1991•Journal of Structural EngineeringRequires access
Bridge Live‐Load Models
Andrzej S. Nowak, Young‐Kyun Hong
Open publisher page 139 citations
Abstract
Live load is an important load component for highway bridges. The paper summarizes the available data base and formulates the approach to calculating maximum moments and shears for various time periods. The live‐load data base consists of truck‐survey results. Moments and shear forces are calculated for surveyed trucks and various spans. The maximum load effects for time periods from one day to 75 years are derived by extrapolations and simulations. Calculations are performed for single‐lane and two‐lane bridges. For single lanes, the maximum moment and shear are caused by a single truck for spans up to about 100 ft (30 m). For longer spans, two trucks following behind each other govern. For two lanes, the maximum effect is obtained for two trucks side‐by‐side, with fully correlated weights. For the maximum 75‐year moment or shear, each side‐by‐side truck is represented by the maximum 1.5‐month truck. The effect of a 1.5‐month truck is about 15% smaller than that of a 75‐year truck.