Engineering

Abstract: Large-scale water infrastructure across the East African Rift System faces severe structural degradation and capacity underutilization. This research presents a forensic engineering investigation into post-construction structural failures and lifecycle performance deficits at the multi-purpose Gerebsegen Dam in northern Ethiopia, positioning the findings within the macro-regional discourse on East African dam safety paradigms. Engineered with a 30-year design lifespan to provide municipal water to Mekelle city and irrigate a 500-hectare command area via a three-outlet pressure conduit configuration, the project exhibits a critical discrepancy between chronological age and operational efficiency. Though 12 years have elapsed since construction completion, the reservoir utilizes a mere 20% of its total design storage volume. This operational yield is restricted exclusively to municipal supply via just one active baseline pipeline, representing a 50% water supply transmission rate and a 0% infrastructural delivery rate for the planned 500-hectare irrigation network. Compounding these severe capacity utilization deficits, acute geotechnical instabilities prompted progressive longitudinal cracking and the partial collapse of the masonry gravity retaining structures flanking the left spillway abutment post-impoundment. Field diagnostics pinpointed an unallowable subsurface seepage rate of 0.568 m³/s bypassing the core via fractured dolerite channels, inducing massive back-of-wall hydrostatic pressures. To mitigate these structural risks, a regional-standard remedial engineering package is evaluated, featuring a structural replacement with a rigid, tapered cantilever reinforced concrete structure up to 7.20 m high, a 1,700.50 m³ upper-slope offloading excavation to a stable 45° profile, and a subsurface pressure-grouting curtain.

Abstract: This paper presents the parametric 3D modelling of a subsea Inline Lateral Tee (ILT) pipe assembly using Autodesk Inventor Professional, applied to an API 5L pipe with an outer diameter of 273.1 mm (10¾ in NPS) and a wall thickness of 12.7 mm (½ in), yielding a D/t ratio of 21.5. The assembly encompasses a main pipeline, tee branch, pup pieces, elbows, and ball valve (BV) sub-assemblies, with all critical dimensions governed by a centralised parameter table comprising seven named variables: L_pipe, L_pup, L_WidthTee, L_elbow, L_BV, L_MainPipe, and L_HeightTee. Two ILT configurations are addressed — Type 1 (single-branch, without left-side BV) and Type 2 (dual-branch, with full BV assemblies on both sides). Parametric update validation confirmed complete model responsiveness with zero feature failures, and the computed D/t ratio of 21.5 satisfies the ASME B31.3 structural limit of 100. The framework provides a reproducible, standards-aligned methodology for ILT component modelling in offshore pipeline design.

Abstract: Dual-gauge railway systems are widely used in Spain to ensure interoperability between Iberian and standard gauges; however, the dynamic behavior of dual-gauge turnouts remains insufficiently characterized due to the scarcity of field measurements. This study presents an experimental campaign aimed at analyzing the vertical dynamic response of a dual-gauge turnout under real traffic conditions. The turnout was instrumented at seven critical sections using displacement transducers and accelerometers, together with a reference section on adjacent plain track, and a total of 68 train passages, including commuter and high-speed services, were analyzed according to train type and operating speed. The vertical displacement time histories and the acceleration signals recorded at the closure panel, together with their corresponding frequency spectra, are also examined to provide a complete characterization of the dynamic response in both the time and frequency domains.. Increasing operating speed leads to higher displacement levels and greater dispersion, whereas differences between train types primarily affect response magnitude rather than its spatial distribution. These findings demonstrate that the dynamic response of dual-gauge turnouts is mainly governed by local geometric discontinuities, providing experimental evidence to support condition monitoring strategies and the validation of vehicle–track interaction models.

Abstract: This study investigates the multi-objective optimization of phase change materials (PCM) in building envelopes for office buildings under sharply continental climate conditions. The study employed simulation modeling with dynamic solutions in EnergyPlus (CondFD algorithm) and the NSGA-II genetic algorithm. During the computational experiments, the optimal values for the PCM melting temperature (24–25°C), layer thickness (15–21 mm), and its position relative to the inner wall surface (10–20 mm) were determined. The results show that a properly selected PCM can reduce annual energy consumption by up to 22% and hours of thermal discomfort by up to 42% compared to a traditional concrete wall. The obtained calculation data can be used by architects and engineers when designing energy-efficient office buildings in regions with a sharply continental climate. As such, these results provide design-oriented practical guidance for integrating PCM into building envelope design to support eidence-based decision-making at early stages of any projects.

Abstract: Tunnels are one of the important components of modern underground infrastructures facilitating movement of people, goods and conveyance of water from one place to another place. Tunnel lining in an important structural component of the tunnel facilitating in bearing the underground load from overburden rocks and soils. Over the last two decades, different earthquakes caused movement of the soil leading to damage to tunnel lining. This study aims to develop a preliminary designing tool using hybrid deep learning models for determining the thickness of tunnel lining in earthquake prone regions. The different input parameters considered for modelling were earthquake micro-zonation, type of fault, fault length, peak ground acceleration, source-to-site distance, maximum observed earthquake, total tunnel length, overburden pressure, diameter of the tunnel, quality of rock, prone to land slide or not and the output from the model is tunnel lining thickness. Two different types of hybrid deep learning models leveraging Convolutional Neural Network (CNN), Long-Short Term Memory (LSTM) Network and transformer architecture were developed to determine the thickness of tunnel lining. The performance (Mean Absolute Error (MAE)) of the CNN-transformer model (model 1) and LSTM-transformer model (model 2) on the test dataset were 19.64 mm and 32.00 mm, respectively. Model 1 was selected for determining the thickness of tunnel lining due to its high accuracy as compared to model 2. The deep learning models showed significant potential for computing the thickness of lining in earthquake prone regions.

Abstract: Expanded Polystyrene (EPS) offers a viable pathway for balancing the fresh and hardened properties of infrastructure with environmental sustainability. This study evaluated six concrete mixes with varying EPS Styrofoam aggregate ratios and three water-to-binder (w/b) ratios, all of which incorporated silica fume and a superplasticizer. Eight ML algorithms (SVM, GPR, ANN, etc.) and a deep-learning LSTM model were utilized to preliminarily predict trends in EPS concrete properties, with SHAP analysis quantifying feature contributions. The experimental results indicated that the fine aggregate replacement outperformed the coarse aggregate replacement, retaining approximately 76% of the density of the control mixture, along with other property reductions. The fine aggregate replacement resulted in a compressive strength reduction of up to 46.4%, with losses in tensile strength of 20.9% and an improvement in workability of 3.4%. Finally, various AI models identified trends in the predictions of EPS properties based on the mixing ratio within a limited experimental dataset. In addition, SHAP analysis revealed that the coarse aggregate replacement exerted a more significant negative impact on the mechanical properties and density than the fine aggregate replacement. Although these mixtures offer significant weight reduction, their use in structural applications requires further verification, as the reduction of nearly half of the compressive strength is significant. These findings provide strategies and a framework to facilitate the precise practical application of EPS concrete in nonstructural or lightly loaded applications.

Abstract: An experiment focused on human-induced vibration monitoring was carried out on the structure of a demountable temporary grandstand for spectators at the Biathlon World Championship in Nové Město na Moravě, Czech Republic. Before the races, a modal analysis was carried out to improve the FE model of the grandstand. The spectators’ behavior was recorded on camera during the races and was statistically evaluated. The vibration of the demountable grandstand was measured during the races too and synchronized with the camera records. The activity of the spectators, the maximal accelerations and the RMS values of the grandstand vibration were evaluated and discussed at the end of the article.

Abstract: The scientific literature on Building Information Modeling (BIM) applied to the structural design of long-span sports facilities remains dispersed across construction management, structural engineering, and digital engineering, hindering the systematic identification of research trends, leading actors, and knowledge gaps. This study conducts a PRISMA-based bibliometric analysis of the scientific production indexed in Scopus on BIM integration in the structural design of long-span sports facilities for the period 2015–2026, aiming to map the intellectual structure of the field, characterize its thematic evolution, and identify directions for future research. Following the PRISMA 2020 statement and the PRISMA-ScR extension for scoping reviews, a structured Boolean query retrieved an initial set of 2,339 records. After applying eligibility criteria—peer-reviewed journal articles published in English with author-supplied abstracts and keywords—a final corpus of 802 articles was retained and analyzed using the Bibliometrix package in R. The analysis encompassed annual publication trends, citation metrics (total citations, citations per publication, h-index, FWCI, SNIP, and CiteScore), Bradford’s Law source distribution, keyword co-occurrence mapping, historical direct citation networks, and country and institutional collaboration structures. The corpus accumulated 20,877 citations, yielding a mean of approximately 26 citations per publication and an h-index of 78, indicating above-average citation impact. Annual output grew from 26 articles in 2015 to 167 in 2025, approximately doubling after 2023. China leads scientific production (533 articles), followed by the United States (141) and the United Kingdom (135). The findings confirm that BIM has consolidated as a multidisciplinary methodology integrating structural design, project optimization, lifecycle management, and environmental assessment, while revealing that domain-specific structural challenges of long-span systems remain comparatively underexplored.

Abstract: Preliminary geotechnical site investigations often sample at intervals determined by cost rather than ground variability, risking missed transitions and inefficient characterization of uniform strata. Portable electrical resistivity offers low-cost, near-continuous screening, but conventional correlations based on absolute resistivity transfer poorly between locations. This study examines whether normalized trend-based descriptors of resistivity profiles provide a more transferable basis for cross-borehole interpretation of Standard Penetration Test (SPT) resistance. A Wenner array was measured at 0.5 m intervals across four boreholes in tropical sandy soils of the Khorat Plateau, Thailand, and paired with SPT and index testing, yielding 63 observations. The resistivity profiles were transformed into log-resistivity trends and represented using descriptors of relative electrical state, nonlinear deviation, and transition intensity. Using leakage-safe leave-one-borehole-out cross-validation, with regression coefficients fitted only from training boreholes and descriptor calculation for each held-out borehole based solely on its resistivity profile, the full descriptor model improved predictive performance beyond a strong depth-only baseline (R² = 0.617 to 0.733), whereas absolute resistivity alone performed poorly (R² = 0.133). Borehole-wise validation indicated consistent predictive capability across the four available validation boreholes. Laboratory indices, including Atterberg limits, fines content, water content, and unit weight, exhibited limited transferability. These findings provide preliminary evidence that resistivity profile structure may be more informative for cross-borehole SPT interpretation than absolute resistivity magnitude.

Abstract: Electromagnetic field (EMF) treatment of irrigation water has been studied as a low-energy conditioning approach to improve soil-plant performance under conventional and unconventional water use. Unlike desalination technologies, EMF does not remove dissolved salts, instead, it is hypothesized to modify water-soil-ion interactions that influence infiltration, solute mobility, and mineral precipitation kinetics. This review synthesizes and critically evaluates evidence on EMF-treated irrigation, focusing on physicochemical mechanisms, soil salinity dynamics, nutrient availability, crop responses, and the role of EMF within agricultural water reuse systems. Across laboratory, greenhouse, and a limited number of field studies, EMF-treated irrigation is most consistently associated with altered wetting behavior and redistribution of salts within the soil profile, commonly expressed as reduced electrical conductivity in surface or root-zone layers accompanied by increased salt accumulation at depth. Reported crop responses include improved ionic balance, enhanced growth, and increased water productivity, particularly under moderate salinity or deficit irrigation. These outcomes are primarily linked to modified transport and crystallization processes rather than persistent changes in bulk water chemistry, and they vary strongly with EMF exposure configuration, hydraulic residence time, irrigation water chemistry, soil texture, drainage conditions, and crop sensitivity. Accordingly, the effectiveness of EMF treatment is better interpreted in terms of cumulative EMF exposure dose rather than magnetic field intensity alone. EMF treatment cannot substitute for reverse osmosis where salinity exceeds crop tolerance thresholds, however, it may serve as a complementary conditioning step within integrated reuse frameworks that combine partial desalination or blending with soil amendments to improve the soil compatibility of unconventional waters. Key research priorities include standardized reporting of EMF exposure, mechanistic validation of soil-water-ion transport pathways and replicated multi-season field trials incorporating soil salinity mass balance and drainage assessment.

Abstract: This paper presents a diagnostic case study of a underground shooting range tunnel affected by recurrent groundwater ingress, with emphasis on diagnosis-driven, low-impact remediation. Despite the demolition and reconstruction of the tunnel be-tween 2019 and 2022, the problem of water ingress was not eliminated, and leakage with water ponding continued to occur after rainfall events. The assessment, conducted in June and July 2024, included documentation review, site inspections, evaluation of previous repairs, ultrasonic concrete testing, bottom slab tomography, verification of the wall-bottom slab interface, and geotechnical investigation. The concrete met strength class C30/37 and was not the primary cause of leakage. Water ingress was mainly caused by underestimated ground and groundwater conditions, water accumulation in the backfilled excavation, lack of drainage, defective waterproofing, and ineffective injection works. The most vulnerable zones were the wall-bottom slab interface, the internal expansion joint, and the connection with the existing building. The original geotechnical investigation was too shallow, and the ground conditions should have been classified as difficult, corresponding to geotechnical category II. Based on the diagnosis, reinjection and sealing of critical joints were selected as the less invasive repair strategy, limiting excavation works, interference with the existing structure, and disruption to facility use.

Abstract: Landslide dam failures pose risks to downstream areas. However, models often overlook backwater and sediment hazards. This study created a two-way coupled 1D–2D hydro-morphodynamic framework to analyze breach evolution, flooding, and sediment movement, which was validated using the 2018 Baige failures (Jinsha River, China). Near-field breach processes use the 1D Saint-Venant and Exner equations, considering erodibility, armoring, and fractional sediment transport, whereas far-field routing uses a 2D shallow-water model on an unstructured mesh (500,000 cells). The master controller exchanges the discharge, sediment, and water levels every second. The calibration of the first event (NSE=0.92) and validation of the second showed similar peak outflow (30,176 vs. 31,000 m³/s; −2.7%) and breach geometry (top width −0.5%). Two-way coupling simulated a 15 m backwater at peak, reducing the gradient by ~20%, peak discharge by 3%, and final breach width by 9% compared with one-way coupling. Downstream routing matched peaks (e.g., 23,150 vs. 22,800 m³/s; +1.5%) and inundation (87.4% fit). The model captures scour (up to 12 m), aggradation (3–6 m), and net deposition (41 Mm³). The coupled workflow runs in 11 h on a workstation (3.3× faster than the full-2D model). The 1D–2D framework provides a standard for hazard assessments in confined valleys.

Abstract: Railway track geometry degradation is a key determinant of infrastructure safety, ride comfort, maintenance demand, and lifecycle cost. This paper presents a measure-ment-based assessment of track geometry degradation on the analyzed section of railway line M300 in Romania, with emphasis on its practical use for maintenance prioritization. The study uses in-situ track-geometry inspection records collected by a track measuring vehicle (VMC) between 2020 and 2023 on a curved double-track sector, and evaluates the main geometric defect families used in railway practice, including alignment, gauge, longitudinal level, cross-level, and twist. In addition to conventional defect identification, severity grading, and penalty-point scoring, the paper introduces three mainte-nance-oriented decision-support tools: the Defect Severity Index (DSI), the Defect Recur-rence Factor (DRF), and a Maintenance Priority Matrix (MPM). These indicators are added to the existing workflow in order to compare inspection campaigns, identify persistent defect families, and translate measured degradation into maintenance priorities. The re-sults show that degradation is spatially selective and defect-family dependent, with cross-level and longitudinal-level defects dominating the cumulative penalty score. The DSI ranged from 467 points/km in September 2022 to 3183 points/km in March 2022, con-firming a non-linear degradation and recovery pattern. The proposed indices provide an interpretable extension of the existing penalty-point framework and support condi-tion-based maintenance planning on conventional railway lines.

Abstract: This study aims to explore the barriers to adopting artificial Intelligence (AI) technolo-gies in advancing circular economy business models in socially sustainable construc-tion enterprises. A thematic analysis was applied to extract the barriers within a sys-tematic literature review (SLR) approach. The analyzed articles which constitute the dataset were sourced from bibliographic databases of Scopus, ProQuest, PubMed, Web of Science and Google Scholar. The findings emphasize barriers in areas of digital adoption, efficiency, competitiveness, sustainability, labor skill deficiencies, organiza-tional and budgetary challenges. From the study, overcoming these barriers requires intentional and well-developed investment and changes in internal practices on digital AI upskilling programs, policy incentivization, and partnerships from stakeholders. The findings are expected to aid digital literacy to prioritize AI in circular economy so-cially responsible construction business practices. Even though the results include a conceptual model (which needs validation), it provides significant directions for har-nessing AI in circular business models of construction organizations. The novelty of the study is that it contributes to the comprehensive knowledge of challenges impeding AI-enabled circularity practices in construction businesses.

Abstract: Classical thin-walled beam theory, following Vlasov, decomposes the longitudinal normal stress field into axial, bending and a single sectorial warping contribution governed by the bimoment B and the warping constant I_w. This work explores a natural generalization of that framework: a modal decomposition of warping in which the classical Vlasov sectorial mode is treated as the first member of a broader, orthogonal family of warping modes. Each additional mode φᵢ(y, z) is defined through orthogonality conditions with respect to area, bending and the sectorial coordinate, carries its own generalized bimoment qᵢ(x) and generalized warping inertia Iᵢ, and induces, through longitudinal equilibrium, a self-equilibrated shear flow governed by a Neumann-type Poisson problem on the cross-section. The resulting strain energy decomposes additively over modes, preserving full compatibility with energy methods. The physical origin of the higher-order modes is discussed, with eigenfunctions of a Laplacian cross-sectional operator, finite element cross-sectional eigenanalysis, and variational energy minimization proposed as candidate generating mechanisms. The framework is formulated independently of any thin-wall or mid-line kinematic hypothesis, making it directly applicable to thick-walled and solid cross-sections as well as to classical thin-walled members. Under this view, Vlasov warping theory emerges as the fundamental mode of a richer modal warping basis, analogous to the role of the fundamental mode in structural vibration theory.

Abstract: CFRP–steel composite strengthening systems are widely used in engineering; however, interface debonding and internal material defects easily lead to overall structural failure, requiring high-precision and quantitative detection methods. In this paper, lead magnesium niobate–lead titanate (PMN–PT) piezoelectric single crystals are used as sensing elements to develop high-sensitivity externally bonded piezoelectric sensors. Combined with ultrasonic guided-wave active detection technology, identification and quantitative evaluation of CFRP–steel interface debonding and CFRP groove defects are systematically carried out. Disperse software is used to analyze the dispersion characteristics of CFRP and steel plates, and 150 kHz is determined as the optimal excitation frequency to effectively suppress multi-mode interference. Specimens with gradient debonding lengths (0–40 mm) and CFRP groove specimens with different geometric parameters are designed. A “pitch–catch” PMN–PT sensing scheme is adopted to collect ultrasonic time-domain signals, extract the first-arrival wave amplitude, and construct a damage index (DI). The experimental results show that the first-arrival wave amplitude changes monotonically with increasing debonding length, and the damage index exhibits a good linear correlation with debonding length. For CFRP groove defects, the first-arrival wave amplitude increases with groove length and decreases with groove depth, enabling effective differentiation of geometric differences. The study confirms that PMN–PT piezoelectric sensing combined with ultrasonic guided-wave technology can sensitively identify CFRP–steel interface damage and achieve quantitative assessment, providing reliable technical support for the health monitoring of CFRP-strengthened steel structures.

Abstract: Sanitary sewer collection systems are among the least observable urban infrastructure assets, with most utilities operating fewer than one sensor per several hundred pipes; placement drives operational value. We develop DPP-SP, a Descriptive–Predictive–Prescriptive Sensor-Placement framework that links machine-learning failure prediction with risk-weighted maximum-coverage placement and apply it to a 33,349-pipe sewer system. The geographic information system (GIS) topology is rebuilt, raising the largest connected component from 29.8% to 89.4% of nodes. Random Forest (RF), eXtreme Gradient Boosting (XGBoost) and a multilayer perceptron (MLP) are trained on combined 2020–2025 failure data; RF achieves the highest receiver-operating-characteristic area under the curve (ROC-AUC) of 0.7626 and supplies per-pipe risk weights. A maximum weighted set-cover problem is solved over 680 candidate sites using greedy, genetic algorithm (GA) and tabu search (TS). At K=48, RF with greedy covers 32.26% of network risk against an 11.73% baseline, a 174.9% improvement; all three metaheuristics converge on the same solution. Extending to K=400 exposes a 56.58% structural ceiling due to isolated fragments, and a six-radius sensitivity study (200–2,500 m) identifies detection range as the dominant design parameter. Risk coverage can be nearly tripled by redeploying the existing 48 stations at no capital cost.

Abstract: A new micropolar peridynamic framework incorporating stress- and stretch-based failure criteria was developed for simulating concrete structures. The micropolar peridynamic stress tensor was postulated for plane stress problems, in which the material horizon was expressed as a function of Poisson’s ratio, the material strength, and the fracture toughness. A direct one-to-one correspondence was established between the classical constitutive stress–strain tensor and the associated micropolar peridynamic stress tensor for linearly elastic materials. In addition, a numerical matrix-based scheme was implemented to model concrete problems using an explicit nonlinear explicit dynamic relaxation solver. To assess the model’s performance, concrete structures under plane stress were examined and the results were compared with experimental data, showing good agreement with the model predictions.

Abstract: Organic matter is widely recognized as a key factor limiting the effectiveness of conventional cement stabilization of soft soils, thereby affecting the performance of reinforced soil layers used in construction. However, the influence of different organic matter components on reactive MgO carbonation reinforcement remains insufficiently understood. In this study, silty clay containing varying contents (0~8%) of fulvic acid (FA) and HA (HA) was treated using Portland cement (PC) stabilization, MgO stabilization, and MgO carbonation. The engineering performance and microstructural characteristics of the reinforced soils were evaluated through measurements of dry density, unconfined compressive strength (UCS), pH, X-ray diffraction (XRD), scanning electron microscopy (SEM), and pore structure analysis. The results indicate that MgO carbonation exhibited the highest densification efficiency among the three curing methods, resulting in significantly higher dry density and UCS values than those obtained under PC curing and MgO curing. Increasing organic matter content generally reduced the alkalinity of the stabilized soils and adversely affected strength development. The inhibitory effect of FA on stabilization performance was more pronounced than that of HA, as evidenced by a lower minimum UCS and greater sensitivity to organic matter dosage. Carbonation treatment effectively mitigated the negative influence of both FA and HA, producing substantially higher strengths than the other curing methods. XRD analysis revealed that nesquehonite, dypingite, and hydromagnesite were the major carbonation products, while increasing organic matter content reduced the formation of these strength-contributing phases and promoted the retention of uncarbonated brucite. SEM observations further confirmed that organic matter altered the morphology and distribution of carbonate products, resulting in a looser microstructure despite a reduction in pore volume. Overall, the findings demonstrate that reactive MgO carbonation stabilization possesses stronger resistance to organic matter interference than conventional PC stabilization and can effectively improve the engineering performance of organic-rich soft soils while facilitating CO₂ sequestration. This study provides experimental evidence and design-relevant insights for the optimal application of low-carbon MgO-CO₂ stabilization technology in reinforced soil construction.

Abstract: Urban accessibility is increasingly shaped by the interaction between physical mobility, digital service accessibility, and social relationships. However, most existing urban simulation models primarily focus on physical transportation networks and rarely incorporate digital accessibility or social interaction mechanisms. This limitation restricts the ability of conventional models to capture emerging behavioral patterns associated with digital service adoption and changing urban lifestyles. To address this gap, this study develops a multi-layer Social Dynamics Simulation (SDS) model that integrates three interdependent network layers: a real network representing physical accessibility, a virtual network representing digital accessibility, and a social network representing interpersonal relationships. The model introduces an integrated accessibility index that combines physical and digital accessibility based on a probabilistic service choice framework estimated using survey data (n = 6,210). The proposed model is applied to a virtual city experiment to examine how digital service usage and social interaction preferences influence long-term urban dynamics. Simulation results indicate that digital accessibility partially relaxes spatial constraints imposed by transportation networks, enabling households to maintain acceptable service access even in locations with lower physical accessibility. However, transportation accessibility remains a dominant factor shaping residential concentration around transit nodes. The results further demonstrate that digital service substitution can reduce travel demand while reinforcing accessibility differences across population groups. The proposed framework contributes to computational urban systems modeling by incorporating digital service substitution and social interaction effects into a multi-layer simulation environment. The results highlight the importance of representing non-physical accessibility processes when evaluating urban dynamics in increasingly digitalized cities.