Buildings, Volume 14, Issue 5 (May 2024) – 292 articles

Excessive column pile heave may result in engineering disasters such as instability of retaining structures and cracking of existing engineering piles in deep excavations. However, factors such as support weight, changeable support restraint resistance, and soil disturbance at the bottom of the excavation are often ignored or simplified in existing calculation methods but have a significant impact on the calculation results. Based on field soil parameters obtained by the rebound–recompression method, a semi-analytical method is proposed for estimating column pile heaves in a deep excavation. This method considers the influence of soil disturbance, the weight of the retaining structure, and the changeable horizontal support restraint, making the calculation result more consistent with the realistic situation. This method can also be used to analyze load transfer between the pile and the surrounding soil. The rationality of this proposed calculation method is verified by measured data, where the variation in pile stress state during deep excavation is analyzed. Finally, a parametric study is conducted, and the results show that the excavation size and the excavation depth have a great influence. However, the heave is hardly affected by the value of the limit relative displacement. The use of long piles with small diameter and the method of small block excavation are effective means to control the column pile heave. When the excavation area is large or the effective pile length is short, the factor of the position of the column pile cannot be ignored. Full article

This study focuses on the core economic zone of East China, utilizing the decoupling model to investigate the relationship between carbon emissions and economic development in the construction industry. Furthermore, it analyzes the driving factors through the application of the logarithmic mean index method. The findings reveal that, firstly, Zhejiang and Jiangsu provinces exhibit higher total carbon emissions in the construction industry. Except for Fujian Province, the other regions exhibit a downward trend after 2019. Secondly, there is considerable spatial variability in carbon emissions in the construction industry within the core economic zone of East China, and it gradually decreases over the study period. While economically developed regions like Zhejiang and Jiangsu provinces tend to concentrate and consume more resources and energy, their impact on surrounding neighboring provinces or cities is relatively limited. Thirdly, carbon emissions from the construction industry in the core economic zone of East China show a development trend shifting from weak decoupling to strong decoupling, indicating a healthy growth in the construction industry. Specifically, different regions show different trends. Lastly, regarding influencing factors, the impact direction of carbon intensity on total carbon emissions shows instability. Energy intensity consistently exhibits inhibitory effects, and the economy and the population scale act as driving forces. Full article

Recently, subsea tunnel construction has developed rapidly in China. The traffic volume of subsea metro tunnels is large. Once a safety accident occurs, economic losses and social impacts will be extremely serious. To eliminate accidents in operational subsea metro tunnel structures, a health risk prediction method is proposed based on a discrete Bayesian network. Detecting and monitoring data of the tunnel structures in operation were used to evaluate the health risk by employing the proposed method. This method establishes a Bayesian network model for the health risk prediction of the shield tunnel structure through the dependency relationship between the health risk of the operational tunnel structure and 13 risk factors in five aspects: the mechanical condition, material performance, integrity state, environmental state, and deformation state. By utilizing actual detection and monitoring data of various risk factors for the health risk of the operational subsea metro shield tunnel structure, this method reflects the actual state of the tunnel structure and improves the accuracy of health risk predictions. The validity of the proposed method is verified through expert knowledge and the subsea shield tunnel structure of the Dalian Subway Line 5. The results demonstrate that the health risk prediction outcomes effectively reflect the actual service state of the shield tunnel structure, thus providing decision support for the control of health risks in the subsea metro shield tunnel. Full article

The wettability and stability of a solution’s film on the filler surface are the key factors determining heat and mass transfer efficiency in liquid desiccant air conditioning systems. Therefore, this study investigates the effects of different air parameters on the flow behavior of a lithium chloride solution’s film. The effects of air velocity, air flow pattern, and pressure on the wettability and critical amount of spray are discussed. The results show that the main mechanism by which the air velocity affects the wettability is that the shear stress generated by the direction of the air velocity disperses the direction of the surface tension and weakens its effect on the liquid film distribution. In addition, in the counter flow pattern, the air flow blocks the liquid film from spreading longitudinally and destroys the stability of the liquid film at the liquid outlet, which increases the critical amount of spray. The pressure distribution is similar under different operating pressures when the flow is stable; thus, pressure has little effect on wettability. The simulation results under 8 atm are compared with the experimental results. It is found that the sudden increase in the amount of moisture removal when the amount of spray changes from 0.05 to 0.1 m³/(m·h) in the experiment is caused by the change in the liquid film flow state. In addition, the results show that within the range of air flow parameters for the liquid desiccant air conditioning system, air flow shear force is not the main factor affecting the stability of the solution’s film, and there is no secondary breakage of the solution’s film during the falling-film flow process. Full article

Industrial heritage is regarded as an important stock of spatial resources in cities, which highlights its utilization value for urban regeneration in high-density urban areas. With the dramatic increase in the number of industrial heritage reuse projects, how to scientifically evaluate the satisfaction with their spatial reuse is a key part of the solution for the mutual balance between heritage preservation and urban renewal. This paper takes eight industrial heritage conversion and utilization projects in the high-density core area of Beijing’s central city as examples; establishes an evaluation system for the satisfaction with the spatial reuse through six dimensions, namely, functional replacement, transportation accessibility, carrying capacity, public space, boundary form, and recognition of value; and uses the IPA method to evaluate the cases. This method is used to determine the degree of user satisfaction with the spatial reuse of industrial heritage in the core area of Beijing’s central city and to summarize the advantages and problems of its reuse. The results of this study reveal a trend toward the “community-oriented” re-generation of industrial heritage in the core area of Beijing’s central city, and this paper proposes recommendations for adaptive use to support high-quality urban regeneration work. Full article

Investigating the mathematical and geometric principles embedded in ancient classic architecture is a significant tradition in the history of architectural development. Drawing inspiration from the modular design and creative ideology based on the geometric proportions of squareness and roundness in ancient Chinese architecture, we propose a new mode of squareness and roundness composition based on scale proportion specifically for the design of multi-story buildings. Taking Yingxian Wooden Pagoda as the case study, we not only re-evaluate the modular system and proportional rules followed in the design of the entire pagoda, but also reveal the technical approaches and geometric rules for effectively controlling the form of multi-story buildings. In particular, the mode of squareness and roundness composition based on scale proportion, utilizing a modular grid combined with squareness and roundness drawings as decision-making tools, can control the scale and proportion of buildings across different design dimensions and organically coordinate the design of multi-story buildings’ plans and elevations. Thus, it can achieve an effective balance of multi-story architectural forms. This study has potential applications in the creation of traditional multi-story buildings and heritage restoration projects, and offers valuable insights for future research on ancient multi-story buildings. Full article

The US real estate market is a complex ecosystem influenced by multiple factors, making it critical for stakeholders to understand its dynamics. This study uses Zillow Econ (monthly) data from January 2018 to October 2023 across 100 major regions gathered through Metropolitan Statistical Area (MSA) and advanced machine learning techniques, including radial kernel Support Vector Machines (SVMs), used to predict the sale-to-list ratio, a key metric that indicates the market health and competitiveness of the US real estate. Recursive Feature Elimination (RFE) is used to identify influential variables that provide insight into market dynamics. Results show that SVM achieves approximately 85% accuracy, with temporal indicators such as Days to Pending and Days to Close, pricing dynamics such as Listing Price Cut and Share of Listings with Price Cut, and rental market conditions captured by the Zillow Observed Rent Index (ZORI) emerging as critical factors influencing the sale-to-list ratio. The comparison between SVM alphas and RFE highlights the importance of time, price, and rental market indicators in understanding market trends. This study underscores the interplay between these variables and provides actionable insights for stakeholders. By contextualizing the findings within the existing literature, this study emphasizes the importance of considering multiple factors in housing market analysis. Recommendations include using pricing dynamics and rental market conditions to inform pricing strategies and negotiation tactics. This study adds to the body of knowledge in real estate research and provides a foundation for informed decision-making in the ever-evolving real estate landscape. Full article

The urban renewal (UR) process involves various stakeholders and related activities, and the various risks arising from this endeavor can affect these stakeholders. Additionally, the impact of adverse factors such as policy discontinuity and inequitable distribution of benefits among stakeholders can easily result in collective tensions or conflicts, as well as the gradual emergence of potential social frictions and confrontations. These social risks (SRs) not only impede the smooth execution of urban renewal projects but also pose challenges to social harmony and stability. Hence, to mitigate and control the SRs in the UR process (URSRs) and ensure the successful implementation of effective and sustainable UR projects, it is of paramount importance to gain a comprehensive understanding of the occurrence and evolution mechanisms of these SRs. Although existing studies have touched upon the influence of stakeholder conflicts on URSRs, there remains a lack of systematic examination of the evolution mechanisms of these risks from the perspective of stakeholder theory. The resulting fragmented and specialized comprehension of URSRs has hindered the effectiveness of risk governance strategies. This study adopts stakeholder theory to analyze the potential sources of risk throughout the entire UR process. By considering the conflicts of interests among stakeholders, a systematic analysis of the evolution mechanisms of URSRs is explored and targeted governance recommendations for URSRs are proposed. Full article

Integrating artificial intelligence (AI) in the construction industry could revolutionise workplace safety and efficiency. However, this integration also carries complex socio-legal implications that require further investigation. Presently, there is a research gap in the socio-legal dimensions of AI use to enhance health and safety regulations and protocols for the construction sector in the United Kingdom, particularly in understanding how the existing legal frameworks can adapt to AI integration effectively. Comprehensive research is indispensable to identify where the existing regulations may fall short or require more specificity in addressing the unique implications introduced by AI technologies. This article aims to address the pressing socio-legal challenges surrounding the integration of AI in the UK construction industry, specifically in enhancing health and safety protocols on construction sites, through a systematic review encompassing the PRISMA protocol. The review has identified that the existing legal and regulatory framework provides a strong foundation for risk management. Still, it needs to sufficiently account for the socio-legal dimensions introduced by AI deployment and how AI may evolve in the future. The Health and Safety Executive (HSE) will require standardised authorities to effectively oversee the use of AI in the UK construction industry. This will enable the HSE to collect data related to AI processes and carry out technical, empirical, and governance audits. The provision of sufficient resources and the empowerment of the HSE within the context of the construction industry are critical factors that must be taken into consideration to ensure effective oversight of AI implementation. Full article

Explosions, once limited to military and accidental contexts, now occur frequently due to advances in warfare, local disputes, and global conflicts. Recent incidents, like urban bombings, emphasize the urgent need for infrastructure to withstand explosions. Slabs, critical in architectural frameworks, are vulnerable to explosive forces due to their slimness, making them prime targets for sabotage. Scholars have explored various strategies to fortify slabs, including the use of advanced materials like CFRP laminates/strips, steel sheets and ultra-high-strength concrete, along with reinforcement techniques such as two-mesh and diagonal reinforcements. A novel approach introduced in current research involves integrating vertical short bars, or studs, to enhance slab resilience against touch-off explosions. The aim of this research endeavor is to assess the impact of studs and their utilization in bolstering the anti-contact-blast capabilities of a concrete slab. To achieve this goal, a specialized framework within the ABAQUS/Explicit 2020 software is employed for comprehensive analysis. Initially, a conventionally reinforced slab devoid of studs serves as the benchmark model for numerical validation, facilitating a comparative assessment of its anti-contact-blast effectiveness against the findings outlined by Zhao and colleagues in 2019. Following successful validation, six additional distinct slab models are formulated utilizing sophisticated software, incorporating studs of varying heights, namely, 15 mm and 10 mm. Each configuration encompasses three distinct welding scenarios: (i) integration with upper-layer bars, (ii) attachment to bottom-layer bars, and (iii) connection to both upper- and bottom-layer bars. The comparative merits of the slabs are evaluated and deliberated upon through the examination of diverse response parameters. The research revealed that the incorporation of studs within slabs yielded notable enhancements in blast resistance. Specifically, taller studs demonstrated exceptional resilience against deformation, cracking, and perforation, while also diminishing plastic damage energy. Particularly noteworthy was the superior performance observed in slabs with studs welded to both upper and lower layers of re-bars. This highlights the critical significance of both the integration of studs and their precise positioning in fortifying structural integrity against blast-induced loadings. Full article

Attapulgite-hydroxyethyl cellulose-poly (acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid) (ATP-HEC-P(AA-co-AMPS)) in-concrete curing material was synthesized by aqueous solution polymerization using attapulgite (ATP) as an inorganic filler and hydroxyethyl cellulose (HEC) as a backbone. The effects of relevant factors such as ATP dosage, HEC dosage, degree of neutralization, initiator quality, and cross-linking agent quality on the water absorption characteristics of ATP-HEC-P (AA-co-AMPS) were investigated through expansion tests. The micro-morphology of ATP-HEC-P (AA-co-AMPS) was also comprehensively characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, a thermal analysis, and other applicable means. The results showed that the prepared ATP-HEC-P (AA-co-AMPS) had a strong water absorption and water retention capacity, with a water absorption multiplicity of 382 g/g in deionized water and 21.55% water retention capacity after being placed at room temperature for 7 d in a bare environment. Additionally, ATP-HEC-P (AA-co-AMPS) showed good performance for absorbing liquids within the pH range of 7–12. The material’s thermal stability and mechanical properties were also significantly improved after the addition of ATP. The preparation cost is low, the process is simple, and the material meets the requirements for concrete curing materials. Full article

This research delves into a case study of a photovoltaic (PV) energy community, leveraging empirical data to explore the integration of renewable energy sources and storage solutions. By evaluating energy generation and consumption patterns within real-world energy communities (a nominal generation capacity of 33 kWn) in Gipuzkoa, Spain, from May 2022 to May 2023, this study comprehensively examines operational dynamics and performance metrics. This study highlights the critical role of energy consumption patterns in facilitating the integration of renewable energy sources and underscores the importance of proactive strategies to manage demand fluctuations effectively. Against the backdrop of rising energy costs and environmental concerns, renewable energies and storage solutions emerge as compelling alternatives, offering financial feasibility and environmental benefits within energy communities. This study emphasizes the necessity of research and development efforts to develop efficient energy storage technologies and the importance of economic incentives and collaborative initiatives to drive investments in renewable energy infrastructure. The analyzed results provide valuable insights into operational dynamics and performance metrics, further advancing our understanding of their transformative potential in achieving a sustainable energy future. Specifically, our study suggests that storage capacity should ideally support an average annual capacity of 23%, with fluctuations observed where this capacity may double or reduce to a minimum in certain months. Given the current market conditions, our findings indicate the necessity of significant public subsidies, amounting to no less than 67%, to facilitate the installation of storage infrastructure, especially in cases where initial investments are not covered by the energy community. Full article

To explore and deal with the difficulty in curing cement-stabilized bases in desert environments, curing agents were prepared to enhance the curing effect on the base in this research. The composite curing agent was prepared through orthogonal experiments and the durability of the curing agent coating were studied by simulating a desert environment. Subsequently, the curing effect on the performance of bases was analyzed. Finally, the hydration degree of cement was studied via scanning electron microscope (SEM), thermogravimetric analysis (TG), and X-ray diffraction analysis (XRD), and the curing mechanism of the curing agent was explored. The results show that the composite (paraffin emulsion is the main component of the film, vinyl acetate-ethylene copolymer dosage is 20%, ethanol ester-12 dosage is 10%, and sodium silicate dosage is 18%) could effectively improve the water-retention performance (water-loss ratio: 2.36%) and mechanical properties of the specimen (7 d compressive strength: 7.48 MPa; 7 d indirect tensile strength: 0.70 MPa). The dry shrinkage coefficient of the specimen with composite curing agent was reduced by 116.26% at 28 days. The compressive strength of dry and wet freeze could reach 7.48 MPa and 6.88 MPa, respectively. The durability of the curing agent-coated base met the requirements of pavement performance in desert areas. The results of XRD, TG, and SEM indicated that the curing agent promoted hydration. In addition, the number of C-S-H gel and AFt crystals significantly increased. The curing difficulty of road bases in desert areas could be reduced effectively through the application presented in this study, which contributes to the conservation of natural and human resources. Full article

This paper proposes transforming actual monitoring data into risk quantities and establishing a Long Short-Term Memory (LSTM) safety risk warning model for predicting the deformation of super-large and ultra-deep foundation pits in river–round gravel strata based on safety evaluation methods. Using this model, short-term deformation predictions at various monitoring points of the foundation pits are made and compared with monitoring data. The results from the LSTM safety risk warning model indicate an absolute error range between the predicted deformation values and on-site monitoring values of −0.24 to 0.16 mm, demonstrating the model’s accuracy in predicting pit deformation. Additionally, calculations reveal that both the overall risk level based on on-site monitoring data and the overall safety risk level based on predicted data are classified as level four. The acceptance criteria for the overall risk level of the foundation pit are defined as “unacceptable and requiring decision-making”, with the risk warning control scheme being “requiring decision-making, formulation of control, and warning measures”. These research findings offer valuable insights for predicting and warning about safety risks in similar foundation pit engineering projects. Full article

To address the issue of insufficient deep contextual information mining in the semantic segmentation task of multiple defects in concrete bridges, due to the diversity in texture, shape, and scale of the defects as well as significant differences in the background, we propose the Concrete Bridge Apparent Multi-Defect Segmentation Network (PID-MHENet) based on a PID encoder and multi-feature fusion. PID-MHENet consists of a PID encoder, skip connection, and decoder. The PID encoder adopts a multi-branch structure, including an integral branch and a proportional branch with a “thick and long” design principle and a differential branch with a “thin and short” design principle. The PID Aggregation Enhancement (PAE) combines the detail information of the proportional branch and the semantic information of the differential branch to enhance the fusion of contextual information and, at the same time, introduces the self-learning parameters, which can effectively extract the information of the boundary details of the lesions, the texture, and the background differences. The Multi-Feature Fusion Enhancement Decoding Block (MFEDB) in the decoding stage enhances the information and globally fuses the different feature maps introduced by the three-channel skip connection, which improves the segmentation accuracy of the network for the background similarity and the micro-defects. The experimental results show that the mean Pixel accuracy (mPa) and mean Intersection over Union (mIoU) values of PID-MHENet on the concrete bridge multi-defect semantic segmentation dataset improved by 5.17% and 5.46%, respectively, compared to the UNet network. Full article

Steel structures are prone to corrosion, a chemical reaction between steel and the atmosphere that gradually weakens the material. Over time, this reaction can significantly reduce the structural integrity and lifespan of steel elements. Without intervention, corrosion can cause structures to fail, leading to financial, environmental, and potential human losses. Enhancing steel’s corrosion resistance is crucial, and one method involves adding niobium (Nb). Niobium microalloyed steels are known for their increased strength, and some research indicates that Nb may also improve corrosion resistance by making the grain structure of the steel finer. However, the complete potential of Nb in corrosion prevention remains underexplored, with significant research gaps across various scales, from microstructural impacts on durability to macroscopic effects on mechanical properties. The research community has utilized numerous experimental approaches to test corrosion resistance under different conditions, but there is a lack of comprehensive studies that aggregate and analyze these findings. This paper seeks to fill that void by reviewing the impact of Nb on the strength and corrosion resistance of structural steels, examining how steel beams’ ultimate capacity degrades over time and identifying key areas where further research is needed to understand Nb’s role in mitigating corrosion. Full article

The COVID-19 pandemic has profoundly reshaped life across the globe, significantly influencing the future of housing. The enactment and densification of diverse activities within one place have resulted in varying degrees of conflict between the built and social environment. This conflict is directly related to the degree of housing adaptability to new life, work, and leisure conditions. Movement restrictions and distance learning have significantly impacted the young population, which is susceptible to ‘enforced togetherness’ conditions. However, studies on post-pandemic housing in Serbia are rare. This paper investigates the relationship between the built and social environment, focusing on current trends in multi-family housing from the perspective of the progressive change of life standards in the post-pandemic era. It also includes a survey of the living conditions of architecture students in Serbia during lockdown and distance learning, offering insights into the impact of the physical environment on virus transmission and social dynamics. The main objective of this study is to formulate guidelines for developing a resilient housing model in Serbia that will address both current and future crises. From the findings, it can be concluded that radical changes in housing policy are necessary to enable less interdependence among layers within the system striving to be resilient. Full article

Throughout the past century, numerous technologies have been suggested to deal with the capillary rise of water through the soil in historic masonry buildings. The aim of this study was to examine the effectiveness of capillary moisture repulsion apparatus that uses the electro-osmosis approach over a prolonged period of time. The Gül mosque was selected as a sample historical building affected by structural problems caused by the absorption of water through small channels on its walls due to capillary action. The moisture repulsion mechanism efficiently decreased the moisture level in the walls from a ‘wet’ state to a ‘dry’ state in roughly 9 months. After the installation of the equipment, the water mass ratio of the building decreased from 14.48% to 2.90%. It was determined that the majority of the water in the building was relocated during the initial measurement period. Furthermore, it inhibited the absorption of water by capillary action by protecting the construction elements that were in contact with the wet ground. Lastly, capillary water repulsion coefficients (C) for various measurement durations and time factors were proposed. The average value of C was calculated to be 0.152 kg/m² s^0.5 by measuring the point at which the water repulsion remained nearly constant. Full article

In permafrost regions with warm frozen soil, the pile foundation is commonly used, but most currently available models for the WFS foundation pile–soil system are either highly empirical or overcomplicated, without a simplified theoretical manner in engineering. This study derives a novel and simplified calculated model of the WFS pile–soil system. The model is formulated in terms of the shear deformation theory and load transfer method based on the rigorous deformation mechanism of the WFS foundation soil around the pile. Considering the different depth soil features and the equilibrium state of the pile–soil system, dividing warm frozen soil foundation into three regions (TPPR, ER, and BPPR) to calculate the D_p and D_s can simply obtain the total displacement of pile under different loads. The results demonstrate that the present theoretical model can well predict the WFS foundation load–displacement response of the pile. The present model provides a simple, practical, and effective approach for the estimation of the load–displacement behavior of piles installed in the WFS foundation. Full article

The construction industry, business models, and smart cities are recognized as pivotal domains with profound implications for fostering sustainability, prompting extensive research endeavors. However, there remains a dearth of interdisciplinary integration within this sphere aimed at fostering sustainable development. Nevertheless, current studies suggest that research in this area could provide theoretical and practical guidance for the sustainable transformation of society and make a positive contribution to the realization of the Sustainable Development Goals (SDGs). Therefore, this paper aims to utilize an innovative mixed research approach combining macro-quantitative bibliometric analysis with subsequent micro-qualitative content examination based on the SDGs to explore the relationship between BIM and smart cities in promoting a sustainability-oriented business model, which provides a comprehensive understanding of the overall situation and development of research topics in the field and contributes to the improvement of the SDGs. The results show that, during the last 13 years (from the year 2011 to 2023), the period from the year 2011 to 2016 was the initial stage of the field, followed by a rapid growth after the year 2018, of which “BIM”, “Smart City”, “Business Model”, “Building Life Cycle”, “Urban Management”, and “Business Model Innovation” are the keywords representing the current research hotspots. The circular economy model that has been developed since 2021 has contributed to life cycle stages, including “briefing stages” and “procurement stages”. As such, the “whole life cycle”, “strategic urban planning frameworks”, and “sustainable business models” have become future research trends, whilst real-world applications such as “smart tourism”, “e-government”, and “green building” have emerged. Further, the key partnerships of “city managers”, “corporate enterprises”, and “public participation” for smart cities contribute to the achievement of SDGs 8 and 17 in terms of integrating urban information technology and urban infrastructure, policy regulation, knowledge-sharing, improving economic efficiency, and promoting sustainable economic growth. Full article

This study investigates the mechanical properties of corroded Q355B structural steel subjected to a simulated marine atmosphere and an industrial atmosphere. The micro-morphology of corroded steel in two different environments was analyzed by SEM (scanning electron microscopy). Tension tests were performed to determine the degradation laws of the mechanical properties of corroded steel, including its yield strength, ultimate strength, elastic modulus, ultimate strain and elongation after fracture. The test results indicate that the elongation after fracture of the steel is the most severely deteriorated property after corrosion. The recommended empirical formula for limiting the maximum corrosion rate is established. It is found that when the initial elongation is 30%, the maximum allowable corrosion rate is 19.2%. Based on the achieved results, a simplified time-dependent stress–strain model of Q355B structural steel is established considering the coupling effects of corrosive environments and applied stress, which is also evaluated using relevant research. In addition, axial compression tests were conducted on corroded square stud columns to verify the effectiveness of the established model. It is indicated that the model can be used for fitness-for-purpose analyses in structural integrity assessments. Full article

Previous studies have focused on task/ambient illumination for visual effects and eye illumination for non-visual effects. In this context, eye illumination within the non-visual realm was defined as vertical non-visual eye illuminance. Considering the functional specificity of central vision and peripheral vision, this study aims to explore whether the distribution of eye illuminance in the horizontal field of view (FOV) affects human performance in home paper-based learning settings. In this study, a within-subject design was used to investigate the effects of eye illuminance distribution on mental perception, task performance, and physiological health while maintaining constant task illuminance and correlated color temperature (CCT). The findings revealed that eye illuminance and its distribution in the horizontal FOV had complex effects on visual fatigue, Landolt ring performance, heart rate variability, and luminous environment appraisal. A relatively optimal lighting configuration was suggested—Scene 4, which was characterized by an eye illuminance level in central FOV of 186 lx and an “m” shaped eye illuminance distribution pattern. This indicates the importance of considering eye illuminance distribution in the horizontal FOV, rather than solely focusing on vertical eye illuminance. Full article

As a sustainable construction material, timber is more promoted than steel, concrete, and aluminum nowadays. The building industry benefits from using timber based on several perspectives, including decarbonization, improved energy efficiency, and easier recycling and disposal processes. The cross-laminated timber (CLT) panel is one of the widely utilized engineered wood products in construction for floors, which is an ideal alternative option for replacing reinforced concrete. One single CLT panel has an outstanding flexural behavior. However, CLT cannot be extended independently without external connections, which are normally made of steel. This article proposes two innovative adhesive-free edge connections made of timber, the double surface (DS) and half-lapped (HL) connections. These connections were designed to connect two CLT panels along their weak direction. Parametric studies consisting of twenty models were conducted on the proposed edge connections to investigate the effects of different factors and the flexural behavior of CLT panels with these edge connections under a four-point bending test. Numerical simulations of all the models were done in the current study by using ABAQUS 2022. Furthermore, the employed material properties and other relevant inputs (VUSDFLD subroutines, time steps, meshes, etc.) of the numerical models were validated through existing experiments. The results demonstrated that the maximum and minimum load capacities among the studied models were 6.23 kN and 0.35 kN, respectively. The load–displacement responses, strain, stress, and defection distributions were collected and analyzed, as well as their failure modes. It was revealed that the CLT panels’ load capacity was distinctly improved due to the increment of the connectors’ number (55.05%) and horizontal length (80.81%), which also reinforced the stability. Based on the findings, it was indicated that adhesive-free timber connections could be used for CLT panels in buildings and replace traditional construction materials, having profound potential for improving buildings’ sustainability and energy efficiency. Full article

The application of Artificial Intelligence (AI) across various industries necessitates the acquisition of relevant environmental data and the implementation of AI recognition learning based on this data. However, the data available in real-world environments are limited and difficult to obtain. Construction sites represent dynamic and hazardous environments with a significant workforce, making data acquisition challenging and labor-intensive. To address these issues, this experimental study explored the potential of generating synthetic data to overcome the challenges of obtaining data from hazardous construction sites. Additionally, this research investigated the feasibility of hybrid dataset in securing construction-site data by creating synthetic data for scaffolding, which has a high incidence of falls but low object recognition rates due to its linear object characteristics. We generated a dataset by superimposing scaffolding objects, from which the backgrounds were removed, onto various construction site background images. Using this dataset, we produced a hybrid dataset to assess the feasibility of synthetic data for construction sites and to evaluate improvements in object recognition performance. By finding the optimal composition ratio with real data and conducting model training, the highest accuracy was achieved at an 8:2 ratio, with a construction object recognition accuracy of 0.886. Therefore, this study aims to reduce the risk and labor associated with direct data collection at construction sites through a hybrid dataset, achieving data generation at a low cost and high efficiency. By generating synthetic data to find the optimal ratio and constructing a hybrid dataset, this research demonstrates the potential to address the problems of data scarcity and data quality on construction sites. The improvement in recognition accuracy of the construction safety management system is anticipated, suggesting that the creation of synthetic data for constructing a hybrid dataset can reduce construction safety-accident issues. Full article

The transition towards a sustainable future requires the reliable performance of the building’s energy system in order for the building to be energy-resilient. “Energy resilient building in cold climates” is an emerging concept that defines the ability to maintain a minimum level of indoor air temperature and energy performance of the building and minimize the occupant’s health risk during a disruptive event of the grid’s power supply loss in a cold climate. The aim is to introduce an extensive definition of the energy resilience of buildings and apply it in case studies. This article first reviews the progress and provides an overview of the energy-resilient building concept. The review shows that most of the relevant focus is on short-term energy resilience, and the serious gap is related to long-term resilience in the context of cold regions. The article presents a basic definition of energy resilience of buildings, a systematic framework, and indicators for analyzing the energy resilience of buildings. Terms such as active and passive habitability, survivability, and adaptive habitable conditions are defined. The energy resilience indicators are applied on two simulated Finnish case studies, an old building and a new building. By systematic analysis, using the defined indicators and thresholds, the energy resilience performance of the buildings is calculated and compared. Depending on the type of the building, the results show that the robustness period is 11 h and 26 h for the old building and the new building, respectively. The old building failed to provide the habitability conditions. The impact of the event is 8.9 °C, minimum performance (P_min) is 12.54 °C, and degree of disruption (DoD) is 0.300 for the old building. The speed of collapse (SoC) is 3.75 °C/h, and the speed of recovery (SoR) is 0.64 °C/h. On the other hand, the new building performed better such that the impact of the event is 4 °C, P_min is 17.5 °C, and DoD is 0.138. The SoC is slow 3.2 °C/h and SoR is fast 0.80 °C/h for the new building. The results provide a pathway for improvements for long-term energy resilience. In conclusion, this work supports society and policy-makers to build a sustainable and resilient society. Full article

A “random-type” sand–concrete interface shear test was developed based on the sand cone method, with a focus on the most commonly encountered triangular contact surface morphology. A “regular-type” triangular interface, matched in roughness to the “random-type”, was meticulously designed. This “regular-type” interface features five distinct triangular groove inclinations: 18°, 33°, 50°, 70°, and 90°. A series of sand–concrete interface direct shear tests were conducted under consistent compaction conditions to investigate the impact of varying compaction densities and triangular groove inclinations on the shear strength at the interface. Particle flow simulations were utilized to examine the morphology of the shear band and the characteristics of particle migration influenced by the triangular contact surface. This analysis is aimed at elucidating the influence of the inclination of the triangular groove on the shear failure mechanism at the sand–concrete interface. The findings indicate that: (1) The morphology of the interface significantly impacts the shear strength of the sand–concrete interface, while the shape of the stress-displacement curve experiences minimal alteration. (2) At smaller inclination angles, particle contact forces are arranged in a wave-like configuration around the sawtooth tip, resulting in a non-uniform stress distribution along the sawtooth slope. However, as the inclination angle grows, the stress concentration at the sawtooth tip diminishes, and the stress distribution across the sawtooth slope becomes more consistent. (3) Particle migration is significantly influenced by the sawtooth’s inclination angle. At lower angles, particles climb the structure’s tip through sliding and rolling. As the angle increases, particle motion shifts to shear, accompanied by a transition in friction from surface friction to internal shear friction. This leads to the formation of a wider shear band and an increase in shear strength. Full article

To repair reinforced concrete beams efficiently in a limited building space, the four-sided application of a reinforcing thin layer of reactive powder concrete (“RPCTL”) was proposed to improve the bending capacity of the members. Static flexural tests of one comparison beam and five reinforced beams were completed on a four-point centralized loading device. Changes in deflection, cracks, stresses, and damage characteristics of the specimens were measured under various levels of loading. The test results showed that the damage patterns of the reinforced specimens were dominated by the yielding of longitudinal tensile reinforcement at the bottoms of the beams and the crushing of the cementitious material in the top compression zones of the beams. The cracking load greatly increased by 1.42 to 7.12 times, and the ultimate bearing capacity increased by 0.29 to 1.41 times. The distribution characteristics and dynamic changes in the displacement, stress, and damage of the specimens were dynamically simulated by finite element software. The effects of reinforcement and initial load-holding level on the reinforcement effect were investigated. A bending capacity calculation formula for RPCTL reinforcement technology is proposed that aligns with the test results and can provide a reference for the design of RPCTL reinforcement. Full article

This study investigated the influence and mechanism of the excavation width on excavation deformations in Shanghai soft clay. Based on three excavations that had different final excavation depths, dissimilar retaining structures and diverse geological conditions, 40 sets of two-dimensional numerical models with different excavation widths were employed to analyze the deformation rules affected by the excavation width. Moreover, a series of simplified models with different excavation widths were employed to analyze the effect of the excavation width on excavation deformations. The results show that under the same excavation depth, both the horizontal displacements of the retaining walls and ground surface settlements increase as the excavation width increases, but the increasing rate gradually decreases. Factors such as the unloading influence depth, the overlap degree of the passive zones, the stress state of the basal soils and the development of the relative shear stress have a significant influence on excavation deformations. With increasing excavation width, the unloading influence depth gradually deepens, the overlap area of the passive zones gradually decreases, the direction of the rotation of the major principal stress gradually reduces and the relative shear stress of the distant and deep soils gradually expands. Therefore, the constraint ability of the passive zones on excavation deformation gradually reduces and excavation deformations gradually increase. Full article

This paper proposed a new method for modelling joints, using anisotropic plate elements and elastic bar elements to address the issue that joints between panels are usually disregarded in numerical modelling. For small-scale deep excavations, which are frequently performed in the construction of various working shafts but have not been sufficiently studied, two numerical models were developed, using the No.1 Shaft of Tongtu Road Utility Tunnel in Ningbo, China, as a research object. One model considered the joints between the panels as proposed, while the other disregarded the joints as conventional. In comparison to the conventional method, the proposed method was validated due to yielding wall displacements that closely matched the results of the field monitoring, with a notable reduction in the error observed in the calculated displacements for the short side of the excavation. Furthermore, 34 numerical models were developed in order to investigate the influence of excavation length, depth, and diaphragm wall thickness on the relative differences between the calculated displacements obtained by the two models. The results of this study can provide references for the development of finite element models for designing small-scale deep excavation. Full article

In various analytical models, modeling the behavior of large-diameter monopiles and piles can be challenging due to these foundations with huge body sizes carrying mechanisms of lateral loads to the surrounding soils. In this paper, the transfer matrix method with the Timoshenko beam theory was used to modify the shear rotation of pile sections under different loading stages, including serviceability limit stages and the ultimate loading stage. In this transfer matrix method, a large-diameter pile is considered according to the Timoshenko beam theory, and the recurring variables in the matrix equation are replaced with constants to simplify the calculation steps. Two model test cases were used to verify the accuracy of the method. Then, a series of comparisons between the Timoshenko beam and the Euler–Bernoulli beam theories, with the relative pile–soil stiffness being equal to 0.15, 0.45, and 0.75, was conducted to investigate the differences in pile response after considering the shear deformation. The results show that the effect of shear deformation of large-diameter piles changes with different loading levels. The values of the pile deformation based on the Timoshenko beam theory divided by those of that based on the Euler–Bernoulli beam theory were in the range of 1.0 to 1.10, and they increased slightly with increasing loads, reaching their maximum value, and then rapidly decreased to 1.0 when close to the ultimate lateral load; the maximum value was influenced by the relative pile–soil stiffness. Furthermore, the ratio of the shear rotation of the pile section to the slope of the deflection curve was in the range of 1.0 to 1.10; these also showed similar but more moderate trends compared with the values of pile deformation based on the Timoshenko beam theory divided by those of that based on the Euler–Bernoulli beam theory. Full article