scholarly journals DEVELOPMENT OF FRAGILITY CURVES FOR REINFORCED DUNES

2018 ◽  
pp. 10
Author(s):  
Brian Maggi ◽  
Christopher Baxter ◽  
Aaron Bradshaw ◽  
Annette Grilli ◽  
Stephen Licht ◽  
...  
Keyword(s):  
Numerical Models ◽  
Fragility Curves ◽  
Field Studies ◽  
Coastal Protection ◽  
Dune System ◽  
Community Stakeholders ◽  
Protection Systems ◽  
Damage States ◽  
Hydraulic Stability

The objective of this paper is to present the results of on-going field studies to assess the performance of geotextile sand-filled container (GSC) reinforced dunes and to develop probabilistic fragility curves for a range of damage states to these structures. While numerous lab experiments and numerical models have been developed to predict the hydraulic stability of coastal revetments made of GSCs, there has been limited in situ validation of these systems, especially when they are used to reinforce the core of a natural system (Dassanayake and Oumeraci, 2012). Furthermore, the formulas and nomograms developed to characterize GSC systems are not intuitive for coastal community stakeholders to assess the level of resiliency provided by a beach and GSC dune system. The development of fragility curves offers a solution to assess the performance and understand the tradeoffs of reinforced dunes for coastal protection systems.

Modelling moisture conditions behind brick veneer cladding: Verification of common approaches by field measurements

2020 ◽  
Vol 44 (2) ◽  
pp. 95-120 ◽  
Author(s):  
Michiel Vanpachtenbeke ◽  
Jelle Langmans ◽  
Jan Van den Bulcke ◽  
Joris Van Acker ◽  
Staf Roels
Keyword(s):  
Numerical Models ◽  
Field Measurements ◽  
Field Studies ◽  
Ventilation Rate ◽  
Two Dimensional ◽  
Building Enclosure ◽  
Air Change Rate ◽  
Brick Veneer ◽  
Moisture Conditions

Cavity walls consisting of an outer leaf, a cavity and an inner leaf are a widespread building enclosure configuration because of their good performance regarding rain tightness. To increase the drying potential, open head joints are typically provided in the brick outer leaf, creating cavity ventilation. Even though this cavity ventilation has a limited effect on the drying out of the brick veneer, it can significantly reduce the moisture levels inside the cavity. This might be crucial when the brick veneer is combined with, for example, a wooden load-bearing wall. A reliable prediction of the cavity moisture levels is hence essential. However, previous studies showed that the ventilation rate in the cavity is highly fluctuating in both magnitude and direction. That is why most numerical models simplify cavity ventilation by neglecting it, replacing it by an equivalent resistance, assuming a constant air change rate and so on. This article verifies common assumptions in numerical models to incorporate cavity ventilation behind a brick veneer cladding, by confronting the simulations with detailed field studies. The results showed that for walls exposed to driving rain and solar radiation, most simplified one-dimensional simulations do not suffice to predict the moisture content in the cavity in a reliable way. Only with two-dimensional simulations, incorporating the airflow in the cavity, a good agreement with the in situ measurements was obtained. Furthermore, the two-dimensional models showed to be able to capture the moisture gradient along with the height of the wall rather precisely.

SEISMIC RISK AND RESILIENCE ASSESSMENT OF INDUSTRIAL FACILITIES: CASE STUDY ON A BLACK CARBON PLANT

2020 ◽  
Author(s):  
George Karagiannakis
Keyword(s):  
Seismic Risk ◽  
Numerical Models ◽  
Fragility Curves ◽  
Human Life ◽  
Mitigation Strategies ◽  
Economic Losses ◽  
Risk And Resilience ◽  
Industrial Plants ◽  
Plant Equipment

This paper deals with state of the art risk and resilience calculations for industrial plants. Resilience is a top priority issue on the agenda of societies due to climate change and the all-time demand for human life safety and financial robustness. Industrial plants are highly complex systems containing a considerable number of equipment such as steel storage tanks, pipe rack-piping systems, and other installations. Loss Of Containment (LOC) scenarios triggered by past earthquakes due to failure on critical components were followed by severe repercussions on the community, long recovery times and great economic losses. Hence, facility planners and emergency managers should be aware of possible seismic damages and should have already established recovery plans to maximize the resilience and minimize the losses. Seismic risk assessment is the first step of resilience calculations, as it establishes possible damage scenarios. In order to have an accurate risk analysis, the plant equipment vulnerability must be assessed; this is made feasible either from fragility databases in the literature that refer to customized equipment or through numerical calculations. Two different approaches to fragility assessment will be discussed in this paper: (i) code-based Fragility Curves (FCs); and (ii) fragility curves based on numerical models. A carbon black process plant is used as a case study in order to display the influence of various fragility curve realizations taking their effects on risk and resilience calculations into account. Additionally, a new way of representing the total resilience of industrial installations is proposed. More precisely, all possible scenarios will be endowed with their weighted recovery curves (according to their probability of occurrence) and summed together. The result is a concise graph that can help stakeholders to identify critical plant equipment and make decisions on seismic mitigation strategies for plant safety and efficiency. Finally, possible mitigation strategies, like structural health monitoring and metamaterial-based seismic shields are addressed, in order to show how future developments may enhance plant resilience. The work presented hereafter represents a highly condensed application of the research done during the XP-RESILIENCE project, while more detailed information is available on the project website https://r.unitn.it/en/dicam/xp-resilience.

Strategies to improve implementation of adaptive management practices for restoration in coastal Louisiana

Shore & Beach ◽  
2020 ◽  
pp. 83-91
Author(s):  
Tim Carruthers ◽  
Richard Raynie ◽  
Alyssa Dausman ◽  
Syed Khalil
Keyword(s):  
Adaptive Management ◽  
Management Practices ◽  
Numerical Models ◽  
The United States ◽  
State Agency ◽  
Coastal Protection ◽  
Coastal Restoration ◽  
Management Actions ◽  
Coastal Louisiana ◽  
Restoration Effort

Natural resources of coastal Louisiana support the economies of Louisiana and the whole of the United States. However, future conditions of coastal Louisiana are highly uncertain due to the dynamic processes of the Mississippi River delta, unpredictable storm events, subsidence, sea level rise, increasing temperatures, and extensive historic management actions that have altered natural coastal processes. To address these concerns, a centralized state agency was formed to coordinate coastal protection and restoration effort, the Coastal Protection and Restoration Authority (CPRA). This promoted knowledge centralization and supported informal adaptive management for restoration efforts, at that time mostly funded through the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA). Since the Deepwater Horizon (DWH) oil spill in 2010 and the subsequent settlement, the majority of restoration funding for the next 15 years will come through one of the DWH mechanisms; Natural Resource and Damage Assessment (NRDA), the RESTORE Council, or National Fish and Wildlife Foundation –Gulf Environmental Benefit Fund (NFWF-GEBF). This has greatly increased restoration effort and increased governance complexity associated with project funding, implementation, and reporting. As a result, there is enhanced impetus to formalize and unify adaptive management processes for coastal restoration in Louisiana. Through synthesis of input from local coastal managers, historical and current processes for project and programmatic implementation and adaptive management were summarized. Key gaps and needs to specifically increase implementation of adaptive management within the Louisiana coastal restoration community were identified and developed into eight tangible and specific recommendations. These were to streamline governance through increased coordination amongst implementing entities, develop a discoverable and practical lessons learned and decision database, coordinate ecosystem reporting, identify commonality of restoration goals, develop a common cross-agency adaptive management handbook for all personnel, improve communication (both in-reach and outreach), have a common repository and clearing house for numerical models used for restoration planning and assessment, and expand approaches for two-way stakeholder engagement throughout the restoration process. A common vision and maximizing synergies between entities can improve adaptive management implementation to maximize ecosystem and community benefits of restoration effort in coastal Louisiana. This work adds to current knowledge by providing specific strategies and recommendations, based upon extensive engagement with restoration practitioners from multiple state and federal agencies. Addressing these practitioner-identified gaps and needs will improve engagement in adaptive management in coastal Louisiana, a large geographic area with high restoration implementation within a complex governance framework.

Post-Hurricane Michael damage assessment using ADCIRC storm surge hindcast, image classification, and LiDAR

Shore & Beach ◽  
2019 ◽  
pp. 3-14 ◽  
Author(s):  
Joshua Davis ◽  
Diana Mitsova ◽  
Tynon Briggs ◽  
Tiffany Briggs
Keyword(s):  
Wave Energy ◽  
Field Studies ◽  
Feedback Mechanism ◽  
Water Velocity ◽  
Airborne Lidar ◽  
Storm Events ◽  
Magnetic Current ◽  
Coastal Mapping ◽  
Electro Magnetic

Wave forcing from hurricanes, nor’easters, and energetic storms can cause erosion of the berm and beach face resulting in increased vulnerability of dunes and coastal infrastructure. LIDAR or other surveying techniques have quantified post-event morphology, but there is a lack of in situ hydrodynamic and morphodynamic measurements during extreme storm events. Two field studies were conducted in March 2018 and April 2019 at Bethany Beach, Delaware, where in situ hydrodynamic and morphodynamic measurements were made during a nor’easter (Nor’easter Riley) and an energetic storm (Easter Eve Storm). An array of sensors to measure water velocity, water depth, water elevation and bed elevation were mounted to scaffold pipes and deployed in a single cross-shore transect. Water velocity was measured using an electro-magnetic current meter while water and bed elevations were measured using an acoustic distance meter along with an algorithm to differentiate between the water and bed during swash processes. GPS profiles of the beach face were measured during every day-time low tide throughout the storm events. Both accretion and erosion were measured at different cross-shore positions and at different times during the storm events. Morphodynamic change along the back-beach was found to be related to berm erosion, suggesting an important morphologic feedback mechanism. Accumulated wave energy and wave energy flux per unit area between Nor’easter Riley and a recent mid-Atlantic hurricane (Hurricane Dorian) were calculated and compared. Coastal Observations: JALBTCX/NCMP emergency-response airborne Lidar coastal mapping & quick response data products for 2016/2017/2018 hurricane impact assessments

VARIAÇÃO MORFOSSEDIMENTAR DO SETOR EXTREMO OESTE DA PRAIA DO ICARAÍ, CAUCAIA-CE

2019 ◽  
Vol 21 (2) ◽  
pp. 364-380
Author(s):  
Antônio Emanuel dos' Santos Silva ◽  
Matheus Silveira Pinheiro ◽  
Davis Pereira de Paula
Keyword(s):  
Civil Society ◽  
Coastal Erosion ◽  
Field Experiments ◽  
Coastal Protection ◽  
Dune System ◽  
Built Heritage ◽  
General Terms ◽  
Methodological Procedures ◽  
Sociedad Civil

Ambientalmente as dunas frontais constituem estruturas verdes de proteção costeira contra o avanço do mar, em muitos casos, são responsáveis pela manutenção do equilíbrio sedimentar do sistema praia-duna, impedindo que processos como a erosão costeira e a inundação marinha se tornem danosos a sociedade civil e ao patrimônio construído. O objetivo deste estudo foi monitorar as variações morfológicas e sedimentares do sistema praia-duna entre os anos de 2016 e 2018, no trecho extremo oeste da Praia do Icaraí, através da determinação das taxas granulométricas, volumétricas e morfológicas do sistema praia-duna na Praia do Icaraí. Os procedimentos metodológicos foram divididos em três etapas principais: levantamento bibliográfico, geocartográfico e experimentos de campo. Considerou-se que as forçantes oceanográficas foram as principais responsáveis pela erosão e solapamento das dunas frontais presentes na área de estudo. Em linhas gerais, os resultados deste trabalho significam um importante instrumento de análise dos impactos das condicionantes oceanográficas e antrópicas sobre uma praia que sofre de erosão costeira acentuada. O estudo em um trecho mais preservado dessa praia indicou de forma direta os impactos sofridos em um litoral que vem passando por transformações contínuas em suas praias, como é o caso do litoral de Caucaia.Palavras-chave: Morfodinâmica; Sistema Praial; Dunas Frontais. ABSTRACTEnvironmentally the frontal dunes constitute green structures of coastal protection against the advance of the sea, in many cases, they are responsible for the maintenance of the sedimentary balance of the beach-dune system, preventing that processes such as coastal erosion and marine flooding become harmful to civil society and built heritage. The objective of this study was to monitor the morphological and sedimentary variations of the beach-dune system between the years 2016 and 2018, in the extreme west section of Icaraí Beach, by determining the granulometric, volumetric and morphological rates of the beach-dune system in Praia of Icaraí. The methodological procedures were divided into three main stages: bibliographic survey, geocartographic and field experiments. It was considered that the oceanographic forcings were the main responsible for the erosion and overlap of the frontal dunes present in the study area. In general terms, the results of this work represent an important instrument for analyzing the impacts of oceanographic and anthropogenic conditions on a beach that suffers from marked coastal erosion. The study in a more preserved stretch of this beach indicated in a direct way the impacts suffered on a coast that has undergone continuous transformations in its beaches, as is the case of the coast of Caucaia.Keywords: Morphodynamics; Praial System; Fore Dunes. RESUMENAmbientalmente, las dunas frontales son estructuras verdes de protección costera contra el avance del mar. En muchos casos, son responsables de mantener el equilibrio sedimentario del sistema de dunas de playa, evitando que procesos como la erosión costera y las inundaciones marinas dañen a la sociedad civil. y el patrimonio construido. El objetivo de este estudio fue monitorear las variaciones morfológicas y sedimentarias del sistema de dunas de playa entre 2016 y 2018, en el extremo occidental de Praia do Icaraí, determinando el tamaño de partícula, las tasas volumétricas y morfológicas del sistema de dunas de playa en Praia de Icaraí Los procedimientos metodológicos se dividieron en tres etapas principales: estudio bibliográfico, geocartográfico y experimentos de campo. El forzamiento oceanográfico se consideró el principal responsable de la erosión y el debilitamiento de las dunas frontales presentes en el área de estudio. En general, los resultados de este trabajo representan un instrumento importante para analizar los impactos de las condiciones oceanográficas y antropogénicas en una playa que sufre una severa erosión costera. El estudio en un tramo más preservado de esta playa indicó directamente los impactos sufridos en una costa que ha sufrido cambios continuos en sus playas, como es el caso de la costa de Caucaia.Palabras claves: Morfodinámica; Sistema de playa; Dunas frontales.

Coliform transport in a pristine reservoir: modeling and field studies

1998 ◽  
Vol 37 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Elisa Garvey ◽  
John E. Tobiason ◽  
Michael Hayes ◽  
Evelyn Wolfram ◽  
David A. Reckhow ◽  
...  
Keyword(s):  
Model Development ◽  
Fate And Transport ◽  
Field Studies ◽  
Meteorological Conditions ◽  
Reservoir Modeling ◽  
Vertical Circulation ◽  
Quality Model ◽  
Circulation Patterns ◽  
In Situ Experiments

This paper reports on field studies and model development aimed at understanding coliform fate and transport in the Quabbin Reservoir, an oligotrophic drinking water supply reservoir. An investigation of reservoir currents suggested the importance of wind driven phenomena, and that both lateral and vertical circulation patterns exist. In-situ experiments of coliform decay suggested dependence on light intensity and yielded an appropriate decay coefficient to be used in CE-QUAL-W2, a two-dimensional hydrodynamic and water quality model. Modeling confirmed the sensitivity of reservoir outlet concentration to vertical variability within the reservoir, meteorological conditions, and location of coliform source.

Real-life Field Studies of the NOx Removing Properties of Photocatalytic Surfaces in Roskilde and Copenhagen Airport, Denmark

2020 ◽  
Vol 01 ◽  
Author(s):  
Henrik Jensen ◽  
Pernille D. Pedersen
Keyword(s):  
Air Quality ◽  
High Stability ◽  
Reference Site ◽  
Real Life ◽  
Field Studies ◽  
The Real ◽  
Before And After ◽  
Parking Lot ◽  
Photocatalytic Concrete

Aims: To evaluate the real-life effect of photocatalytic surfaces on the air quality at two test-sites in Denmark. Background: Poor air quality is today one of the largest environmental issues, due to the adverse effects on human health associated with high levels of air pollution, including respiratory issues, cardiovascular disease (CVD), and lung cancer. NOx removal by TiO2 based photocatalysis is a tool to improve air quality locally in areas where people are exposed. Methods: Two test sites were constructed in Roskilde and Copenhage airport. In Roskilde, the existing asphalt at two parking lots was treated with TiO2 containing liquid and an in-situ ISO 22197-1 test setup was developed to enable in-situ evaluation of the activity of the asphalt. In CPH airport, photocatalytic concrete tiles were installed at the "kiss and fly" parking lot, and NOx levels were continuously monitored in 0.5 m by CLD at the active site and a comparable reference site before and after installation for a period of 2 years. Results: The Roskilde showed high stability of the photocatalytic coating with the activity being largely unchanged over a period of 2 years. The CPH airport study showed that the average NOx levels were decreased by 12 % comparing the before and after NOx concentrations at the active and reference site. Conclusion: The joined results of the two Danish demonstration projects illustrate a high stability of the photocatalytic coating as well as a high potential for improvements of the real-life air quality in polluted areas.

scholarly journals Development of Fragility Curves for Piping and Slope Stability of River Levees

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić
Keyword(s):  
Slope Stability ◽  
Fragility Curves ◽  
Safety Margin ◽  
Water Levels ◽  
Flood Event ◽  
Soil Parameters ◽  
Design Code ◽  
A Site ◽  
Insight Into

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.

scholarly journals Sub-Level Stoping in an Underground Limestone Quarry: An Analysis of the State of Stress in an Evolutionary Scenario

2016 ◽  
Vol 61 (1) ◽  
pp. 199-216 ◽  
Author(s):  
Marilena Cardu ◽  
Sergio Dipietromaria ◽  
Pierpaolo Oreste
Keyword(s):  
Numerical Models ◽  
The State ◽  
In Situ Tests ◽  
Future Scenario ◽  
Limestone Quarry ◽  
Geomechanical Properties ◽  
State Of Stress ◽  
Upper Level ◽  
Pillar Structure

Abstract The aim of this study was to evaluate the state of stress of a „voids-pillar“ structure excavated by means of the sub-level stoping method in an underground limestone quarry near Bergamo (Italy). Both the current structure of the quarry (i.e. the rooms exploited till now) and a possible future scenario were analysed using the (FDM) FLAC 2D code. The quarry has been in operation since 1927; at present, exploitation is carried out underground via the sub-level stoping method. Exploitation involves two levels, with 5 rooms on the upper level and 9 rooms on the lower level. After analysing data obtained from laboratory and in situ tests carried out on rock samples and natural discontinuities, the geomechanical properties of the medium, knowledge of which is essential in order to establish the parameters that must be included in the numerical model, were evaluated. The implementation of three numerical models made it possible to study both the present conditions of quarry exploitation and the evolution of the exploited rooms, as well as a possible expansion involving a third level of rooms. Using the results obtained regarding the stress-strain present in the pillars, a potential change in room geometry was proposed aimed at reducing the stress state inside the pillars, decreasing plasticity and increasing overall quarry safety.

scholarly journals Mechanics-based fragility curves for Italian residential URM buildings

2020 ◽  
Author(s):  
Marco Donà ◽  
Pietro Carpanese ◽  
Veronica Follador ◽  
Luca Sbrogiò ◽  
Francesca da Porto
Keyword(s):  
Reference Model ◽  
Fragility Curves ◽  
National Level ◽  
Building Stock ◽  
Damage Scenarios ◽  
Complex Evaluation ◽  
Proposed Model ◽  
2009 L’Aquila Earthquake ◽  
Damage States ◽  
Observed Damage

Abstract Seismic risk assessment at the territorial level is now widely recognised as essential for countries with intense seismic activity, such as Italy. Academia is called to give its contribution in order to synergically deepen the knowledge about the various components of this risk, starting from the complex evaluation of vulnerability of the built heritage. In line with this, a mechanics-based seismic fragility model for Italian residential masonry buildings was developed and presented in this paper. This model is based on the classification of the building stock in macro-typologies, defined by age of construction and number of storeys, which being information available at national level, allow simulating damage scenarios and carrying out risk analyses on a territorial scale. The model is developed on the fragility of over 500 buildings, sampled according to national representativeness criteria and analysed through the Vulnus_4.0 software. The calculated fragility functions were extended on the basis of a reference model available in the literature, which provides generic fragilities for the EMS98 vulnerability classes, thus obtaining a fragility model defined on the five EMS98 damage states. Lastly, to assess the reliability of the proposed model, this was used to simulate damage scenarios due to the 2009 L’Aquila earthquake. Overall, the comparison between model results and observed damage showed a good fit, proving the model effectiveness.

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