Infrastructures

26 pages, 2930 KB

Open AccessArticle

Risk Analysis of Tunnel Construction Projects Using Tunnel Boring Machines: A Hybrid BWM–DEA–PROMETHEE Framework

by Nitidetch Koohathongsumrit and Wasana Chankham

Infrastructures 2026, 11(2), 72; https://doi.org/10.3390/infrastructures11020072 - 22 Feb 2026

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Underground tunnel construction projects using tunnel boring machines (TBMs) require a holistic risk perspective. Such projects face various risks arising from social, economic, political, workforce, and regulatory aspects during project execution. It is necessary to develop preventive strategies for managing these risks and [...] Read more.

Underground tunnel construction projects using tunnel boring machines (TBMs) require a holistic risk perspective. Such projects face various risks arising from social, economic, political, workforce, and regulatory aspects during project execution. It is necessary to develop preventive strategies for managing these risks and thereby ensure timely project delivery, cost efficiency, and safety. In this study, we aimed to develop a comprehensive hybrid decision-making framework for analyzing risks in TBM-based tunnel construction projects. The proposed approach integrates the best–worst method (BWM), data envelopment analysis (DEA) model-based risk assessment, and the preference ranking organization method for enrichment evaluation (PROMETHEE). The BWM was applied to determine the weights of decision criteria with fewer comparisons and improved consistency. Subsequently, the DEA model was then used to compute local risk scores under multiple input and output conditions. Finally, PROMETHEE was employed to analyze the risks based on positive and negative outranking flows. The proposed approach was applied to a realistic metro construction project in Bangkok. The findings indicated that the proposed approach effectively compromised all the decision-making attributes to manage the uncertainties. The proposed methodology can support project managers, stakeholders, engineers, and relevant authorities in identifying high-priority risks and implementing effective mitigation strategies to enhance risk management in tunnel construction. Full article

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18 pages, 2235 KB

Open AccessArticle

Qualitative Modelling of Failure Scenarios for Long Linear Transport Infrastructures in Mountain Areas

by Théotime Michez, Laurent Peyras, Stéphane Lambert, Sébastien Reynaud and Patrick Garcin

Infrastructures 2026, 11(2), 71; https://doi.org/10.3390/infrastructures11020071 - 22 Feb 2026

Viewed by 200

Abstract

In mountain areas, long linear transport infrastructures (roads, motorways, railways, etc.) are exposed to numerous natural hazards, especially hydrological and gravity-driven events such as slope instabilities, rockfalls, or torrential hazards. These phenomena can damage infrastructure, or even lead to the destruction of large [...] Read more.

In mountain areas, long linear transport infrastructures (roads, motorways, railways, etc.) are exposed to numerous natural hazards, especially hydrological and gravity-driven events such as slope instabilities, rockfalls, or torrential hazards. These phenomena can damage infrastructure, or even lead to the destruction of large sections, causing a risk for users and a deterioration of service. Infrastructure managers face several difficulties in handling these risks. One of them is identifying and representing them, due to the scale of the infrastructure, which is composed of numerous structures and exposed to multiple hazards. In this context, a model is proposed to represent all potential failure scenarios for such infrastructures. This model is based on system reliability analysis methods: functional analysis, failure mode and effect analysis (FMEA), and fault tree analysis (FTA). It is intended to be applied to a linear infrastructure, several kilometres long, exposed to various hazards. The proposed approach allows for the identification of all possible failure modes, including damage to structures and its functional consequences. Its applicability is being tested on a simple case study. Full article

(This article belongs to the Topic Disaster Risk Management and Resilience)

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18 pages, 7275 KB

Open AccessArticle

Sustainable Concrete for Rigid Pavements Using Alkali-Activated Recycled Pumice: Strength and Carbonation Assessment

by Pablo Julián López-González, Oscar Moreno-Vázquez, Sergio Aurelio Zamora-Castro, Tania Irene Lagunes-Vega, Efrén Meza-Ruíz, Brenda Suemy Trujillo-García, Rodrigo Vivar-Ocampo, David Reyes-González and Joaquín Sangabriel-Lomelí

Infrastructures 2026, 11(2), 70; https://doi.org/10.3390/infrastructures11020070 - 22 Feb 2026

Viewed by 235

Abstract

This study investigates alkali-activated recycled pumice as a sustainable cement replacement for hydraulic concrete used in rigid pavements. Cement was replaced at 15%, 25%, and 50% by mass and activated using NaOH solutions at 1 N, 0.5 N, and 0.25 N, resulting in [...] Read more.

This study investigates alkali-activated recycled pumice as a sustainable cement replacement for hydraulic concrete used in rigid pavements. Cement was replaced at 15%, 25%, and 50% by mass and activated using NaOH solutions at 1 N, 0.5 N, and 0.25 N, resulting in nine mixture variants. Mechanical performance was assessed through compressive strength at 7, 14, and 28 days, and flexural strength at 28 days. Durability was evaluated via natural carbonation depth at 210 and 1090 days. X-ray diffraction (XRD) identified aluminosilicate phases in the pumice, supporting its alkali-reactive potential. Mixtures with 15% pumice replacement achieved compressive strengths up to 20.99 MPa, comparable to the control mix (20.45 MPa), whereas 25% and 50% replacements produced moderate strength reductions. Flexural strength in 15% mixtures (7.38–7.44 MPa) was also comparable to the control (7.30 MPa), while higher replacement levels reduced flexural performance. Carbonation resistance improved for mixtures with an optimized alkaline-to-pumice ratio (APR, defined as NaOH concentration relative to pumice content) between 0.0167 and 0.02, indicating more balanced activation and reduced CO₂ ingress. Overall, alkali-activated recycled pumice enables partial cement replacement while maintaining mechanical performance and carbonation resistance at 15% substitution, supporting circular economy strategies and lowering the carbon footprint of rigid pavement concrete. Full article

(This article belongs to the Section Sustainable Infrastructures)

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22 pages, 5086 KB

Open AccessArticle

Geotechnical Challenges and Foundation Performance of the Cairo Monorail System Based on Field and Numerical Investigations

by Ashraf Ahmed El-Shamy and Yasser Moghazy El-Mossallamy

Infrastructures 2026, 11(2), 69; https://doi.org/10.3390/infrastructures11020069 - 21 Feb 2026

Viewed by 155

Abstract

The Cairo Monorail System presents significant geotechnical challenges due to its integrated structural configuration and its alignment across heterogeneous soil conditions, including collapsible and swelling soils. This study investigates the foundation performance of the monorail through a combination of advanced site investigations, full-scale [...] Read more.

The Cairo Monorail System presents significant geotechnical challenges due to its integrated structural configuration and its alignment across heterogeneous soil conditions, including collapsible and swelling soils. This study investigates the foundation performance of the monorail through a combination of advanced site investigations, full-scale pile load testing under dry and wetted conditions, and finite-element modeling incorporating soil–structure interaction. Field load tests on large-diameter bored piles founded in collapsible soils demonstrated a pronounced increase in settlement and a reduction in stiffness following wetting, confirming the sensitivity of pile behavior to moisture variations. Three-dimensional numerical analyses of the integrated monorail system showed that differential settlements between adjacent columns are generally limited to less than 9 mm under serviceability loading conditions, satisfying passenger comfort requirements. Long-term coupled seepage–deformation analyses conducted using PLAXIS indicated that surface water infiltration into swelling soils may induce time-dependent monopile heave of approximately 10 mm over a 50-year design life, which remains within acceptable serviceability limits. The results demonstrate that detailed geotechnical characterization, combined with appropriate numerical modeling strategies, can effectively control differential deformation and long-term heave in continuous monorail systems, ensuring their operational safety and long-term performance. Full article

(This article belongs to the Section Infrastructures and Structural Engineering)

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24 pages, 7978 KB

Open AccessArticle

The Impact of Recycled Glass and Demolition Sand on Delayed Ettringite Formation and Mechanical Performance of Sustainable Concrete

by Seleem S. E. Ahmad, Samah A. Ahmed, Ahmed A. Elshami and Yasmine Elmenshawy

Infrastructures 2026, 11(2), 68; https://doi.org/10.3390/infrastructures11020068 - 16 Feb 2026

Viewed by 446

Abstract

Concrete poses many environmental and economic problems due to its heavy reliance on natural resources. The objective of this study was to explore the potential of utilizing recycled materials, specifically waste glass powder and demolition sand, to assess their effectiveness in reducing the [...] Read more.

Concrete poses many environmental and economic problems due to its heavy reliance on natural resources. The objective of this study was to explore the potential of utilizing recycled materials, specifically waste glass powder and demolition sand, to assess their effectiveness in reducing the formation of delayed ettringite and consequently enhancing the strength of sustainable concrete. This study assesses the combined effects of waste glass powder and demolition sand on stable, sustainable concrete under sulfate exposure. A comprehensive experimental program included 23 mixes using different types of fine aggregate in concrete: standard sand, demolition sand, and mixes with 10–30% ground glass fines replacing Portland cement (PC). Also, the effects of added sodium sulfate and gypsum (1%, 3%, and 5%) on compressive, tensile, and flexural strengths were analyzed by conducting mechanical tests at 7, 28, and 56 days. Finally, SEM, EDS, and XRD were conducted to analyze the microstructures of the concrete mixes. Using gypsum and sodium sulfate provides sulfate ions to study their effects on Delayed Ettringite Formation and mechanical performance. The results of the present work showed that the optimal mix (20% glass powder with 1–3% gypsum) achieved a 21% increase in 28-day compressive strength and a denser microstructure with reduced microcracking. Gypsum showed more stable behavior under the tested conditions compared with sodium sulfate. The microstructure studies supported this conclusion and further demonstrate that optimal amounts of glass result in a denser concrete matrix with less cracking, which is used much more effectively. Full article

(This article belongs to the Special Issue Recent Advances in Enhancing Sustainability and Durability of Cement and Concrete)

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26 pages, 5384 KB

Open AccessArticle

Strength, Transport Properties, and Life Cycle Impacts of Mortar Containing German Natural Pozzolan

by Houssam Affan, Laurent Fehr, Ginan Al-Massri, Farjallah Alassaad, Amro Yaghi and Hassan Ghanem

Infrastructures 2026, 11(2), 67; https://doi.org/10.3390/infrastructures11020067 - 16 Feb 2026

Viewed by 343

Abstract

Portland cement production is energy- and carbon-intensive. Substituting part of the clinker with natural pozzolans is a promising route to lower-impact mortars. This work evaluates mortar where Portland cement is partially replaced by a German natural pozzolan (12–56% by mass). Compressive and flexural [...] Read more.

Portland cement production is energy- and carbon-intensive. Substituting part of the clinker with natural pozzolans is a promising route to lower-impact mortars. This work evaluates mortar where Portland cement is partially replaced by a German natural pozzolan (12–56% by mass). Compressive and flexural strengths were measured at 7, 28, and 90 d. Water-accessible porosity (28 d) and 24 h water absorption were also determined. Strength development and water transport were interpreted using (i) a three-parameter strength–age model and (ii) a capillary–diffusive model. The results showed delayed reactivity typical of pozzolanic materials. At 90 d, 12% replacement slightly exceeded the control by 3.38% and 1.4% in compressive and flexural strengths respectively. Higher replacement levels caused a drop in strength at 90 d (18.3% at 36% and 42.5% at 56% in compression; 25.3% and 31.0% in flexure). Porosity and absorption increased with replacement, consistent with the mechanical trends. The compressive and flexural strengths were strongly correlated. Life cycle analysis showed a significant reduction in embodied carbon, reaching approximately 52% at 56% replacement. Overall, moderate replacement (12–21%) provides the best balance between performance and carbon reduction. Full article

(This article belongs to the Special Issue Recent Advances in Enhancing Sustainability and Durability of Cement and Concrete)

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17 pages, 1980 KB

Open AccessArticle

Influence of High-Performance Recycled Aggregates on Mechanical Properties of High-Strength Concrete

by Juan Sebastián Diosa-Arenas, Manuel Alejandro Rojas-Manzano, Ingrid Elizabeth Madera-Sierra and Aníbal Maury-Ramírez

Infrastructures 2026, 11(2), 66; https://doi.org/10.3390/infrastructures11020066 - 13 Feb 2026

Viewed by 312

Abstract

One of the major challenges in developing a sustainable construction industry is the reincorporation of construction and demolition waste (C&DW) into the materials cycle. An interesting end-of-life cycle strategy is the recycling of C&DW as aggregates for new concrete. Although promising results have [...] Read more.

One of the major challenges in developing a sustainable construction industry is the reincorporation of construction and demolition waste (C&DW) into the materials cycle. An interesting end-of-life cycle strategy is the recycling of C&DW as aggregates for new concrete. Although promising results have mostly been reported for applications with low mechanical and durability requirements, this research evaluates the use of a high-performance recycled concrete aggregate (HP-RCA), a low-porosity, high-abrasion-resistance aggregate obtained from the demolition of high-strength concrete, with almost no additional treatment, unlike what is traditionally required. First, the production and characterization of the HP-RCA was carried out, to continue with the manufacture of four high-strength concrete mixtures that included one reference (0%) and three with different natural coarse aggregate replacements (10%, 20% and 40%). Then, fresh and hardened properties were evaluated, with the main focus being mechanical properties (i.e., compressive strength, diametric compressive tensile strength and elasticity modulus). Results indicate that when the recycled aggregate content increased, the mechanical properties substantially improved, and the mixture with 40% replacement improved the compressive strength by 37.8% at 56 days. Although durability performance still needs to be further assessed, the mechanical results presented here are very promising for advancing a truly sustainable construction industry, especially considering that the extraction of natural coarse aggregates has significant environmental impacts and that the final disposal of C&DW remains a major environmental and economic challenge. Full article

(This article belongs to the Special Issue Recent Advances in Enhancing Sustainability and Durability of Cement and Concrete)

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31 pages, 4263 KB

Open AccessArticle

A Uniform Framework for Climate Change Adaptation of Critical Infrastructure Using Nature-Based Solutions

by Diamando Vlachogiannis, Ioannis Zarikos, Athanasios Sfetsos, Juliette Rimlinger, Alexandra Jaumouillé, Catherine Freissinet, Ville Santala, Dimitrios Tzempelikos and Maria Dubovik

Infrastructures 2026, 11(2), 65; https://doi.org/10.3390/infrastructures11020065 - 13 Feb 2026

Viewed by 409

Abstract

With climate change expected to intensify hazards across Europe, empowering communities and strengthening local adaptation is urgent. The challenge is bolstering the resilience of critical infrastructure (CI), which faces substantial risks. Transitioning from predominantly “grey” infrastructure to integrated “green-grey” solutions provides an effective [...] Read more.

With climate change expected to intensify hazards across Europe, empowering communities and strengthening local adaptation is urgent. The challenge is bolstering the resilience of critical infrastructure (CI), which faces substantial risks. Transitioning from predominantly “grey” infrastructure to integrated “green-grey” solutions provides an effective way to safeguard societal and infrastructural assets against hazards and environmental degradation. Although several frameworks developed by international networks and regional authorities exist, they often fail to fully address the nuanced challenges of CI climate proofing, disaster risk reduction, and biodiversity protection. In response to these limitations and to address key societal challenges, the work here introduces an innovative, integrative blueprint framework. This framework synthesises existing approaches to CI climate adaptation, systematically strengthening resilience with nature-based solutions (NBS). The framework is partially applied and validated through the Public-Private-Civil Partnership (PPCP^®) approach, and operationalised in two climatically distinct but heatwave-prone regions: Egaleo (Greece) and Helsinki (Finland). These Labs have promoted more inclusive policymaking by supporting collaboration among key stakeholders, encouraging knowledge sharing and co-designing strategies to advance NBS implementation for heatwave mitigation. The approach facilitated the design of interconnected activities and simplified technical details. Adapting methods to local needs, such as site visits and participatory mapping, has led to concrete outcomes. The prefeasibility analysis outcomes and the targeted NBS-based strategies identified from these areas ensure that solutions are culturally relevant, technically feasible, and collectively owned, incorporating local knowledge and fostering long-term sustainability. Full article

(This article belongs to the Special Issue Nature-Based Solutions and Resilience of Infrastructure Systems)

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29 pages, 2915 KB

Open AccessArticle

Nano-Silica-Enhanced Binder Synergy and Multi-Index Performance of Resource-Efficient Alkali-Activated Composites for Sustainable Infrastructure Applications

by Mahmoud Abo El-Wafa

Infrastructures 2026, 11(2), 64; https://doi.org/10.3390/infrastructures11020064 - 12 Feb 2026

Viewed by 176

Abstract

This study presents a multi-index performance approach that moves beyond the conventional reliance on compressive strength, offering a more holistic evaluation of nano-silica-enhanced binders in resource-efficient alkali-activated composites. Based on the Strength Activity Index (SAI) framework described in ASTM C618, the method integrates [...] Read more.

This study presents a multi-index performance approach that moves beyond the conventional reliance on compressive strength, offering a more holistic evaluation of nano-silica-enhanced binders in resource-efficient alkali-activated composites. Based on the Strength Activity Index (SAI) framework described in ASTM C618, the method integrates fresh state flowability with mechanical strength indices to capture the overall binder synergy. High-calcium fly ash (HCFA) and low-calcium fly ash (LCFA) were used with fine aggregate replacement, the level of which was kept constant at 20% by mass, and nano-silica was incorporated at 0, 1, 2, and 3 wt% of the binder to prepare alkali-activated slag fly ash composites. The fresh-state performance was assessed using the Initial Flow Index (IFI) and Flow Retention Index (FRI), while the mechanical performance was evaluated using the compressive, tensile, and flexural indices (SAI, TSI, and FSI). These results indicate that with an increase in nano-silica content, flowability and workability retention reduce systematically, with LCFA-based mixtures always exhibiting higher fresh-state retention than HCFA systems. Optimal mechanical performance was achieved with an intermediate nano-silica concentration of about 2 wt%, with consequent maximum SAI performance of about 120% at 28 days with HCFA-based mixtures and 118% at 28 days with LCFA-based mixtures, as well as a uniform improvement in TSI and FSI. Correlation analyses between SAI and tensile and flexural indices revealed clear linearity (R² of about 0.91–0.95), which indicated that compressive strength is not a sufficient measure of total mechanical performance. The mineralogical and microstructural analyses assisted by X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that the performance trends observed depend on the interactions of the calcium supply, amorphous aluminosilicate and the nucleation effects of nano-silica. Therefore, the proposed multi-index framework offers a robust and practical tool for quantifying binder synergy and optimizing nano-silica dosage, advancing the understanding and development of sustainable alkali-activated composites for infrastructure applications. Full article

(This article belongs to the Special Issue Recent Advances in Enhancing Sustainability and Durability of Cement and Concrete)

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15 pages, 4762 KB

Open AccessArticle

Crack Control and Support Optimization of Long-Span Prestressed Concrete Box Girders During SPMT Transportation

by Zhao-Zhong Wang, Wen-Wen Yu and Wen-Huo Sun

Infrastructures 2026, 11(2), 63; https://doi.org/10.3390/infrastructures11020063 - 12 Feb 2026

Viewed by 225

Abstract

The Hong Kong Tseung Kwan O Cross Bay Link project adopted Self-Propelled Modular Transporter (SPMT) for the first time for the floating-state loading and transportation of large-span prestressed concrete box girders, allowing the 75 m box girders to be placed on the SPMT [...] Read more.

The Hong Kong Tseung Kwan O Cross Bay Link project adopted Self-Propelled Modular Transporter (SPMT) for the first time for the floating-state loading and transportation of large-span prestressed concrete box girders, allowing the 75 m box girders to be placed on the SPMT fixture in a multi-point support manner. To prevent concrete cracking during transportation, this paper studies the stress and deformation characteristics of large-span box girders under a multi-support system through a combination of theoretical research, numerical calculation, and field testing. Based on crack control of box girders, a SPMT vehicle arrangement and segmented jacking method are proposed. The results show that the SPMT vehicle group arrangement range at both ends of the box girder should be controlled within 1/3 of the box girder span; during the jacking process of the box girder, the torsion of the box girder caused by the differential oil pressure in segmented jacking should be controlled, and synchronous jacking should be adopted as much as possible; the SPMT vehicle arrangement and jacking should control the support force to be smaller closer to the mid-span. The research results have been successfully applied in the Hong Kong Tseung Kwan O project and can provide technical reference for similar projects. Full article

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18 pages, 385 KB

Open AccessArticle

Evolution of the National Toll Network Towards a Free-Flow Model: Mobility, Safety and Environmental Impacts of a Real-World Case Study

by Cristian Giovanni Colombo, Nicoletta Matera, Michela Longo and Fabio Borghetti

Infrastructures 2026, 11(2), 62; https://doi.org/10.3390/infrastructures11020062 - 11 Feb 2026

Viewed by 351

Abstract

This study analyses the transition from traditional barrier-based toll collection to a free-flow tolling (FFT) system on a national motorway corridor. The aim is to quantify how FFT affects mobility, safety and environmental performance when physical toll plazas are replaced by overhead gantries. [...] Read more.

This study analyses the transition from traditional barrier-based toll collection to a free-flow tolling (FFT) system on a national motorway corridor. The aim is to quantify how FFT affects mobility, safety and environmental performance when physical toll plazas are replaced by overhead gantries. Operational data at toll barriers and booths are first characterised in terms of traffic volumes, queue events and accident frequency, and a set of Key Performance Indicators is defined to describe both mobility and environmental effects. Travel times are modelled for light and heavy vehicles, distinguishing between electronic toll collection and manual payment, while demand variations are estimated using elasticities with respect to travel time. Environmental impacts are assessed through an energy-based model of deceleration, queueing and acceleration combined with fuel-specific emission factors for CO₂-equivalent and PM₁₀. The results show that removing physical toll plazas reduces queues by about 79.5% and is expected to reduce accidents in toll areas by roughly 50%, with CO₂-equivalent emissions at toll locations decreasing by up to 80% for light vehicles and 85% for heavy vehicles, and corridor-wide emissions also being significantly reduced, even when induced demand is considered. A final application to a photovoltaic green island on a decommissioned toll plaza illustrates how FFT can be coupled with infrastructure reuse to support cost-effective decarbonisation. Full article

(This article belongs to the Special Issue Sustainable Road Design and Traffic Management)

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18 pages, 1639 KB

Open AccessArticle

A Hybrid Optimization Approach for Multi-Criteria Decision Making in Emergency Response Coordination

by Ning Zhang, Jikai Wang, Shengtao Zhang, Fei Meng, Chuanyi Ma, Yuan Tian and Jianqing Wu

Infrastructures 2026, 11(2), 61; https://doi.org/10.3390/infrastructures11020061 - 11 Feb 2026

Viewed by 295

Abstract

Optimizing the allocation of emergency vehicles is essential for enhancing route-planning efficiency and ensuring road safety during traffic incidents. Traditional dispatch methods often struggle with complex scenarios due to their inability to integrate and balance multiple conflicting factors. This study proposes a multi-objective [...] Read more.

Optimizing the allocation of emergency vehicles is essential for enhancing route-planning efficiency and ensuring road safety during traffic incidents. Traditional dispatch methods often struggle with complex scenarios due to their inability to integrate and balance multiple conflicting factors. This study proposes a multi-objective dispatch framework for emergency vehicles that integrates regression analysis, deep learning, and an enhanced ant colony algorithm. Key environmental factors (e.g., weather, visibility) are selected through logistic regression, and a BP neural network predicts the impact ranges of accidents. The adaptive ant colony algorithm optimizes dynamic routing through innovations such as adjusting state transition probability and implementing pheromone reward—penalty strategies. It achieves faster convergence (with a comprehensive index of 86 in 8 iterations compared to 158 in 20 iterations) and superior path quality (a 9% reduction in rescue time and a 12% decrease in costs). Compared with existing hybrid frameworks, this study is the first to integrate logistic regression-selected environmental factors with BP neural network-predicted accident impact ranges, and further proposes adaptive state transition and pheromone reward-penalty update mechanisms, thereby achieving faster convergence speed and superior path quality in dynamic multi-objective rescue route planning. Full article

(This article belongs to the Special Issue Smart Transportation Infrastructure: Optimization and Development)

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12 pages, 2055 KB

Open AccessArticle

Terrestrial Laser Scanning as a Part of Railway Comprehensive Diagnostics

by Jana Izvoltova, Stanislav Hodas, Jakub Chromčák and Daša Smrčková

Infrastructures 2026, 11(2), 60; https://doi.org/10.3390/infrastructures11020060 - 10 Feb 2026

Viewed by 231

Abstract

A comprehensive diagnosis of the railway line aims to control its actual structure and geometric arrangement. Such railway inspections can help detect potential track deformation caused by operational loads and climatic effects. Geodetic monitoring appears to be a beneficial component of such diagnostics, [...] Read more.

A comprehensive diagnosis of the railway line aims to control its actual structure and geometric arrangement. Such railway inspections can help detect potential track deformation caused by operational loads and climatic effects. Geodetic monitoring appears to be a beneficial component of such diagnostics, particularly when modern terrestrial or aerial laser-scanning techniques are employed. The reliable determination of track deformation using geodetic contactless methods relies on precise measurements, high-quality instruments, and point-cloud processing, which is based on specific numerical procedures that help reveal possible track displacements or deformations. At the same time, the used geodetic methods should reflect the required minimal resolution depending on the size and type of the measured track geometric parameter. The paper presents a brief description of a comprehensive diagnostic conducted on the Tatra Electric Railway, a single-track, narrow-gauge line in the mountain tourist resort of northern Slovakia, with a closer focus on point-cloud processing acquired using geodetic methods. Full article

(This article belongs to the Section Infrastructures and Structural Engineering)

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17 pages, 1980 KB

Open AccessArticle

Effect of Cohesive Sediments in Scour Morphology Downstream of Submerged Sluice Gates

by Ali Mahdian Khalili and Mehdi Hamidi

Infrastructures 2026, 11(2), 59; https://doi.org/10.3390/infrastructures11020059 - 9 Feb 2026

Viewed by 271

Abstract

The scouring of cohesive and non-cohesive materials downstream of sluice gates is primarily based on high-velocity flow. The present study considered an experimental hydraulic model of submerged water flow issuing from a sluice gate installed on an apron that leads to the scour [...] Read more.

The scouring of cohesive and non-cohesive materials downstream of sluice gates is primarily based on high-velocity flow. The present study considered an experimental hydraulic model of submerged water flow issuing from a sluice gate installed on an apron that leads to the scour hole and dune in a downstream mixture of sand and clay bed. The purpose was to achieve a suitable efficiency of the weight ratio of clay in the sand–clay mixture (c) for the sediment bed. Scour parameters, including maximum scour depth (d_se) and its longitudinal location (x_se), and maximum dune height (h_d) and its location (x_d), were measured and compared for three variations, c = 0.1, 0.2, and 0.3, under five hydraulic conditions. Results revealed that all scour parameters were reduced by adding clay to the sand soil, and the maximum reduction was for d_se with the maximum value of 27.66%. The observed data were analyzed by multiple nonlinear regression analyses for each scour parameter to present new prediction equations for practical uses. The computed statistical parameters of correlation coefficient (R²), root mean square error (RMSE), mean absolute percentage error (MAPE), Nash–Sutcliffe efficiency (NSE), and scatter index (SI) present good accuracy for the predicted equations in the ranges of experimental data. Full article

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21 pages, 3880 KB

Open AccessArticle

Lime Stabilization of Tropical Soils: Mechanical Parameters for Mechanistic–Empirical Pavement Design

by Thaís Radünz Kleinert, Henrique Falck Grimm, Washington Peres Núñez and Alex Theo Visser

Infrastructures 2026, 11(2), 58; https://doi.org/10.3390/infrastructures11020058 - 9 Feb 2026

Viewed by 357

Abstract

The mechanical behavior of lime-stabilized layers is essential for mechanistic–empirical pavement design, particularly in tropical regions where soil behavior differs from that of temperate residual soils. This study investigated three tropical soils (Argisol, Luvisol, and Latosol) stabilized with two hydrated lime sources (calcitic [...] Read more.

The mechanical behavior of lime-stabilized layers is essential for mechanistic–empirical pavement design, particularly in tropical regions where soil behavior differs from that of temperate residual soils. This study investigated three tropical soils (Argisol, Luvisol, and Latosol) stabilized with two hydrated lime sources (calcitic and dolomitic) at contents of 3% and 5%, compacted at standard or modified effort. Unconfined compressive strength (UCS) was measured at 7, 28, and 90 days, while flexural tensile strength (FTS) was obtained at 28 days, from which the flexural static modulus (FSM) and strain at break (ε_b) were derived. The results showed a strong soil-dependent response to lime treatment, with Argisol and Latosol behaving as lime-stabilized materials, whereas Luvisol exhibited more moderate improvements typical of soil modification. Compactive effort, lime type, and lime content significantly influenced UCS, FTS, and FSM, with compactive effort being the dominant and operationally achievable factor. Higher compactive effort, calcitic lime, and a 5% lime content consistently resulted in improved mechanical behavior, while curing time strongly influenced compressive strength due to progressive pozzolanic reaction. In contrast, strain at break was not significantly affected by the studied controllable factors and converged toward approximately 200 microstrain for soil–lime mixtures with UCS > 1 MPa, indicating a less brittle behavior relative to cement-stabilized materials and providing a representative input for preliminary design. Finally, significant correlations were established between UCS and FTS and between UCS and FSM, enabling the estimation of flexural parameters directly from compressive strength and supporting design simplifications when flexural testing is unavailable. Full article

(This article belongs to the Special Issue Cold and Warm Techniques for Sustainable Pavement Construction and Maintenance)

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19 pages, 11697 KB

Open AccessArticle

A CFD Description of the Breach Flow of an Overtopped Embankment Dam

by Rui M. L. Ferreira, Nuno M. C. Martins, Teresa Alvarez and Teresa Viseu

Infrastructures 2026, 11(2), 57; https://doi.org/10.3390/infrastructures11020057 - 9 Feb 2026

Viewed by 219

Abstract

We investigate the flow over a breached dam through combined measurements and numerical simulations, revealing key topological features of the mean flow, including separation and stagnation surfaces, attached vortices, secondary currents, and boundary layer development. PIV measurements of velocities are complemented with simulations [...] Read more.

We investigate the flow over a breached dam through combined measurements and numerical simulations, revealing key topological features of the mean flow, including separation and stagnation surfaces, attached vortices, secondary currents, and boundary layer development. PIV measurements of velocities are complemented with simulations with the interFoam solver of OpenFOAM-v2106 (URANS with k-ω SST closure model and rough-wall corrections). We show the development of the boundary layer over the crest, influenced by the breach crest wall curvature and strong lateral flow convergence. Three-dimensional separation is observed in the plunging pool. Two different attached vortices develop along the bottom and side walls of the breach, where underscouring is known to be strong. The first is associated with an adverse pressure gradient while the second results from the flow curvature imposed by the evolving geometry of the plunging pool. A counter rotating vortex pair is observed in the flow exiting the dam breach channel. We discuss the significance of these structures for hydraulic erosion and underscouring. We also provide recommendations for CFD modeling of dam breaches. Full article

(This article belongs to the Special Issue Preserving Life Through Dams)

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26 pages, 7859 KB

Open AccessArticle

Study on Interannual Variation Characteristics of Thermal and Humid Environments in Metro Tunnels Based on Different Climate Zones in China

by Jiangyan Ma, Shuang Qiu, Lin Huang, Baoshun Deng, Lei He, Xiaoling Cao and Qian Zhang

Infrastructures 2026, 11(2), 56; https://doi.org/10.3390/infrastructures11020056 - 7 Feb 2026

Viewed by 186

Abstract

To systematically investigate the issues of tunnel overheating and excessive humidity, this study integrates theoretical analysis, experimental research, and numerical simulations. It examines the coupled heat and moisture transfer behavior in the surrounding rock of metro tunnels and its impact on the tunnel’s [...] Read more.

To systematically investigate the issues of tunnel overheating and excessive humidity, this study integrates theoretical analysis, experimental research, and numerical simulations. It examines the coupled heat and moisture transfer behavior in the surrounding rock of metro tunnels and its impact on the tunnel’s thermal and humid environment. Based on the theory of heat and moisture transport in porous media, a coupled mathematical model is developed using relative humidity and temperature gradients as the driving potentials. Taking into account the climatic zoning of China, Beijing, Shanghai, Guangzhou, and Kunming are selected as representative cities for cold, hot summer/cold winter, hot summer/warm winter, and temperate climate regions, respectively. The interannual variation characteristics of the thermal and humidity conditions inside metro tunnels in these cities are analyzed and compared. The results indicate that across different climatic zones, higher outdoor peak air temperatures lead to higher peak air temperatures inside the tunnels. The thickness of the thermal regulation zone is primarily influenced by the initial rock temperature and the annual average atmospheric temperature. The thickness of the moisture regulation zone is affected by both the annual temperature fluctuation and the annual average relative humidity, increasing with greater annual atmospheric temperature variation. Full article

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22 pages, 3535 KB

Open AccessArticle

Bridge Health Monitoring and Assessment in Industry 5.0: Lessons Learned from Long-Term Real-Time Field Monitoring of Highway Bridges

by Prakash Bhandari, Shinae Jang, Song Han and Ramesh B. Malla

Infrastructures 2026, 11(2), 55; https://doi.org/10.3390/infrastructures11020055 - 7 Feb 2026

Viewed by 319

Abstract

The rapid aging of bridges has increased interest in real-time, data-driven monitoring for predictive maintenance and safety management; however, practical deployment on in-service bridges remains limited. This paper presents lessons learned from long-term field deployment of real-time bridge joint monitoring systems on three [...] Read more.

The rapid aging of bridges has increased interest in real-time, data-driven monitoring for predictive maintenance and safety management; however, practical deployment on in-service bridges remains limited. This paper presents lessons learned from long-term field deployment of real-time bridge joint monitoring systems on three in-service highway bridges and demonstrates how these insights can support the transition toward Industry 5.0. A unified framework is introduced to integrate key enabling technologies, including Internet of Things (IoT), digital twins, and artificial intelligence (AI), into a practical, human-centric monitoring architecture. Best practices for achieving durable, site-compliant, and cost-effective system design are summarized, with emphasis on sensor selection, wireless communication strategies, modular system development, and maintaining seamless operation. The development of a Docker-based analytics and visualization platform illustrates how interactive dashboards enhance human–machine collaboration and support informed decision-making. The role of advanced analytical tools, including digital twins, AI, and statistical modeling, in providing reliable structural assessments is highlighted, along with guidance on balancing cloud and edge computing for energy-efficient performance under constraints such as limited power, weather exposure, and site accessibility. Overall, the findings support the development of scalable, resilient, and human-centric real-time monitoring systems that advance data-driven decision-making and directly contribute to the realization of Industry 5.0 objectives in bridge health management. Full article

(This article belongs to the Special Issue Advances in Structural Health Monitoring and Industry 5.0 Innovations for Bridge Management and Conservation)

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25 pages, 3844 KB

Open AccessReview

A Comprehensive Review on Constitutive Models and Damage Analysis of Concrete Spalling in High Temperature Environment and Geological Repository for Spent Fuel and Nuclear Waste Disposal

by Toan Duc Cao, Lu Sun, Kayla Davis, Cade Berry and Jaiden Zhang

Infrastructures 2026, 11(2), 54; https://doi.org/10.3390/infrastructures11020054 - 5 Feb 2026

Viewed by 722

Abstract

This paper reviews constitutive models used to predict concrete spalling under elevated temperatures, with emphasis on fire exposure and concrete linings in deep geological repositories for spent fuel and nuclear waste. The review synthesizes (1) how material composition (ordinary Portland cement concrete, geopolymer [...] Read more.

This paper reviews constitutive models used to predict concrete spalling under elevated temperatures, with emphasis on fire exposure and concrete linings in deep geological repositories for spent fuel and nuclear waste. The review synthesizes (1) how material composition (ordinary Portland cement concrete, geopolymer concrete, and fiber-reinforced systems using polypropylene and steel fibers) affects spalling resistance; (2) how coupled environmental and mechanical actions (temperature, moisture, stress state, chloride ingress, and radiation) drive damage initiation and spalling; and (3) how constituent-scale characteristics (microstructure, porosity, permeability, elastic modulus, and water content) govern thermal–hydro–mechanical–chemical (THMC) transport and damage evolution. We compare major constitutive modeling frameworks, including plasticity–damage models (e.g., concrete damage plasticity), statistical damage approaches, and fully coupled THM/THMC formulations, and highlight how key parameters (e.g., water-to-binder ratio, temperature-driven pore-pressure gradients, and crack evolution laws) control predicted spalling onset, depth, and timing. Several overarching challenges emerge: lack of standardized experimental protocols for spalling tests and assessments, which limits cross-study benchmarking; continued debate on whether spalling is dominated by pore pressure, thermo-mechanical stress, or their interaction; limited integration of multiscale and constituent-level material characteristics; and high data and computational demands associated with advanced multi-physics models. The paper concludes with targeted research directions to improve model calibration, validation, and performance-based design of concrete systems for high-temperature and repository applications. Full article

(This article belongs to the Special Issue Recent Advances in Enhancing Sustainability and Durability of Cement and Concrete)

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26 pages, 10129 KB

Open AccessArticle

Numerical and Experimental Study on the Influence of Large-Section Rectangular Pipe Jacking Construction on Existing Subway Tunnels: A Case Study

by Chenze Huang, Jizhixian Liu, Junzhou Huang, Pei Fu, Shan Yang, Kai Liu and Cai Wu

Infrastructures 2026, 11(2), 53; https://doi.org/10.3390/infrastructures11020053 - 4 Feb 2026

Viewed by 253

Abstract

With the increasing density of urban underground space development, the soil disturbance induced by large-section rectangular pipe jacking poses a significant threat to the safety of underlying subway tunnels. Taking the Lihe Road utility tunnel project in Wuhan, which crosses over Metro Line [...] Read more.

With the increasing density of urban underground space development, the soil disturbance induced by large-section rectangular pipe jacking poses a significant threat to the safety of underlying subway tunnels. Taking the Lihe Road utility tunnel project in Wuhan, which crosses over Metro Line 4, as the engineering background, a three-dimensional finite element (FE) model was established using Midas GTS NX to simulate the entire pipe jacking process. Field monitoring data from caisson excavation, ground improvement, pipe jacking, and backfill grouting were introduced for validation, enabling a systematic investigation of the influence mechanism of pipe jacking on existing tunnels. In the numerical simulation, the modified Mohr–Coulomb constitutive model was adopted for the soil, and a “portal-type” reinforcement system was introduced. The pipe jacking process was simulated equivalently with a 1.2 m advance per cycle. The results indicate that the ground settlement induced by pipe jacking exhibits a stage-wise accumulation pattern and eventually develops into a stable settlement trough. The vertical settlement of the tunnel follows an evolutionary law of “early occurrence in the near field, delayed response in the far field, and final convergence,” with peak settlements of 2.44 mm and 2.53 mm for the left and right lines, respectively. Ground improvement significantly mitigates soil deformation, reducing the maximum surface settlement from 45.5 mm to 11.1 mm, decreasing the tunnel’s peak vertical settlement by 37%, and reducing horizontal displacement by 64%, thereby effectively suppressing lateral soil extrusion. The proposed closed-loop analysis method of “numerical simulation–monitoring validation–measure evaluation” reveals the spatiotemporal evolution law of soil–tunnel interaction during pipe jacking construction and provides valuable reference for risk control in similar engineering projects. Full article

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18 pages, 3776 KB

Open AccessArticle

Spectral Matching of Selected Earthquake Ground Motions for the Performance-Based Design of Seaports

by Aydın Mert

Infrastructures 2026, 11(2), 52; https://doi.org/10.3390/infrastructures11020052 - 4 Feb 2026

Viewed by 229

Abstract

This study investigates the selection and scaling of recorded strong ground motions in the time-domain spectral matching framework to realistically represent the seismic demands on the superstructure and secondary systems in the seismic design of complex facilities such as marine ports. The time-domain [...] Read more.

This study investigates the selection and scaling of recorded strong ground motions in the time-domain spectral matching framework to realistically represent the seismic demands on the superstructure and secondary systems in the seismic design of complex facilities such as marine ports. The time-domain spectral matching method iteratively adjusts the original record in the time domain by adding wavelets with limited durations and specific period ranges to achieve compatibility with the specified target acceleration response spectrum. A site-specific probabilistic seismic hazard analysis (PSHA) was performed for a port facility in İskenderun Bay, an area affected by the 6 February 2023 earthquakes. Horizontal Ground-Motion Response Spectra (GMRS) were derived for different return periods. Based on the hazard deaggregation, recorded ground motions compatible with the seismotectonic context of the region and the site conditions were selected. These records were then processed using time-domain spectral matching (TDSM) to match their elastic response spectra with the target GMRS over specific period ranges. The method utilizes spectral matching in the time domain to improve the match with the target spectrum while preserving the phase information and non-stationary nature of the records. The results show that the mean spectral acceleration curves of the scaled records are highly consistent with the target GMRS over a wide range of periods and that near-fault pulse-like characteristics, when present, are reasonably preserved. These results confirm that time-domain spectral matching provides a reliable framework for the performance-based assessments of complex port infrastructures by achieving high compatibility with the target spectra while preserving the physical characteristics of the waveforms Full article

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16 pages, 3204 KB

Open AccessArticle

Comfort Assessment of Micromobility Infrastructure with an Instrumented Vehicle

by Víctor Just-Martínez, Ana María Pérez-Zuriaga, David Llopis-Castelló, Carlos Alonso-Troyano and Alfredo García

Infrastructures 2026, 11(2), 51; https://doi.org/10.3390/infrastructures11020051 - 3 Feb 2026

Viewed by 250

Abstract

Micromobility studies sustainable urban mobility. In this area, bicycles have been the most popular vehicle for several years. However, the recent growth of users of alternative mobility vehicles, such as stand-up electric scooters (e-scooters), has raised several questions on how they interact with [...] Read more.

Micromobility studies sustainable urban mobility. In this area, bicycles have been the most popular vehicle for several years. However, the recent growth of users of alternative mobility vehicles, such as stand-up electric scooters (e-scooters), has raised several questions on how they interact with the infrastructure and other users, as well as whether the existing infrastructure is suitable for these vehicles. One of the variables to be analyzed is riding comfort, which can be measured through the vibrations transmitted to users by the pavement. Thus, this paper presents a methodology to assess the comfort of the micromobility infrastructure based on the vertical accelerations registered by an instrumented e-scooter. This methodology has been applied in ten sections of the cycling infrastructure network of Valencia (Spain). The analysis showed that asphalt presented less vibrations than any other material, followed by concrete and square tiling alike, and finishing with transversely oriented cobblestones. This translates directly to comfort, with asphaltic pavements being more comfortable than any other. The analysis also showed that higher speeds mean higher vibrations. This proves to be a useful tool for infrastructure management, where the administrator can place more uncomfortable pavements to lower the riding speed in desired areas (e.g., schools). Full article

(This article belongs to the Special Issue Advances in Pavement Engineering: Materials, Performance, and Sustainability)

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24 pages, 3473 KB

Open AccessArticle

Signal-Based Dynamic Identification of Composite Steel–Concrete Bridges Using Short-Duration Records

by Mario Ferrara, Gabriele Bertagnoli, Alessandro Imperiale and Davide Masera

Infrastructures 2026, 11(2), 50; https://doi.org/10.3390/infrastructures11020050 - 2 Feb 2026

Viewed by 282

Abstract

Structural Health Monitoring (SHM) of existing bridges increasingly relies on dynamic measurements to assess structural performance and detect potential damage. However, the practical implementation of long-term vibration-based monitoring is still constrained by the volume of data required and the complexity of continuous acquisition [...] Read more.

Structural Health Monitoring (SHM) of existing bridges increasingly relies on dynamic measurements to assess structural performance and detect potential damage. However, the practical implementation of long-term vibration-based monitoring is still constrained by the volume of data required and the complexity of continuous acquisition systems. In the context of ensuring the safety and performance of existing bridge infrastructure, vibration-based monitoring offers a powerful tool for detecting changes in structural behavior. This study presents an extended investigation of dynamic monitoring applied to composite steel–concrete viaducts, focusing particularly on the signal-analysis framework and methodological enhancements. Short-duration accelerometric records are processed through an automated signal-selection pipeline and advanced modal-parameter extraction algorithms to yield identification of modal features. Emphasis is placed on the statistical evaluation of modal-parameter stability, effects of operational and environmental variability, and the potential for long-term trend detection. The results highlight the limits of short-length recordings when OMA techniques are applied. Nevertheless, appropriate signal processing and data handling can provide acceptable insights into the dynamic characteristics of large bridge systems. The methodological findings provide a foundation for improved monitoring workflows, showing the amount of information that can be retrieved using a cost-effective hardware deployment and supporting further development toward structural digital twins. Full article

(This article belongs to the Special Issue Structural Health Monitoring in Bridge Engineering)

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18 pages, 1906 KB

Open AccessArticle

Assessment of Community Risk from Seismic-Induced Damage to Hazardous Materials Storage Tanks in Marine Ports

by Mohamad Nassar, Fatiha Mouri and Ahmad Abo El Ezz

Infrastructures 2026, 11(2), 49; https://doi.org/10.3390/infrastructures11020049 - 2 Feb 2026

Viewed by 316

Abstract

Marine ports located in regions of moderate seismicity can face high Natech (natural hazard-triggered technological) risk because large inventories of hazardous materials are stored near dense urban populations. This study proposes and applies a Natech risk framework to a representative port on the [...] Read more.

Marine ports located in regions of moderate seismicity can face high Natech (natural hazard-triggered technological) risk because large inventories of hazardous materials are stored near dense urban populations. This study proposes and applies a Natech risk framework to a representative port on the Saint-Laurence River in Quebec, Canada. Site-specific peak ground accelerations (PGA) are first estimated for 12 earthquake scenarios using regional ground motion prediction equations adjusted for local site conditions. These hazard levels are combined with a damage probability matrix to estimate Hazardous Release Likelihood Index (HRLi) scores for atmospheric steel storage tanks. Offsite consequences are then evaluated to obtain Maximum Distances of Effect (MDEs) for different types of hazardous materials. MDE footprints are intersected with block-level demographic data and complemented by a domino-effect based on inter-tank spacing, yielding a tank-level Natech Risk Index

N R I_{i, s}

for each storage tank (

i

) and seismic scenario (

s

). These values are then averaged over all tanks to obtain a scenario-level mean Natech Risk Index (

\bar{N R I}

) for each tank substance. Regression equations relating

\bar{N R I}

to PGA are provided as a practical tool for defining critical intensity thresholds for seismic Natech risk management in marine ports. Full article

(This article belongs to the Special Issue Earthquake and Multi-Hazard Resilience: Community-Level Insights and AI/ML Applications)

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37 pages, 48357 KB

Open AccessArticle

Extracting Geometric Parameters of Bridge Cross-Sections from Drawings Using Machine Learning

by Benedikt Faltin, Rosa Alani and Markus König

Infrastructures 2026, 11(2), 48; https://doi.org/10.3390/infrastructures11020048 - 31 Jan 2026

Viewed by 304

Abstract

Bridges are a crucial part of infrastructure, but many are in urgent need of maintenance. Digital methods like Building Information Modeling (BIM) and Digital Twinning can support this process but depend on digital models that are often missing for existing structures. Automating the [...] Read more.

Bridges are a crucial part of infrastructure, but many are in urgent need of maintenance. Digital methods like Building Information Modeling (BIM) and Digital Twinning can support this process but depend on digital models that are often missing for existing structures. Automating the reconstruction of these models from existing documentation, such as construction drawings, is essential to accelerate digital adoption. Addressing a key step in the reconstruction process, this paper presents an end-to-end pipeline for extracting bridge cross-sections from drawings. First, the YOLOv8 network locates and classifies the cross-sections within the drawing. The results are then processed by the segmentation model Segment Anything Model (SAM), which generates pixel-wise masks without requiring task-specific training data. This eliminates the need for manual mask annotation and enables straightforward adaptation to different cross-section types, making the approach broadly applicable in practice. Finally, a global optimization algorithm fits parametric templates to the masks, minimizing a custom loss function to extract geometric parameters. The pipeline is evaluated on 33 real-world drawings and achieves a median parameter deviation of −2.2 cm and 2.4 cm, with an average standard deviation of 35.4 cm. Full article

(This article belongs to the Special Issue Advances in Artificial Intelligence for Infrastructures)

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28 pages, 2834 KB

Open AccessArticle

Shear Performance of High-Strength Concrete (HSC) Beams Reinforced with Steel and Fiber Composite Grids

by Mohammad Azhar Mudaqiq, Mohd Tahseen Islam Talukder, Hojat Hematabadi and Ahmed Ibrahim

Infrastructures 2026, 11(2), 47; https://doi.org/10.3390/infrastructures11020047 - 30 Jan 2026

Viewed by 332

Abstract

This study investigates the shear performance of high-strength concrete (HSC) beams reinforced with steel, fiber composite grids (CFRP and GFRP), and their hybrid configurations in the absence of transverse reinforcement. A total of six full-scale beams with varying reinforcement configuration and shear span-to-depth [...] Read more.

This study investigates the shear performance of high-strength concrete (HSC) beams reinforced with steel, fiber composite grids (CFRP and GFRP), and their hybrid configurations in the absence of transverse reinforcement. A total of six full-scale beams with varying reinforcement configuration and shear span-to-depth (a/d) ratios were experimentally tested under monotonic loading to evaluate their load capacity, cracking characteristics, failure modes, and serviceability behavior. The results revealed that beams reinforced solely with fiber grids exhibited significantly reduced strength and brittle shear failure. Hybrid systems incorporating both steel and fiber grids demonstrated improved strength and ductility, closely matching or surpassing control specimens with conventional steel reinforcement. Key structural parameters such as effective moment of inertia, cracking moment, shear strength, and midspan deflection were compared against analytical predictions based on ACI 318-16 and the Canadian Education Module code. While predictions generally aligned for hybrid beams, notable discrepancies were found for FRP-only systems, particularly in serviceability performance. The findings highlight the potential of hybrid reinforcement as a viable design strategy for HSC beams, offering a balance between strength, ductility, and service performance. Full article

(This article belongs to the Special Issue Advances in Reinforced Concrete Infrastructure: Enhancing Structural Resilience and Promoting Sustainability, 2nd Edition)

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23 pages, 3738 KB

Open AccessArticle

Enhancing Concrete Strength Prediction from Non-Destructive Testing Under Variable Curing Temperatures Using Artificial Neural Networks

by Ghazal Gholami Hossein Abadi, Kehinde Adewale, Muhammad Usama Salim and Carlos Moro

Infrastructures 2026, 11(2), 46; https://doi.org/10.3390/infrastructures11020046 - 29 Jan 2026

Viewed by 565

Abstract

Non-destructive testing (NDT) methods are widely used to evaluate the performance of concrete, but their accuracy can be influenced by external factors such as curing temperature. Temperature not only modifies hydration kinetics and strength development but may also change the correlation between NDT [...] Read more.

Non-destructive testing (NDT) methods are widely used to evaluate the performance of concrete, but their accuracy can be influenced by external factors such as curing temperature. Temperature not only modifies hydration kinetics and strength development but may also change the correlation between NDT measurements and compressive strength. However, no prior research has systematically examined how different curing temperatures influence the reliability of various NDT techniques. This study evaluates three curing temperatures and their effect on the correlation between NDTs and compressive strength at various ages (1, 3, 7, 28, and 90 days). Both simple regression analysis and artificial neural networks (ANNs) were employed to predict strength from NDT measurements. Results show that NDT sensitivity to curing temperature is most pronounced at early ages, and that linear regression models cannot adequately capture the complexity of these relationships. In contrast, ANNs demonstrated superior predictive capability, though initial training with limited data led to overfitting and instability. By applying Gaussian Noise Augmentation (GNA), model accuracy and generalization improved substantially, achieving R2 values above 0.95 across training, validation, and test sets. These findings highlight the potential of non-linear models, supported by data augmentation, to improve prediction reliability, lower experimental costs, and more accurately capture the role of curing temperature in NDT–strength correlations for concrete. Full article

(This article belongs to the Special Issue Next-Generation Transportation Infrastructures: Sustainability, Digitalization, and Resilience)

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26 pages, 2864 KB

Open AccessArticle

The Prerequisites for Development of LNG/CNG Filling Stations Network: The Crucial Role of Lithuania and the Baltic States in the North Sea–Baltic Sea Corridor

by Laurencas Raslavičius

Infrastructures 2026, 11(2), 45; https://doi.org/10.3390/infrastructures11020045 - 28 Jan 2026

Viewed by 350

Abstract

The multimodal North Sea–Baltic corridor, consisting of 6934 km of road, is an integral part of the EU’s trans-European transport network. However, an unsatisfied level of development of alternative fuels infrastructure for road transport is considered one of the obstacles to connecting northern [...] Read more.

The multimodal North Sea–Baltic corridor, consisting of 6934 km of road, is an integral part of the EU’s trans-European transport network. However, an unsatisfied level of development of alternative fuels infrastructure for road transport is considered one of the obstacles to connecting northern Member States and North-East countries. A “what-if” scenario was employed to obtain useful insights into how a given situation might be handled, and a comparison of several paths forward to make better decisions was analysed. Environmental insights for transportation sector scenarios in 2030–2035 were explored and analysed using the COPERT v5.5.1 software program. In this study, the installation of natural gas infrastructures of various station sizes and with varying capacities and types of natural gas (LNG, CNG, bio-methane) dispensed was evaluated in detail. Replacement of the existing HDV fleet (heavy-duty vehicles) with LNG-powered trucks would result in the following investment to upgrade the existing network and build new stations to meet rising LNG demand: from €21.47 to €32.3 million (the scenario of 10% market share for HDVs running on LNG), €42.94 to €64.6 (20%), and €64.4 to €96.9 (30%). The dual-fuel 10–diesel fuel 90% scenario seems to be the safest option for a large-scale investment until 2035 which may lead to moderate emission savings of 84.6 kton CO₂ eq. compared to 2022 levels. Full article

(This article belongs to the Section Infrastructures and Structural Engineering)

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14 pages, 2252 KB

Open AccessArticle

Performance Development of Graphene-Modified Electrically Conductive High-Performance Cementitious Composites Under Sub-Zero Temperature Curing: Attempt Towards Infrastructure Construction in Cold Regions

by Mengying Liu, Yue Xu, Peng Sun and Abba Auwal

Infrastructures 2026, 11(2), 44; https://doi.org/10.3390/infrastructures11020044 - 28 Jan 2026

Viewed by 238

Abstract

Cement-based construction in cold regions faces severe challenges due to the dramatic retardation of hydration and strength development under sub-zero temperatures. Joule curing as a novel curing method showed certain advantages in solving this problem, while the curing efficiency was low for Joule [...] Read more.

Cement-based construction in cold regions faces severe challenges due to the dramatic retardation of hydration and strength development under sub-zero temperatures. Joule curing as a novel curing method showed certain advantages in solving this problem, while the curing efficiency was low for Joule curing under severely cold temperatures. This study systematically investigates the performance of graphene nanoplatelet (GNP)-modified electrically conductive cementitious composites under sub-zero temperature curing conditions. Joule curing method was employed to ensure a high-quality curing at ambient temperatures of −20 °C, −40 °C, and −60 °C. The results demonstrate that GNP incorporation significantly enhances electro-thermal performance. For the electrical conductivity of the specimens, the specimens containing 0.5 wt% GNP showed a much stable electric resistance development under severely cold environment, illustrating the value of 1169 Ω after 1 day Joule curing at the environmental temperature of −60 °C, which was 36% lower than the Ref. group. As for the curing temperature, the specimen with 0.5 wt% GNP effectively maintained the internal temperature within 50–60 °C during the 24 h curing period, even under extreme conditions. Mechanical tests reveal that the GNP-modified specimens exhibit remarkable strength retention, with the 0.5% GNP composite maintaining 86.3% of its compressive strength and 95.9% of its flexural strength at −60 °C compared to standard curing values. Microstructural characterization through XRD and TG analyses confirms that while the crystalline phase composition remains unchanged across different curing regimes, the hydration degree directly correlates with the mechanical performance, explaining the observed strength variations. MIP analysis further proved the advantage of Joule curing on refining the microstructure for the specimens. The findings establish that GNP modification, combined with Joule curing, presents an effective strategy for winter concrete construction, ensuring adequate strength development through enhanced electrical conductivity and controlled internal curing temperature, without altering the fundamental hydration chemistry. Full article

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22 pages, 3373 KB

Open AccessArticle

Optimization of Control Measures for Rock Mass Disturbed by Repeated Tunnel Repairs and Engineering Practice

by Zenghui Liu and Minjun Chen

Infrastructures 2026, 11(2), 43; https://doi.org/10.3390/infrastructures11020043 - 27 Jan 2026

Viewed by 194

Abstract

To address the difficulty of controlling surrounding rock subjected to repeated repair-induced disturbances, the characteristics of the roadway surrounding rock and its deformation–failure mechanisms were examined. An experimental scheme for surrounding-rock control was formulated, and a three-dimensional numerical model was established. Four support [...] Read more.

To address the difficulty of controlling surrounding rock subjected to repeated repair-induced disturbances, the characteristics of the roadway surrounding rock and its deformation–failure mechanisms were examined. An experimental scheme for surrounding-rock control was formulated, and a three-dimensional numerical model was established. Four support schemes were evaluated to identify a rational support method and corresponding parameters: (a) rock bolts and cable bolts; (b) rock bolts, cable bolts, and floor cable bolts; (c) rock bolts, cable bolts, floor cable bolts, and U-shaped closed steel sets; and (d) rock bolts, cable bolts, floor cable bolts, U-shaped closed steel sets, and grouting. Comparative analyses were conducted in terms of plastic-zone evolution, stress-field distribution, surrounding-rock displacement, and the mechanical response of the support structures. The results indicate that, in roadways experiencing multiple repair disturbances and supported only by rock bolts and cable bolts, distinct stress-concentration zones develop within the supported surrounding rock, suggesting that reliance solely on bolts and cables is unfavorable for effective rock-mass control. Grouting improves the overall integrity and self-bearing capacity of the surrounding rock. Both the U-shaped closed support and the combined U-shaped closed support with grouting effectively restrain surrounding-rock deformation, and the corresponding stress distribution shows no pronounced stress-concentration zones. Based on the analyses of surrounding-rock displacement, support-structure loading, and incremental shear strain, the effectiveness of the support schemes in mitigating roof and floor displacement ranks, in descending order, as (d), (c), (b), and (a). Engineering practice further demonstrates that the combined support system consisting of 29U-type sets, grouted bolts, and bundle-type grouted cable bolts provides effective control over the deformation and failure of the roadway surrounding rock. Full article

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