Study On Highway Bridge Vehicle Loads Of Heavy Load Traffic

With the development of transportation, vehicle load type on the highway Bridges, great changes have taken place in overloading trend is obvious.Frequent of overloading vehicles can produce damage to Bridges, even endanger the safety.Through investigation and analysis of characteristics and law of overloading vehicles load, we can not only get technical parameters from quantitative analysis of overloading traffic effects on the fatigue damage of bridge structure,can also provide a reference for bridge design units and operation management department.the research has great realistic significance and research value.This article get relevant information through investigating the highway traffic load of some key Bridges in Hebei province.And then,analyze and census for the relevant data.The main contents are:1.According to the differences between the number of axes of the vehicle, cars are divided into five main operating.Then statistic every model’s characteristic, vehicle weight, axle load distribution, traffic changes, car spacing distribution, heavy overload rate rule separately.2.Using the multimodal distribution and the logarithmic fall to get the probability distribution fittingvehicle from the car weight and the car space.and based on the principle of equivalent fatigue, using the coaxial merger and the weighted average from the actual vehicle load.Calculation has been applied to the province’s typical vehicle load spectrum, and provides a standard form tired cars.3.Compared with the load effects in Britain, the United States and other countries it is concluded that our country standard highway grade I load across the maximum bending moment effect produced by 0.84 times, in the United States for the specification of 0.80 times, for the British standard 0.80 times,car load standard specification is small on the whole.4.With the help of Matlab programming language and monte carlo numerical simulation method,the calculation generates random load flow model in different models calculating bending moment on the beam bridge and continuous girder bridge of effect.The actual vehicle load effect is bigger than standard highway- grade I after the contrast.Load increase coefficient is proposed:Bridge design should use the standard specification of 1.2 times when the span is less than 20 meters:Bridge design should use the standard specification of 1.3 times when the span is more than 20 meters.