Evaluation of dynamic responses of bridges considering traffic flow and surface roughness. (15th December 2020)

• Record Type: Journal Article
• Authors: Ho, Hoai; Nishio, Mayuko
• Is Part Of: Engineering structures. Volume 225(2020)
• Publication Date: 2020-12-15
• Subjects: Traffic loading -- Dynamic effect -- Random traffic flow -- Surface roughness -- Structural monitoring; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2020.111256
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: A numerical calculation scheme to evaluate the dynamic live load effect on bridge. Input forcing function to represent the traffic flow and the surface roughness. Scheme was validated by applying to an existing bridge using monitoring data. Truck ratio and vehicle speed influence on RMS acceleration. Maximum acceleration depends on speed, surface roughness, and vehicle passing order. Abstract: The variations in the vehicle types, speeds, and passing order in the traffic flow and roughness conditions cause the dynamic effects of live loads on the bridges. In this study, a numerical calculation scheme is proposed to evaluate the bridge dynamic response under random traffic flow, considering the surface roughness condition. Traffic vehicles with a random passing order are constructed as the time history of the transient force functions assigned at each discretised deck node of the numerical model. The random effects of the vehicle types, speeds, and surface roughness are represented by the amplitude levels of the transient force functions. The validity of the calculation scheme is verified by applying it to an existing steel box-girder bridge using dynamic monitoring data, traffic data, and a finite element model. The behaviour of the calculated root mean square (RMS) of the accelerations agrees with that of the measurement data, particularly in the traffic situation with a high truck ratio. Moreover, a parametric study is conducted to investigate the effects of the traffic flow characteristics and surface roughness conditions on the bridge dynamic responses. The results demonstrate that the RMS of acceleration depends on the truck ratio and traffic flow speed; however, the maximum acceleration may be influenced by the vehicle speed and passing order, as well as the surface roughness condition. It is concluded that the calculation scheme is applicable for evaluating the dynamic responses of existing bridges with the given dynamic monitoring data, traffic flow, and surface roughness conditions.