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The frequent occurrences of bridge fires and the substantial disruptions and direct/indirect economic losses resulting from these events highlight the immediate need for effective fire-safety-oriented design of new bridges and retrofit approaches for vulnerable existing bridges. In this Perspective, we discuss why a holistic engineering approach integrating innovative fire analysis methods and structural design/retrofit strategies into multi-hazard and future-oriented risk modeling frameworks represents the way forward to more sustainable and resilient infrastructure in an uncertain and rapidly changing built environment. Bridge fires cause significant disruptions and economic losses in modern society, yet fire hazards are still often ignored or oversimplified in bridge design. This Perspective emphasizes the need for more holistic and comprehensive fire-safety design when retrofitting or designing new bridges.

Purpose This paper aims to present a literature review on the problem of fire following earthquake (FFE) as a potential hazard to communities in seismically active regions. The paper is important to work toward resilient communities that are subject to extreme hazards. Design/methodology/approach The paper lists and reviews the historical FFE events (20 earthquakes from 7 countries), studies the available analytical tools to evaluate fire ignition and spread in communities after an earthquake, discusses the available studies on performance of individual buildings under post-earthquake fires and summarizes the current literature on mitigation techniques for post-earthquake fires. Findings FFE can be considered a potential hazard for urban communities that are especially not prepared for such conditions. The available analytical models are not yet fully up to the standards that can be used by city authorities for decision-making, and therefore, should be further validated. Limited structural analyses of individual buildings under FFE scenarios have been completed. Results show that the drift demand on the building frame increases during post-earthquake fires. Despite the mitigation actions, there are still urban cities that are not prepared for such an event, such as certain areas of California in the USA. Originality/value The paper is a complete and an exhaustive collection of literature on different aspects of FFE. Research in earthquake engineering is well advanced, while structural analyses under fire load and performance of communities under FFE can be further advanced.

Recent studies have demonstrated the potential of hyperbolic paraboloid (hypar), a doubly curved geometry, in coastal engineering applications. Predicting pressure distribution, critical for subsequent finite element analysis, on such novel three-dimensional structures require Computational Fluid Dynamics (CFD) simulations, which are computationally intensive. To address this challenge, the current study develops an artificial neural network (ANN) surrogate to predict pressure distributions on hypar free-surface breakwaters (FSBWs) under solitary wave loading. Using Smoothed Particle Hydrodynamics (SPH) as the CFD tool, simulations generate the supervised learning dataset, where inputs are the hypar warping R[sub.n], breakwater draft d[sub.r], and wave height H. The targets consist of two 30×30 pressure maps at wave arrival (hydrostatic) and peak, together with the wave rise time P(t[sub.0]), P(t[sub.peak]), Δt=t[sub.peak]−t[sub.0]. Three architectures, FNN, CNN, and DeepONet, are trained with homoscedastic uncertainty loss weighting, each at two parameter sizes (~50k and ~500k). Results for training and testing show that all models achieve low errors, with models with ~50k parameters found to be sufficient, and scaling to ~500k yields some generalization improvement. Further reducing the parameters (~5k) degrades accuracy for all models, with DeepONet proven most robust to parameter size reduction. Overall, this study introduces a novel SPH-ANN workflow for predicting wave pressures on hypar FSBWs, where inference on new samples occurs in a few milliseconds per sample, delivering orders-of-magnitude speedups relative to running new SPH simulations. This computational efficiency enables rapid design iteration and optimization of hypar FSBWs, facilitating their potential deployment in coastal defense.

This paper presents a simplified parametric model for the estimation of depth-limited hurricane wave spectra, accounting for swell and wind-sea components, for coastal engineering applications. The model was evaluated against observations obtained from three shallow water sites in Florida during Hurricane David in September 1979. It was revealed that the parametric approach increases in accuracy with decreasing distance to the storm center and generally provides a conservative representation of the significant wave height, albeit overestimating the peak wave frequency. The model was subsequently adopted to evaluate the performance of tilted hyperbolic paraboloidal (hypar) shells (referred to as “kinetic umbrellas”) as an adaptable alternative to conventional floodwalls via smoothed particle hydrodynamics (SPH). The introduction of hypar geometry proved superior to conventional sloped barriers in reducing overtopping waves but decreases in effectiveness at levels of inundation greater than two-thirds the deployed height. Furthermore, umbrellas exhibiting larger geometrical warping were more capable at suppressing overtopping but must sustain larger base shear forces when subjected to irregular waves consistent with landfalling hurricanes.

This study investigates the potential of hyperbolic paraboloid (hypar) shapes for enhancing wave attenuation and structural efficiency in Free-Surface Breakwaters (FSBW). A decoupled approach combining Smoothed Particle Hydrodynamics (SPH) and Finite Element Method (FEM) is employed to analyze hypar-faced FSBW performance across varying hypar warping values and wave characteristics. SPH simulations, validated through experiments, determine wave attenuation performance and extract pressure values for subsequent FEM analysis. Results indicate that hypar-faced FSBW produces increased wave attenuation compared to traditional flat-faced designs, particularly for shorter wave periods and smaller drafts. Furthermore, hypar surfaces exhibit up to three times lower principal stresses under wave loading compared to the flat counterpart, potentially allowing for thinner surfaces. The study also shows that peak-load static stress values provide a reasonable approximation for preliminary design, with less than 6% average difference compared to dynamic analysis results. In summary, this research presents hypar-faced FSBW as a promising alternative in coastal defense strategies, offering effective wave attenuation and structural efficiency in the context of rising sea levels and increasing storm intensities.

Fire fragility functions are a powerful method to characterize the probabilistic vulnerability of buildings to fire in the context of urban resilience assessment. But this method is recent and the influence of the different uncertain parameters on the functions has not been systematically studied. The first objective of this paper is to identify the prevailing parameters in constructing fire fragility functions for steel frame buildings. To this end, sensitivity analyses are conducted using Monte Carlo Simulations and a variance-based method, focusing on column failure fragilities. Fragilities for buildings with 3 to 12 stories, 0 to 3 h fire resistance rating and various occupancies are compared, assuming compartment areas ranging from 15 m2 to 80 m2. Results show that uncertainties in fire, heat transfer and structural models all generate significant variability in the fire fragility. In addition to fire load as the intensity measure, significant probabilistic parameters are the compartment geometry and openings, the thickness and thermal conductivity of fire protection, and the temperature dependent mechanical properties of steel. The second objective is to clarify the incorporation of fragility functions in a comprehensive structural fire reliability framework. A methodology for combining the functions with the ignition likelihood per year and with the fire loading in MJ/m2 is described, yielding annual probability estimates of column failure due to fire in the buildings. For a sprinklered office building designed according to prescriptive provisions, this annual probability ranges from 1.90 × 10−7 to 0.12 × 10−7 per year as a function of the building height. The probabilistic modeling techniques proposed in this paper can be used to establish consistent reliability levels in different buildings and to evaluate resilience for fire scenarios.

The Pacific Northwest faces the looming threat of a massive 9.0 earthquake coming from the Cascadia Subduction Zone of the Juan de Fuca plate off the coast of Northern California, Oregon, Washington, and British Columbia. City officials, emergency managers, and researchers are preparing for this event by examining not only the earthquake itself, but also the cascading hazards that will follow it, such as fire and tsunami. Additionally, they must measure the effects of these hazards not just on the infrastructure systems they affect (e.g., water, power, transportation, communication, emergency services, etc.) but also how each system is affected by the failure of one or more of the others, or its “dependency.” The following paper discusses the effects of two cascading hazards—earthquake and fire—and the vulnerability of three infrastructure systems—building stock, water, and transportation—with a special focus on the needs of firefighters and other emergency services in the 12 h following a major seismic event. It then frames these methodologies in the context of a fine-grain case study of Seattle downtown and identifies three critical zones where mitigation measures would provide the most benefit. The discussion includes challenges in approaching such studies—the largest being available data, the uncertainties in making these evaluations, and general best practices for increased resilience in urban communities similar to the case study.

PurposeThis paper aims to develop a framework to assess the reliability of structures subject to a fire following an earthquake (FFE) event. The proposed framework is implemented in one seamless programming environment and is used to analyze an example nine-story steel moment-resisting frame (MRF) under an FFE. The framework includes uncertainties in load and material properties at elevated temperatures and evaluates the MRF performance based on various limit states.Design/methodology/approachSpecifically, this work models the uncertainties in fire load density, yield strength and modulus of elasticity of steel. The location of fire compartment is also varied to investigate the effect of story level (lower vs higher) and bay location (interior vs exterior) of the fire on the post-earthquake performance of the frame. The frame is modeled in OpenSees to perform non-linear dynamic, thermal and reliability analyses of the structure.FindingsResults show that interior bays are more susceptible than exterior bays to connection failure because of the development of larger tension forces during the cooling phase of the fire. Also, upper floors in general are more probable to reach specified damage states than lower floors because of the smaller beam sizes. Overall, results suggest that modern MRFs with a design that is governed by inter-story drifts have enough residual strength after an earthquake so that a subsequent fire typically does not lead to results significantly different compared to those of an event where the fire occurs without previous seismic damage. However, the seismic damage could lead to larger fire spread, increased danger to the building as a whole and larger associated economic losses.Originality/valueAlthough the paper focuses on FFE, the proposed framework is general and can be extended to other multi-hazard scenarios.

STEM education should not be focused solely on producing STEM professionals. Universities educate students who often transition in to leadership positions in government, education, civic administration, law and business, with significant influence in society. Thus it is our obligation to graduate students who can question, think, and analyze for themselves, and are scientifically and technically literate. Recognizing this, most universities require non-STEM students to take at least one STEM class. This paper illustrates effective teaching practices of an introductory course on structural engineering – to all majors – with research-based pedagogical techniques. The approach that has been taken to meet the objectives of effective practices, and evaluation is to “predict, experience, reflect” within the context of teaching fundamental physics as applied to engineering design. In this paper the research-based pedagogical techniques of teaching resonance in tall buildings is illustrated. Evaluation studies show that 90% of students reported moderate to great gain in interest in engineering; 100% reported moderate to great gain in recognizing engineering as a creative profession; 78% reported moderate to great gain in understanding how engineering helps people address real world issues; and, on average, 86% of students reported a moderate to great grain in their civil engineering content knowledge. Furthermore, a large majority of students reported moderate, good, or great learning gains from lecture demonstrations (100%), from the instructional approach taken in the class (95%), and from the hands-on activities (95%). These last 3 results further highlight the efficacy of the active learning pedagogies being developed and implemented in this course.

We report on the progress of a multi-institutional NSF-funded education project called the Creative Art of Structural and Civil Engineering. The specific goals of the project are to: 1. Transform an introductory engineering course with dramatically improved interactivity and accessibility for students of all backgrounds and majors; 2. Ensure that the course takes a form that can be readily adopted into the engineering and general education curricula of many types of institutions of higher learning; 3. Facilitate the dissemination, adoption, and continuous improvement of these course materials and teaching methods. In this report, we focus on the version of this course taught at Princeton University, Structures and the Urban Environment. The course examines the great works of engineers through case studies, critically evaluating them on scientific and aesthetic grounds, as well as analyzing the social context in which these works arose. For example, the minimal and sleek reinforced concrete bridges of Robert Maillart, or the ultra-lightweight thin-shell structures built by Félix Candela highlight how engineers can innovate with new materials to develop new aesthetic forms. Furthermore, by integrating efficiency, economy, and elegance, these works stress the importance of finding optimal forms for structures, and demonstrate how great works of engineering can be well-integrated into their environment. This project is relevant to the wider civil engineering community as it serves to engage a wide student body in understanding and appreciating the role of civil engineers in society. Furthermore, by spreading inspiring and engaging introductory course materials that adopt research-based teaching methods, integrate STEM with the humanities, and emphasize the social relevance, technical challenges, and creative aspects of the discipline, this project helps meet an urgent need to improve the retention of students in STEM disciplines. Since the launch of this project, our activities have included: developing, incorporating, and documenting active learning exercises and lecture materials; developing and analyzing student surveys, and conducting interviews and focus groups; identifying themes and learning goals; developing a website to disseminate teaching materials; organizing an annual workshop for universities interested in adopting course materials and teaching methods; and continuing to mentor workshop participants. We adapted the Student Assessment of Learning Gains survey to assess learning outcomes. In the first year of implementing this project, a large majority of students reported moderate, good, or great learning gains from lecture demonstrations (94%), the instructional approach taken in the class (90%), and hands-on activities (83%). With regard to course themes, 80% or more of students reported moderate to great learning gains in evaluating significant works of civil engineering based on their social, scientific and symbolic importance; relating the forms of structures they encounter in daily life to their function and to forces; possessing an aesthetic and technical appreciation for bridges, towers, shells, and other structures; and comparing, contrasting, and critiquing structures as works of structural art. These results highlight the efficacy of the teaching methods adopted and active learning exercises developed and implemented in this project.