Lateral Live-Load Distribution of Dual-Lane Vehicles with Nonstandard Axle Configurations

AbstractThe numbers and sizes of permitted vehicles that consist of at least four wheel lines have been increasingly crossing on highways and bridges. For safety purposes, it is necessary to understand how those truck loads are distributed to the primary bridge elements. It is widely accepted that the lateral live-load distribution factor (LDF) is affected by the spacing of adjacent wheel lines of truck loads. However, current specifications for the LDF are applicable only for vehicles that have standard axle configurations, whereas oversized vehicles usually have nonstandard wheel-line spacing. Furthermore, Iowa’s 5-ft (1.5-m) spacing requirement, which specifies that dual-lane trucks with interior-pair wheel-line spacing ≥5 ft (1.5 m) are allowed to have an axle weight up to 20 kips/lane (90 KN/lane), should also be evaluated. The objective of this paper was to investigate the impact of the wheel-line spacing of four-wheel dual-lane loads on lateral live-load distribution on slab-on-girder bridges. Twen...