scholarly journals Quantifying lahar damage using numerical modelling

2016 ◽  
Author(s):  
Stuart R. Mead ◽  
Christina Magill ◽  
Vincent Lemiale ◽  
Jean-Claude Thouret ◽  
Mahesh Prakash
Keyword(s):  
Numerical Modelling ◽  
Critical Infrastructure ◽  
Human Life ◽  
Bending Moment ◽  
Building Damage ◽  
Minor Role ◽  
Building Vulnerability ◽  
Hazard Exposure ◽  
Inundation Area

Abstract. Lahars are volcanic flows containing a mixture of fluid and sediment that have caused significant damage to buildings, critical infrastructure and human life. The extent of this damage is controlled by properties of the lahar, location of elements at risk and susceptibility of these elements to the lahar. Here we focus on understanding lahar-induced building damage. Quantification of building damage can be difficult due to the complexity of lahar behaviour (hazard), uncertainty in number and type of buildings exposed to the lahar (exposure) and the uncertain susceptibility of buildings to lahar induced damage (vulnerability). In this paper, we quantify and examine the relative importance of lahar hazard, exposure and vulnerability in determining building damage with reference to a case study in the city of Arequipa, Peru. Numerical modelling is used to investigate lahar properties important in determining the inundation area and forces applied to buildings. Building vulnerability is quantified through the development of critical depth–pressure curves based on the ultimate bending moment of masonry structures. In the case study area, results suggest that building strength plays a minor role in determining overall building losses in comparison to the effects of building exposure and lahar hazard properties such as hydraulic characteristics of the flow.

scholarly journals Examining the impact of lahars on buildings using numerical modelling

2017 ◽  
Vol 17 (5) ◽  
pp. 703-719 ◽  
Author(s):  
Stuart R. Mead ◽  
Christina Magill ◽  
Vincent Lemiale ◽  
Jean-Claude Thouret ◽  
Mahesh Prakash
Keyword(s):  
Numerical Modelling ◽  
Critical Infrastructure ◽  
Human Life ◽  
Bending Moment ◽  
Building Damage ◽  
Minor Role ◽  
Building Vulnerability ◽  
Inundation Area ◽  
The Impact

Abstract. Lahars are volcanic flows containing a mixture of fluid and sediment which have the potential to cause significant damage to buildings, critical infrastructure and human life. The extent of this damage is controlled by properties of the lahar, location of elements at risk and susceptibility of these elements to the lahar. Here we focus on understanding lahar-induced building damage. Quantification of building damage can be difficult due to the complexity of lahar behaviour (hazard), varying number and type of buildings exposed to the lahar (exposure) and the uncertain susceptibility of buildings to lahar impacts (vulnerability). In this paper, we quantify and examine the importance of lahar hazard, exposure and vulnerability in determining building damage with reference to a case study in the city of Arequipa, Peru. Numerical modelling is used to investigate lahar properties that are important in determining the inundation area and forces applied to buildings. Building vulnerability is quantified through the development of critical depth–pressure curves based on the ultimate bending moment of masonry structures. In the case study area, results suggest that building strength plays a minor role in determining overall building losses in comparison to the effects of building exposure and hydraulic characteristics of the lahar.

scholarly journals Framework of Spatial Flood Risk Assessment for a Case Study in Quang Binh Province, Vietnam

2020 ◽  
Vol 12 (7) ◽  
pp. 3058
Author(s):  
Chinh Luu ◽  
Hieu Xuan Tran ◽  
Binh Thai Pham ◽  
Nadhir Al-Ansari ◽  
Thai Quoc Tran ◽  
...  
Keyword(s):  
Risk Assessment ◽  
High Risk ◽  
Flood Risk ◽  
Agricultural Land ◽  
Human Life ◽  
Early Warning Systems ◽  
Flood Risk Assessment ◽  
Inundation Area ◽  
Medium Risk

Vietnam has been extensively affected by floods, suffering heavy losses in human life and property. While the Vietnamese government has focused on structural measures of flood defence such as levees and early warning systems, the country still lacks flood risk assessment methodologies and frameworks at local and national levels. In response to this gap, this study developed a flood risk assessment framework that uses historical flood mark data and a high-resolution digital elevation model to create an inundation map, then combined this map with exposure and vulnerability data to develop a holistic flood risk assessment map. The case study is the October 2010 flood event in Quang Binh province, which caused 74 deaths, 210 injuries, 188,628 flooded properties, 9019 ha of submerged and damaged agricultural land, and widespread damages to canals, levees, and roads. The final flood risk map showed a total inundation area of 64,348 ha, in which 8.3% area of low risk, 16.3% area of medium risk, 12.0% area of high risk, 37.1% area of very high risk, and 26.2% area of extremely high risk. The holistic flood risk assessment map of Quang Binh province is a valuable tool and source for flood preparedness activities at the local scale.

scholarly journals Remotely assessing tephra fall building damage and vulnerability: Kelud Volcano, Indonesia

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
George T. Williams ◽  
Susanna F. Jenkins ◽  
Sébastien Biass ◽  
Haryo Edi Wibowo ◽  
Agung Harijoko
Keyword(s):  
Fragility Curves ◽  
Satellite Image ◽  
Building Damage ◽  
Building Vulnerability ◽  
Tephra Fall ◽  
Building Collapse ◽  
2014 Eruption ◽  
Remote Assessment ◽  
Fold Cross Validation

AbstractTephra from large explosive eruptions can cause damage to buildings over wide geographical areas, creating a variety of issues for post-eruption recovery. This means that evaluating the extent and nature of likely building damage from future eruptions is an important aspect of volcanic risk assessment. However, our ability to make accurate assessments is currently limited by poor characterisation of how buildings perform under varying tephra loads. This study presents a method to remotely assess building damage to increase the quantity of data available for developing new tephra fall building vulnerability models. Given the large number of damaged buildings and the high potential for loss in future eruptions, we use the Kelud 2014 eruption as a case study. A total of 1154 buildings affected by falls 1–10 cm thick were assessed, with 790 showing signs that they sustained damage in the time between pre- and post-eruption satellite image acquisitions. Only 27 of the buildings surveyed appear to have experienced severe roof or building collapse. Damage was more commonly characterised by collapse of roof overhangs and verandas or damage that required roof cladding replacement. To estimate tephra loads received by each building we used Tephra2 inversion and interpolation of hand-contoured isopachs on the same set of deposit measurements. Combining tephra loads from both methods with our damage assessment, we develop the first sets of tephra fall fragility curves that consider damage severities lower than severe roof collapse. Weighted prediction accuracies are calculated for the curves using K-fold cross validation, with scores between 0.68 and 0.75 comparable to those for fragility curves developed for other natural hazards. Remote assessment of tephra fall building damage is highly complementary to traditional field-based surveying and both approaches should ideally be adopted to improve our understanding of tephra fall impacts following future damaging eruptions.

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.

scholarly journals Segment-Based Approach for Assessing Hazard Risk of Coastal Highways in Hawai‘i

2019 ◽  
Vol 2673 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Harrison Togia ◽  
Oceana P. Francis ◽  
Karl Kim ◽  
Guohui Zhang
Keyword(s):  
Qualitative Method ◽  
Data Sets ◽  
Regional Environment ◽  
The Road ◽  
Hazard Exposure ◽  
Multiple Indicators ◽  
System Data ◽  
Rural Highway ◽  
Geographic Information System Data

Hazards to roadways and travelers can be drastically different because hazards are largely dependent on the regional environment and climate. This paper describes the development of a qualitative method for assessing infrastructure importance and hazard exposure for rural highway segments in Hawai‘i under different conditions. Multiple indicators of roadway importance are considered, including traffic volume, population served, accessibility, connectivity, reliability, land use, and roadway connection to critical infrastructures, such as hospitals and police stations. The method of evaluating roadway hazards and importance can be tailored to fit different regional hazard scenarios. It assimilates data from diverse sources to estimate risks of disruption. A case study for Highway HI83 in Hawai‘i, which is exposed to multiple hazards, is conducted. Weakening of the road by coastal erosion, inundation from sea level rise, and rockfall hazards require adaptation solutions. By analyzing the risk of disruption to highway segments, adaptation approaches can be prioritized. Using readily available geographic information system data sets for the exposure and impacts of potential hazards, this method could be adapted not only for emergency management but also for planning, design, and engineering of resilient highways.

scholarly journals Linking Conservation, Community Knowledge, and Adaptation to Extreme Climatic Events: A Case Study in Gorongosa National Park, Mozambique

2021 ◽  
Vol 13 (11) ◽  
pp. 6478
Author(s):  
Amemarlita Matos ◽  
Laura Barraza ◽  
Isabel Ruiz-Mallén
Keyword(s):  
National Park ◽  
Animal Species ◽  
Human Life ◽  
Management Strategies ◽  
Forest Products ◽  
Buffer Zone ◽  
Structured Interviews ◽  
Extreme Climatic Events ◽  
Water Provision

This study is based on ethnographic research that analyzes how traditional knowledge and local beliefs on biodiversity conservation relates to the local ability to adapt and be resilient to climatic changes in two communities around Gorongosa National Park, Mozambique: Nhanfisse in the buffer zone and Muanandimae in the core area. A total of 78 semi-structured interviews with heads of households were conducted. We found that both communities carried out practices and held beliefs associated with conservation, such as protecting trees and animal species considered sacred or perceived as beneficial for human life in terms of water provision and agricultural production. In addition to traditional ceremonies that respond to extreme climatic events such as drought and flood, other adaptation strategies used by the communities include moving to neighboring areas in search of better living conditions and using forest products in times of scarcity. We discuss that the management of the park should be agreed on, in a shared way, between local communities and conservation agents to ensure that these areas continue to perform the ecological, subsistence, and spiritual functions required. Our research results contribute to a better understanding of local adaptation dynamics towards extreme climatic events and improvement of management strategies.

scholarly journals The effect of flexural–torsional buckling on the stability of timber members: a case study

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Osama A. B. Hassan
Keyword(s):  
Axial Compression ◽  
Bending Moment ◽  
List Type ◽  
Torsional Buckling ◽  
Solution Methods ◽  
Simplified Solution ◽  
The Stability ◽  
Flexural Torsional Buckling ◽  
Building Engineering

Abstract This study investigates the stability of timber members subjected to simultaneously acting axial compression and bending moment, with possible risk for torsional and flexural–torsional buckling. This situation can occur in laterally supported members where one side of the member is braced but the other side is unbraced. In this case, the free side will buckle out of plane while the braced side will be prevented from torsional and flexural–torsional buckling. This problem can be evident for long members in timber-frame structures, which are subjected to high axial compression combined with bending moments in which the member is not sufficiently braced at both sides. This study is based on the design requirement stated in Eurocode 5. Solution methods discussed in this paper can be of interest within the framework of structural and building Engineering practices and education in which the stability of structural elements is investigated. Article Highlights This case study investigates some design situations where the timber member is not sufficiently braced. In this case, a stability problem associated with combined torsional buckling and flexural buckling can arise. The study shows that the torsional and/or flexural–torsional buckling of timber members can be important to control in order to fulfil the criteria of the stability of the member according to Eurocode 5 and help the structural engineer to achieve safer designs. The study investigates also a simplified solution to check the effect of flexural torsional buckling of laterally braced timber members.

Sign in / Sign up

Export Citation Format

Share Document