A vessel-bridge collision can result in severe loss of life and substantial damage. This study presents a numerical analysis of the vessel impact on a column of the Ilok-Bačka Palanka bridge in Croatia. Using finite element modelling, different barge–column interactions under multiple loading conditions were simulated. The numerical model includes realistic vessel and bridge-pier geometry, as well as material behaviour. The numerical simulation results were compared with the damage caused to the column after the impact. The column damage was evaluated using a concrete degradation modelled via an erosion-based algorithm driven by instantaneous geometric strain. The calibrated numerical model was also used in a parametric analysis to determine the influence of the impact direction and speed on the observed bridge pier.
Infrastructure projects support the fulfilment of society’s most fundamental needs (e.g. transportation and water supply) and constitute an indicator of economic competitiveness. Globally, infrastructure investments amounting to approximately EUR 82 trillion are projected by 2040. This research analyses the organisational environment and project delivery performance based on a sample of fifty infrastructure projects in the Republic of Croatia, with the aim of addressing the lack of research in this field. The results indicate that Croatia is currently undergoing a major investment cycle, with emphasis on transport and municipal infrastructure, driven by co-financing from EU funds. The organisational environment is complex in the majority of projects, while management models remain relatively traditional. Cost overruns are present in 58% of projects, whereas schedule overruns occur in as many as 84% of projects. The construction phase is frequently extended by more than 20 % beyond the contractual duration. Social infrastructure projects demonstrated weaker cost performance compared to civil infrastructure projects, with overruns often exceeding 20 % of the contract value; this issue will be investigated in greater detail in future research. Given the importance of critical infrastructure for the development of the Republic of Croatia, public contracting authorities and other key stakeholders should address challenges such as delays, budget overruns, and the frequent use of traditional procurement models. Possible starting points include innovative administrative frameworks and procurement models analysed in this paper, whose implementation has not yet been recorded in Croatia.
The construction industry experiences numerous accidents of varying severity. This study analyses 434,134 occupational accident records from the construction sector in Turkey (2012–2021) using ordinal logistic regression for four-category severity modelling. Unlike previous studies, the dataset was split into 70 % training and 30 % independent test sets. The model achieved a classification accuracy of 56.0 %, demonstrating strong sensitivity in identifying rare, high-severity outcomes, such as death and permanent disability. These results provide a validated predictive equation and identify critical risk factors, thereby offering a data-driven framework for prevention strategies. This comprehensive modelling approach bridges the gap between theoretical regression and practical safety decision-making.
Based on the geomechanical analysis of typical examples of slope reinforcement and indoor model test analysis, this study analyses the influence of earthquakes on the dynamic response of anti-slide piles supporting gravel soil slopes under different embedment depths and soil strengths. The aim is to reveal the variation law of the earth pressure gauge value behind the pile in the embedded section of anti-slide piles with different embedment depths and seismic time histories. When the embedment depth is relatively deep or the soil strength is relatively large, it may not fully exert the retaining effect of the anti-slide pile, and the construction is difficult and may not be economical. When the embedment depth is relatively shallow or the soil strength is relatively small, the seismic resistance effect of the anti-slide pile is poor, and the supported slope is not very stable. Based on the strength reduction unbalanced transfer coefficient method, relevant research on the embedment depth of anti-slide piles is carried out. An empirical discriminant formula is established for determining the optimal embedment depth of anti-slide piles in soils of different strengths under a certain landslide thrust condition. It further reveals the specific impacts of many sensitive factors, such as the embedment depth, soil water content, and pile-soil properties, on the distribution mode of external loads, and provides a theoretical basis and relevant scientific guiding suggestions for explaining the force mechanism of its support system and research on the specific embedment depth.
Railway subgrades in desiccated salt lake regions are prone to swelling hazards under complex environmental conditions. To investigate the water–salt–thermal–mechanical multi-field coupling responses and the synergistic evolution of microstructure, this study examined saline soils from the Lop Nur salt lake area. A multi-physical field coupling experimental system was established to analyse mechanical responses under different environmental coupling conditions, factor sensitivity affecting mechanical parameters, microstructural evolution, and the regulatory role of pore structure in mechanical stability. Results indicate that in high-temperature zones (≥ 20°C), shear strength is negatively correlated with water content, whereas in low-temperature zones (≤ 0°C) a positive correlation exists. Lower temperatures also markedly suppress cumulative plastic strain. Low-temperature-induced microstructural evolution of saline soil systems proceeds through four stages: initial nucleation, chain-like growth, dynamic reconstruction, and critical failure. The synergistic evolution of multi-field coupling responses and microstructure is primarily reflected in pore structure development. These findings provide a scientific basis for evaluating mechanical stability and guiding the design and maintenance of railway subgrades in cold, arid salt lake environments.
This study introduces a method for identifying vehicle load levels by analysing the characteristics of sound signals generated when vehicles pass over bridge expansion joints. The proposed approach is non-invasive and independent of lighting conditions, offering significant advantages. Experimental tests were initially conducted and effective impact sound signals were extracted by analysing the trend of the sound pressure amplitude following filtering, pre-emphasis, and signal detection processes. Typical characteristics of sound signals in the frequency, time, and time-frequency domains were extracted. The relationships between short-term energy, empirical mode decomposition (EMD) energy entropy, spectral centroid features, and vehicle weight were found to be significant for vehicle weight identification. Finally, aclassifier based on the k-nearest neighbour (KNN) algorithm was employed forvehicle weight classification by analysing the identification results under varying vehicle speeds and feature parameters. The results indicated that the KNN classifier achieved high accuracy in vehicle weight identification: 90.8% at low speeds and 83.1% at high speeds. The confusion matrix revealed that misclassifications tended to predict vehicle weights in adjacent categories.
Using recycled and waste materials in construction instead of natural aggregates contributes to the conservation of natural resources and reduction of construction costs. River sediment obtained via dredging represents one such material which, following appropriate stabilisation, is likely suitable for road construction applications. This study analysed the physical and mechanical properties of both unstabilised and hydraulically stabilised sediments sourced from the Begej River in the Republic of Serbia. Based on the evaluation of the measured properties and their comparison with technical criteriafor road construction of Republic of Serbia, the results indicated that unstabilised sediment is suitable for subgrade and embankment construction. Furthermore, specific stabilised mixtures met the 7-day compressive strength requirements for application as stabilised subgrades and stabilised subbase layers in lower-category roads.
This study proposes a multi-scale damage correlation path to characterise the softening behaviour of soft rock under dry-wet cycles, based on multi-scale damage variables. By testing the mineral composition and internal structural changes of soft rocks under different dry-wet cycles, and based on the energy evolution mechanism and damage constitutive characteristics, the multi-scale correlation effects of soft rock softening under dry-wet cycles were analysed. The results indicate that as the number of dry-wet cycles increase, the mechanical properties of soft rock exhibit an exponential decay mode, and mineral particles exhibit Weibull-distributed random failure behaviour.
Recent seismic events have highlighted the vulnerability of buildings in high-risk zones, resulting in substantial damage and economic loss. This study investigated the effectiveness of fluid viscous dampers in enhancing the seismic performance of a 10-story reinforced concrete building located in Jakarta, an area highly susceptible to earthquakes. A comparative analysis of the seismic responses of both conventional and damped buildings was conducted. A series of linear time-history analyses were performed employing seven spectrally matched ground motions, targeting the maximum considered earthquake level response spectrum. Key seismic performance parameters, including dynamic characteristics, base shear, roof acceleration, interstory drift ratio, and energy dissipation, were examined. These findings demonstrate that the incorporation of FVDs results in significant reductions in the fundamental period of a structure, base shear, and roof acceleration. Furthermore, a substantial reduction in the interstory drift ratios was observed, in conjunction with a significant increase in the overall energy-dissipation capacity of the building. These findings position FVDs as an effective and suitable solution for improving the structural resilience.
Blended cement paste systems are considerably complex owing to the diverse physical morphologies and chemical compositions of the constituent raw materials. Despite this complexity, these systems are increasingly recognised for their enhanced longterm performance and contribution to sustainability. This study examines the hydration characteristics of ternary blended cement pastes employing Taguchi Analysis, a robust statistical tool for investigating multifactorial interactions in material systems. This study systematically evaluates the effects of supplementary cementitious materials, water-to-binder ratio, superplasticiser dosage, and curing conditions to optimise cement paste performance. An orthogonal array design based on the Taguchi method was employed to quantify the influence of these parameters on the chemical shrinkage, hydration kinetics, and pozzolanic activity. Statistical analyses highlight the relative significance of each factor in governing the hydration mechanisms, thereby providing valuable insights for the development of advanced performance-driven cementitious materials.
The development of ultrahigh-performance concrete (UHPC) has prompted extensive research into the preparation and evaluation of UHPC performance. However, limited studies have explored the coordinated working performance of UHPC in conjunction with high-strength rebars within structural systems, particularly from a material-level perspective. This study investigated the relationship between the material mechanical properties and seismic performance of specimens under varying parameters by conducting cyclic tests on five reinforced UHPC columns with different configurations. The results demonstrated that high-strength rebars effectively constrains UHPC and enhances the bearing capacity of UHPC columns. In addition, incorporating a CFRP sheet or increasing the lateral confinement strength mitigated the expansion of UHPC in the core area and the concentration of local plastic damage. The UHPC and longitudinal reinforcement exhibited effective cooperative performance as the axial compression ratio increased.
The construction industry has a higher rate of occupational accidents at construction sites than other sectors. Therefore, it is necessary to take effective measures to prevent accidents from occurring on the construction site. This study examines the attitudes of construction staff towards construction safety, the sources of their safety knowledge, and their views on the likelihood of accident occurrence. It identifies the causes of accidents and the most common types of injuries at construction sites, focusing on three specific regions in China: Shanghai, Qinghai, and Henan. Data were collected using questionnaires. Overall, the results show that the main reasons for occupational accidents are workers' lack of safety awareness (over 90%), work fatigue, and the older age of staff, all of which contribute to unsafe behaviour at the construction site.
The adhesive nature of the binder determines the strength of concrete. Although cement is the most efficient binding material, it is not cost-effective or eco-friendly. Therefore, alternative building materials such as geopolymer concrete (GPC) deserve consideration. In the case of geopolymer concrete, the need for cement as a binding material is eliminated, and strength is achieved through the polymerisation reaction between alkali activators and fly ash/ground granulated blast furnace slag (GGBS). The adequate specimens were then tested at 7th day and 28th day to find their compressive strength, split tensile strength, and Young's modulus. Compared with cement concrete composites, GPC, in which fly ash is replaced with 100 % GGBS and 40 % OPC, showed superior strength without the need for curing at elevated temperatures. The strength was further improved by the addition of OPC to GGBS replaced GPC, and showed an ultimate increase in strength with OPC content as low as 12 %. The experimental investigation revealed a visible decrease in the cement requirement, establishing GPC to be economical and eco-friendly.
The construction industry is increasingly adopting sustainable practices to mitigate the environmental impact from excessive consumption of natural aggregates. This study investigated the incorporation of copper slag (CS) and recycled ceramic tiles (RCT) as partial aggregate replacements in concrete at levels ranging from 50 % to 90 %, with a focus on both the structural integrity and gamma radiation shielding performance. Results indicated improvements in slump, density, and compressive, tensile, and flexural strengths. The optimal mixture, with 60 % replacement, exhibited a maximum density increase increases of 45.9 % and an 18.18 % enhancement in attenuation coefficient (μ). A strong correlation (R² = 0.9743) between density and μ confirms the effectiveness of these materials, making CS and RCT viable sustainable aggregate alternatives for radiation shielding concrete.
To address traditional limitations, this study investigated the flexural performance of large-section PEC beams with varied web openings using experiments and machine learning (ML). Four-point bending tests on specimens with different sections and openings demonstrated excellent ductility (coefficient >4.0), although openings slightly reduced yield strength without significantly affecting overall performance. A database of 15 variables was used to train and validate four ML models (RF, CatBoost, KNN, LightGBM). The RF model achieved the highest accuracy (similar to 2.6% MAE). Shapley analysis improved interpretability by identifying key parameters. Integrating explainable ML substantially enhances the prediction accuracy and interpretability of PEC flexural capacity, offering a promising approach for intelligent structural design and assessment.
This paper presents the design and construction of a home prototype incorporating 3D-printed elements built in Chile. It provides a novel review of the process, which involved multidisciplinary planning, structural and environmental analysis, parametric design, and the printing of elements in a university laboratory, followed by on-site assembly and full construction. Compliance with local standards and the optimisation of activities is also examined. The study demonstrates the feasibility of developing housing with 3D-printed elements in the country, enabling architectural variety, local adaptation, and continuous improvement.
Reinforced concrete beam-column joints are prone to damage during severe earthquakes. Substituting normal concrete with ultra-high-performance fibre-reinforced concrete (UHPFRC), which has outstanding mechanical properties, can improve the earthquake resistance capacity of these joints. However, UHPFRC joints with ordinary-strength stirrups do not reduce the amount of transverse reinforcement, causing construction difficulties. This study investigates UHPFRC beam-column joints with high-strength stirrups and evaluates their mechanical properties under combined axial and cyclic lateral loads via a detailed experimental program. Four beam-column joint specimens were fabricated and tested. The joint core of one specimen was made of ordinary concrete and that of the other three was made of UHPFRC. The test parameters included the types of materials used, yield strength, and volumetric ratio of the stirrups. The experimental results demonstrated that high-strength stirrups restrained the shear deformation, effectively improved the ductility and energy dissipation of the joints, and reduced the amount of transverse reinforcement while maintaining the same seismic capacity.
The design procedure for reinforced concrete T-sections according to the standard HRN EN 1992-1-1:2023 (second generation of Eurocode 2) is described in this paper. Rectangular stress-strain diagram was used for concrete, while bilinear stress-strain diagram with a horizontal post-elastic branch without strain limit was applied for the reinforcing steel. Due to the use of such stress-strain diagrams, while designing reinforced concrete T-sections, it is necessary to reach and limit strain in the compressive zone of the concrete, so that the cross-section is in the ultimate limit state. Hence, by using rectangular stress-strain diagram for concrete, it is possible to apply direct analytical procedure for the design of reinforced concrete T-sections, in which, by solving the quadratic equation, the depth of the neutral axis is obtained, and subsequently, the required cross-sectional area of tensile reinforcement and possibly compressive reinforcement. Tables for the design of reinforced concrete T-sections are also provided, which were obtained based on derived equations by direct analytical procedure.
The interaction between soil and structures is significantly affected by freeze-thaw (F-T) cycles, which alter soil strength and deformation behaviour. This study investigates the effects of F-T cycles on the shear strength, adhesion, and interface friction angle of the G & uuml;ng & ouml;ren clay-concrete interface under varying water content. Samples were prepared at 5 % below and 5 % above the optimum water content and subjected to 0, 3, 7, and 10 F-T cycles between-20 degrees C and +20 degrees C. Direct shear tests were conducted under both freezing and thawing conditions. The results indicate that adfreezing, ice bonding at the interface, significantly enhanced the strength of frozen samples with shear strength increasing by 1.6-2.7 times in frozen wet-side samples and 1.05-1.19 times in dry-side samples. After thawing, dry-side samples exhibited strain-softening and reduction in strength 0.80-0.95 times the initial value, whereas wet-side samples largely preserved their strength. Adhesion increased slightly in dry-side frozen samples, whereas in wet-side samples, it increased nearly threefold after the third cycle and then stabilised. The interface friction angle exhibits differenttrends depending on the moisture content and thermal state. These variations are attributed to the combined effects of ice cementation, unfrozen water, particle interactions, and moisture redistribution at the interface.
