Climate change is posing new challenges for the design of civil engineering both in terms of accelerated material degradation processes and shifts in the frequency and intensity of climate extremes. While recent studies have emphasised the impact of climate change on climate extremes, existing European climatic load maps used for structural design often remain outdated, unable to incorporate recent observations and future climate scenarios. To address these issues, the second generation of Structural Eurocodes, now under publication, have introduced climate adaptation measures, notably the scaling factor approach, to account for projected changes in climatic actions on structures. This paper presents the rationale behind the scaling factor approach, its integration into EN1991 Actions on Structures, and a pilot application involving the update of thermal maps in the Italian National Annex to EN1991-1-5:2004, highlighting a cost-effective pathway toward climate-resilient structural design.
A finite element model of a single-storey cold-formed thin-walled steel house frame structure was established using ABAQUS software to analyze the effects of different impact locations and impact angles on the dynamic response of the structure under a single impact load. Also, to establish a continuous impact model of single-storey cold-formed thin-walled section steel house skeleton structure at different locations and analyze the effect of two impact objects on the dynamic response of house skeleton structure under different impact time intervals. Combined with the basic theory of impact dynamics, the principle of the energy method was to determine the impact dynamic response analysis method of low-storey cold-formed thin-walled section steel housing skeleton structure under the impact-prone position, and put forward two measures to improve the impact resistance of cold-formed thin-walled section steel housing skeleton structure. The results show that: the lower node of the side column, the lower node of the middle of the wall and the lower middle point of the side column are the dangerous impact points of the housing skeleton structure; an impact angle of 90 degrees (whether horizontal or vertical) represents the most critical scenario for the structure; the two impact objects acting at the same moment have the greatest degree of damage to the housing skeleton structure; after the side column is increased from double-limb to three-limb C-section steel collocation form, the impact resistance of the dangerous impact point of the side column is significantly improved, and the displacement is reduced by 37%; the addition of diagonal bracing at the side column of the impacted wall skeleton. The plastic strain energy of other members in the skeleton structure of the house is significantly reduced, and the displacement along the impact force direction is reduced by 18%.
This study presents a rapid and economic strengthening method for existing RC framed and infill walled buildings with poor concrete quality especially those located in seismic regions and such as Turkiye. An important difference of this paper from similar studies is the preparation of frame specimens using low-quality concrete, aiming for a more accurate simulation of the existing building stock in Turkiye. To achieve this goal, six reinforced concrete (RC) specimens with different combinations of carbon fiber-reinforced cement-based composites (CFRC) were fabricated. These specimens were both experimentally and analytically tested under reversed repeated axial loading and compared with un-strengthened bare and infilled specimens. Accordingly, certain parameters such as maximum lateral load capacity, stiffness, damage-crack formations, ductility, and energy dissipation capacities were examined. The application of CFRC-strengthening prevented the dispersion and out-of-plane collapse of the infill walls. The strengthened specimens exhibited fewer cracks in comparison to the un-strengthened bare and infilled specimens. In addition to presenting the CFRC strengthening combination with the highest overall performance, this study also introduced cost-effective alternatives with acceptable performance and ineffective application combinations with inadequate strength. In conclusion, this study is believed to make a valuable contribution to the field and serves as a useful guide for retrofitting structures constructed in seismic regions with poor concrete quality.
UHPFRC stands for ultra-high-performance fibre-reinforced-cementitious composite material, that is complemented by reinforcing steel bars to form a R-UHPFRC strengthening layer. UHPFRC "upcycling" has the goal to enhance the resistance and durability of deficient structural elements in reinforced concrete. It helps to avoid the still widespread and material- and cost-intensive practice of "demolition-replacement" of deficient reinforced concrete bridges. As UHPFRC "upcycling" often offers significant cost and environmental benefits, it should become the default option when dealing with deficient reinforced concrete bridges. This report is intended to serve for the structural engineering community to profit from the 20-year long application experience in Switzerland to broadly apply this new technology.
Inspire Resort, located in Yeongjong-do, Incheon, is a large-scale integrated complex with a total gross floor area of approximately 348,000 m2. This study summarizes the structural design of the project's long-span roof systems, focusing on the Pool Dome and Arena roofs. The Pool Dome employs radially arranged one-way steel trusses with ring trusses spanning 74.6 m, while the Arena roof employs arched one-way steel trusses spanning 95.8 m. This paper presents the design considerations, including realistic loading scenarios, boundary details, and key considerations for fabrication and erection of the long-span roof truss systems of the Pool Dome and Arena.
The dynamic and static behaviour of a pedestrian hybrid steel-timber arch bridge is investigated in this article. The main interest of this study is the modular design of the timber arches consisting of mechanically connected glulam beams. The individual arch segments are interconnected with a novel steel hinge connection. Dynamic and static tests were performed on a full-scale model of an arch segment (3.95 m long) in a laboratory. This study has been thoroughly presented in Bergenudd J, Battini J-M, Crocetti R. Nedev G, et al. [Analysis of a Mechanically Connected Timber Arch Section and Steel Hinge Connection for an Arch Bridge. In ICTB 2025. 5th International Conference on Timber Bridges, Rotorua, New Zealand, 2025] and only a summary is given in this article. In situ dynamic tests were performed on the finished bridge. The results showed that the partial composite action of the arches affected the out-of-plane modes of vibration and critical buckling load of the bridge substantially. The stiffness of the steel hinge connections in the arches reduced the critical buckling load of the bridge slightly. The analysis also showed that the slip modulus between the structural elements affected both the dynamic and buckling behaviours. Finally, the experimental damping ratios were around 1-1.5% for the bridge which is similar to the recommended values in the technical guidelines.
Reinforced concrete structures are increasingly subjected to the coupled effects of climate change and time-dependent deterioration, which jointly threaten structural performance and service life. This study performs a comprehensive bibliometric analysis to map the evolution, thematic structure, and knowledge gaps of climate-change research focused on RCSs. Using Scopus as the sole database, a structured search strategy yielded 2,061 English-language publications spanning 1994-2025. Performance indicators were computed in Microsoft Excel, while science-mapping and keyword co-occurrence networks were developed in VOSviewer. Results show an exponential growth in publications after 2010, aligning with major global climate policy milestones and the consolidation of climate change as an explicit engineering concern. Science mapping reveals a clear transition from early sustainability- and material-oriented studies toward climate-informed durability modeling, extreme-event impacts, and multi-hazard risk frameworks, with recent emphasis on resilience, structural health monitoring, digital twins, and machine-learning-based prediction. Despite this progress, research output remains geographically concentrated in North America and Western Europe, leaving highly exposed regions underrepresented. The findings underscore the need to expand localized studies, systematically integrate climate projections (e.g. RCPs and SSPs) into structural assessments, and advance compound multi-hazard approaches for aging RCSs.
Proof load testing on bridges requires high magnitude loads. Stop criteria are used to avoid irreversible damage or failure during proof load testing. These stop criteria are thresholds to measurable parameters during the test. After reaching a stop criterion, the proof load test needs to be terminated. While in the past, stop criteria have been identified as a single level, this research proposes to use a traffic light system for stop criteria: green light (related to the serviceability limit state), yellow light (as an intermediate level) and red light (further testing is not permitted). The green light relates to the development of cracking, whereas the yellow and red light relate to the failure modes of flexure and shear. To develop stop criteria for the brittle failure mode of shear, thresholds are derived from mechanical models, based on strain measurements and crack widths, as well as using acoustic emission measurements. To validate the stop criteria, three series of experiments are analyzed: reinforced concrete slab strips, straight slabs, and skewed slabs. While field validation of the traffic light system is pending, the developed tool is a step forward to safely test concrete bridges without shear reinforcement.
Bridges are an important part of the transportation network for moving people and goods quickly and safely. In areas prone to seismic activity, one of the most concerning aspects of bridge structures is how well they will perform during strong seismic activity. When a bridge structure rests on the ground with some degree of deformation, the interaction of the soil with the structural system is called soil-structure interaction (SSI). The purpose of the study is to present a comprehensive literature review of SSI and how it affects the seismic capacity of bridge systems. Through the combination of numerous studies examining the dynamic interplay between bridge substructure and surrounding soils during seismic events, the study illustrates the prevalence of nonlinear SSI behavior in overall bridge performance. In addition to evaluating analytical, numerical and experimental methods for quantifying SSI effects, the research investigates interaction between the foundation and soil in integral and conventional abutment bridges. The results indicate that nonlinear SSI behavior and flexibility of substructure can considerably impact displacement and force demands and may result in inaccurate prediction of bridge demand through simplified models. The review identifies areas for further investigation to advance development of more resilient bridge systems.
This study presents an analytical method for effective cross-section design of cylindrical hollow columns under axial compression, based on the Buckling Postulate-Reference Solid Column approach. The aim is to ensure structural stability while optimising material use. A solid long column with the same material, dimensions, and cross-section area is used as a reference to guide the design of an intermediate hollow column. According to the postulate, if a factor alpha defines the ratio of safely carried loads between solid and hollow columns, the same factor also governs the ratio of their critical buckling loads. Using American Institute of Steel Construction (AISC) equations, analytical relationships are formulated between the critical load ratio, effective design factor, and dimensionless geometric parameters. An illustrative application verifies the Buckling Postulate, showing that the proposed method maintains the buckling strength of hollow columns while achieving substantial material savings-up to 65% compared with a solid column. The results highlight the influence of geometric and material properties on effective design and enable accurate prediction of buckling performance. Overall, the approach provides an efficient and practical framework for designing cylindrical hollow columns, linking analytical formulations with established AISC principles to achieve material economy without compromising structural safety.
The lifting method of lattice girders in the construction of concrete-filled steel tube (CFST) arch bridges has always been a critical challenge in engineering practice. The construction process typically faces a series of technical difficulties, including limited lifting space, complex hoisting conditions, and intricate installation procedures. To address these challenges, this paper designs a novel crane capable of traveling along arch ribs and develops a corresponding lattice girder installation process. First, finite element analysis is conducted to comprehensively verify the structural stiffness and stability of the arch crane under extreme loading conditions. Second, a mechanical performance evaluation of critical load-bearing components of the bridge during construction is performed to ensure that the proposed method does not adversely affect the long-term serviceability of the structure. Finally, through an engineering application on a CFST arch bridge, the proposed method is validated in terms of construction efficiency, economic feasibility, and operational safety, demonstrating its practical applicability.
Terrain-induced irregularities exacerbate the seismic vulnerabilities of hill buildings. Conventional force-based nonlinear static methods often overlook higher-mode energy interactions, resulting in unrealistic capacity curves. This study examines the effectiveness of energy-based modal pushover analysis (EMPA) approach in assessing the seismic response of reinforced concrete (RC) buildings located on hill slopes. For this, typical RC frame configurations, i.e. step-back, step-back setback, and split foundation, are analysed using modal pushover analysis and EMPA methods across varying slopes and heights. Their responses are compared with those from a nonlinear time history analysis to assess the efficacy of the EMPA method in capturing seismic responses of hillside buildings.
The impact of climate change on key environmental variables is well-known; yet its effect on complex phenomena such as corrosion due to carbonation and chloride ingress remains a subject of ongoing debate. While several studies have examined these processes individually, the interaction between carbonation and chloride penetration in reinforced concrete structures is less understood. Chloride ion ingress is particularly relevant in marine environments, where salt spray and carbonation may occur concurrently. Similarly, structures in urban areas exposed to de-icing salts and high $CO_2$CO2 levels due to traffic and pollution face increased corrosion risks. Previous research suggests that carbonation can significantly influence chloride ion transport in concrete, but its exact effect-whether it accelerates or decelerates damage-varies across studies. Some models estimate that the probability of corrosion initiation under combined carbonation and chloride ingress conditions may be nearly twice as high compared to considering these mechanisms separately. Therefore, understanding this interaction is crucial for improving durability predictions and developing effective mitigation strategies. This study reviews key experimental and modeling research addressing the combined effects of carbonation and chloride penetration in concrete structures.
With a world record in main span length of 2023 m, the 1915 & Ccedil;anakkale Bridge is located at the north-eastern end of the & Ccedil;anakkale Strait in T & uuml;rkiye which has the heaviest navigation traffic and severe windy conditions. The planning, design and construction of the bridge having the design life of 100 years raised various technical challenges against extreme loadings such as live loads on long span, strong wind, earthquake and even ship collision. To define the design loads, geological investigation, geophysical study, meteorological study and traffic study were thoroughly progressed at the beginning stage of design. The ultimate challenge was to complete the project within only 5 years. The detailed design process had to be efficient and firmly optimized to allow for fast construction. Significant design challenges for aerodynamics, ship collision, seismic and poor soil conditions had to be managed. Various three-dimensional global analysis models including detailed local models based on the most advanced Finite Element Model technology were developed to overcome strong wind, earthquake and ship collision. Then, the design was verified by wind tunnel test and simulations. Also, the project had been proceeded by fast-track construction to accelerate the opening, and efficient fabrication and installation methods were adopted.
