the structure over its lifetime. This article presents the history of the retrofit interventions of the Basilica through the centuries, focusing mainly on the roof, which has been subjected to three major restorations through its life. It is shown using simple analytical models that the cumulative effects of the changes made to the roof of the Basilica affected the structure's dynamic behavior in a negative manner, increasing the seismic loads on the existing structural members. In particular, the numerical results show that the 1958 roof intervention has stiffened the structure, redistributing the seismic loads on the facade and the transept. This overload might explain the collapse of the two Gothic vaults during 1997 earthquake

    Vulnerability Assessment of a Civic Tower Using Ambient Vibration Tests

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    This paper focuses on the vulnerability assessment of a civic tower built in 1512, which is now considered a national monument. It is the original bell tower of S. Ambrogio church that was destroyed in 1809. Experimental investigations have been carried out on this historical tower. First, detailed investigations have been carried out to identify the geometry of the tower as well as the mechanical features of the constituting materials. Then, ambient vibration tests have been applied using five Micro Electro-Mechanical Systems (MEMS) sensors to detect of the main dynamic features, e.g., modal parameters and damping. Two output-only identification methods, including Frequency Domain Decomposition and Random Decrement Techniques, have been used. The outcomes of the modal identification have been employed to inform the FE model. The numerical analysis can be used for vulnerability assessment, providing a valuable picture of possible damage evolution, tower collapse mechanism, and subsequently, useful hints for the execution of structural retrofitting strategies

    Community resilience assessment integrating network interdependencies

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    The concept of Disaster Resilience has received considerable attention in recent years and it is increasingly used as an approach for measuring response of communities to natural disasters. Recently a framework named PEOPLES has been developed by MCEER to measure performance of communities to natural disasters. The method includes seven dimensions that include both technical and socio-economic aspects. All resilience dimensions and their respective indices to measure community performances are obviously interdependent. As first step, the physical dimension has been implemented in software and indices have been proposed to measure performance of buildings and lifelines. This paper tries to focus on developing methodologies to consider interdependencies between buildings (e.g. hospitals, strategic buildings, etc) and lifelines (road networks, etc.). An approach considering network interdependencies have been developed which is based on the time series analysis of the restoration curves of the different infrastructures. The case study of 2011 Tohoku Earthquake has been presented to illustrate the implementations issue

    Fire Emergency Evacuation from a School Building Using an Evolutionary Virtual Reality Platform

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    In the last few years, modern technologies such as numerical simulations, virtual and augmented reality, and agent-based models represented effective tools to study phenomena, which may not be experimentally reproduced due to costs, inherent hazards, or other constraints (e.g., fire or earthquake emergencies and evacuation from buildings). This paper shows how to integrate a virtual reality platform with numerical simulation tools to reproduce an evolutionary fire emergency scenario. It is computed in real time based on the building information model and a fluid dynamic software. A specific software was also used to simulate in real time the crowd dynamic in the virtual environment during the emergency evacuation process. To demonstrate the applicability of the proposed methodology, the emergency fire evacuation process for an existing school building is presented. The results show that the proposed virtual reality-based system can be employed for reproducing fire emergency scenarios. It can be used to help decision-makers to determine emergency plans and to help firefighters as a training tool to simulate emergency evacuation actions

    Reliability and resilience of wastewater networks

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    The wastewater network is a critical infrastructure in a community and damages or disruption due to a hazard event implicate consequences in the economic security, public health and wellness of the community. Therefore, using an index to evaluate the vulnerability and the functionality of the system is essential for designers and utility managers for the design, operation and protection of wastewater network. In this paper, a functionality index for the wastewater network has been proposed that is the product of three different indices: (i) the number of users still connected to the system, (ii) the quality of sewer discharge into the water body after the treatment, in term of two pollutants, biochemical oxygen demand and total suspended solids, and (iii) the presence of leaks into the network. Seaside, a small city in Oregon, in the West cost of USA has been selected as case of study using an earthquake scenario and a restoration plan. The results show the critical elements of the networks that under the observed operating conditions would not be able to present reliable performances. Using the proposed indices in a decision support tool for governmental agencies could give guidelines for the restoration of elements that have more weight in the functionality of the system

    Resilience of critical structures, infrastructure, and communities

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    In recent years, the concept of resilience has been introduced to the field of engineering as it relates to disaster mitigation and management. However, the built environment is only one element that supports community functionality. Maintaining community functionality during and after a disaster, defined as resilience, is influenced by multiple components. This report summarizes the research activities of the first two years of an ongoing collaboration between the Politecnico di Torino and the University of California, Berkeley, in the field of disaster resilience. Chapter 1 focuses on the economic dimension of disaster resilience with an application to the San Francisco Bay Area; Chapter 2 analyzes the option of using base-isolation systems to improve the resilience of hospitals and school buildings; Chapter 3 investigates the possibility to adopt discrete event simulation models and a meta-model to measure the resilience of the emergency department of a hospital; Chapter 4 applies the meta-model developed in Chapter 3 to the hospital network in the San Francisco Bay Area, showing the potential of the model for design purposes Chapter 5 uses a questionnaire combined with factorial analysis to evaluate the resilience of a hospital; Chapter 6 applies the concept of agent-based models to analyze the performance of socio-technical networks during an emergency. Two applications are shown: a museum and a train station; Chapter 7 defines restoration fragility functions as tools to measure uncertainties in the restoration process; and Chapter 8 focuses on modeling infrastructure interdependencies using temporal networks at different spatial scales

    Seismic Damage Assessment of a Virtual Large Scale City Model

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    Recent social developments and economic transformation have changed the engineering design approach from building design level towards community design level (city, region, country). The latter approach involves modeling of interconnections between different systems (buildings, transportation, water network, etc.) rather than designing the buildings individually. Thus, new analysis tools are expected to be developed to simulate the complex response of a community subsequently to disasters. The need of such rational tools is the object of this research work. Two different numerical approaches to simulate the response of a large-scale built envi-ronment after a seismic scenario are explored by developing multipurpose numerical codes. A district of a vir-tual city is considered as a case study and the level of damage for built environment is estimated. This work could be the first step for further urban loss analysis, e.g. through agent-based models that could be updated online with the proposed simulation

    Sul setto retto-vaginale: lesioni traumatiche ed eventi patologici

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    Gli Autori, dopo la descrizione della struttura anatomica e istologica del setto retto-vaginale e della sua importanza per il mantenimento della statica dei visceri pelvici (retto e vagina), riassumono le lesioni che possono verificarsi durante il parto per via vaginale ed evidenziano la necessità di una tempestiva riparazione chirurgica di queste lesioni, che a volte può richiedere l’ausilio di trapianti allogenici. Inoltre, per quanto riguarda i noduli endometriosici e i processi neoplastici a carico del setto retto-vaginale, che di solito vengono diagnosticati tardivamente, si richiama l’attenzione sull’impiego della endosonografia ano-rettale (ARES) e della risonanza magnetica a scopo diagnostico e per la valutazione degli esiti degli interventi chirurgici di ricostruzione o di demolizione. Queste due procedure sono raccomandate specialmente per i noduli endometriosici e per le neoplasie del setto rettovaginale, che di solito sfuggono ad una diagnosi precoc
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