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• A comprehensive analysis is conducted to reveal the mechanism of widespread failure of light poles on an elevated bridge. • Large eddy simulation is performed to model the wind filed and aerodynamic pressures on the light poles. • Nonlinear Finite Element modeling is conducted to analyze the structure responses of the light poles. • The bridge superstructure can significantly enhance the local wind field, leading to increased wind loads (mean & fluctuating) on light poles. • Under enhanced wind loads, significant plastic strains/stresses develop at the bottom of the light poles. Light poles are critical secondary structural components that support the functionality and safety of transportation systems. However, they are tall slender structures vulnerable to wind load. This research attempts to analyze the mechanism of the widespread failure (69 poles failed) of light poles on an elevated highway bridge exposed to Category 4 Hurricane Laura (2020). First, large eddy simulation is performed to simulate the wind field and the aerodynamic pressure on light poles considering and without considering the presence of the bridge superstructure, respectively. Simulation result shows that the presence of the bridge superstructure strengthens the local wind field and the aerodynamic pressures. A nonlinear finite element model is created to simulate the structural responses. Research results indicate that, when considering the presence of the bridge superstructure, stresses at the pole bottom exceed the yielding strength and significant inelastic strains are developed, which is the main cause of the widespread pole failure. The present study can be used to evaluate the current design standard for luminaire pole structures on elevated bridges. [ABSTRACT FROM AUTHOR]

• Stress distributions, contact statuses and slip characteristics of strands and wires along arc contact paths in the saddle were explored. • Effects of pretension, applied load and coefficient of friction on contact and slip behaviors were investigated. • The friction and slip test rig between cable strands and saddle was established to explore slip characteristics, radial and tangential forces between strands and saddle. In order to ensure the anti-slip safety of main cable in the main saddle of long-span suspension bridge, contact and slip behaviors of main cable of the long-span suspension bridge were investigated in this study. Mechanical characteristics of main cable were explored according to statics theory. Finite element models were established to analyze effects of pretension, applied load and coefficient of friction on stress distributions, contact statuses and slip characteristics of strands/wires along arc contact paths in the saddle. A friction and slip test rig was developed to explore slip characteristics between strands and saddle in order to validate finite element models. The results show that there are micro slips at both ends and adhesion in the central region along the arc contact paths between strand/steel wire and saddle in all cases. The micro slips decrease with increasing pretension and coefficient of friction, and increase with increasing applied load. The strand and steel wire at the lower layer exhibit the easier gross slip and the larger difference between axial stresses at both ends as compared to those at the upper layer. The axial stress difference of strand increases with increasing pretension and coefficient of friction, respectively. The friction and slip tests show that the upper layer strand exhibits the larger maximum displacement amplitude corresponding to gross slip, and the tangential force increment of strand along the arc contact path decrease in the order: tight end, central location and loose end, which validates finite element models. [ABSTRACT FROM AUTHOR]