Structures最新文献

{"title":"Mechanical behavior of sand reinforced with conventional and NPR geogrids: A numerical study on structural influence","authors":"Yifei Sun ,&nbsp;Yang Guan ,&nbsp;Xingbo Huang","doi":"10.1016/j.istruc.2025.110170","DOIUrl":"10.1016/j.istruc.2025.110170","url":null,"abstract":"<div><div>As engineering infrastructures face increasingly complex loads, conventional geo-structures demonstrate inadequate strength and energy-absorbing capacity when subjected to seismic events. To address this critical gap, this study introduces the development of a novel geogrid with negative Poisson's ratio (NPR) effect, which significantly improves the strength and energy absorption efficiency during sand deformation. The finite element analysis was carried out to compare the mechanical performances of sand reinforced by the NPR geogrids and the conventional geogrids with square shape. The biaxial shear tests under static load and periodic dynamic load were simulated. It is found that the NPR geogrids can effectively increase the shear strength of sand under compression, through enhanced shear dilation in dense sand and increased compaction in loose sand. Furthermore, this paper explores the influence of NPR geogrid on soil behavior by examining their effects on Young's modulus and protrusion angle, where it is found that the shear strength increases with an increase in the Young’s modulus, while it firstly increases and then decreases with the increasing protrusion angle.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110170"},"PeriodicalIF":4.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the behavior of notched connections in timber-concrete composite beams","authors":"Sepideh Mirshekar,&nbsp;Vahid Sadeghian","doi":"10.1016/j.istruc.2025.110146","DOIUrl":"10.1016/j.istruc.2025.110146","url":null,"abstract":"<div><div>The existing design procedures for timber-concrete composite (TCC) beams typically rely on pushout tests or simplified analytical methods developed from pushout tests to estimate the capacity of notched connections. However, these methods do not account for the differences in loading conditions and stress distributions between pushout tests and actual beams. In addition, there is limited guidance on optimizing the design of notched connections in TCC beams to enhance structural performance at ultimate load. This study addresses these gaps through both numerical and analytical modeling of notched connections. A detailed finite element (FE) modeling approach is developed and validated against experimental results from various TCC beam and pushout tests. Following validation, an extensive parametric study is carried out to assess the influence of key design parameters, such as notch geometry, spacing, location, and material properties, on connection effectiveness and beam behavior. Corresponding pushout models are also developed to evaluate the reliability of pushout tests in predicting connection capacity in beams. The use of FE analysis enables direct comparison of connection behavior between pushout and beam models. Based on the results of over 100 case studies, strength modification factors are proposed to adjust pushout capacities to more accurately represent connection behavior in TCC beams. These factors are incorporated into a previously developed simplified analytical method, improving its prediction accuracy and extending its applicability. The findings provide practical guidance for designing more reliable and efficient notched connections in TCC beams.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110146"},"PeriodicalIF":4.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural performance and implementation challenges of next-generation concrete materials","authors":"Salim Barbhuiya ,&nbsp;Bibhuti Bhusan Das ,&nbsp;Aditya Rajput ,&nbsp;Vasudha Katare ,&nbsp;Avik Kumar Das","doi":"10.1016/j.istruc.2025.110169","DOIUrl":"10.1016/j.istruc.2025.110169","url":null,"abstract":"<div><div>Conventional concrete faces limitations in durability, sustainability, and adaptability to modern structural demands, constraining its use in high-rise, bridge, and extreme-environment applications. This study examines emerging concrete mixes—HPC, UHPC, SCC, FRC, GPC, and 3D-Printed Concrete—by evaluating their mechanical properties, implementation challenges, and future opportunities. A review of experimental data, case studies, and comparative analyses was conducted to assess strength, durability, workability, and structural applications. Results show that HPC and UHPC reach compressive strengths of 60–200 MPa, GPC achieves 40–80 MPa with reduced CO₂ emissions, SCC demonstrates slump flows of 600–800 mm, and fibre reinforcement enhances tensile strength to 8–15 MPa. These findings highlight superior performance, sustainability, and constructability, though high costs, lack of standards, and scalability issues remain obstacles to widespread adoption. This review uniquely integrates comparative insights on High-Performance, Ultra-High-Performance, Self-Compacting, Fibre-Reinforced, Geopolymer, and 3D-Printed concretes, bridging laboratory findings with real-world applications. Unlike existing reviews, it emphasizes structural implementation challenges and opportunities. Key obstacles—including high cost, lack of standards, and scalability—are outlined to contextualize pathways for sustainable adoption. Overall, next-generation concretes deliver enhanced strength, durability, and sustainability, making them viable for critical infrastructure. Future studies should focus on advancing standardization, integrating nanotechnology and AI for mix optimization, and developing cost-effective, large-scale deployment strategies.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110169"},"PeriodicalIF":4.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isotherm maps of temperature gradient for CFST in China: Statistical evaluation using long-term meteorological data","authors":"Zhiyuan Ma ,&nbsp;Yongjian Liu ,&nbsp;Jiang Liu ,&nbsp;Haotian Wu ,&nbsp;Yongxin Bai","doi":"10.1016/j.istruc.2025.110143","DOIUrl":"10.1016/j.istruc.2025.110143","url":null,"abstract":"<div><div>Bridge codes tend to employ generalized temperature gradient specifications derived from historical extremes. These provisions neglect site-specific environmental interactions that critically influence thermal behavior. The varied environments increase the uncertainty of temperature gradients. This study develops geospatially refined temperature gradient models for concrete-filled steel tube (CFST) bridges through isotherm maps. Long-term historical meteorological data from 839 stations in China were collected, and missing solar radiation data were supplemented using the Bahel model. A “layer-by-layer” method for temperature gradient isotherm maps is proposed. Long-term simulations of the temperature field at 91 radiation stations were carried out based on meteorological data. Meanwhile, the formulas for predicting the temperature gradients based on meteorological parameters were established. Then, Peak over threshold model based on the generalized Pareto distribution was used to calculate the temperature gradient loads at each meteorological station with a 100-year return period. Finally, the spatial interpolation method was used to draw the isotherm contour maps of temperature gradients. The results show that the temperature gradients of CFST bridges in China vary significantly across different regions. The regional differences can reach up to 17.91°C. Therefore, the specified values of temperature gradient for CFST bridges may lead to non-conservatism in design for most regions in China. Compared to the current specification, the temperature gradient isotherm maps presented in this paper offer enhanced geographic resolution. This will contribute to the more refined design of CFST bridges in China and serve as a valuable supplement to the Chinese specifications.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110143"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shear capacity of FRP-RC beams: XML modeling and reliability evaluation","authors":"Abouzar Jafari ,&nbsp;Amir Ali Shahmansouri ,&nbsp;Arsam Taslimi ,&nbsp;M.Z. Naser ,&nbsp;Ying Zhou","doi":"10.1016/j.istruc.2025.110150","DOIUrl":"10.1016/j.istruc.2025.110150","url":null,"abstract":"<div><div>The accurate prediction of the shear capacity of concrete beams reinforced with FRP bars remains a significant challenge due to the distinct mechanical characteristics of FRP, including its linear-elastic behavior and relatively low stiffness compared to steel. To address this, the present study develops two machine learning (ML)-based solutions—a practical multilayer perceptron (MLP) model with a minimalist structure and an enhanced MLP model—for predicting the shear capacity of FRP-RC beams reinforced with both longitudinal FRP bars and FRP stirrups. A curated dataset of 144 experimental tests conducted between 1993 and 2021 was used for model development and validation. Both models achieved superior predictive accuracy compared to existing empirical equations, with goodness-of-fit values of 0.93 and 0.97 and root mean square errors of 27.5 kN and 14.5 kN, respectively, while avoiding systematic over- or underestimation. Feature ranking and sensitivity analysis showed that beam dimensions (effective depth and width) have the strongest positive correlations with shear capacity (0.90 and 0.65). The FRP stirrup ratio and bend radius-to-diameter ratio also influence shear capacity (around 0.45), while the span-to-depth ratio has a moderate negative correlation (–0.51), consistent with the mechanics of FRP-RC beams. SHapley Additive exPlanations (SHAP) analysis revealed that beam section dimensions, span-to-depth ratio, and FRP stirrup properties are the most influential input variables. The enhanced MLP model captured more complex feature interactions, while the practical model preserved interpretability and is better suited for design applications. Reliability analysis performed using Monte Carlo simulation showed that the practical model has a lower probability of failure (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>f</mi></mrow></msub></math></span> = 0.0035) compared to the enhanced model (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>f</mi></mrow></msub></math></span>= 0.045), indicating its conservative and robust nature. Sensitivity reliability analysis highlighted variations in beam dimensions, FRP stirrup properties, and concrete compressive strength significantly affect structural reliability, providing useful insights for design optimization. Overall, the proposed solutions offer accurate, interpretable, and robust tools for predicting the shear capacity of FRP-RC beams, with promising applications in structural design and safety assessment.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110150"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-scale evaluation of key performance of novel welded connectors in precast airport pavement under fatigue loading","authors":"Qianqian Liu ,&nbsp;Pengfei Song ,&nbsp;Xuhao Wang ,&nbsp;Haiqiang Guo ,&nbsp;Xinmin Gao ,&nbsp;Rengbing Liu ,&nbsp;Yuan Long","doi":"10.1016/j.istruc.2025.110104","DOIUrl":"10.1016/j.istruc.2025.110104","url":null,"abstract":"<div><div>Precast concrete systems, characterized by their environmental sustainability and rapid construction, demonstrate significant potential for expedited airport pavement construction and maintenance. The inherent low thickness-to-size ratio of the thin precast slab leads to localized stress concentrations at joint interfaces, making the configuration and mechanical performance of joints critically govern the long-term serviceability of precast airport pavements. This study introduced two welded connectors optimized for rapid assembly and disassembly. A full-scale experimental structure was developed using ABAQUS, enabling systematic comparative analysis of load transfer efficiency (LTE) degradation, fatigue life, and failure modes across rigid and flexible base. To further validate the operational LTE of both connectors, heavy weight deflectometer (HWD) testing was conducted on the field test section. Results demonstrated that under laboratory static testing, the maximum LTE for connector-A and connector-B were 100 % and 43.7 %, respectively, while field testing yielded average LTE of 79 % and 52 %, indicating significantly superior load transfer performance of connector-A. Fatigue test results indicated that LTE for connector-A under flexible base degraded from 100 % to 20 %, and connector-B degraded from 43.7 % to 15.8 %, whereas rigid base maintained stable LTE for both connectors. Correspondingly, connector-A endured 100,000 cycles without fracture, contrasting with connector-B's failure at 50 000 cycles on rigid base and 6 000 cycles on flexible base. Both connectors failed via rod fracture rather than weld cracking, with fractures localized on the loaded side under low-stiffness bases with poor LTE and shifting to the unloaded side under enhanced LTE conditions. The findings provided actionable guidelines for precast airport pavement joint design, prioritizing the use of connector-A and advocating for high-stiffness base to mitigate LTE degradation and extend service life.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110104"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fourier series-based reliability analysis of train-bridge interaction under crosswind action using fuzzy random uncertainty","authors":"Patrick Arnaud Wandji Zoumb ,&nbsp;Ming Wang ,&nbsp;Adangba Raphael Kouame","doi":"10.1016/j.istruc.2025.110148","DOIUrl":"10.1016/j.istruc.2025.110148","url":null,"abstract":"<div><div>High-speed trains crossing long-span railway bridges under crosswind loads can lead to complex dynamic responses, posing risks to both running safety and structural serviceability. These scenarios involve non-stationary wind excitations, high-frequency train–bridge interactions due to wheel–rail contact forces, and uncertain bridge damping arising from limited experimental data. Traditional analysis methods, deterministic, probabilistic, or fuzzy, often isolate individual uncertainty sources and may fail to capture the coupled, nonlinear behaviour of such systems. To overcome these limitations, a hybrid Fourier–fuzzy–reliability framework is proposed. The Fourier series characterizes dominant frequency-domain features, such as cyclic wheel–rail forces. Fuzzy logic models’ epistemic uncertainties, including imprecise damping ratios and variable wind parameters, while inherent randomness is represented by stochastic variables. These elements are unified through reliability analysis to evaluate failure probabilities of the train–bridge system under crosswind conditions. The framework is applied to a case study involving a high-speed train traversing the Yibin Lingang Bridge in China, and the method is validated against a Monte Carlo simulation, reducing computation time by up to 97 %. Results demonstrate that, unlike traditional methods, the proposed approach reveals a more realistic and progressive transition in failure probability with increasing vibration amplitudes, offering enhanced reliability insights for wind-resilient railway bridge design and operation.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110148"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexural performance of steel-concrete composite beams strengthened with a CFRP grid-ECC layer at the hogging moment region","authors":"Jing Li ,&nbsp;Xiaoyang Liu ,&nbsp;Chenghua Peng ,&nbsp;Weikang Gong ,&nbsp;Guotao Yang ,&nbsp;Jian-Guo Dai","doi":"10.1016/j.istruc.2025.110160","DOIUrl":"10.1016/j.istruc.2025.110160","url":null,"abstract":"<div><div>The combination of carbon fibre reinforced polymer (CFRP) grid with engineered cementitious composite (ECC) provides a promising solution for structural strengthening. This paper presents an investigation into the application of the CFRP grid-ECC method for strengthening steel-concrete composite beams at the hogging moment region. Four composite beams are fabricated and tested to investigate the effects of the ECC thickness and the number of CFRP grids on their flexural responses, in terms of failure mode, load-carrying capacity, load-deflection, load-slip behaviour, and ductility. The obtained results demonstrate that the ECC layer provides effective bonding between the CFRP grid and the concrete substrate, and this strengthening technique effectively enhances the hogging moment capacity of the composite beams, achieving improvements of 11.3 % in yield load and 10.1 % in peak load. Additionally, a finite element (FE) model is developed for the strengthened composite beams to further investigate the effects of ECC thickness, rebar strength, reinforcement ratio, number of CFRP grids, steel beam strength, as well as the thicknesses of the top and bottom flanges on the hogging moment capacity. Furthermore, an analytical formula is developed for evaluating the hogging moment capacity of the strengthened composite beams, and the results exhibit reasonable agreement with the test results.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110160"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interpretable machine learning approach for predicting the workability and mechanical properties of betel nut husk fiber-reinforced concrete","authors":"Mehedi Hasan ,&nbsp;Md Soumike Hassan ,&nbsp;Kamrul Hasan ,&nbsp;Fazlul Hoque Tushar ,&nbsp;Majid Khan ,&nbsp;Ramadhansyah Putra Jaya","doi":"10.1016/j.istruc.2025.110152","DOIUrl":"10.1016/j.istruc.2025.110152","url":null,"abstract":"<div><div>Natural fiber-reinforced concrete (NFRC) is gaining attention for its sustainability, cost-effectiveness, and biodegradability, making it a promising material for construction and repair. Betel nut husk fiber (BNHF) is being incorporated into concrete due to its eco-friendly, nontoxic, and biodegradable properties. However, traditional methods for measuring slump, compressive strength (CS), and split tensile strength (STS) are often time-consuming, labor-intensive, and costly. To address this, machine learning (ML) models offer an efficient alternative for predicting these properties, enabling faster and more economical adjustments to BNHF-reinforced concrete mixes. This study explores the use of five ensemble ML models: Random Forest (RF), XGBoost, CatBoost, AdaBoost, and LightGBM to predict slump, CS, and STS. Model performance was evaluated using five metrics: coefficient of determination (R²), root mean square error (RMSE), normalized root mean square error (NRMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). The results showed that the CatBoost model performed best in predicting slump and CS, with R² values of 0.989 and 0.918, and RMSEs of 2.116 mm and 1.986 MPa, respectively. For STS, XGBoost outperformed other models, achieving an R² of 0.862 and an RMSE of 0.406 MPa on the test set. SHapley Additive exPlanations (SHAP) analysis indicated that BNHF percentage and fiber content had the greatest influence on slump, while curing time was the most significant factor affecting both CS and STS. The findings demonstrate that CatBoost and XGBoost can accurately predict the mechanical properties, offering a practical alternative to extensive laboratory testing and enabling time and cost savings in construction.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110152"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation on vortex-induced vibrations of a single-box girder with extended cantilevers and its mitigation strategies","authors":"Zhen Wang ,&nbsp;Xuhui He ,&nbsp;Haiquan Jing ,&nbsp;Lingfei Tan ,&nbsp;Naeem Muhammad ,&nbsp;Lulu Liu ,&nbsp;Lei Yan","doi":"10.1016/j.istruc.2025.110163","DOIUrl":"10.1016/j.istruc.2025.110163","url":null,"abstract":"<div><div>This study experimentally investigates the vortex-induced vibrations (VIVs) of a single-box girder with long cantilevers, focusing on the impact of handrail modifications on mitigating VIV amplitudes. The results highlight that the VIVs of the bridge occur in both vertical bending and torsion, with the VIV peaks exceeding the permissible values in both degrees of freedom. The analysis reveals that both the outer handrails and maintenance rails influence the VIV performance, with the outer handrails playing a dominant role. Smoke flow visualization provides significant insights, demonstrating that large amplitude VIVs are closely associated with the curbstone and bottom porosity of the outer handrails. Modifications to the outer handrails, particularly the streamlining of the curbstone's aerodynamic shape and improvements to the bottom porosity, are found to significantly reduce the VIV amplitudes in both vertical bending and torsion. The findings suggest that modifying the outer handrails could be an effective approach to controlling VIVs in similar bridge structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110163"},"PeriodicalIF":4.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}