A numerical solution for addressing the overturning phenomena of heritage assets

Historical heritage represent a crucial aspect for societies and therefore it should be preserved from natural disasters such as earthquake. Base isolation systems are widely used to mitigate the horizontal effects of strong ground motions on important buildings and bridges, but there are also interesting applications on statues. However, such systems are characterized by properties that are quite different from the ones that belong to traditional civil structures. For this reason, national and international regulations are not exhaustive and actual dynamics of the system should be studied through numerical and experimental methods. Starting from analytical formulations, the paper investigates the sliding and rocking motion in details, being the typical one of statues under seismic loads. The presented numerical model describes the problem and is an alternative to the analytical formulation to perform several analyses automatically. In addition, it allows running parametric analyses to assess the influence of various parameters, such as eccentricity, stiffness, mass, geometric ratios, etc. Future work is geared to validate the numerical model trough performing experimental tests on shaking table

Resilience Assessment of Urban Communities

The multiple uncertainties of both natural and man-made disasters have prompted increased attention in the topic of resilience engineering. In this paper, an indicator-based method for measuring urban community resilience is proposed. The method is based on the PEOPLES framework, which is a hierarchical framework for defining disaster resilience of communities at various scales. It consists of seven dimensions summarized with the acronym PEOPLES: Population; Environment; Organized governmental services; Physical infrastructures; Lifestyle; Economic; and Social capital. Each of the dimensions is split into several components and indicators, which have been derived by the authors or collected from a wide range of literature. Each indicator is represented using a performance function, which portrays the functionality of the indicator in time. Higher functionality of the indicator leads to higher resilience of the community. These functions can be constructed in a systematic manner using damage and restoration parameters. The aggregation of the performance functions, passing through the different hierarchical levels of PEOPLES framework, leads to one function that represents the dynamic performance of the analysed community. This paper also introduces a matrix-based interdependency technique that serves as a weighting scheme for the different indicators. As a case study, the proposed methodology is applied to the city of San Francisco for which a resilience curve and a resilience metric have been computed

Deterministic and fuzzy-based methods to evaluate community resilience

Community resilience is becoming a growing concern for authorities and decision makers. This paper introduces two indicator-based methods to evaluate the resilience of communities based on the PEOPLES framework. PEOPLES is a multi-layered framework that defines community resilience using seven dimensions. Each of the dimensions is described through a set of resilience indicators collected from literature and they are linked to a measure allowing the analytical computation of the indicator’s performance. The first method proposed in this paper requires data on previous disasters as an input and returns as output a performance function for each indicator and a performance function for the whole community. The second method exploits a knowledge-based fuzzy modeling for its implementation. This method allows a quantitative evaluation of the PEOPLES indicators using descriptive knowledge rather than deterministic data including the uncertainty involved in the analysis. The output of the fuzzy-based method is a resilience index for each indicator as well as a resilience index for the community. The paper also introduces an open source online tool in which the first method is implemented. A case study illustrating the application of the first method and the usage of the tool is also provided in the paper

Integrated platform to assess seismic resilience at the community level

Due to the increasing frequency of disastrous events, the challenge of creating large-scale simulation models has become of major significance. Indeed, several simulation strategies and methodologies have been recently developed to explore the response of communities to natural disasters. Such models can support decision-makers during emergency operations allowing to create a global view of the emergency identifying consequences. An integrated platform that implements a community hybrid model with real-time simulation capabilities is presented in this paper. The platform's goal is to assess seismic resilience and vulnerability of critical infrastructures (e.g., built environment, power grid, socio-technical network) at the urban level, taking into account their interdependencies. Finally, different seismic scenarios have been applied to a large-scale virtual city model. The platform proved to be effective to analyze the emergency and could be used to implement countermeasures that improve community response and overall resilience

Resilience of critical structures, infrastructure, and communities

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

A new tool to assess the resilience of an urban environment under an earthquake scenario

This paper presents a new methodology to predict the potential damage and physical impacts of an earthquake on the built environment. A new methodology to the urbanized systems and large-scale simulations within a seismic scenario are explored, by evaluating multipurpose codes for numerical simulation. A 3-D building shape of a standard virtual city is developed for evaluating the seismic effects at increasing intensities. Once the buildings are integrated into the city, parallel simulations are applied to compute the global behavior of buildings after a disruptive scenario. Monte Carlo Simulations (MCS) are applied to take into account the epistemic uncertainties associated with geometry and mechanical properties within the range of observations. For each set of buildings’ data, the nonlinear dynamic analysis is performed through SAP2000 Application Programming Interface (API) in order to assess the dynamic response of the buildings in an organized and automatic fashion. Accordingly, the city is mapped into different zones representative to the possibility of having different levels of damage (complete, extensive, moderate, and slight). This tool supports decision-makers to explore how their community will respond to a disruptive event, to develop different strategies for monitoring and control the emergency in urbanized areas

Smart cities to improve resilience of communities

This paper presents a new approach to predict the potential damage and physical impacts of an earthquake on the built environment. A new methodology to the urbanized systems and large-scale simulations within a seismic scenario is explored, by evaluating multipurpose codes for numerical simulation. A 3-D building shape of a standard virtual city is developed for evaluat-ing the seismic effects at increasing intensities. Four different building sectors that provide essential functions to a community, including housing, education, business, and public ser-vices are considered. Once the buildings are integrated into the city, parallel simulations are applied to compute the system functionality following a disruptive scenario. Tri-linear elasto-plastic backbone curve representative of global shear behavior of each building is estimated considering the dominant modal shapes and building irregularities. Monte Carlo Simulations (MCS) are applied to take into account the epistemic uncertainties associated with geometry and mechanical properties within the range of observations. For each set of buildings’ data, the nonlinear dynamic analysis is performed through SAP2000 Application Programming In-terface (API) in order to assess the dynamic response of the buildings in an organized and au-tomatic fashion. Accordingly, the city is mapped into different zones representative to the possibility of having different levels of damage (complete, extensive, moderate, and slight). This methodology supports decision-makers to explore how their community will respond to a disruptive event, to develop different strategies for monitoring and control the emergency in urbanized areas, and to plan better resilience-building and evacuation strategies

Seismic Damage Assessment of a Virtual Large Scale City Model

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

Egg yolk cholesterol, egg quality, and performance in response to copper–methionine chelates and alfalfa powder supplementation in Nick chick laying hen diets

This experiment was designed to investigate the effects of different levels of copper–methionine chelates and alfalfa powder on egg yolk cholesterol content, egg quality, and performance in laying hens. In this experiment, a total of 100 laying hens (Nick Chick strain, from 109 to 117 weeks of age) were arranged into five experimental treatments, consisting of 2 different dietary alfalfa powder and 2 different copper chelate levels in a (2x2) factorial completely randomized design (CRD). The treat-ments groups included: T1 Control (Corn and soybean meal), treatments T2 (3% alfalfa powder+50 mg/kg copper-methionine chelate), T3 (3% alfalfa powder+100 mg/kg copper-methionine chelate), T4 (6% alfalfa powder+50 mg/kg copper-methionine chelate) and T5 (6% alfalfa powder+100 mg/kg cop-per-methionine chelate). The results of this study have shown that, different levels of alfalfa powder and copper-methionine chelate in laying hens diet except feed conversion ratio and shell-less eggs, oth-er performance parameters were not substantially affected by the level of 3% alfalfa powder through-out of experimental period (P>0.05). Moreover, different levels of alfalfa powder and copper-methionine chelate except egg yolk color had no significant effect on internal and external egg quality traits during the whole experimental period (P>0.05). As well as, the egg yolk color index was signifi-cantly increased by increasing the level of alfalfa powder in the laying hens’ diet (P<0.001). The high-est egg yolk color index was observed in treatment 5 which (containing 6% alfalfa powder+ 100 mg / kg copper-methionine chelate in per kg of diet). Meanwhile, the treatment group that received (6% al-falfa powder+100mg/kg copper- methionine chelate) the egg yolk cholesterol concentration was signif-icantly decreased compared to the control group (P<0.001). Therefore, addition of alfalfa powder and copper methionine chelate to the diet of laying hens reduced egg yolk cholesterol and increased egg yolk color