A Multi-lane Traffic Flow Simulation And Random Vehicle Load Effect Based On WIM Data

Bridge Engineering, as the hub of highway engineering, is the transportation throat in which the vehicle load undertakes the main load in bridge using stage and is the one of important factors impacting the security and usability of bridge structure. Based on the traffic survey data of Weigh-in-Motion system(WIM) of a highway in 7 days, this thesis analysis and studies all the parameters’ random character of the highway vehicles: Through the K-S goodness of fit test method, the distribution pattern and parameter of the random character are calculated for each vehicle type of running vehicles, meanwhile, the Monte-Carlo method is applied to simulate the traffic flow; According to the loading principle of influence line, this thesis figures up the load effects of the bridge researched in the traffic flow simulation. Additionally, it programs composition used to the random parameter of traffic flow statistics and query on the basis of WIM data and simulates the vehicle load effect according to random traffic flow generated from the parameter statistics before. The main content includes as follows:Firstly, this thesis explains research status of the vehicle load model of Highway Bridge and shows the detailed process of vehicle load survey. It introduces some kinds of common probability distribution patterns and K-S goodness of fit test method of vehicle load so that the random parameters of traffic flow are analysed comprehensively including the distribution pattern and parameters of vehicle type, speed, horizontal position, spacing, weight and axles base.Secondly, the traffic characteristics are analysed by using the WIM data recorded through high speed observation in 7 days. According to the transportation parameters by investigating the vehicle type, horizontal position, spacing, weight and axles base, this thesis adopts the Monte-Carlo method to generate random data of traffic flow, and compiles analogue simulation program of random traffic flow to simulate vehicle load effect by virtue of MATLAB software platform. Then the load effect of different spans of simply supported beam is calculated under the traffic flow simulation in accordance with the loading principle of influence line and the differences among vehicle load effect are discussed in different beam end position; Comparing with the load effect of highway-Ⅰ, the differences are explored between the load effects of vehicle simulation and vehicle design. through the extreme value extrapolation of vehicle load of each simply supported beam with different spans in the design reference period by adopting Rice formulation, the diversity is discussed between the extreme value of vehicle load effect and the load effect of design vehicle.Thirdly, According to the simulation of random traffic presents a calculation of the cross, a new method of longitudinal reduction coefficient. Using different methods in different lanes of traffic load data to calculate the lateral lane reduction factor, given three lanes when the lane reduction coefficient; calculating random traffic flow under the action of a different span gross vehicle weight to calculate the data, defined as the longitudinal reduction factor and gives the longitudinal reduction factor formula..