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The production of pulp and paper from recycled paper generates significant quantities of deinking paper sludge (DPS). This sludge contains a significant amount of organic matter (36%) as well as heavy metals such as Pb, Zn, and Cr. In this work, the incorporation of DPS (0%, 8%, 10%, and 12%) in the manufacture of clay bricks leads to valorization of this waste by showing that two of its contents considered problematic (organic matter and heavy metals) have several positive effects. It was found that the organic parts were transformed into pores after brick firing (850°C), which improved thermal insulation while keeping mechanical resistance in conformity with usual standards. For the heavy metals, which make DPS a hazardous waste, a leaching test was employed. The results show that these metals were trapped in the ceramic matrix after the firing of bricks at a high temperature, resulting in a final product that was not dangerous. Other tests were carried out on bricks with DPS to evaluate density, water absorption, shrinkage, loss on ignition, porosity, and microstructure in order to characterize this new product. It was concluded that DPS can be used in clay bricks as an asset for the formation of pores to enhance thermal insulation. The addition of DPS can be optimized at 10% to comply with the standard and not exceed the required values for shrinkage, water absorption, and loss on ignition. [ABSTRACT FROM AUTHOR]

The filter paper (FP) method, a cost-effective, versatile, and convenient approach, has found extensive application in analyzing fine-grained soils, enabling the successful measurement of a broad spectrum of total and matric suctions. However, using the FP method in sand with a limited range of suction profiles has been notably underrepresented in the existing literature. Therefore, this study investigated the applicability of the contact FP method in establishing soil water retention curves (SWRCs) using five distinct FP calibration curves for 10 poorly graded sands. Among these calibration curves, the one presented by Chandler yielded the highest suction values, which were followed by those of ASTM. Furthermore, the FP results were subjected to fitting with a mathmatical model, which led to the observation that the overall trends in the obtained SWRCs displayed smooth sigmoidal shapes, resulting in a complete and coherent SWRCs. The SWRC results of five sand samples were assessed through validation against the hanging column technique (HCT) results, indicating a high degree of concordance and affirming the suitability of the FP method for sands characterized by a limited suction profile. Notably, the entire range of suction values fell within the 0.01–20 kPa range based on the calibration curves presented by Chandler and ASTM for all the examined sand samples, except sands 9 and 10. Furthermore, the suction values were unobtainable using the two aforementioned calibration curves within the ranges of 0.01–1.47 kPa and 0.01–0.172 kPa. [ABSTRACT FROM AUTHOR]

The article discusses the importance of reproducibility in academic research, particularly in the field of structural engineering. It acknowledges the challenges in achieving reproducibility, such as data storage and computing requirements, as well as proprietary issues. The authors argue for the development of a reproducibility policy in the Journal of Structural Engineering and the Journal of Bridge Engineering, taking into account the nature and culture of research in these subdisciplines. They propose a classification system that emphasizes the availability of data and metadata, and encourage authors to go beyond data availability by making models and other materials accessible. To incentivize research and data availability, the journals will provide a visible recognition badge for papers with open data/models/codes and may consider special recognition for these papers. The authors also outline the review process for data-verified papers, which involves three associate editors verifying the availability and representativeness of the data. [Extracted from the article]

The Journal of Construction Engineering & Management has announced the recipients of the 2023 Best Paper Award. The winning paper, titled "Deep Learning Image Captioning in Construction Management: A Feasibility Study," explores the automation of deep learning for image captioning in the construction management field. The authors present a systematic approach that includes developing a linguistic schema, creating a dataset of manually captioned images, and evaluating six deep-learning methods using eight metrics. The paper concludes that a method combining two advanced deep learning processes performed the best, and that automatic captioning in construction management is feasible. The article provides valuable insights and suggestions for future development in this area. [Extracted from the article]

This paper presents a unique study on the dynamic identification of the tallest glue-laminated timber frame building in the world using forced vibration tests (FVTs) and long-term ambient vibration tests (AVTs). Because the amount of sway in service under wind has become the governing design criterion for tall timber buildings, this paper aims to provide useful information and evaluate available tools and methods for modal identification in tall glulam timber frame buildings. First, combined operational modal analysis schemes based on the variational mode decomposition with the stochastic subspace identification and the random decrement technique were adopted to identify the modal properties from nonstationary ambient data. Then, unique full-scale forced vibration tests were conducted using two different methods to excite the building: measured electrodynamic shakers excitation and unmeasured rhythmic human-induced excitation. Finally, a finite-element (FE) model of the tall glulam frame building was developed and frequency response function (FRF)–based model updating was conducted showing that the FE model was able to predict the modal behavior of the test building. The results show that natural frequencies identified from output-only techniques are in good agreement with the FVT results. Damping ratios obtained from both AVTs and FVTs exhibited amplitude-dependent behavior with a larger variation observed in the FVT results due to larger range of response amplitudes. These results have significant consequences for the design of tall timber buildings under serviceability-level loading, where damping plays an important role. The resulting damping ranges presented in this paper can serve as a useful guideline for practicing engineers in developing their prediction models of tall timber buildings under serviceability-level loading. [ABSTRACT FROM AUTHOR]

This document is a discussion of various research papers on different topics. The first paper explores the influence of downstream channel width on flow features in a T-shaped open-channel confluence. The authors conducted numerical simulations to study flow characteristics such as stagnation zone location, tributary inflow angles, separation zone dimensions, flow acceleration, secondary flow patterns, and bed shear stresses. The second paper focuses on the backwater effect in a T-shaped junction channel, examining the impact of junction angle, width ratio, discharge ratio, and bed level discordance. The third paper discusses the backwater effect in river channels caused by variations in bed level and width ratios, finding that increasing discharge upstream and enlarging the downstream width of the main channel can mitigate the backwater effect. The final report analyzes the properties of the star system GJJ211936, including its spectral type, luminosity, and distance from Earth. It also examines the potential habitability of the system's exoplanets and emphasizes the importance of further research in the search for extraterrestrial life. [Extracted from the article]

As the service age of bridges increases, the degeneration of the bridge components leads to changes in the importance of corresponding state assessment indices. Employing fixed weights in bridge service condition assessments may result in inconsistent outcomes with the actual conditions. Therefore, this paper proposes an index weight updating method that aims to achieve index weight updating based on the operational status of bridges, thereby enhancing the accuracy of bridge service condition assessment results. This method utilizes the bidirectional projection of fuzzy numbers representing index state intervals and ideal targets as the technique for order preference by similarity to an ideal solution (TOPSIS) evaluation criteria for index importance. This paper conducts case analyses of a suspension bridge across multiple service periods which comprise three primary conditions: periods of intact bridge status, suboptimal conditions resembling expected degradation, and damaged status due to external effects. The case study results demonstrate that the updated weight using the proposed method effectively reflects the influence of actual changes in bridge status on the importance of indices. In the cases of good condition or matching the expected degradative state, the updated weights obtained could better reflect the actual service condition of the bridge compared to fixed weights provided by standards. When considering the effect of accidents or other incidental factors, the updated weights obtained through the proposed method could reflect the influence of actual component conditions on the importance of indices while the initial weights and age-dependent updated weights cannot. Thereby, the assessment results derived from this approach are more consistent with expected states and maintenance levels, validating its effectiveness and comparative advantages over alternative methodologies. The results indicate that the proposed method can significantly enhance the rationality of assessment index weights, serving as a more effective and rational approach for evaluating bridge service conditions. [ABSTRACT FROM AUTHOR]

Ground penetrating radar (GPR) is a widely utilized nondestructive testing technique for the detection and assessment of internal corrosion in concrete bridge decks. However, abnormal data generated during the practical application of this technology can reduce the accuracy of concrete bridge deck corrosion assessment. Aiming at this problem, this paper analyzes some common abnormal data from actual bridges GPR data and proposes corresponding automatic algorithms for anomaly correction to enhance assessment accuracy. The automatic algorithm focuses on two main aspects: correcting anomalies in direct coupling wave amplitudes based on data statistics and mitigating the impact of abnormal data due to incorrectly picked rebar on depth correction using density clustering. The specific process of the automatic method can be divided into four steps. First, automatic rebar picking is performed based on the preprocessed GPR data. Next, data statistics analysis is implemented on the extracted rebar data to identify and correct abnormal amplitude data. Then, the true rebar data are identified for depth correction based on density clustering. Finally, the bridge deck corrosion map is generated based on the corrected rebar reflection amplitudes and rebar positions. The feasibility of this method was verified through a case study with GPR data from two in-service bridges. The results show that this method can effectively and automatically identify and correct abnormal data. Moreover, the bridge deck corrosion map obtained by the proposed method is also more accurate. It can be concluded that the proposed algorithms can be used in bridge deck corrosion detection and assessment with GPR. Practical Applications: Ground penetrating radar (GPR) is a widely utilized nondestructive testing technique for concrete bridge deck corrosion detection and assessment. However, abnormal data generated during the practical application of this technology can reduce the accuracy of concrete bridge deck corrosion assessment. Aiming at this problem, this paper proposes a set of automatic data processing procedures for anomaly correction to improve the corrosion assessment accuracy. The feasibility of the proposed algorithms was validated through a case study with GPR data from two in-service bridges. The results show that these algorithms can effectively automatically identify and correct abnormal data. Moreover, the bridge deck corrosion map obtained by these algorithms is also more accurate. It can be concluded that the proposed algorithms can be used in bridge deck corrosion detection and assessment with GPR. [ABSTRACT FROM AUTHOR]

The identification of damage to concrete bridge surfaces is of great significance to maintaining the durability and reliability of bridges. However, it is difficult to identify small areas of damage, especially in high-resolution images. To conduct damage identification research in a targeted manner, this paper proposes a method of multidamage identification in high-resolution images based on You Only Look Once version 5 (YOLOv5). In this paper, a data set labeled with four types of damage (crack, spallation, hole, and rebar) is used for training, validation, and testing. To ensure that the network adequately learns the damage features, the high-resolution images are cropped into subimages via the autoadaptive window cropping method (AWCM) proposed in this paper. The cropping method can crop images according to the label information and protect the damage features from destruction during the cropping process. To avoid overfitting, it is necessary to balance the volume of different types of damage. After balancing, the count for each category is as follows: crack (4,980), spallation (5,225), hole (5,211) and rebar (5,020). The balanced data set can be used to train the deep learning network and construct the multidamage identification model. After identification, the subimages, and the prediction boxes of damages in them are restored to their original high-resolution images. The results show that the mean average precision (mAP) of all classes is 94.2%, and the values for cracks, spallation, holes, and rebars are 86.9%, 98.1%, 92.3%, and 99.4%, respectively, which indicates that the proposed method outperforms the other three methods (inputting original images directly, the sliding window cropping method, and the random centroid cropping method). [ABSTRACT FROM AUTHOR]

In this paper, we present a brief review of the most prevalent computer vision–based traffic signal recognition studies in the literature. Based on the adopted computer vision approaches, we classify the traffic signal recognition studies into three categories: model-based, classical machine learning–based, and deep learning–based methods. Additionally, we include an extensive analysis of the traffic signal data sets used for training and evaluating traffic signal recognition deep learning models. This paper provides researchers and practitioners with insight into the research trends in traffic signal recognition used in vehicle perception, emphasizing various adopted methodologies and their detailed performance parameters. Practical Applications: Traffic signal recognition is a crucial component of autonomous driving and involves detecting and recognizing different states of traffic signals. Over the years, researchers have explored a wide range of digital image processing and machine learning methods for traffic signal recognition applications. This paper provides a brief literature review of the most prominent traffic signal recognition studies. Innovations in this field are crucial to revolutionizing how autonomous vehicles interact with the existing traffic signal infrastructure and the surrounding traffic, leading to improved safety and better traffic management. Some of the significant challenges in this field derive from the requirements of addressing different lighting conditions, weather, and occlusions, which makes the ongoing research indispensable. [ABSTRACT FROM AUTHOR]

Accurate identification of structural displacements is important for structural state assessment and performance evaluation. This paper proposes a real-time structural displacement detection model based on computer vision and deep learning. The model consists of three stages: identification, tracking, and displacement resolution. First, the displacement target is identified and tracked by the improved YOLO v7 algorithm and the improved DeepSORT algorithm. Then, the Euclidean distance method based on inverse perspective mapping (IPM-ED) is proposed for the analytical conversion of the displacement. Next, the accuracy and effectiveness of this displacement detection model are evaluated through four groups of bamboo axial compression tests. A comparative analysis is conducted between the IPM-ED displacement analysis method and the commonly used ED displacement analysis method. Finally, the robustness of this method is tested by using a cable breakage test of a cable dome structure as an application case. The research results demonstrate that the maximum average error of the four groups of bamboo displacement tests is only 3.10 mm, and the maximum relative error of peak displacement is only 6.54 mm. The RMSE basically stays around 3.5 mm. The maximum displacement error in the application case is only 4.91 mm, with a maximum MAPE of 4.94%. In addition, the error percentage under the IPM-ED algorithm is basically within 5%, while the error percentage of the ED algorithm is more than 10%. The method in this paper achieves efficient and intelligent identification of structural displacements in a non-contact manner. The proposed method is suitable for environments where the contact displacement sensor is easily affected by vibration, the site is complex and requires additional displacement sensor fixing equipment, the displacement sensor with super-high structure is unsafe to deploy, and the contact displacement sensor in narrow space is inconvenient to deploy, so it has broad application prospects. [ABSTRACT FROM AUTHOR]

The construction industry is characterized by its fragmented nature, which introduces numerous uncertainties and challenges for project management. Analyzing project impact factors is crucial for federal agencies to mitigate risks, make informed decisions, and ensure successful project outcomes. Although many previous studies explored critical project impact factors for various project types, this paper's primary objective is to identify and categorize the impact factors critical to projects' success in federal facilities. Additionally, the study ranked impact factors based on their significance and relevance to project management teams in federal facilities. The study surveyed federal agencies to identify the top-ranking factors within and across categories based on their impact. The research methodology encompassed a thorough literature review, data mapping, survey development, and analysis to identify, classify, and rank impact factors for federal projects. Spearman's rank-order correlations were computed for correlations between the impact factor categories. The impact factors were ranked based on their relevance and importance for the federal facilities based on frequency distributions of survey results—aligning with the data mapping and correlations exercises. The study's findings indicate that the top five factors with a maximum negative impact on the federal capital facility project belong to the early project life cycle phases, classified within the Governance and Stakeholders and Planning and Execution categories. The paper's findings aim to emphasize the optimization of stakeholder engagement and strategic planning to address critical risks for federal capital facilities projects early in the project life cycle—particularly the detailed engineering and procurement stages. The study's findings contribute to a better understanding of project management in the federal sector and offer beneficial guidance for future project planning and execution. [ABSTRACT FROM AUTHOR]

The creep of bamboo scrimber is an important factor to be considered in engineering applications. Simply using the creep test method not only consumes a lot of time and money, but also cannot be extended to the full stress level. Therefore, in this paper, the short-term creep tests of bamboo scrimber under different stress levels (30% and 40%) and ambient temperatures (30°C–70°C) were carried out. The multicomponent Kelvin-Voigt model and generalized Maxwell shear relaxation model of bamboo scrimber were established. The Maxwell-3 shear relaxation model was used as the constitutive model of bamboo scrimber, and the creep finite-element model of bamboo scrimber under parallel-to-grain compression was established, which verified the creep constitutive model of bamboo scrimber. The results showed that the shear relaxation modulus exhibited a significant decrease during the unstable creep stage, reaching a maximum reduction of 62.0%. It showed nonlinear for the effect of ambient temperature on the compression creep of bamboo scrimber, and the creep rate near the glass transition temperature was significantly higher than that at other temperatures. The fitting coefficients, R -square of creep compliance models, were sorted as KV-4 and KV-5>KV-3>Burgers>KV-2. The fitting coefficients, R -square of the generalized Maxwell model of shear relaxation modulus, were sorted as Maxwell-4 and Maxwell-3>Maxwell-2>Maxwell-1. The simulated creep displacement error of the two specimens was 2.8% and 0.1%, respectively, which verified the accuracy of the numerical simulation method. The paper proposed creep behavior and a constitutive model for bamboo scrimber under parallel-to-grain compression, which holds significant theoretical implications for its widespread application. [ABSTRACT FROM AUTHOR]

This paper presents a new analytical solution to predict the ultimate depth and holding capacity of plate anchors based on an integrated analysis of the anchor and mooring system. The configuration equations of the mooring line, both in soil and water, have been solved to obtain the complete line profile. A key advancement is that the mooring line angle at mudline varies compatibly with the whole anchor–mooring system. This is different from the solutions available in literature that neglect the mooring line segment in water and only assume a constant mooring line angle at the mudline. The system of equations is solved by using an iteration scheme, and parametric studies are demonstrated. The effects of line length, water depth, and seabed strength profile are explored by demonstrating the performance of a commercial plate anchor. It is found that neglecting the mooring line in water can significantly overestimate the ultimate embedment and capacity, especially when the mooring line length is relatively short. This paper can be used as an engineering tool to predict the ultimate capacity of an anchor–mooring system considering the integrated behavior of the whole system. [ABSTRACT FROM AUTHOR]

When the temporary backfilled subgrade is not sufficiently compacted, the result is low stiffness of the track system. Excessive deformation of railway tracks under the action of freight trains will aggravate track wear and reduce service life. However, traditional reinforcement technology to increase the stiffness of the track system is sometimes limited due to requirements of working space, efficiency, and little disturbance of the normal operation of the existing railway. Battered grouted helical piles (BGHP) are a kind of strengthening technology that has little influence on the existing railway and high construction efficiency. This paper presents a field case study of the implementation of BGHP to reinforce the freight railway subgrade. The paper evaluates the effect of the BGHP on the dynamic response of the treated subgrade. The subgrade soil was initially characterized by cone penetration tests at one location before BGHP reinforcement. The subgrade dynamic deformation modulus was measured before and after BGHP installation. In addition, the acceleration and velocity time histories of the subgrade were monitored during the passage of a freight train before and after BGHP reinforcement. The field measurement showed that the vibration acceleration, velocity, and displacement of the subgrade all decreased while the dynamic deformation modulus of the subgrade increased after BGHP reinforcement. Further, the vibration level reduced remarkably, mainly in the frequency band of 44.7 to 56.2 Hz, and the distribution of the normalized accumulated energy of velocity and acceleration was significantly influenced after BGHP reinforcement. The findings from this case study are of practical value to the emerging application of the freight railway subgrade reinforced by BGHP. [ABSTRACT FROM AUTHOR]

A major full-scale experiment called the Tunnelling and Limitation of Impacts on Piles (TULIP) project was conducted in 2020 on Line 16 of the Grand Paris Express project to analyze the tunnel boring machine–soil–pile interactions during tunnel excavation near deep structures. This paper presents the greenfield ground response observed when the tunnel boring machine (TBM) crossed the TULIP site: surface displacements, subsurface displacements, and pore water pressures are presented. The originality of the paper lies in the fact that details are provided not only on the site geological and geotechnical characteristics, but also on the TBM operation: a detailed analysis of the variations in pressure inside the cutting chamber of the earth-pressure balanced machine (EPBM) is proposed. This paper reports factual data without bias induced by a preconceived numerical model, but highlights open questions that challenge the advanced numerical models, that will be required to analyze completely the tunnel–soil–pile interactions. [ABSTRACT FROM AUTHOR]

Recent studies in earthquake engineering have outlined the difficulty of ground response analyses (GRAs) to replicate the observed ground motion and related variability at borehole array sites. Improvement of the seismic site response estimation requires accounting for and propagating the uncertainties in local soil conditions into surface ground motion. Uncertainties in site conditions arise from a number of factors, which include the uncertainties in the shear-wave velocity (VS) that are mainly caused by the natural spatial variability of soils and rocks. In this paper, a novel VS randomization approach is proposed to propagate the small-scale spatial VS heterogeneities into samples of VS profiles within a nonstationary probabilistic framework, to be further used in one-dimensional (1D) GRAs. The nonstationary approach is based on partitioning a borehole base-case VS profile into several locally stationary layers. The proposed approach was applied at three European sites exhibiting different subsurface soil conditions. Compared with both the classical stationary and an approach from the literature for VS randomization, the proposed approach provides a set of VS profiles fully consistent with the pseudoexperimental site signatures in terms of surface-wave dispersion curves, fundamental and higher-mode resonance frequencies, and site amplification. This paper also outlines the importance of the method used to measure VS profile in both the estimation of depth-dependent variability of VS at a given site and the prediction of site response variability. [ABSTRACT FROM AUTHOR]

Solutions for unloading stress waves in the continuous medium are widely applied to analyze the transient effect of excavation unloading in deep-buried tunnel engineering. This paper explores a semianalytic model for studying dynamic stress adjustments during transient excavation unloading in deep underground tunnels. The model employs finite time steps and toroidal elements on temporal and spatial scales, utilizing an iterative algorithm for dynamic response calculation. Griffith and Mohr–Coulomb strength criteria are introduced to calculate the difference in the critical generalized additional stress. This difference classifies stress adjustment paths into crack–shear (crack first and then shear) and shear models (shear only). Updated discontinuous boundaries are considered in the cracked element. Investigating the effects of unloading duration and initial in situ stress on dynamic response, a stress release index is realized to quantify the dynamic stress adjustment. Shorter unloading durations lead to more pronounced stress fluctuations, and higher stress release aggregation results in smaller plastic zones. Positive correlations between initial in situ stress and response characteristics are observed, resembling triaxial unloading test results. The model proposed in this paper enhances the understanding of the failure mechanism in the unloading process for deep hard rocks in underground engineering. [ABSTRACT FROM AUTHOR]

This paper pertains to the finite-element lower bound limit analysis (FELA-LB) of vertical strip anchors embedded in cohesionless and cohesive soils and subjected to static and earthquake forces (using pseudostatic analysis) to estimate the optimal horizontal pullout capacity using nonlinear programming (NLP) technique for isolating the optimal solution. In the developed procedure, a mesh of finite-number triangular elements and assuming a linear stress field that satisfies all the equations of internal equilibrium at all points within the soil medium, elemental interface equilibrium, boundary conditions and no-yield conditions at all the nodal points, has been adopted. In contrast to the use of linear programming (LP), as used in the early phase of the development of FELA of stability problems, in the adopted optimization scheme (NLP), the nonlinear no-yield conditions are incorporated directly, eliminating the necessity of successive linearization of the no-yield constraints. The convergence of the solutions (by varying the number of elements in the soil mesh) and extensibility of the selected stress field (by extending the mesh of elements) has been checked and ensured. The correctness of the estimated lower bound has been checked by comparing the obtained solutions with those reported in the literature. Parametric studies showing the effect of the embedment depth of the vertical anchor, soil properties, and earthquake acceleration on the horizontal pullout capacity of the vertical anchor have also been presented in the paper. Practical Applications: Anchor plates are used in the design and construction of foundation for retaining walls, sheet piles, bulkheads, transmission towers, bridge abutments, and buried pipelines to withstand the horizontal, vertical, or inclined loads. The present study adds to the existing state of art for the design and installation of anchor systems subjected to static and seismic conditions and may improve the performance of such foundation systems. [ABSTRACT FROM AUTHOR]

The enhancement of construction safety performance heavily relies on effective safety training. While virtual reality (VR) technologies have been utilized to improve construction safety training programs, the extent and mechanisms of improvement brought by VR remain unexplored. This study provided explanations on how the effectiveness of VR-based safety training for a heterogeneous workforce was achieved by investigating two mechanisms, namely embodied cognition and emotion arousal, from the physiological perspective. Randomized controlled experiments were conducted with three forms of safety training, namely paper-based training, VR-based learning, and VR-based experiencing, for both novice learners (NPs) and learners with prior knowledge (PPs). Digital eye-tracking and physiological devices and measurements were used to collect objective data. The results revealed better hazard recognition performance in both VR-based learning and VR-based experiencing groups than that in paper-based training groups. The results also revealed that VR-based learning was more effective for NPs than for PPs in acquiring safety knowledge, but VR-based experiencing was more effective for PPs than for NPs in stimulation of emotions. This means that the NPs benefit more from embodied cognition provided by the immersive environment of VR-based learning, and the PPs would be trained better with emotional arousal from the thrill of VR-based experiencing. The discovered mechanisms of embodied cognition and emotion arousal shed light on the underlying processes that contribute to the positive outcomes and promotion of VR-based training. [ABSTRACT FROM AUTHOR]

The social risk of a community renewal project is a macro concept, which is composed of many micro social risk factors. Community renewal projects involve a large number of stakeholder subjects, and the relationship between the subjects is intricate and complex, which leads to a more diversified source of social risk factors behind community renewal projects. There are interactions and interdependence among many factors, and complex interactions form a coupled relationship between the factors. In this paper, an original corpus is constructed based on online and offline data, and 19 risk factors of community renewal projects and the coupling effects of the factors are identified through the grounded theory. The factor weights are solved through the analytic network process (ANP). The dynamic evolution model of social risks is constructed through the system dynamics model based on the factors, the coupling effects of the factors, and the factor weights, so as to simulate the dynamic evolution process of the social risks. The results show that factors such as the management mechanism soundness have larger weights, and in the process of social risks evolution, core factors such as unsound management mechanism will trigger a series of other risk factors, which will increase the overall social risks. This paper identifies the key factors of social risks, clarifies the complex coupling relationship between the factors, provides a dynamic evolution model, reveals the dynamic evolution process of social risks, and provides theoretical basis and countermeasure suggestions for efficiently identifying and controlling the social risks of community renewal projects. Practical Applications: Community renewal projects involve numerous stakeholders, including the government, enterprises, and residents. These stakeholders interact frequently, creating complex relationships that significantly impact the project. The diverse factors from these stakeholders can lead to significant social risks in community renewal projects, with these factors influencing and interacting with each other. This paper constructs a dynamic evolution model of social risks, which can reveal how social risk factors from diverse entities evolve dynamically. It uncovers the micro-level components behind the macro concept of social risks, helping managers and practitioners clarify the constituent factors of social risks and their dynamic interrelationships. By predicting social risks and their evolution in community renewal projects, this model provides a theoretical basis and feasible suggestions for efficiently identifying, evaluating, analyzing, and controlling social risks. Ultimately, it contributes to enhancing the efficiency and sustainability of community renewal projects. [ABSTRACT FROM AUTHOR]

Recent technological advancements are transforming the architecture, engineering and construction (AEC) industry, focusing on digitalization and automation opportunities as drivers for improvement. In a realm as complex as building permitting, the drive for automation should be anchored in a comprehensive understanding of the process it seeks to transform. Furthermore, analyzing the process from a global perspective is essential for identifying opportunities for improvement. This article addresses the need for a systematic and robust approach to evaluate and compare building permit processes globally. Traditional approaches for process comparisons fail to capture the intricacies of a building permit process. Hence, in this paper, the authors propose and introduce the Process Analysis and Comparative Evaluation methodology, PACE-BP, which was tailored for building permit processes. The proposed method relies on a previously developed framework for process mapping which provides a comparable data set of building permit process maps in different countries. The comparative evaluation is then performed by assessing the maps based on predefined indicators, which are used to compile a representative vector for each process. The computational method for compiling the vectors and calculating the similarity measures between pairs of processes is described in detail. The application of PACE-BP for analyzing and comparing building permit processes in Germany, the US, Israel, and Italy is demonstrated in this paper. Our findings challenge the pursuit of a universal "best practice," emphasizing the need to balance priorities and stakeholder's objectives. The PACE-BP method is a powerful tool for policymakers and stakeholders, providing meaningful insight into existing processes and pinpointing drawbacks and limitations in current practices, while revealing opportunities for improvement. [ABSTRACT FROM AUTHOR]

Conducting an assessment of ecosystem service values and examining the influence of changes in land utilization on these values in Chengdu City help to deepen our comprehension of the ecological and environmental impacts of such changes. This, in turn, provides valuable insights into the construction of an ecological civilization and the sustainable utilization of land resources in Chengdu City. Based on land-use data from 2005 to 2020, this paper employs a dynamic model of land-use change, the land-use structure change index method, and an ecosystem service value measurement model to analyze the impact of land-use change on ecosystem service value in Chengdu City. The results showed that (1) the area of construction land in Chengdu City increased and those of cultivated land and unused land decreased; (2) from 2005 to 2014, the ecosystem service value in Chengdu City witnessed a rise of 1.559 billion yuan, while from 2014 to 2020, it experienced a decline of 947.77 million yuan; and (3) the sensitivity index of the ecosystem value shows that forest land contributes the most to the total value of ecosystem services. This paper comprehensively analyzes the impact of land-use change in Chengdu City from 2005 to 2020 on the ecosystem service value. It offers a reference foundation for advancing the efficient allocation of land resources in Chengdu City and nurturing the balanced and sustainable development of the economy and ecology. [ABSTRACT FROM AUTHOR]

In today's increasingly complex stock era, resilient community planning for uncertainty risks is important for building resilient cities and communities and for realizing the refinement, process, and systematization of planning. Therefore, this paper proposes the concept of community planning resilience based on resilience theory and explores a framework system for evaluating the planning resilience of renewal and transformation community by taking renewal and transformation future community planning of Zhejiang as the research object. At the same time, the technical path of realizing public participation in community planning is explored through the method, mechanism, and technical platform of fuzzy group decision-making. Finally, the feasibility of the aforementioned framework and approach is experimentally explored and verified based on a typical case of renewal and renovation of future community planning. In order to make community regeneration planning more planning resilient, this paper develops a community planning group decision-making study from the perspective of community planning resilience, which provides a new research perspective for the field of community resilience and provides a reference for community planning evaluation and the construction of resilient communities. Practical Applications: In China's advancing urbanization, major cities are grappling with diverse risks, necessitating urban planning and governance with heightened resilience to face unforeseen black swan events and foreseeable gray rhinoceros challenges. This urgency is particularly pronounced in community renewal, prompting a vital shift from rigid to resilient planning methodologies. To address this shift, this paper advocates for resilient community construction to be a focal point in both policy and practical implementation of community regeneration. A novel approach utilizing the fuzzy decision-making method is proposed to establish a comprehensive resilient community renewal decision-making technology support system. This system employs a fuzzy comprehensive evaluation method, integrating an empowerment approach to simplify the complexities of a multicriteria index system. By mitigating the risks inherent in resilience planning, our approach enhances the scientific foundation and feasibility of decision-making in community renewal. A case study on the Future Community in Zhejiang Province validates the effectiveness of our approach, providing practical insights for constructing resilient community renewal models and system technology platforms. This research contributes to the ongoing exploration of strategies and technologies capable of addressing diverse challenges in urban development, providing references in enhancing urban resilience. [ABSTRACT FROM AUTHOR]

Doha, the capital city of Qatar, has experienced remarkable urban growth over the last two decades. This raises concerns regarding the city's fulfillment of compactness, complexity, and connectivity. This paper considers transit-oriented development (TOD) as a potential tool to attain a sustainable and diverse urban landscape in a situated context. Qualitative research methods, which include observations and mapping, are employed to gain a deeper understanding of the physical aspects of a situated context in the neighborhood of Al-Slata, Doha. Specifically, this paper aims to investigate the implementation of TOD in metro station precincts within Al-Slata based on five design aspects: (1) walkability; (2) balance of ground use; (3) mixed-use spaces; (4) intermodality and transportation hubs; and (5) a public transportation network. The findings include a lack of complexity and connectivity between urban activities and spaces adjacent to the metro station. In addition, these findings demonstrate the potential of metro stations to preserve the cultural heritage and social identity in a rapidly developing city like Doha. The recommendations include a layout design proposal to increase connectivity and complexity within the situated context and suggestions on how transit nodes and metro stations could become active hubs within the city. [ABSTRACT FROM AUTHOR]

From the perspective of transportation infrastructure upgrading, this paper discussed the motivation behind industrial firms' pollution transfer to provincial borders. Using a panel data set of 41 cities in China's Yangtze River Delta from 2005 to 2020, this paper empirically tested the impact of intracity and intercity transportation infrastructure upgrading on pollution transfer through a two-way fixed-effects model. The results revealed the following: First, intracity transportation infrastructure upgrading forces local industrial firms to transfer pollution outward. Second, intercity transportation infrastructure upgrading accelerates pollution transfer to provincial borders. Third, in the central region, intracity transportation infrastructure upgrading does not significantly impact local pollution transfer. Intercity transportation infrastructure upgrading can aggravate border pollution, whether in the eastern or central regions. Furthermore, border pollution is more serious in the central region. The results have important practical significance for improving China's regional development planning and environmental governance system. [ABSTRACT FROM AUTHOR]

Environmental issues are often neglected in previous studies on site layout evaluation problems. To address this research gap, a comprehensive evaluation model is developed to evaluate construction site layout planning in this paper. The proposed evaluation model includes four aspects: (1) land use; (2) safety; (3) logistics; and (4) sustainability evaluations. To make the results of the evaluation more accurate, the evaluation model includes the subjective factors that need to be scored by the experts and the objective factors that could be gained from the inspections of the projects and the related materials. Then, the entropy weight method-based Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is chosen to solve the proposed multicriteria evaluation model. In this paper, the construction site layout planning for four different typical and practical cases, which include two commercial mixed buildings, a residential building, and a sewage treatment plant, is studied. The evaluation results proved that the proposed model is suitable to evaluate common types of construction, such as residential and commercial buildings but not specific functional types, such as the sewage treatment plant. [ABSTRACT FROM AUTHOR]

Even though advanced heuristic and metaheuristic models have been developed for minimizing financing cost by using total float to adjust the start times of activities, these models overlook the fact that the attempt to minimize financing cost may result in more than one work schedule with minimum financing cost. It is therefore not surprising that no research has been conducted to select the best financing schedule out of the multiple optimal work schedules. It is well known that total float must be used sparingly to avoid the creation of too many critical and near-critical activities that may cause delays in the project duration. Indeed, the loss of schedule flexibility caused by the use of total float comes at a cost. It is argued in this paper that the cost of float consumption should be a vital part of models designed to minimize financing cost. The research presented in this paper attempts to fill this gap. A model is proposed in this study that not only minimizes financing cost but also demonstrates the negative impact of not considering the cost of float consumption in reaching the optimal solution, an area of research that is mostly overlooked in the finance-based scheduling literature. This research contributes to the body of knowledge by demonstrating that there may be more than one work schedule with minimum financing cost, and that the cost of float consumption must be considered to find the most optimal solution. [ABSTRACT FROM AUTHOR]

The growing demand for sustainable and affordable construction, paired with labor shortages, requires more efficient tools and methodologies. Industrialized construction (IC) is one solution that has the ability to address construction efficiency by utilizing techniques such as modularization, construction automation, and building information modeling. One particular aspect of IC is Design for Manufacture and Assembly (DfMA) since the design phase determines up to 80% of the operating costs. However, DfMA is yet to be implemented in the construction industry due to some challenges in DfMA that inhibit full implementation. The majority of construction manufacturers have to regenerate the construction drawings for manufacturing which add substantial time to the schedule. Delays are caused by the lack of coordination of these components, as well as assemblies' connections, compliance with building codes, and other related policies. Although many scholarly manufacturing and assembly works have studied and reviewed various aspects, techniques, and applications of DfMA, none have looked at the design process, tools and methods, or challenges in design automation. Using a systematic literature review, this study reviews the most recent innovative design responses for manufacturing and assemblies, and tools and methods. The study then analyzes the identified challenges of DfMA automation and processes in the existing literature on the construction industry, such as the lack of autonomous design and construction manufacturing. The literature analysis suggests future studies are required to improve DfMA not only as a technique but as a design strategy, particularly during the design process and prior to the production phase. Finally, future directions are provided to lead the next generation of research to advance building construction. Significantly, the results of this research provide an up-to-date status on autonomous DfMA and contribute to the body of knowledge of IC by synthesizing the state-of-the-art of building design automation and methods for manufacture and assembly. Practical Applications: Shifting the construction work from a jobsite to a factory environment and utilizing automation are resolutions to a lack of construction efficiency. Factory automation highly relies on DfMA processes. Automating the manufacturing process itself requires advanced knowledge, particularly DfMA; which is a common term referring to both management and technology that enables designers to ease a product's material selection, cost, and factory production. Studies have addressed the state-of-the-art for DfMA, but none have looked at the design process from the early design stage, tools and methods, and the associated challenges. This paper provides a review of design automation techniques in various thematic categories including (1) design scale, from an entire building scale to a small component like a wall, (2) design parameters like structural strengths and sustainability, (3) building material types, (4) tools and methods, and (5) the challenges for implementation. The provided paper is a fundamental resource for DfMA research in construction manufacturing. Manufacturers, developers, and builders require such a resource to learn more about various aspects of the design process and associated challenges to either improve their production lines or establish new state-of-the-art factories. [ABSTRACT FROM AUTHOR]

Asphalt pavement's density measurement is an important step in the quality control of asphalt road construction. It is usually achieved by applying the coring method (CM), nuclear density gauge (NDG), and electromagnetic density gauge (EDG). CM is the most accurate method, but it is a destructive method because the pavement is damaged when the cores are taken. NDG and EDG are nondestructive methods with high efficiency, but their measurement accuracy is poorer than that of CM. An EDG commonly used in density measurement is named pavement quality indicator (PQI). A novel method named density profiling system (DPS) is also based on the potential EDG. However, it was not applied to this research because more tests are required to verify its accuracy. This paper presents an approach to improve the accuracy of the nondestructive methods with NDG and PQI. It is based on the artificial neural network (ANN), which processes the raw data got from NDG and PQI and produces the predicted asphalt density as the output. The density measured in CM was used as the target density and the error between ANN-predicted density and target density was computed. To minimize this error, various ANN architectures and learning algorithms were tried in the ANN training process. Each established ANN model makes a substantial improvement in the performance of NDG or PQI in asphalt density measurement. Practical Applications: This research was initiated by Fulton Hogan (FH) Limited, a large road construction and maintenance company in New Zealand. FH lab teams are responsible for asphalt road density measurement in FH's road projects. One of the main method they use is to measure the densities of the cores taken from asphalt pavements (coring method). It is quite accurate but destructive and very time-consuming. They also use NDG or PQI, which are highly efficient nondestructive measurement devices. However, their measurement accuracy is poorer than that of the coring method. FH lab teams wanted to have a new density measurement method that is both accurate and efficient. An ANN-based approach is presented in this paper to address the issues faced by the FH lab teams. Densities collected with coring methods, NDG, and PQI were used to train and validate the ANN models. The results from the ANNs show substantial improvements of the measurement accuracy and efficiency. The proposed approach has been presented to the FH lab teams, who are impressed with its performance and plan to implement it in their projects. [ABSTRACT FROM AUTHOR]

Wind turbine blades are primarily composed of fiberglass composite, posing a significant recycling challenge for the wind energy industry. This paper introduces a novel recycling approach by comprehensively analyzing the pozzolanic reactivity of recycled powder as a new supplementary cementitious material (SCM). A systematic characterization using laboratory techniques is first described, establishing both the chemical and morphological properties of the powder and suggesting that the material was likely to be capable of acting as a pozzolan. The effects of thermal and mechanical processing on the reactivity characteristics of the material were elucidated using a suite of analytical and standardized characterization approaches. It was found that through heat treatment to remove impinging resin and subsequent mechanical processing to synthesize a fine powder, the reactivity of the material could be improved to an extent at which the performance characteristics of a conventional class F fly ash were closely matched. For instance, mortar containing 10% of thermally-mechanically processed powder achieves 95% of the 28-day strength of cement mortar. This paper opens the door for both the use of these materials to bolster dwindling supplies of supplementary cementitious materials, and to provide a much-needed reprocessing route for waste fiberglass which are otherwise highly challenging to dispose of cost-effectively. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is a solid waste generated by phosphate fertilizer industries that is currently used in concrete materials. However, adding PG to concrete usually results in reducing its water resistance and corrosion resistance. This paper presents a new method of applying PG to concrete to improve its water resistance. In this paper, a green superhydrophobic PG (SPG) coating was prepared using modified PG as a hydrophobic medium and cement as the bonding material. The contact angle between the superhydrophobic phosphogypsum coating (SPG coating) and water was 156°, and the coating reached a superhydrophobic state with good self-cleaning ability. Even when sandpaper was used to polish the coating, the water contact angle of the coating was still greater than 150°, indicating that the coating had good wear resistance. In addition, the results of water absorption and electrochemical experiments indicated that mortar coated with SPG had better water resistance and corrosion resistance than ordinary mortar. The SPG coatings with water resistance, wear resistance, and self-cleaning properties have potential applications in building exterior walls. [ABSTRACT FROM AUTHOR]

The cooperative operation of cascade reservoir systems is an efficient way to regulate water resources. However, noncooperation among various reservoir stakeholders is often observed in practice; this produces an interesting dilemma in the game of water resource management. Considering the upper Yellow River cascade reservoir system as a case study, in this paper we model and analyze the cooperation dilemma in a cascade reservoir system. In our game theoretical analysis, we find that, except for the most upstream reservoir, all reservoirs have free-ride strategies. The free-ride strategy indicates that a reservoir obtains free gain from the cooperation of other reservoirs due to spatial connections, and this fact changes the cooperative game in terms of equilibrium and benefit allocation. The results show that the regulation capacity of the free rider directly affects the equilibrium and benefit allocation of the game. A midstream reservoir with a small or medium regulation capacity tends to employ a free-ride strategy. A midstream reservoir with a large regulation capacity can entirely interrupt the cooperation between upstream and downstream reservoirs, interestingly, which can lead to the disappearance of the free-ride strategy for the midstream reservoir. However, the downstream reservoir may employ a free-ride strategy when the midstream reservoir chooses to cooperate. This implies that grand cooperation is not stable when considering free-ride, whereas partial coalitions are more likely to form. In this paper, we derive equilibrium in the cooperative game of cascade reservoirs, providing theoretical interpretation of the noncooperation phenomenon in the operation of cascade reservoirs. [ABSTRACT FROM AUTHOR]

Marginalized communities disproportionately experience the impacts of climate change, including more intense flooding and longer recovery times from disasters. Youth, particularly those belonging to marginalized communities, are consistently underrepresented in infrastructure planning decisions despite being the group most impacted by the long time scales of climate change, water management, and community infrastructure decisions. This paper investigates the novel perspectives that youth bring to planning processes and resulting impacts on recommendations for green stormwater infrastructure solutions to address flooding and community-scale factors important to achieving disaster resilience. Particular attention is paid to the infrastructure benefits prioritized by youth and characteristics of selected locations for infrastructure solutions. Further, the capabilities possessed by youth to effectively advocate for specific community infrastructure changes are not well researched, and the education and resources required to transform youth advocacy into action are not well understood. Through mixed methods, including quantitative and qualitative data and analysis, this paper explores the impact of youth education on building advocacy and the ability to create implementable stormwater infrastructure designs. The research is based on the development and implementation of a new interdisciplinary program called Youth Advocacy for Resilience to Disasters (YARDs). Funded by the National Science Foundation, the YARDs program teaches youth about natural disasters, resilience, data communication, green infrastructure, and presentation skills. The curriculum was developed by interdisciplinary researcher teams, combining civil engineering, sociology, urban planning, digital media, and education research. The program was piloted as a weeklong summer program for middle school students, and later implemented as a semester-long program. Both implementations focused on students developing green infrastructure recommendations that address flooding and other student-identified risks to communicate to community decision makers. The methods are readily transferable to other potential youth programs in areas impacted by flooding with expansion to additional communities facing different combinations of disasters. [ABSTRACT FROM AUTHOR]

Rapid launching is a crucial technology for the digitalization and regularization of space transportation systems. This paper focuses on the fast trajectory prediction of the launch-vehicle boost phase. A high-precision and high-efficiency analytical solution of the whole boost phase dynamics model of the rocket is obtained by adopting one of the regular perturbation methods called the state-space perturbation method in the launch rotated coordinate system. An analytical framework known as the perturbation expansion framework is proposed by first figuring out the correlation with the state variables/independent variables and then performing the approximate expansion. This framework can successfully address the issue of analytically solving the transfer matrix and integral term caused by the coupling and time-varying properties among state variables of the affine equations of the boost phase. The analytical solution developed in this paper has great fidelity and takes into account the combined effects of various factors, including thrust, aerodynamic force, Earth's gravity, oblateness, and rotation. It can serve as a theoretical guide for the rapid launch requirements and iterative design processes for early rocket demonstrations in engineering. [ABSTRACT FROM AUTHOR]

This paper presents the mathematical derivation and numerical implementation of a novel regularized density-driven damage mechanics (D3M) model for simulating failure in concrete members. The novel idea behind the derivation of the approach is that damage is described as a function of the local change in material density. This choice is justified by the fact that the development of local damage directly corresponds to a reduction in local density since undamaged cementitious composites inherently have a higher density than the fluid or gas that occupies damaged regions. For this reason, devising numerical approaches that can predict the material behavior as a function of density could open up new possibilities for the prediction of the nonlinear behavior of concrete structures, as well as the derivation of novel testing procedures for the evaluation of strength by means of direct and indirect measures of density. In this context, a three-phase mesoscopic representation of concrete material is used, where coarse aggregate, mortar, and the interfacial transition zone are explicitly modeled to obtain a realistic representation of the material internal structure. The manuscript first presents the mathematical derivation of the model, with emphasis devoted to the regularization of the computational implementation. This paper then proceeds to demonstrate that the novel regularized D3M is insensitive to the mesh size chosen to represent the three material phases while also predicting realistic compression-to-tension strength ratios and damage patterns at failure. In addition, a parametric study is carried out to illustrate the effect of the relevant mechanical parameters on the observed response. Finally, the proposed model is validated by comparison with experimental results of 3-point bending tests on plain concrete beams of various sizes, also demonstrating that the regularized D3M is capable of predicting size effect in concrete members. [ABSTRACT FROM AUTHOR]

High-rise structures with large aspect ratios are subjected to unexpected motions under wind excitation. Structural vibrations induced by vortices in the wake were captured by aeroelastic real-time hybrid simulation (aeroRTHS) in the companion paper. An effective and practical method is critical for explaining the mitigation of adverse wind loading impact upon these structures. Analyzing the performance of structural control devices against wind excitation in an aeroelastic wind tunnel test often is time- and cost-intensive. In this paper, aeroRTHS testing is extended to include (1) a vibration control device numerically added to the numerical substructures and tested to mitigate the cross-wind oscillation in the aeroRTHS framework; and (2) the use of 128 pressure sensors installed on two side faces of a physical building model in a boundary layer wind tunnel (BLWT) at the University of Florida Natural Hazards Engineering Research Infrastructure Equipment Facility (UF NHERI EF) to provide a more complete description of the wind-force distributions imparted on nine building configurations both with and without a tuned mass damper (TMD) at various constant wind speeds. Wind-force distribution was characterized in the time domain in terms of time histories of equivalent forces and displacements, and envelopes of wind forces. Frequency response analysis was conducted based on power spectral densities of input equivalent wind forces and output structural dynamic response. Results from the aeroRTHS tests demonstrated that the aeroRTHS method is capable of investigating aeroelastic structures with passive mitigation devices. The aeroRTHS tests in the wind tunnel demonstrated that the augmentation of buildings with TMDs is an effective way to attenuate the cross-wind vibration in tall buildings. [ABSTRACT FROM AUTHOR]

The warming climate in high-latitude permafrost regions is leading to permafrost degradation. Estimating seismic wave velocities in permafrost could help predict the geomechanical properties of permafrost and provide information to plan and design resilient civil infrastructure in cold regions. This paper evaluates the performance of seven models when predicting the seismic wave velocities of permafrost statistically; these models are the time-average, Zimmerman and King, Minshull et al., weighted equation, three-phase, Biot–Gassmann theory modified by Lee (BGTL), and Dou et al. models. The data used in the evaluation are from published laboratory and in situ data, which includes 369 data points for joint P and S wave velocities from nine publications and 943 unfrozen water content data points from 12 publications. The unfrozen water content that is used in these models is determined from a modified Dall'Amico's model that is proposed, which is evaluated against six existing unfrozen water content models based on soil temperature. This paper finds that saturated nonsaline permafrost generally shares similar linear trends between the P and S wave velocities, regardless of soil type, porosity, grain size, and temperature. Fitting all existing data, an empirical linear relationship is derived between the P and S wave velocities. Among the seven models evaluated, the Minshull et al. and BGTL models are the most accurate when predicting the seismic velocities of permafrost. Practical Applications: Unfrozen water content and seismic wave velocity models are valuable tools for quantitatively predicting permafrost dynamics and degradation, with practical applications in various engineering areas with permafrost environments. As permafrost thaws due to rising temperatures, these models could be used to guide the quantitative interpretation of geophysical changes in subsurface conditions, assess the potential for ground instability, and predict future permafrost degradation. Unfrozen water content models are used to predict the percentage of unfrozen water within permafrost, which links the changes with permafrost temperature. Unfrozen water content models of permafrost are essential when assessing permafrost thaw, thermal performance, heat transfer processes in permafrost, and the effect of civil infrastructure on permafrost (Chen et al.,). The seismic wave velocity models could help engineers assess the subsurface conditions in permafrost areas; this assessment is crucial for environmental and seismic monitoring, land use planning, infrastructure design and construction, and natural resources exploration. [ABSTRACT FROM AUTHOR]

This paper presents a comparison of numerical properties of the fixed-grid method of characteristics resulting from space and time linear interpolation used for the solution of transient flow in pipe equations. Modified equation analysis method is applied, in which the modified equations derived for the simplified linear version of the transient pipe flow equations provide explicitly the coefficients of numerical diffusion and dispersion generated by the method of characteristics. Through this approach the value of the numerical diffusion coefficient generated in the solution can be precisely estimated. Consequently, the effects resulting from the interpolation in time and space can be compared. The conclusions presented were confirmed by the results of numerical calculations. Practical Applications: If a valve is suddenly closed at the end of a pipeline in which water flows, a pressure wave will appear in it. This phenomenon, known as the water hammer, commonly occurs in water supply networks and in various industrial installations. The wave propagation process is described by a system of differential equations, which are solved using numerical methods. Numerical methods are approximate; they allow to solve the mathematical problems in which both the data and the results of calculations are given in the form of numbers. Numerical methods enable the calculation of approximate pressure and velocity values at selected cross-sections of the pipeline and at selected moments of time. The calculated values contain an error that depends on the solution method. This error determines the quality of the water hammer simulation results. There are a number of methods for numerical solution of water hammer equations. In this paper, the method of characteristics is used, which requires interpolating pressure and velocity values between selected points. The article shows that the generated numerical error depends on the applied technique of interpolation. Two techniques, interpolation in space and interpolation in time, are considered. [ABSTRACT FROM AUTHOR]

Offshore structures are deployed extensively to harvest marine resources. Due to the harsh marine environments and heavy-duty working conditions, the risks associated with failure due to scour are high, and the need for accurate prediction of these risks is increasing. Often, pipelines and cables are critical elements of subsea energy transportation and telecommunication, and they are highly susceptible to scour-induced failure. The scour around spheres is relevant to the offshore industry as a simplified three-dimensional representation of subsea structures. This paper presents a numerical study, using FLOW-3D HYDRO, of the scour around on-bottom cylinders and spheres. Whereas most published research investigated scour around stationary solid objects, this paper presents numerical results of a more challenging case of scour around sagging cylinders and spheres. The model was validated against published experimental and numerical results. The scour depth was found to increase with the decrease of the sagging velocity of the solid object. For sagging horizontal cylinders, the scour depth reaches a plateau of 1.1 times the cylinder diameter when the dimensionless sagging velocity is smaller than 0.094. For sagging spheres, the maximum scour depth reaches 0.37 times the sphere diameter when the dimensionless sagging velocity is reduced to 0.0103. The findings provide guidelines for future research on more complicated interactions between flow, solid objects, and the seabed, accounting for the deformation of infrastructure over time. Practical Applications: This paper concerns the flow, sediment transport, and scour around horizontal cylinders and spheres undergoing slow downward motion, which resembles the sagging of on-bottom infrastructure under the influence of gravity and bed erosion. Offshore structures are deployed extensively to harvest marine resources. Pipelines and cables are critical subsea infrastructures that are susceptible to scour-induced failure. Spherical objects are commonplace in the offshore industry, so a sphere can be deemed as an idealized three-dimensional body. This paper provides detailed FLOW-3D simulations and developed empirical relationships between the dimensionless scour depth and dimensionless sagging speed. Most previous research considered only the scour around fixed objects, so this paper provides a novel addition to the existing knowledge on the scour phenomenon. The computational methods established in this study are useful for simulating more-complicated scenarios. The findings provide guidelines for more-realistic predictions of scour and for the design of scour mitigation measures. [ABSTRACT FROM AUTHOR]

Under various stress paths, the deformation characteristics represented great differences. In this paper, a series of cyclic triaxial tests have been conducted with Fujian standard sand. By comparing the constant deviatoric (CDS) and constant axial stress paths (CAS), the influence mechanism of the cyclic amplitude of the deviatoric stress was discussed. The test results showed that the stress path significantly influenced the volumetric and shear strains. The increasing and decreasing trend in the volumetric strain (ɛv) was consistent with the spherical stress (lnp). Compared with the two stress paths, the slope of the ɛv−lnp curve during the loading and unloading stages was larger under the CAS path. In the CDS path, qc almost did not affect the cumulative volumetric strain, and in the CAS path, the effect was obvious. The shear strain curve was in accordance with the direction of the stress path. As the cyclic number increased, the shear strain gradually accumulated. The shear strain accumulation under the CAS path was larger. The shear strain largely depended on the relative position between the critical state line (CSL) and the stress state of the soil during cyclic loading and unloading. Practical Applications: In practical engineering, the soil will experience various stress paths. For example, in slope or earth–rock dam engineering, where the water level rises and falls repeatedly, the soil often goes through the stress path of constant deviational stress with the cyclic increase and decrease in the spherical stress. In foundation pit engineering, the soil often experiences the stress path of the constant axial stress (CAS) with cyclic loading and unloading of the lateral stress. The stress path greatly influences the deformation and strength of soil. Therefore, the previous two stress paths are compared in this paper to discuss the influence of the cyclic amplitude of deviatoric stress. Under three different consolidation states, the cyclic amplitude of the deviatoric stress significantly influenced the volumetric and shear strains. The shear strain largely depended on the relative position between the critical state line (CSL) and the stress state of the soil during cyclic loading and unloading. Therefore, in practical engineering, if the stress path in the experiment differs from the actual value, the influence of the stress path should be properly considered. The results should be modified according to the degree of influence of each stress condition. [ABSTRACT FROM AUTHOR]

A novel finite-element (FE) procedure for analyzing slope stability was recently developed and encoded into a Fortran computer code S4DINA 2.0. This innovative approach involves a gradual increment in the principal stress deviator in a specific way until an unstable condition is reached. In the original version of S4DINA 2.0, the initial stress field was assessed using the gravity loading procedure (GLP), which has various limitations. This paper introduces the fictitious excavation method (FEP) as an alternative procedure for estimating initial stresses. After incorporating the FEP into S4DINA 2.0, a parametric investigation was conducted to explore the effect of the coefficient of soil pressure at rest (K0) and Poisson's ratio (ν) on the GLP and FEP, which used three selected slope examples. The evolution of the factor of safety (FOS), as determined by the stress deviator increasing model (SDIM), was examined for ν for a variety of soil friction angles (ϕ′). The findings of this paper were documented in detail. The inclusion of K0 as an inherent soil property in the GLP was unfeasible due to the formulation nature of the GLP. In addition, when this method is used, the resulting FOS might significantly deviate from the accurate result in numerous instances. However, in scenarios where K0 exceeds one, the FEP remains the exclusive solution, and when K0 is less than one, selecting the FEP with an appropriate ϕ′ value is the best choice for achieving a rigorous FOS. [ABSTRACT FROM AUTHOR]

In this research, the finite-element numerical software COMSOL Multiphysics is used to simulate the electric pulse rock-breaking process, and the novel numerical model takes into account the multiple fields of electrical, thermal, and mechanical physics. The electric field strength inside the rock under the action of the electric pulse is updated by the full coupling function of COMSOL (version 6.1) software, and the electric damage variable χ is used to describe the process of electric breakdown inside the rock, to simulate the formation of plasma channel in the process of electric pulse rock-breaking. The voltage change curves and plasma channel trajectories in the electric breakdown process of the model in this paper are compared with the literature to verify the accuracy of the model. The formation process of plasma channels captures the temperature and stress changes during the whole process of electric pulse rock-breaking, to reveal the mechanism of the electric pulse rock-breaking process. With the presence of conductive particles inside the rock, the particles can effectively promote the formation of plasma channels, increase the area of electrical damage, and improve rock-breaking efficiency. Before the formation of the plasma channel, the internal temperature of the rock is about 600 K, and the stress is about 10−2 MPa; when the channel is formed, the energy of the electric pulse is mainly concentrated in the plasma channel, and the temperature of the plasma channel rises to 104 K. When the maximum stress exceeds the critical stress of the rock, the rock undergoes fracture. Furthermore, an appropriate increase in the rise time of the electric pulse increases the speed and area of rock-breaking, subsequently improving the efficiency of rock fracture. The results of the numerical modeling in this paper help to better understand the mechanism of the electric pulse rock-breaking process, which is of great engineering significance for the development of new electric pulse rock-breaking technology in the realm of geotechnical engineering. [ABSTRACT FROM AUTHOR]

Density is an important indicator for evaluating diesel fuel quality that directly affects the injection timing and injection rule of the engine, and also has a significant impact on the spray broken particle size, the spray penetration distance, the spray cone angle, and so forth, which in turn affects the combustion process and pollutant emission of the compression-ignition engine. Therefore, it is important to accurately predict the diesel fuel mixture density in industrial and compression-ignition engines. However, the mathematical models for predicting the density of diesel fuel mixture with changed temperature are relatively lacking and less accurate, especially for ternary diesel fuel mixtures with different physicochemical properties. This paper proposes a mathematical model including binary and ternary diesel mixtures under changed fuel volume fraction and temperature, and published data were used for verification. The data verification results show that: for the density prediction of binary diesel fuel mixtures at constant temperature, the average relative deviation (ARD) is 0.0245%, the RMS error (RMSE) is 0.000344, and the correlation coefficient (R) is 0.9993. For the density prediction of binary diesel fuel mixtures at changed temperature, the ARD is 0.0609%, the RMSE is 0.000695, and R is 0.9980. For the density prediction of ternary diesel fuel mixtures at constant temperature, the ARD is lower than 0.0571%, the RMSE is lower than 0.000610, and R is higher than 0.9861. For the density prediction of ternary diesel fuel mixtures at changed temperature, the ARD is 0.0484%, the RMSE is 0.000513, and R is 0.9996. The diesel mixed fuel density prediction model proposed in this paper has good accuracy and calculation convenience, and provides important reference value for measuring or designing the density of diesel mixed fuel in the field of compression-ignition engines. [ABSTRACT FROM AUTHOR]

Lithium iron phosphate (LFP) batteries are widely utilized in energy storage systems due to their numerous advantages. However, their further development is impeded by the issue of thermal runaway. This paper offers a comparative analysis of gas generation in thermal runaway incidents resulting from two abuse scenarios: thermal abuse and electrical abuse. The study initially focuses on 13-Ah lithium iron phosphate single-cell batteries. Experiments were conducted to induce thermal runaway through both forms of abuse, analyzing the production and dispersion of H2 and CO gases in each case. It was observed that thermal abuse–induced thermal runaway resulted in higher gas concentrations and more pronounced fluctuations, whereas electrical abuse–induced thermal runaway exhibited lower gas concentrations and lower fluctuations. Subsequently, key materials and temperature variations at the positive and negative electrodes were investigated under both types of thermal runaway, revealing distinct differences that are identified as the primary reasons for the significant disparities in H2 and CO gas generation during the two thermal runaway conditions. The conclusions drawn in this paper advance the understanding of the mechanisms underlying H2 and CO gas concentration generation in thermal runaway scenarios. [ABSTRACT FROM AUTHOR]

One of the key tasks to ensure infrastructure safety is the periodic detection of bridge cracks. Since manual crack detection is subjective and inefficient, it is very important to develop an automatic crack recognition system by using machine vision. Inspired by the pyramid vision transformer (PVT) and the feature pyramid network (FPN) variants, a method combining PVT, residual transformer (REST), holistically nested edge detection (HED), and downstream detection tasks is proposed in this paper, which is named EVPTMFF (efficient visual pyramid transformer and multiple-feature fusion). Based on the PVT, the multiheaded attention module was replaced and the efficient attention module was adopted, which could process the data efficiently and flexibly. To improve the performance of EVPTMFF, the original perceptual field windows were changed. The adjacent windows were partially overlapped, which was more conducive to feature interaction and improves detection performance. To prove the generalization ability of the model, three different data sets related to bridges were collected and formed. We carried out experiments on these three data sets, and EVPTMFF showed good results. Especially for larger data sets, the performance advantage was more significant. Practical Applications: The crack detection model proposed in this paper presents a good detection effect under different illumination and interference. And the detection results, collected data, time, and other information are saved to the bridge crack detection software. This can help engineers quickly and accurately detect cracks on the bridge surface, as well as predict the development trend of cracks and possible safety issues. In practical application, the bridge crack detection system can help engineers find and solve the bridge crack problem in time and avoid the security risks and economic losses caused by cracks. At the same time, the efficiency and accuracy of bridge maintenance can be improved, and the maintenance cost and time can be reduced. The bridge crack detection system can be integrated with other hardware equipment and management systems to form a complete bridge management platform, which contributes to the traffic construction and social and economic development of the city. [ABSTRACT FROM AUTHOR]

As the lifeblood of national energy, oil and gas pipelines are vulnerable to corrosion, third-party damage, and natural disasters. Among these, third-party damage accidents have a high probability and serious consequences. However, China lacks a mature and unified pipeline accident database, making it difficult to assess and manage the risk of such incidents. To address this issue, this paper identifies 20 key risk factors for third-party damage to oil and gas pipelines through literature and case studies. The paper then proposes a multistate probabilistic assessment model using the Decision-Making Trial and Evaluation Laboratory (DEMATEL), interpretative structural modeling method (ISM), Røed method, and Bayesian network (BN). Real case studies demonstrate that the model not only predicts the probability of third-party damage risks but also clearly identifies key influencing factors and causal chains in the risk system. This provides a new approach for assessing third-party damage risks to oil and gas pipelines and offers a scientific basis for decision-making in managing actual pipelines. Practical Applications: The high probability and serious consequences of third-party damage accidents of oil and gas pipelines have caused certain hidden dangers to social security, environment, and economy, and put forward higher requirements for pipeline operation and management. In order to scientifically manage and effectively control the occurrence of third-party damage accidents of oil and gas pipelines, this paper, in the absence of an applicable pipeline failure database. Based on expert knowledge, a model that can be used for the assessment and prediction of third-party damage probability of oil and gas pipelines is constructed. Through the application of real cases, it is shown that the model can be used not only to predict the probability of third-party damage of oil and gas pipelines, but also to identify the key influencing factors and key causal chains leading to third-party damage. The results of the study not only provide theoretical support for pipeline management in reality, but also provide new ideas for risk assessment of oil and gas pipelines that lack actual data. [ABSTRACT FROM AUTHOR]

Segmental tunnel linings have a complex structural behavior that is difficult to predict. Full-scale in situ structural monitoring allows us to gain access to these structures, observe the acting mechanisms, and better understand the actual structural behavior under realistic boundary conditions. In a recent structural monitoring project in Frankfurt, Germany, strains, deformations, and temperatures were measured at the segmental lining of a twin-tube tunnel boring machine (TBM) tunnel. Hereby, internal forces were back-calculated from the strain measurements. The results of the monitoring are presented and discussed in this paper. The measurements began immediately after the assembly of the segments and have been performed continuously over several years. Because of that, it was possible to observe that the internal forces differ significantly between the construction stage and the final state. During the construction stage, the internal forces develop quickly within hours after ring assembly, showing a distribution along the lining's circumference that is hard to predict. Almost all radial deformations occur during this period and remain unchanged afterward. After this first early phase, a period of stress redistribution follows, including significant changes in the internal forces. At its end, the stable, final state is reached. In this state, the internal forces match better with expectations. In the monitored areas, the stresses during the construction stage slightly exceeded those of the final state, which should be avoided for economic reasons. Additional investigations regard the temperature development within the lining, the influence of the second tube construction on the already built tube, and the development of longitudinal ring interaction over time. The latter significantly influences the structural behavior, but its development is often subject to uncertainties. In this case, it was observed that the longitudinal interaction decreases considerably over time. Practical Applications: In the structural design of segmental tunnel linings, structural or geotechnical engineers have various options regarding the available calculation methods and modeling strategies. All of these options are part of the state of the art, and the selection is up to the engineer. However, the results can be quite different depending on the chosen option. Consequently, uncertainties remain regarding the real linings' internal forces and structural reliability. The actual mechanisms can be identified by investigating the real structural behavior of segmental tunnel linings with in situ structural monitoring. Then, with back-analyses, on the one hand, it can be tested to determine how well different calculation methods and modeling strategies correspond to reality. On the other hand, the monitoring data can contribute to improving existing calculation methods, developing new modeling approaches, and establishing more detailed recommendations or optimizations regarding the design and construction of segmental tunnel linings. This paper presents findings derived from a structural monitoring project on a segmental lining. Different mechanisms and aspects, sometimes uncertain or debatable in tunnel design, are discussed regarding their real in situ appearance. The gained data will also be used for further back-analyses and investigations. [ABSTRACT FROM AUTHOR]

Sustainable remediation demonstrates that the benefit of undertaking remediation is more significant than its impact, and the optimum remediation solution is selected through a balanced decision-making process. Assessing sustainable remediation is site and project-specific and is strongly multifactorial across a wide range of categories, which may or may not be readily quantifiable. The applied socio-economic survey framework is based on the 2020 SuRF-UK guidance. The assessment was carried out in three steps. A small core team, an interim evaluation by the project of all beneficiaries, and a final assessment including the views of a broad range of external stakeholders developed an initial "pilot" sustainability assessment. The sustainability assessment process compared options across 45 individual criteria in 15 overarching "headline" categories: environmental, social, and economic. Members selected suitable criteria and the individual rankings of the project consortium from research, service providers and the site owner. The assessments compared Wetland+ with the wastewater treatment plant (WWTP) and no-intervention scenario. Wetland+ outranked the use of WWTP, and both performed significantly better than the no-intervention scenario. The quantitative data from LCA confirmed the results devoted to environmental impact. Practical Applications: Remediation of contaminated sites is site-specific, and each site requires a specific targeted approach that should take into account not only the environmental benefits of the measures but also economic and social aspects. In the case of water contaminated with hexachlorocyclohexane (HCH) substances, there are various methods of dealing with it, ranging from removal and relocation to a secure site-to-site encapsulation to various methods of contaminated water treatment. In the case of mega-sites, the solution often reduces to water treatment, as other solutions are not acceptable, especially economically, but also environmentally (transporting large volumes of materials) and socially (large construction and material handling). The present paper gives guidance on the selection of the most accepted water treatment option from a sustainability point of view. A three-step process based on a multiparametric assessment shows how the subjective approach of technologists, activists, or the public can be eliminated. The paper shows that a wetland-based solution is accepted significantly more than a WWTP or a no-action scenario. The approach will be further applied to similar localities with HCH contamination but can be generalized to a much broader set of contaminated sites. [ABSTRACT FROM AUTHOR]

When deciding which project to fund, the comparison of project-required resources and monetary or financial benefits is relatively straightforward (as these can be presented in dollar values). In contrast, comparing the nonmonetary benefits of projects can be challenging. The literature often overlooks this problem and only provides high-level approaches (e.g., comparing a project's contributions to the organization's strategic goals). Such approaches are inefficient as they are highly subjective and may be impacted by decision-makers' bias. To this point in time, the literature has not effectively addressed this problem. This literature gap and the practical importance of the problem motivate the development of detailed step-by-step methodological processes to reduce subjectivity and enable a quantitative comparison of the nonmonetary benefits of projects. This paper develops such a novel straightforward methodology and illustrates its application through a case study where nonmonetary benefits of a railway construction project are compared against a hospital expansion project. In addition to this methodological contribution, this paper also contributes to the current literature on construction engineering and management by showing how to perform an effective comparison of the nonmonetary benefits in the project investment decision. The paper also sheds light on how the reasoning structures of different project decision makers may be impacted by their degree of optimism. Practical Applications: Construction projects may deliver a range of dissimilar benefits. Unlike monetary values (such as required resources and financial or monetary benefits), the comparison of nonmonetary benefits (e.g., social values) of different proposals can be challenging. This paper provides a two-phased methodology to facilitate this comparison. In the first phase, two straightforward questions are asked to draw benefit satisfaction graphs, and in the second phase, different future scenarios are integrated to make the comparison process more reliable. Ultimately, a methodology is developed to show how the nonmonetary benefits of different projects can be compared. It is then illustrated on a case from the Australian government where the nonmonetary benefits of a railway construction project are compared against those of a hospital expansion project to assist with the decision as to which project should be given a higher priority to be funded. [ABSTRACT FROM AUTHOR]