Hasil untuk "Disasters and engineering"

Yabo HE

In order to achieve a novel disaster early warning mode of “autonomous modeling + integrated early warning + root cause tracing”, and improve the knowledge engineering infrastructure for integrated intelligent disaster warning, this study developed an ontology model for integrated knowledge graphs of disaster based on the “human-machine-environment” system engineering theory. The model was constructed through a top-down approach across four dimensions: temporal, spatial, managerial, and process mechanisms. It encompasses eight core concepts in this field of personnel, equipment, environment, region, process, document, index, and disaster, along with three categories of data attributes (basic information, spatial information, and temporal information). Three types of relationships were established: spatial positioning, numerical correlations, and process mechanism linkages. A hybrid data storage architecture integrating relational, spatial, temporal, and graph databases was built. Data extraction for entities, attributes, and relationships was achieved through a combination of rule-driven workflow engines and manual data supplementation, forming mine-specific disaster-integrated knowledge graphs. By adopting graph database relationship reasoning methods, coupled with anomaly identification criteria for graph objects, root cause analysis of mine disasters was realized. The results show that a “top-down” knowledge graph construction scheme that involves expert modeling and regularized data extraction is suitable in the early stage in the field of integrated analysis of mine disasters; the framework of “eight core concepts, three data attributes, and three relationship types” significantly enriches disaster knowledge systems; the hybrid methodology of rule-driven engines and manual supplementation effectively addresses the needs of mines at varying intelligentization stages; knowledge graph relationship reasoning integrated with object attribute anomaly detection provides a robust technical solution for accident causation analysis.

Jonathan D. Paul, Aneena Ajmi, Doris Bolaji‐Dada et al.

ABSTRACT Groundwater behavior in superficial gravel aquifers is globally poorly understood, especially across urban regions where drinking water is sourced from elsewhere. This study focuses on one such region around Staines, SE UK, where local River Terrace Gravels form a thin (< 10 m) superficial aquifer. The objective was to explain the unusually broad and long‐lived distribution of flooding by investigating local groundwater level fluctuations and flow. Over a period in January 2024, a targeted citizen science program was instigated to leverage local knowledge of floodwater, which was determined to match groundwater chemistry. Geophysical surveys (ground‐penetrating radar and seismic refraction) were designed to produce high‐resolution water table maps, validated against well measurements. Flow rates and hydraulic conductivity, K, of the gravels were determined both in the field (via pumping and tracer tests) and laboratory, to obviate any scale effects. K depended nonlinearly on hydraulic gradient, with Darcyan behavior breaking down at low (< 0.03) gradients, in conditions approaching turbulent flow. Large and localized fluctuations in groundwater level, combined with the existence of several fast‐flow pathways, are explained by the strong heterogeneity of the gravels, as well as their sensitivity to the imposition of subsurface obstacles such as clay‐lined backfilled gravel pits, or deep basements. These manifestations of urbanization drive observed patterns of groundwater emergence, together with aquifer thickness, rather than changes in river stage or surface elevation alone. Our experience motivates us to suggest that groundwater flooding be considered as significant as fluvial flooding in the production of risk maps by environmental regulatory bodies.

Zhaoming YAO, Xun WANG, Hang WEI et al.

Ensuring the stability of the frozen wall is critical in freezing construction, but traditional onsite detection methods, due to their intermittent nature, fail to provide real-time monitoring, limiting timely responses to potential catastrophic events. Deep in-situ precise detection of frozen soil is an effective means to reveal the mechanisms of major engineering disasters in frozen walls and to provide disaster early warning. A convolutional neural network-based image data-driven intelligent recognition method for frozen soil strength is proposed. This method involves capturing multi-angle images of 93 sample specimens and conducting subsequent uniaxial compressive strength tests. The labeled sample images and actual strength data, combined with image data augmentation techniques, were used to construct the image dataset required for training the deep learning model. A 34-layer deep residual network (ResNet-34) model using transfer learning was employed. By comparing the training processes and test results of different models, it was found that the ResNet-34 model performed the best, achieving an accuracy of 92.8% with no signs of overfitting. The deep learning model was applied to identify the influencing factors of frozen soil strength, including soil type, temperature, and moisture content. It was found that the model effectively recognized these three variables, demonstrating the scientific validity and reliability of the model in identifying frozen soil strength. In addition, the model’s performance under different disturbance conditions was studied by simulating typical interference scenarios and analyzing their impact on the model’s predictive performance, providing a basis for future improvements in data augmentation strategies and model optimization. Grad-CAM (Gradient-weighted Class Activation Mapping) interpretability analysis method was introduced to reveal the internal feature extraction process of the convolutional neural network in the frozen soil strength recognition task. It was found that the model could extract and analyze key image features of frozen soil, enabling rapid strength assessment. The research results provide a new approach for real-time monitoring of the frozen wall state and early disaster warning, offering technical support for the safe construction of freezing projects.

Peng Cui, Nazir Ahmed Bazai, Zou Qiang et al.

Abstract Globally, the 2022 Pakistan mega-flood displaced over 33 million people and incurred economic losses exceeding $ 40 billion. By coupling seventy years of historical flood data with advanced machine learning techniques (GeoPINS within FloodCast), this study quantifies the event’s primary drivers and projects future risk under climate change. Results show that the 2022 monsoon, amplified by low-pressure systems, delivered 7–8 times the 1990–2020 mean rainfall, flooding over 2100 streams and breaching 177 check dams. In Balochistan alone, these dam failures caused 80–85% of the province’s economic losses. Spatial–spectral analysis reveals that monsoon intensification, infrastructural vulnerability, and orographic forcing collectively govern inundation patterns. Under the SSP5 scenario, the area of high flood risk zones is projected to expand by 6.62% by 2080, even when modeling data-scarce regions. These findings underscore an urgent need for climate-resilient dam design, strategic sediment management, and adaptive flood-risk governance in similar vulnerable areas.

Hongqi Wang, Zixia Liu, Jingyun Feng et al.

ABSTRACT Amidst intensifying climate change, flash floods are becoming more recurrent, posing significant threats to safety and assets, especially in mountainous areas. Given the non‐negligible influence of bridges on flash floods, this research capitalized on fluid dynamics simulations to examine the mechanisms by which six bridges within the investigation zone affect the evolution of flash floods. Moreover, bridge blockage from debris accumulation was methodically investigated under multiple return periods. Results indicated that during the two historical floods, the bridges altered the distribution pattern of flash floods from various flood elements, including the backwater effect, flow velocity, and inundation. It is noteworthy that the spillway bridge (M1) notably raised water levels and slowed flows, whereas the influence of other bridges on flood dynamics was more muted. The presence of six bridges resulted in expanded flooded areas, particularly near the upstream bridges, raising risks for Qishi Village. Furthermore, the increasing blockage ratios at bridge B2 during multiple return periods exacerbated the impacts on flood elements, consequently amplifying the disaster of flash floods. This research strongly emphasizes the importance of incorporating bridges and their blockages into flood risk management. It further provides technical insights to bolster the basin's resilience against extreme hydrological events.

Diego Panici, Prakash Kripakaran, Richard E. Brazier

ABSTRACT Bridge owners and regulatory agencies have a duty to assess risks derived from hydraulic actions including scour, uplift, drag, debris impact, deck displacement, and other consequences that can lead to a loss in the load carrying capacity of a bridge. In the UK, the CS469 (Management of scour and other hydraulic actions at highway structures) is the standard for the assessment of hydraulic actions to highway bridges. The methodology in CS469 for the calculation of the hydraulic characteristics of the flow at critical cross‐sections within the channel and the bridge crossing, although simplistic by design to minimize computational effort, is intrinsically inaccurate since it makes use of unrealistic (i.e., non‐physically based) approximations. This results in estimations of risk and vulnerability levels that could include high levels of uncertainty. In this paper, we propose to bypass these approximated hydraulic calculations by harnessing the computational power of 2D hydraulic models, which would not require any additional field data collection than needed for the original CS469 method. We recommend a fully 2D HEC‐RAS model with the inclusion of bridges as 1D elements within the flow areas and only requiring publicly available data or data obtained from existing assessments in order to future‐proof the approaches and adhere to an open‐source/open‐access philosophy, but also imposing only a marginal increase in cost for bridge management teams. Results from the two models—2D HEC‐RAS and the existing approach in CS469, are compared for a number of real‐world bridges. The comparisons show that the estimations by HEC‐RAS are substantially higher for water depth (up to 138%) and lower for flow velocity (down by 58%). When these values are applied to the estimation of hydraulic vulnerability and scour risk, the differences are significant. Scour depths with the use of HEC‐RAS models are typically much lower (up to 3.9 m, and on average 1.7 m) than with simplified hydraulic equations, and this translates into lower (yet, more appropriate) scour risk levels. Hydraulic vulnerability to submergence of the assessed bridges is also assessed very differently, typically higher by the 2D model method. Overall, the results show that 2D numerical hydraulic simulations present a much more accurate estimation than existing methods, better balancing risks deriving from scour and hydrodynamic actions and with comparable effort and data requirements. The model displays consistency across an exhaustive set of simulations for a range of variables and bridges, showing limited variability and proneness to errors, whilst values estimated by CS469 are in most cases significantly different. Future versions of CS469 and similar documents should prioritize this methodology to provide a more accurate and realistic risk estimation.

Xuewen Rong, Shuo Deng, Baozhen Liang et al.

The structural properties of loess are susceptible to change when subjected to external loads and complex environments, leading to various geological disasters. To investigate the mechanical behavior and strengthening mechanism of loess stabilized with biopolymers such as xanthan gum and guar gum, especially for soils with low bearing capacity and stability in engineering applications, we conducted research on the improvement of soil with xanthan gum and guar gum, tests including unconfined compressive strength, disintegration, direct shear, and microstructure tests were conducted. Among the four different dosages of biopolymers (0%, 0.5%, 1%, 2%) and four different curing ages (1 day, 3 days, 7 days, 14 days), the 2% content of biopolymer and 14 days had the greatest impact on the mechanical properties of loess, Both the compressive and shear strength, as well as the water stability of solidified loess, improve with higher content of xanthan gum and guar gum or prolonged curing time; however, the disintegration rate decreases. Microscopic analysis indicates that the biopolymers effectively fill the gaps between soil particles and attach to the particle surfaces, forming fibrous and reticular structures that improve the interparticle bonding and ultimately increase the strength and water stability of the loess. Xanthan gum and guar gum biopolymers can improve the mechanical properties and water stability of loess, enhance the erosion resistance and improve the water-holding capacity. These outcomes suggest that guar gum and xanthan gum biopolymers have the potential to serve as environmentally sustainable alternatives to conventional soil stabilizers.

Renato Amorim, Gabriele Villarini

Abstract The detection of nonstationarities in partial duration time series (PDS) depends on several factors, including the length of the time series, the selected statistical test, and the heaviness of the tail of the distribution. Because of the more limited attention received in the literature when compared to the trend detection on block maxima variables, we perform a Monte Carlo simulation study to evaluate the performance of different approaches: Spearman's rho, Mann–Kendall, ordinary least squares (OLS), Sen's slope estimator (SEN), and the nonstationary generalized Pareto distribution fit to identify the presence of trends in PDS records characterized by different sample sizes (n), shape parameter (ξ) and degrees of nonstationarity. The results point to a power gain for all tests by increasing n and the degree of nonstationarity and by reducing ξ. The use of a nonparametric test is recommended in samples with a high positive skew. Furthermore, the use of sampling rates greater than one to increase the PDS sample size is encouraged, especially when dealing with small records. The use of SEN to estimate the magnitude of a trend is preferable over OLS due to its slightly smaller probability of occurrence of type S error when ξ is positive.

V.N. Oparin

It is shown that modern achievements in the field of experimental and theoretical researches and developments of innovative measuring systems for monitoring of non-linear dynamic and kinematic characteristics allow to formulate basics of new academic discipline, designated as “geomechanical thermodynamics”. The following circumstances can be considered as the most important prerequisites for development of this new discipline.(1) Practical completeness of the classical thermodynamics, based on kinetic gas theory and molecular movements in solid bodies; (2) Creation of “formular construction tool” for the description of dynamic and kinematic characteristics of pendulum waves and energy conditions of their occurrence and propagation from dynamic sources, located in multi-phased stressed rock mass and geomaterials with block-hierarchical structure; (3) Principal opportunity to establish formal relations between substantial energy carriers of “packages” of non-linear pendulum waves (geoblocks of certain hierarchical levels according to their diameters) and “molecules”: their movement, velocity and acceleration of the “molecules” ↔ “geoblock”; “force interactions between molecules” ↔ “non-linear elastic interaction between geoblocks”, etc.The term of “geomechanical temperature” is introduced and its analytical expression, which is proportional to kinetic energy of movement of geoblocks with defined volume for their hierarchical subsequence at “confined” conditions of the stressed rock mass, is shown. The similar aspects are discussed, when emission acoustic-electromagnetic fields are fixed using corresponding coefficients of mechanical-electrical and mechanical-acoustic transformations. In order to quantitively describe the evolution of energy state of local zones of stress-strain concentration and surroundings of their non-linear influence from catastrophic events at the natural and mine-engineering systems (earthquakes, rock bursts, etc.), the terms of their geomechanical and thermodynamic stages are introduced and specified: Ti(i∈0,+,±,−,∗)‒ with background states (i∈0,∗) and three major stages (i∈+,±,−) outlined, where (+) is the concentration, (±, ‒) are the failure and relaxation and (∗) is the quasi-recovering up to “background” level after the occurred catastrophic event. Using certain examples, the existence of critical elastic energy content of local zones with “meta-stable state”, which is transforming to quasi-resonance process of failure and relaxation of “excessive” energy, is shown (T±).

Peter R. Davids, Sally Priest, Thomas Hartmann

Abstract This paper investigates the role of flood risk experts in supporting homeowners to implement property‐level flood risk adaption (PLFRA). Homeowners can reduce their flood risks by implementing PLFRA. However, oftentimes they need advice on what sort of and how to implement PLFRA. This means that tailored experts advice is necessary to inform homeowners on such measures. But experience shows that mere information is often insufficient to motivate homeowners to realise measures. This contribution explores the reasons for the ineffectiveness of expert advice by investigating how expert advice responds to homeowners' rationalities. Based on a case study from Flanders, Belgium, this paper reveals how the relation between experts and homeowners differs related to different rationalities of homeowners. The paper uses Cultural Theory to discuss strategies on how experts, providing advice on property‐level risk adaption, could move beyond engineering skills by also using risk communication skills in order to involve homeowners in flood risk governance.

Yating Zhang, Bilal M. Ayyub, Juan F. Fung

Climate change can accelerate infrastructure deterioration in coastal areas because increased temperature and humidity can promote steel corrosion. This study (1) projects corrosion rate changes for reinforced concrete and steel structures in 223 coastal counties, (2) assesses the impact of corrosion rate changes on the useful life of structures, and (3) evaluates direct economic losses due to shortened useful life of highway bridges over the period 2000-2100. The results show that the useful life of concrete structures may decrease by 1.7-2.7% under the representative concentration pathway (RCP) 8.5 and decrease by 0.7-1.1% under RCP 4.5 by the end of the 21st century. The useful life of steel structures may decrease by 7.9-15.9% under RCP 8.5 and 3.3-6.7% under RCP 4.5. Concrete bridges may suffer an average loss of $6.5-11.7/m2 under RCP 8.5 and $3.3-16.5/m2 under RCP 4.5 due to shortened useful life. Steel bridges may suffer an average loss of $73.4-111.3/m2 under RCP 8.5 and $46.9-81.2/m2 under RCP 4.5. In both climate scenarios, 10% of counties may have negative losses and 10% of counties may have losses greater than $20 million due to corrosion rate changes for concrete and steel bridges. The results reveal the spatial difference of climate change impacts on infrastructural deterioration and suggest the importance of developing regional specific adaptation strategies.

Tony Rey, Frederic Leone, Stéphanie Defossez et al.

The objective of our study is to establish an assessment of four volcanic hazards in a country threatened by the eruption of the OlDoinyo Lengai volcano. The last major eruption dates back to 2007-2008 but stronger activity in 2019 has revived the memory of volcanic threats to the Maasai and Bantu communities and human activities (agro-pastoral and tourism). The methods chosen have had to be adapted to the scarce and incomplete data. The volcanic hazards and their probability of occurrence were analysed on the basis of data available in the scientific literature and were supplemented by two field missions combining geography and hydro-geomorphology. Our study enabled us to map the hazards of ash fall, lava flows, lahars and avalanches of debris. Each hazard was spatialised by being ascribed an intensity. They are sometimes synchronous with the eruption sometimes they occur several months or years after a volcanic eruption. The results are the first step towards developing a volcanic risk management strategy, especially for the pastoral communities living around Lengai and for the growing tourist activities in this area.

Giovanni Gullà, Gianfranco Nicodemo, Settimio Ferlisi et al.

Abstract This paper proposes a three-phase method that combines multi-source (i.e. topographic, thematic, monitoring) input data in a GIS environment to rank—at small (1:250,000) scale—administrative units (e.g. municipalities) based on their exposure to slow-moving landslide risk within a selected area (e.g. a region) and, accordingly, detect those primarily requiring mitigation measures. The method is applied in the Calabria region (southern Italy) where several municipalities are widely affected by slow-moving landslides that systematically cause damage to buildings and infrastructure networks resulting in significant economic losses. The results obtained are validated based on the information gathered from previous studies carried out at large (municipal) scale. The work undertaken represents a first, fundamental step of a wider circular approach that can profitably facilitate the decision makers in addressing the issue of the slow-moving landslide risk mitigation in a sustainable way.

Natalie Wright, Lucy Fagan, Jostacio M. Lapitan et al.

Abstract The Sendai Framework for Disaster Risk Reduction 2015–2030 recognizes health at the heart of disaster risk management (DRM) at the global policy level. Five years on, it has catalyzed the rapid development of the field of Health Emergency and Disaster Risk Management (Health EDRM) by providing a mandate for building partnerships as well as enhancing scientific research. Key milestones achieved include publication of the World Health Organization’s Health EDRM Framework, development of the WHO Thematic Platform for Health EDRM and the WHO Health EDRM Research Network, and further application of health information principles to DRM. Furthermore, health actors at all levels have continued to engage in the Sendai Framework processes and have had a key role in its implementation and proposed monitoring. There have been significant gains made through the partnership of health and DRM, but the relationship has not been without its challenges. Many national, regional, and global initiatives continue to operate with a lack of consistency and of linkages to respond to the Sendai Framework’s call for embedding health resilience in DRM, and conversely, embedding DRM in health resilience. Overcoming this hurdle is important, and doing so will be a key marker of success of the next 10 years of partnership under the Sendai Framework.

Xuesong Cai, Shijun Sun, Guangchun Zhou

Rice husks as common agricultural remnants with low density and good thermal conductivity properties have been used in infill walls in the northern area of China. Accordingly, many tests and numerical simulations were conducted to address a difficult issue, the inaccurate estimation on the lateral load-bearing capacity of different types of husk mortar energy-saving (HMES) wallboards. The difficulty has not been overcome so far, implying that the novel methods are anticipated to achieve the accurate estimation. This paper tests the full-scale HMES wallboards with different openings and obtains the strains at the points distributed on the wallboard sides. The experimental strains are modeled as the approximate strain energy values to produce the characteristic parameter of the HMES wallboard&#8217;s stressing state. Furthermore, the inherent working state characteristic points of HMES wallboards are revealed from the evolution of the characteristic parameter called as the normalized approximate strain energy sum, leading to the redefinition of the failure loads for the HMES wallboards. Finally, it investigates the stressing state mode evolution of the HMES wallboard around the failure loads. The achieved results provide the reference to the accurate estimation of the bearing capacity of the HMES wallboards.

Francisco Javier Jorquera Santis

El presente trabajo tiene como objetivo conocer los significados que el desastre del 27 de febrero de 2010 en Chile tuvo en las trayectorias de vidas de los individuos de las comunas de Constitución y Pelluhue, y describir las acciones colectivas que desplegaron ambas comunidades en función de responder y afrontar el incidente crítico. Además, se explora la forma en que el Estado, la Comunidad y su cultura influyeron en las estrategias desplegadas y en las significaciones elaboradas por los individuos protagonistas, entendiendo dicha articulación como factor de vulnerabilidad. Dichos objetivos se plantean con el propósito de contribuir al desarrollo de estrategias locales orientadas a la reducción del riesgo de desastres. La investigación es de carácter social cualitativa basada en narrativas, y considera como sujetos de estudio a quienes vivieron la experiencia en ambas comunas. Los resultados describen el comportamiento del colectivo en ambas localidades durante la respuesta y recuperación, y concluye que fueron condicionados por factores de vulnerabilidad socioeconómicos, político-institucionales y psicosociales, incidiendo además en la capacidad de resiliencia de dichas comunidades. También se destaca la promoción del individuo como actor social capaz de transformar su realidad social.

Johan Askman, Olof Nilsson, Per Becker

Abstract To investigate why people live in areas at high risk of floods, a qualitative case study was carried out in the areas around Akuressa, in southwest Sri Lanka. Data collection consisted mainly of semistructured interviews with local residents and government officials. The purpose was to study why people live in areas at high risk of floods, by looking beyond the purely physical aspects of living with hazards and exploring the underlying social factors. Four main factors were identified: an overall good living situation; a sense of place; difficulties relocating; and being well-adapted to the situation. The analysis also examined whether government officials shared the views of local residents. The findings highlighted both areas of consensus and discrepancies related to risk awareness, and the efficiency of risk reduction measures that had been implemented by the government. The case study identified and explored underlying social factors, such as risk normalization, risk trade-offs, and push-and-pull processes, which seem to influence the decision to live in a high-risk area.