Dynamic Impact of Heavy Long Vehicles With Equally Spaced Axles on Short-Span Highway Bridges

Abstract

Extremely large trucks with a weight exceeding the standard require a permit before they are allowed to cross the bridges of a specific route. For the purpose of safety, an escort is often employed to maintain a distance between vehicles and to ensure that the bridge load remain below the allowed maximum. Given that the speed of these large vehicles is quite slow and that the amplitude of vibrations normally declines when the vehicle mass is large, a minor dynamic amplification of the bridge response is expected. However, some of these large trucks have a unique feature characterized by “multiple equally-spaced axles”, something that is uncommon in normal vehicle. The application of axle forces at equal intervals can dynamically excite bridges to a considerable extent, even at low speeds. These “critical” low speeds are estimated a priori from the axle spacing of the truck and the main frequency of vibration of the bridge. This paper demonstrates that when the “critical” speed is unavoidable, a relatively high dynamic allowance must be added to static calculations before granting a permit to a long heavy vehicle.

Investigation of the Stiffness of a Specially Strengthened Bridge When Crossed by Very Heavy Vehicles – A Case Study

“…Investigations on abnormal road transports are conducted in various countries (Gnap et al, 2022;Godavarthy et al, 2016;Hammada et al, 2013;Macioszek, 2020, Mohammed et al, 2018, Petru & Krivda, 2017, Petru & Krivda, 2021, Vrabel et al, 2022, Wood et al, 2007Yudhistira et al, 2022). According to the data reported in (Petru & Krivda, 2021), the weight of abnormal transports most often amounts to about 100 t (1000 kN).…”

Impact Coefficient Analysis of Curved Box Girder Bridge Based on Vehicle-Bridge Coupling

“…Neves et al [9] presented a direct method for analyzing the nonlinear vehicle-structure interaction based on the Hertzian spring model. Mohammed et al [10] researched the dynamic impact coefficient of highway bridges under overweight vehicles with equidistant axle. Although the Hertzian spring method considers the wheel-rail contact, it does not belong to real contact analysis.…”

Impact coefficient analysis on long-span beam bridge

“…Many researches on the vehicle-bridge coupling vibration responses and the dynamic impact coefficients have been conducted so far, the research contents are mainly focused on the establishment of numerical model [6][7][8], arithmetic [8][9][10][11][12][13], the influence of cross section type of beam [14], bridge deck roughness [15,16], vehicle stiffness and damping [17][18][19][20], speed [15,20], wind [21], randomness of influence factors [21], deceleration [8] and soil properties [7] on the dynamic responses of vehicle-bridge coupling system. Besides, the types of bridge such as PC simply supported box girder bridge with corrugated steel webs [22,23], highway bridges [24], railway bridges [20] and cable-stayed bridge [25] are also involved.…”