Scientific publications and conference papers
Published papers
S. Vern, F. Paolacci and R. Nascimbene, Advanced Hybrid Strand Solutions Applied to Cable-Stayed Bridges: Static and Seismic Performance. 18th World Conference on Earthquake Engineering, WCEE2024.
Abstract: This paper introduces a novel hybrid composite cable section and its application for one of the most challenging civil structures, cable-stayed bridges, under the FIRST-WIRE project “FIber Reinforced STeel WIREs for high-performance, lightweight ropes and cables operating in demanding scenarios.” The hybrid cable section comprises carbon fiber-reinforced polymers and high-strength steel. Using the hybrid stay cable section first, a construction stage analysis has been performed to determine the static loading and deformation profile of the bridge while also compiling an in-depth examination and performance of the hybrid cable at different construction stages and finally comparing the results with the standard steel cable equipped cable-stayed bridge. Since the hybrid cables are significantly lighter in weight than the normal stay cables and have higher resistance towards fatigue, the present study also aims to explore the advantages and disadvantages of hybrid stay cables’ performance under seismic excitations over the standard steel stay cables. In addition, construction stage and seismic analysis have been performed for a real case of a short-span pedestrian cable-stayed bridge in Italy. The response quantities of interest include the displacement of the tower and deck, variation in prestress force in cables, torsional in the tower, and bending moment at the supports. Results of the construction stage analysis show that using the hybrid stay cable, the final designed strength in stay cables can be achieved more effectively than steel cables. As for the seismic performance, response quantities such as cable tension, tower moment, and deck moment show superior seismic performance.
S. Vern, F. Paolacci and R. Nascimbene, Static and Seismic Performance of Long-Span Cable-Stayed Bridge Using Advanced Hybrid Cables. 7th International Conference on Earthquake Engineering and Seismology, 7ICEES.
Abstract: The present study investigates the application of advanced hybrid cables for improving the static and seismic performance of the long-span cable-stayed bridges under the FIRST-WIRE project (FIber Reinforced Steel WIREs for high-performance, lightweight ropes and cables operating in demanding scenarios). The hybrid cable section comprises carbon fiber reinforced wire (CFRP) and high-strength steel. To illustrate, a three-dimensional cable-stayed bridge with a 420m span is investigated. An in-depth construction stage analysis consisting of 32 different stages for different stay cable materials has been presented. Finally, a parametric investigation uses a finite element platform to investigate the seismic performance of the hybrid stay cables. The parameters considered in the present study include modal analysis, the effect of variation in peak ground acceleration (PGA), and a comparison between different stay materials on the displacement of the tower and deck, variation in prestress force in cables, shear force, and bending moment at the support. The results of the construction stage study reveal that the final designed strength in stay cables can be attained more efficiently with hybrid stay cables. Response quantities such as cable tension, the moment in the tower, and the deck demonstrate improved earthquake performance for the hybrid cables.
Keywords: Cable-Stayed Bridge, Hybrid Cables, CFRP, NTHA, PGA
S. Vern, F. Paolacci and R. Nascimbene, Seismic Behavior of Cable-Stayed Bridges Under Strong Ground Motions, IOP Conference Series: Materials Science and Engineering, TISDIC-23.
Abstract: Seismic behavior analysis of the long-span cable-stayed bridge is a complex process involving different uncertainties. This paper performs a sensitivity analysis of cable-stayed bridges using the finite element method on Midas/Civil. They include different types of ground motions scaled to different peak ground acceleration (PGA) levels, the effect of the multi-support excitations due to time-lag propagation or nonsynchronous excitations, and the effect of the angle of the incidence of the earthquake is determined. To evaluate the optimum initial cable prestress forces in cables unknown load factors method is used. The response quantities of interest include the displacement of the tower and deck, variation in prestress force in cables, torsional in the deck, shear force, and bending moment at the supports. Results show that the effect of the PGA variation and angle of incidence of the earthquake is moderate. In contrast, the synchronous and nonsynchronous seismic excitation effect on the response quantities is significant.
For publication
J. Ferino, A.Meleddu, W. Frick, S. Hecht, K. Brunelli, L.Pezzato, M.N.Amin, M.Meleddu, Finite element modeling of steel wire and wire rope to analyze/ characterize mechanical properties, Ilmenau Wire Day – with contributions from industry and research, Technical University of Ilmenau (Germany), 11-12 June, 2024.
Abstract: The paper aims at investigating the mechanical properties of steel wires and ropes for demanding operational scenarios such as mooring lines for offshore platforms or cable stayed bridges. Two types of rope are considered: Φ36.5mm Open Strand Spiral rope (OSS) consisting of round wire, and a Φ60mm Fully locked coil rope (FLC) consisting of profiled wires. Finite Element models are developed including the drawing manufacturing process as well as the following rope closing and testing. Full-scale testing is performed to evaluate the tensile and torsional properties of the ropes and results are compared to a finite element model representing both types of ropes. Experimental-to-numerical results comparison show that a good agreement is achieved provided that correct material properties are employed in the model. The activity is performed in the frame of the FIRST-WIRE, a project co-funded by the Research Fund for Coal and Steel, an EU program supporting research projects in the coal and steel sectors.
J. Ferino, A. Meleddu, W. Frick, S. Hecht, K. Brunelli, L.Pezzato, M.N.Amin, M.Meleddu, Fiber reinforced steel wire for high performance rope applications, Ilmenau Wire Day – with contributions from industry and research, Technical University of Ilmenau (Germany), 11-12 June, 2024.
Abstract: An innovative type of carbon fibers reinforced steel wire is under development in the Framework of FIRST-WIRE. The project is co-funded by the Research Fund for Coal and Steel, a EU programme supporting research projects in the coal and steel sectors. The aim is to design a lightweight yet resistant wire for demanding onshore/offshore rope application such as mooring lines for offshore platforms or cable stayed bridges. In the present paper the hybrid concept is discussed and results from a dedicated full-scale test program presented. A Finite element investigation is also performed, and numerical-to-experimental results are presented. Results suggest that hybrid exhibits a good resistance-to-weight ratio, when compared to traditional full steel solutions. Still, cable terminations remain an issue and deserve further investigation as socketing reveals to be critical to exploit the full potential of the hybrid solutions.
S. Vern, F. Paolacci, G. Quinci, R. Nascimbene, and J. Ferino, Seismic response of a cable-stayed bridge equipped with hybrid cables. Composite Part-B (Engineering), Elsevier Publications
Abstract This paper presents a novel hybrid composite cable section designed for cable-stayed bridges, developed under the “FIber Reinforced Steel WIREs for high-performance, lightweight ropes and cables operating in demanding scenarios” (FIRST-WIRE) project. The cable section comprises high-strength steel and carbon fiber-reinforced polymers. The study begins with a construction stage analysis that compares the performance of the hybrid cable with that of a standard steel cable solution under static and dynamic loading profiles. Additionally, the study investigates the advantages and disadvantages of hybrid stay cables under seismic excitations compared to standard steel stay cables. To demonstrate the proposed solution, the study analyzes a short-span pedestrian cable-stayed bridge located in a high seismic zone in Italy. The analysis includes parameters such as the tower and deck’s displacement, variation in cables’ prestress force, torsional moment in the tower, and bending moment at the supports. The results indicate that the hybrid stay cable is more effective than steel cables in achieving the final designed strength of the cables. Moreover, the hybrid stay cable exhibits superior seismic performance, as demonstrated by response quantities such as cable tension, tower moment, and deck moment.
Keywords: cable-stayed bridges, CFRP, hybrid cables, construction stages, seismic analysis
S. Vern, F. Paolacci, G. Quinci, R. Nascimbene, and J. Ferino Advancing Cable-Stayed Bridges: Performance Assessment of Novel Hybrid Composite Cables. Advances in Structural Engineering, Sage Publications
Abstract: Developing innovative structural solutions for cable-stayed bridges represents a focal point within civil engineering research. In this context, introducing the hybrid composite cable section as part of the FIRST-WIRE project signifies a significant advancement in the field. By combining carbon fiber-reinforced polymers with high-strength steel, this novel hybrid cable section offers the potential for enhanced performance and reduced weight, addressing the demand for high-performance, lightweight structural elements. This paper delves into the practical application and performance assessment of hybrid cable solutions by exploring a case study involving a short-span pedestrian cable-stayed bridge in Italy. The analysis spans various aspects, starting with construction stage evaluation to determine static loading and deformation profiles and extending to seismic performance, aerodynamic stability, pedestrian loading, and fatigue analysis. This comprehensive approach sheds light on the versatility and resilience of hybrid cables in challenging environments, underscoring their potential to elevate the standards of structural engineering practice. Thus, this study contributes valuable insights to the ongoing discourse on bridge engineering, offering promising avenues for developing sustainable and resilient infrastructure systems.
Keywords: Hybrid composite cables, cable-stayed bridges, seismic analysis, aerodynamic stability, pedestrian loading, fatigue analysis, structural resilience
S. Vern, F. Paolacci, G. Quinci, R. Nascimbene, and J. Ferino, Innovative Seismic Risk Assessment Methodology for Long-Span Cable-Stayed Bridges Equipped with Hybrid. Journal of Bridge Engineering, ASCE Publications
Abstract: Assessing seismic risk for long-span cable-stayed bridges with hybrid cables as part of the FIRST-WIRE project is a complex task involving conducting both seismic hazard and vulnerability analyses. Traditional approaches often rely on specific seismic intensity measures (IMs), which can lead to uncertainties and overly conservative risk estimates. To address these challenges and improve the precision of seismic risk assessment for such bridge structures, a new framework has been proposed in this paper. This methodology focuses on controlling response variability in seismic hazard curves while considering the randomness inherent in ground motion prediction equations (GMPEs). The framework also considers the unique characteristics of hybrid cables created by combining carbon fiber-reinforced polymers with high-strength steel. By transferring variability to fragility curves constructed from groups of accelerograms, an accurate representation of median and 84% fractile spectra for different return periods is achieved. A novel search algorithm is developed for selecting natural records, making the process more efficient. By eliminating the dependence on specific IMs, the proposed approach enables a more precise assessment of three-dimensional structures. The method is applied to a typical long-span cable-stayed bridge equipped with hybrid cables to demonstrate its robustness and practical independence from the record set used. This pioneering methodology marks significant progress in seismic risk assessment for long-span cable-stayed bridges, offering a promising avenue for enhancing risk management strategies in civil engineering practice.
Keywords: Seismic risk assessment, Long-span cable-stayed bridges, Hybrid cables, Ground motion prediction equations (GMPEs), Fragility curves, Risk management
S. Vern, F. Paolacci, G. Quinci, R. Nascimbene, and J. Ferino, Economic Evaluation of Hybrid Cable-Stayed Bridges: A Comprehensive Life Cycle Cost Analysis. Reliability Engineering & System Safety, Elsevier Publications
Abstract: The economic performance of cable-stayed bridges, particularly in the context of super long-span structures, has garnered significant attention in civil engineering. Central to this discussion is evaluating life cycle costs (LCC), which considers initial construction expenses, maintenance requirements, and prevailing interest rates. In recent studies, there has been a notable focus on hybrid cables as part of the FIRST-WIRE project, formed from a composite section of steel and hybrid materials, as a potential alternative to traditional steel cables. These hybrid cables offer enhanced durability and reduced maintenance needs, potentially resulting in lower life cycle costs. However, the economic viability of such hybrid cable-stayed bridges warrants careful examination, particularly in comparison to their steel counterparts. By conducting rigorous LCC analyses and economic comparisons, researchers seek to elucidate the cost-effectiveness and feasibility of implementing hybrid cable systems in long-span cable-stayed bridges. Such investigations contribute valuable insights to the ongoing discourse surrounding infrastructure development and management, with implications for decision-makers in bridge engineering and beyond.
Keywords: carbon-fiber-reinforced polymer; cable-stayed bridge; long-span; life-cycle cost