Vehicle Loads And Their Effects On Girder Bridges In The Freight Channel Highway

:Vehicle load is the main operating load for the built highway bridge. With the rising traffic volume and vehicle tonnage in our country, bridge structures have suffered increasingly prominent hazards of heavy vehicles and vehicle overloading, so research on heavy traffic loads on bridges is particularly important. Current research on vehicle load is still not sufficient, so this paper devotes to the study of heavy load applied on highway freight channel. The main contents are as follows:This paper describes and compares the provisions of highway bridge specifications for vehicle load of various countries.Investigates the actual traffic volume of the typical sections of overloaded highway freight traffic channel, analyzes and statistics date of distribution of motorcycle type and spacing and vehicle weight, and analyzes the law of traffic volume variation with time.According to the traffic survey data and relevant specification, modal of vehicle load of general and intensive running state is built. Common span freely supported beam and continuous beam bridge model are chosen to calculate the action effects of key sections of bridge under actual vehicle load, and the action effects are coMPared with effects calculated under standard load. The results show that the ratio of the actual vehicle load effects to the standardized load effects increases with the bridge span.In order to better express the actual vehicle load effects on bridges,a simply T-beam bridge was checked in ultimate limit state and crack resistance under kinds of actual vehicle loads, and results show that they are not satisfied the requirement when the vehicles are densely distributed in multi-lane of the bridge.Finally,with the results of this paper on overloaded vehicles,it was recommend that the load standard in heavy-duty should be increased,and measures should be taken to avoid congestion of overloaded vehicles in long-span bridges.